feat: add intro page, rotated TOC headers, progress indicator, fix TOC padding (Closes #33)

- Add intro/title page before TOC (configurable via intro.enabled in songbook.yaml)
- Rotate reference book column headers 90° in TOC to prevent text truncation
- Add progress callback to SongbookPipeline.build() with CLI and GUI integration
- Make GUI song loading async with spinner indicator
- Fix TOC page padding: use actual rendered page count instead of blindly adding tocPages-1 blank pages
- Pre-render TOC to measure actual pages needed (TocRenderer.measurePages)
- Account for intro pages in pagination offset and page numbering

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.plans/issue-17-page-overflow.md

@@ -0,0 +1,109 @@
+# Issue #17: Fix page overflow — bounds checking and content splitting
+
+## Summary
+
+The PDF renderer (`PdfBookRenderer.renderSongPage()`) currently renders all song sections on page 0 and leaves page 1 blank for 2-page songs. There is no bounds checking — the `y` coordinate can go below the bottom margin, causing content to render outside the visible page area. This plan adds proper `y`-position tracking against a minimum `yMin` boundary, splits content across pages at section boundaries when a song exceeds one page, and reserves space for bottom metadata/references on the last page.
+
+## AC Verification Checklist
+
+1. The renderer tracks `y` against the bottom margin during song page rendering
+2. For 2-page songs, content splits across pages when it exceeds page 0's available space — remaining sections continue on page 1
+3. Content that would be rendered below the bottom margin (minus reserved footer space) is moved to the next page
+4. If metadata is "bottom" position, sufficient space is reserved at the bottom of the last page
+5. No text or images are rendered outside the printable page area
+6. Existing tests continue to pass
+7. New tests verify content splitting for songs exceeding one page
+
+## Implementation Steps
+
+### Step 1: Add a section height calculation helper in PdfBookRenderer
+
+Add a private method `calculateSectionHeight()` that computes how many PDF points a given `SongSection` will consume when rendered. This mirrors the measurement engine logic but uses the actual PDF `BaseFont` widths (not stubs). This is needed to decide whether a section fits on the current page.
+
+The method signature:
+```kotlin
+private fun calculateSectionHeight(
+    section: SongSection,
+    fontMetrics: PdfFontMetrics,
+    config: BookConfig,
+    contentWidth: Float
+): Float
+```
+
+### Step 2: Add footer space reservation calculation
+
+Add a private method `calculateFooterReservation()` that computes how much vertical space must be reserved at the bottom of the **last** page of a song for:
+- Bottom-position metadata (if `metadataPosition == "bottom"`)
+- Notes
+- Reference book footer
+
+```kotlin
+private fun calculateFooterReservation(
+    song: Song,
+    fontMetrics: PdfFontMetrics,
+    config: BookConfig,
+    contentWidth: Float
+): Float
+```
+
+### Step 3: Refactor renderSongPage() to split content across pages
+
+The key change: Instead of `val sections = if (pageIndex == 0) song.sections else emptyList()`, determine which sections belong on each page by:
+
+1. Calculate `yMin` = bottom margin in points (plus footer reservation for the last page)
+2. For `pageIndex == 0`: Render sections in order. Before rendering each section, check if the section's height fits above `yMin`. If not, stop — remaining sections go to page 1.
+3. For `pageIndex == 1`: Render the sections that didn't fit on page 0. The split point is stored via a `splitIndex` that is computed during page 0 rendering.
+
+**Approach:** Since `renderSongPage()` is called separately for page 0 and page 1, we need a way to know the split point on both calls. The cleanest approach is to compute the split index as a function:
+
+```kotlin
+private fun computeSplitIndex(
+    song: Song,
+    fontMetrics: PdfFontMetrics,
+    config: BookConfig,
+    contentWidth: Float,
+    availableHeight: Float  // total space on page 0 (contentTop - yMin)
+): Int  // index of first section that goes to page 1
+```
+
+This method calculates the cumulative height of header + sections. When the cumulative height exceeds `availableHeight`, it returns the section index. If all sections fit, it returns `song.sections.size`.
+
+### Step 4: Update renderSongPage() to use bounds checking during rendering
+
+Even after determining the split, the actual rendering loop should still check `y >= yMin` as a safety net. If a section that was estimated to fit actually overflows (due to measurement inaccuracy), clamp rendering — do not render below `yMin`.
+
+### Step 5: Update footer rendering for multi-page songs
+
+Currently `isLastPage` is hardcoded to `pageIndex == 0`. Change it to correctly identify the last page:
+- For 1-page songs: `pageIndex == 0` is the last page
+- For 2-page songs: `pageIndex == 1` is the last page
+
+The song's `pageCount` isn't directly available in the renderer, but we can determine it: if `pageIndex == 1`, it's always the last page. If `pageIndex == 0`, it's the last page only if the song fits on one page (i.e., `computeSplitIndex == song.sections.size`).
+
+A simpler approach: pass the total page count as a parameter, or compute whether the song needs 2 pages inside `renderSongPage()`.
+
+**Decision:** Add a `totalPages: Int` parameter to `renderSongPage()`. The caller already knows this from the `PageContent.SongPage` list (consecutive song pages with pageIndex 0 and 1 for the same song).
+
+Actually, the simplest approach: The renderer sees `PageContent.SongPage(song, 0)` and `PageContent.SongPage(song, 1)` in the page list. We can pre-scan the pages list to know if a song has 2 pages. But even simpler: we can compute `computeSplitIndex` to know whether the song needs a second page. If `splitIndex < song.sections.size`, the song has 2 pages.
+
+### Step 6: Move notes and bottom-metadata to the last page
+
+Currently notes and bottom metadata only render on `pageIndex == 0`. Change this to render on the last page (which might be page 1 for 2-page songs). The logic:
+- Compute `isLastPage` based on split index
+- Render notes, bottom metadata, and reference footer only on the last page
+
+### Step 7: Write tests
+
+Add tests in `PdfBookRendererTest`:
+
+1. `render handles two-page song with content split across pages` — Create a song with many sections that exceed one page, render with pageIndex 0 and 1, verify PDF is valid.
+
+2. `render does not overflow below bottom margin` — Create a very long song, verify rendering completes without error.
+
+3. `render places metadata at bottom of last page for two-page songs` — Use `metadataPosition = "bottom"`, create a 2-page song, verify PDF is valid.
+
+4. `render handles notes on last page of two-page song` — Song with notes that spans 2 pages, verify rendering.
+
+### Step 8: Verify existing tests pass
+
+Run `gradle :renderer-pdf:test` and `gradle :app:test` to ensure no regressions.

.plans/issue-18-page-preview.md

@@ -0,0 +1,44 @@
+# Issue #18: Add page-by-page preview in the GUI after building
+
+## Summary
+
+Add a PDF preview panel to the GUI that appears after a successful build. It renders PDF pages as images using Apache PDFBox and displays them with previous/next navigation and a page counter. The preview loads pages lazily for performance and updates automatically on new builds.
+
+## AC Verification Checklist
+
+1. After a successful build, a preview panel appears showing generated pages
+2. Users can navigate between pages (previous/next buttons)
+3. Current page number and total count displayed (e.g., "Seite 3 / 42")
+4. Preview renders actual PDF pages as images (PDF-to-image via PDFBox)
+5. Preview panel can be closed/hidden to return to normal view
+6. Preview updates automatically when a new build completes
+7. GUI remains responsive while preview is loading (async rendering)
+
+## Implementation Steps
+
+### Step 1: Add PDFBox dependency to gui module
+
+Add `org.apache.pdfbox:pdfbox:3.0.4` to gui/build.gradle.kts.
+
+### Step 2: Create PdfPreviewState class
+
+A state holder for the preview: current page index, total pages, rendered page images (cached), loading state. Pages are rendered lazily — only the current page is rendered at a time.
+
+### Step 3: Create PdfPreviewPanel composable
+
+A Compose panel with:
+- An Image composable showing the current page
+- Navigation row: "< Prev" button | "Seite X / Y" label | "Next >" button
+- A close/hide button
+- Loading indicator while page is rendering
+
+### Step 4: Integrate preview into App composable
+
+After a successful build:
+- Show a "Vorschau" button in the action buttons row
+- When clicked, show the preview panel (replacing or overlaying the song list area)
+- When a new build succeeds, update the preview automatically
+
+### Step 5: Lazy page rendering
+
+Render pages on demand using coroutines on Dispatchers.IO to keep the UI responsive.

.plans/issue-19-drag-and-drop.md

@@ -0,0 +1,41 @@
+# Issue #19: Add drag-and-drop song reordering in the GUI
+
+## Summary
+
+Add drag-and-drop reordering of songs in the GUI song list. When `songs.order` is "manual", users can drag songs to rearrange them. The custom order is passed to the pipeline at build time. When order is "alphabetical", drag-and-drop is disabled with a hint.
+
+## AC Verification Checklist
+
+1. Songs can be reordered via drag-and-drop
+2. Reordered list is used when building (overrides config order)
+3. Visual indicator shows drop target (highlight)
+4. Order can be reset via a button
+5. Reordering only enabled when songs.order is "manual"
+6. When alphabetical, list shows alphabetical order and drag is disabled (with hint)
+7. GUI remains responsive during drag operations
+
+## Implementation Steps
+
+### Step 1: Add customSongOrder parameter to SongbookPipeline.build()
+
+Add an optional `customSongOrder: List<String>? = null` parameter. When provided, use this ordered list of file names to sort the parsed songs instead of the config-based sort.
+
+### Step 2: Create ReorderableSongList composable
+
+Build a song list that supports drag-and-drop reordering:
+- Use `detectDragGesturesAfterLongPress` on each item to detect drag start
+- Track the dragged item index and current hover position
+- Show a visual indicator (highlighted background) at the drop target
+- On drop, reorder the list
+
+### Step 3: Integrate into App.kt
+
+- Track `songsOrder` config value ("alphabetical" or "manual")
+- Track `originalSongs` list (from file loading) to support reset
+- When manual: enable drag-and-drop, show reset button
+- When alphabetical: disable drag-and-drop, show hint
+- Pass custom order (file names) to pipeline on build
+
+### Step 4: Add reset button
+
+"Reihenfolge zurücksetzen" button restores `songs` to `originalSongs`.

CLAUDE.md

@@ -35,16 +35,17 @@ Requires Java 21 (configured in `gradle.properties`). Kotlin 2.1.10, Gradle 9.3.
 
 ## Architecture
 
-**Pipeline:** Parse → Measure → Paginate → Render
+**Pipeline:** Parse → Validate → Measure → Paginate → Render
 
 `SongbookPipeline` (in `app`) orchestrates the full flow:
 1. `ConfigParser` reads `songbook.yaml` → `BookConfig`
-2. `ChordProParser` reads `.chopro` files → `Song` objects
-3. `Validator` checks config and songs
-4. `MeasurementEngine` calculates each song's height in mm using `FontMetrics`
-5. `TocGenerator` estimates TOC page count and creates entries
-6. `PaginationEngine` arranges songs into pages (greedy spread packing)
-7. `PdfBookRenderer` generates the PDF via OpenPDF
+2. `ChordProParser` reads `.chopro`/`.cho`/`.crd` files → `Song` objects
+3. `ForewordParser` reads optional `foreword.txt` → `Foreword` (if configured)
+4. `Validator` checks config and songs
+5. `MeasurementEngine` calculates each song's height in mm using `FontMetrics`
+6. `TocGenerator` estimates TOC page count and creates entries
+7. `PaginationEngine` arranges songs into pages (greedy spread packing)
+8. `PdfBookRenderer` generates the PDF via OpenPDF
 
 **Module dependency graph:**
 ```
@@ -62,14 +63,39 @@ app, parser ← gui (Compose Desktop)
 
 ## Key Types
 
-- `Song` → sections → `SongLine` → `LineSegment(chord?, text)` — chord is placed above the text segment
-- `PageContent` — sealed class: `SongPage`, `FillerImage`, `BlankPage`
+- `Song` → sections → `SongLine` → `LineSegment(chord?, text)` — chord is placed above the text segment. Also has `aliases`, `lyricist`, `composer`, `key`, `tags`, `notes: List<String>`, `references: Map<String, Int>` (bookId → page), `capo`
+- `SongLine` — holds `segments` plus optional `imagePath` (when set, the line is an inline image)
+- `Foreword` — `quote`, `paragraphs`, `signatures` — parsed from a plain-text file
+- `PageContent` — sealed class: `SongPage`, `FillerImage`, `BlankPage`, `ForewordPage`
 - `SectionType` — enum: `VERSE`, `CHORUS`, `BRIDGE`, `REPEAT`
+- `BookConfig` — top-level config with `FontsConfig`, `LayoutConfig`, `TocConfig`, `ForewordConfig`, `ReferenceBook` list. `FontSpec.file` supports custom font files. `LayoutConfig.metadataLabels` (`"abbreviated"` or `"german"`) and `metadataPosition` (`"top"` or `"bottom"`) control metadata rendering
 - `BuildResult` — returned by `SongbookPipeline.build()` with success/errors/counts
 
 ## Song Format
 
-ChordPro-compatible `.chopro` files: directives in `{braces}`, chords in `[brackets]` inline with lyrics, comments with `#`. See `songs/` for examples.
+ChordPro-compatible `.chopro`/`.cho`/`.crd` files: directives in `{braces}`, chords in `[brackets]` inline with lyrics, comments with `#`. See `songs/` for examples.
+
+**Metadata directives:** `{title: }` / `{t: }`, `{alias: }`, `{lyricist: }`, `{composer: }`, `{key: }`, `{tags: }`, `{note: }`, `{capo: }`
+
+**Section directives:** `{start_of_verse}` / `{sov}`, `{end_of_verse}` / `{eov}`, `{start_of_chorus}` / `{soc}`, `{end_of_chorus}` / `{eoc}`, `{start_of_repeat}` / `{sor}`, `{end_of_repeat}` / `{eor}`. Section starts accept an optional label. `{chorus}` inserts a chorus reference, `{repeat}` sets a repeat label.
+
+**Notes block:** `{start_of_notes}` / `{son}` … `{end_of_notes}` / `{eon}` — multi-paragraph rich-text notes rendered at the end of a song.
+
+**Inline image:** `{image: path}` — embeds an image within a song section.
+
+**Reference:** `{ref: bookId pageNumber}` — cross-reference to a page in another songbook (configured in `reference_books`).
+
+## Configuration
+
+`songbook.yaml` at the project root. Key options beyond the basics:
+
+- `fonts.<role>.file` — path to a custom font file (TTF/OTF) for any font role (`lyrics`, `chords`, `title`, `metadata`, `toc`)
+- `layout.metadata_labels` — `"abbreviated"` (M:/T:) or `"german"` (Worte:/Weise:)
+- `layout.metadata_position` — `"top"` (after title) or `"bottom"` (bottom of last page)
+- `toc.highlight_column` — abbreviation of the reference-book column to highlight (e.g. `"CL"`)
+- `foreword.file` — path to a foreword text file (default `./foreword.txt`)
+- `reference_books` — list of `{id, name, abbreviation}` for cross-reference columns in the TOC
+- `songs.order` — `"alphabetical"` or `"manual"` (file-system order)
 
 ## Test Patterns
 

app/src/main/kotlin/de/pfadfinder/songbook/app/SongbookPipeline.kt

@@ -4,7 +4,9 @@ import de.pfadfinder.songbook.model.*
 import de.pfadfinder.songbook.parser.*
 import de.pfadfinder.songbook.parser.ForewordParser
 import de.pfadfinder.songbook.layout.*
-import de.pfadfinder.songbook.renderer.pdf.*
+import de.pfadfinder.songbook.renderer.pdf.PdfBookRenderer
+import de.pfadfinder.songbook.renderer.pdf.PdfFontMetrics
+import de.pfadfinder.songbook.renderer.pdf.TocRenderer
 import mu.KotlinLogging
 import java.io.File
 import java.io.FileOutputStream
@@ -21,16 +23,29 @@ data class BuildResult(
 
 class SongbookPipeline(private val projectDir: File) {
 
-    fun build(): BuildResult {
+    /**
+     * Build the songbook PDF.
+     *
+     * @param customSongOrder Optional list of song file names in the desired order.
+     *   When provided, songs are sorted to match this order instead of using the
+     *   config-based sort (alphabetical or manual). Files not in this list are
+     *   appended at the end.
+     * @param onProgress Optional callback invoked with status messages during the build.
+     */
+    fun build(customSongOrder: List<String>? = null, onProgress: ((String) -> Unit)? = null): BuildResult {
         // 1. Parse config
+        onProgress?.invoke("Konfiguration wird geladen...")
         val configFile = File(projectDir, "songbook.yaml")
         if (!configFile.exists()) {
             return BuildResult(false, errors = listOf(ValidationError(configFile.name, null, "songbook.yaml not found")))
         }
         logger.info { "Parsing config: ${configFile.absolutePath}" }
-        val config = ConfigParser.parse(configFile)
+        val rawConfig = ConfigParser.parse(configFile)
 
-        // Validate config
+        // Resolve font file paths relative to the project directory
+        val config = resolveFontPaths(rawConfig)
+
+        // Validate config (including font file existence)
         val configErrors = Validator.validateConfig(config)
         if (configErrors.isNotEmpty()) {
             return BuildResult(false, errors = configErrors)
@@ -50,19 +65,23 @@ class SongbookPipeline(private val projectDir: File) {
             return BuildResult(false, errors = listOf(ValidationError(config.songs.directory, null, "No song files found")))
         }
 
+        onProgress?.invoke("Lieder werden importiert (${songFiles.size} Dateien)...")
         logger.info { "Found ${songFiles.size} song files" }
 
-        val songs = mutableListOf<Song>()
+        val songsByFileName = mutableMapOf<String, Song>()
         val allErrors = mutableListOf<ValidationError>()
 
-        for (file in songFiles) {
+        for ((index, file) in songFiles.withIndex()) {
+            if (index > 0 && index % 50 == 0) {
+                onProgress?.invoke("Lieder werden importiert... ($index/${songFiles.size})")
+            }
             try {
                 val song = ChordProParser.parseFile(file)
                 val songErrors = Validator.validateSong(song, file.name)
                 if (songErrors.isNotEmpty()) {
                     allErrors.addAll(songErrors)
                 } else {
-                    songs.add(song)
+                    songsByFileName[file.name] = song
                 }
             } catch (e: Exception) {
                 allErrors.add(ValidationError(file.name, null, "Parse error: ${e.message}"))
@@ -73,10 +92,20 @@ class SongbookPipeline(private val projectDir: File) {
             return BuildResult(false, errors = allErrors)
         }
 
-        // Sort songs
-        val sortedSongs = when (config.songs.order) {
-            "alphabetical" -> songs.sortedBy { it.title.lowercase() }
-            else -> songs  // manual order = file order
+        val songs = songsByFileName.values.toList()
+
+        // Sort songs: custom order takes priority, then config-based sort
+        val sortedSongs = if (customSongOrder != null) {
+            val orderMap = customSongOrder.withIndex().associate { (index, name) -> name to index }
+            songs.sortedBy { song ->
+                val fileName = songsByFileName.entries.find { it.value === song }?.key
+                orderMap[fileName] ?: Int.MAX_VALUE
+            }
+        } else {
+            when (config.songs.order) {
+                "alphabetical" -> songs.sortedBy { it.title.lowercase() }
+                else -> songs  // manual order = file order
+            }
         }
 
         logger.info { "Parsed ${sortedSongs.size} songs" }
@@ -95,21 +124,39 @@ class SongbookPipeline(private val projectDir: File) {
         }
 
         // 3. Measure songs
+        onProgress?.invoke("Layout wird berechnet...")
         val fontMetrics = PdfFontMetrics()
         val measurementEngine = MeasurementEngine(fontMetrics, config)
         val measuredSongs = sortedSongs.map { measurementEngine.measure(it) }
 
         // 4. Generate TOC and paginate
         val tocGenerator = TocGenerator(config)
-        val tocPages = tocGenerator.estimateTocPages(sortedSongs)
+        val estimatedTocPages = tocGenerator.estimateTocPages(sortedSongs)
 
+        // Intro page takes 2 pages (title + blank back) for double-sided printing
+        val introPages = if (config.intro?.enabled == true) 2 else 0
         // Foreword always takes 2 pages (for double-sided printing)
         val forewordPages = if (foreword != null) 2 else 0
 
+        val headerPages = introPages + estimatedTocPages + forewordPages
         val paginationEngine = PaginationEngine(config)
-        val pages = paginationEngine.paginate(measuredSongs, tocPages + forewordPages)
+        val pages = paginationEngine.paginate(measuredSongs, headerPages)
 
-        val tocEntries = tocGenerator.generate(pages, tocPages + forewordPages)
+        // Generate initial TOC entries, then measure actual pages needed
+        val initialTocEntries = tocGenerator.generate(pages, headerPages)
+        val tocRenderer = TocRenderer(fontMetrics, config)
+        val tocPages = tocRenderer.measurePages(initialTocEntries)
+
+        // Re-generate TOC entries with corrected page offset if count changed.
+        // Since tocPages is always even, the pagination layout (left/right parity)
+        // stays the same — only page numbers in the TOC entries need updating.
+        val actualHeaderPages = introPages + tocPages + forewordPages
+        val tocEntries = if (tocPages != estimatedTocPages) {
+            logger.info { "TOC pages: estimated $estimatedTocPages, actual $tocPages" }
+            tocGenerator.generate(pages, actualHeaderPages)
+        } else {
+            initialTocEntries
+        }
 
         // Build final page list with foreword pages inserted before song content
         val allPages = mutableListOf<PageContent>()
@@ -120,14 +167,17 @@ class SongbookPipeline(private val projectDir: File) {
         allPages.addAll(pages)
 
         val layoutResult = LayoutResult(
+            introPages = introPages,
             tocPages = tocPages,
             pages = allPages,
             tocEntries = tocEntries
         )
 
-        logger.info { "Layout: ${tocPages} TOC pages, ${pages.size} content pages" }
+        val totalPages = introPages + tocPages + pages.size
+        logger.info { "Layout: ${introPages} intro, ${tocPages} TOC, ${pages.size} content pages" }
 
         // 5. Render PDF
+        onProgress?.invoke("PDF wird erzeugt (${sortedSongs.size} Lieder, $totalPages Seiten)...")
         val outputDir = File(projectDir, config.output.directory)
         outputDir.mkdirs()
         val outputFile = File(outputDir, config.output.filename)
@@ -139,23 +189,49 @@ class SongbookPipeline(private val projectDir: File) {
             renderer.render(layoutResult, config, fos)
         }
 
-        logger.info { "Build complete: ${sortedSongs.size} songs, ${pages.size + tocPages} pages" }
+        logger.info { "Build complete: ${sortedSongs.size} songs, $totalPages pages" }
 
         return BuildResult(
             success = true,
             outputFile = outputFile,
             songCount = sortedSongs.size,
-            pageCount = pages.size + tocPages
+            pageCount = totalPages
         )
     }
 
+    /**
+     * Resolves font file paths relative to the project directory.
+     * If a FontSpec has a `file` property, it is resolved against projectDir
+     * to produce an absolute path.
+     */
+    private fun resolveFontPaths(config: BookConfig): BookConfig {
+        fun FontSpec.resolveFile(): FontSpec {
+            val fontFile = this.file ?: return this
+            val fontFileObj = File(fontFile)
+            // Only resolve relative paths; absolute paths are left as-is
+            if (fontFileObj.isAbsolute) return this
+            val resolved = File(projectDir, fontFile)
+            return this.copy(file = resolved.absolutePath)
+        }
+
+        val resolvedFonts = config.fonts.copy(
+            lyrics = config.fonts.lyrics.resolveFile(),
+            chords = config.fonts.chords.resolveFile(),
+            title = config.fonts.title.resolveFile(),
+            metadata = config.fonts.metadata.resolveFile(),
+            toc = config.fonts.toc.resolveFile()
+        )
+        return config.copy(fonts = resolvedFonts)
+    }
+
     fun validate(): List<ValidationError> {
         val configFile = File(projectDir, "songbook.yaml")
         if (!configFile.exists()) {
             return listOf(ValidationError(configFile.name, null, "songbook.yaml not found"))
         }
 
-        val config = ConfigParser.parse(configFile)
+        val rawConfig = ConfigParser.parse(configFile)
+        val config = resolveFontPaths(rawConfig)
         val errors = mutableListOf<ValidationError>()
         errors.addAll(Validator.validateConfig(config))
 

cli/src/main/kotlin/de/pfadfinder/songbook/cli/BuildCommand.kt

@@ -18,7 +18,7 @@ class BuildCommand : CliktCommand(name = "build") {
         echo("Building songbook from: ${dir.path}")
 
         val pipeline = SongbookPipeline(dir)
-        val result = pipeline.build()
+        val result = pipeline.build(onProgress = { msg -> echo(msg) })
 
         if (result.success) {
             echo("Build successful!")

gui/build.gradle.kts

@@ -11,6 +11,7 @@ dependencies {
     implementation(compose.desktop.currentOs)
     implementation("io.github.microutils:kotlin-logging-jvm:3.0.5")
     implementation("ch.qos.logback:logback-classic:1.5.16")
+    implementation("org.apache.pdfbox:pdfbox:3.0.4")
 }
 
 compose.desktop {

gui/src/main/kotlin/de/pfadfinder/songbook/gui/App.kt

@@ -1,6 +1,7 @@
 package de.pfadfinder.songbook.gui
 
 import androidx.compose.desktop.ui.tooling.preview.Preview
+import androidx.compose.foundation.text.selection.SelectionContainer
 import androidx.compose.foundation.VerticalScrollbar
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyColumn
@@ -20,6 +21,7 @@ import androidx.compose.ui.window.application
 import de.pfadfinder.songbook.app.BuildResult
 import de.pfadfinder.songbook.app.SongbookPipeline
 import de.pfadfinder.songbook.parser.ChordProParser
+import de.pfadfinder.songbook.parser.ConfigParser
 import de.pfadfinder.songbook.parser.ValidationError
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -44,47 +46,83 @@ data class SongEntry(val fileName: String, val title: String)
 fun App() {
     var projectPath by remember { mutableStateOf("") }
     var songs by remember { mutableStateOf<List<SongEntry>>(emptyList()) }
+    var originalSongs by remember { mutableStateOf<List<SongEntry>>(emptyList()) }
+    var songsOrderConfig by remember { mutableStateOf("alphabetical") }
+    var isCustomOrder by remember { mutableStateOf(false) }
     var statusMessages by remember { mutableStateOf<List<StatusMessage>>(emptyList()) }
     var isRunning by remember { mutableStateOf(false) }
+    var isLoadingSongs by remember { mutableStateOf(false) }
     var lastBuildResult by remember { mutableStateOf<BuildResult?>(null) }
+    val previewState = remember { PdfPreviewState() }
 
     val scope = rememberCoroutineScope()
 
+    val reorderEnabled = songsOrderConfig != "alphabetical"
+
     fun loadSongs(path: String) {
         val projectDir = File(path)
         songs = emptyList()
+        originalSongs = emptyList()
+        isCustomOrder = false
         if (!projectDir.isDirectory) return
 
-        val configFile = File(projectDir, "songbook.yaml")
-        val songsDir = if (configFile.exists()) {
-            try {
-                val config = de.pfadfinder.songbook.parser.ConfigParser.parse(configFile)
-                File(projectDir, config.songs.directory)
-            } catch (_: Exception) {
-                File(projectDir, "songs")
+        isLoadingSongs = true
+        statusMessages = listOf(StatusMessage("Lieder werden geladen...", MessageType.INFO))
+
+        scope.launch {
+            val (loadedSongs, order) = withContext(Dispatchers.IO) {
+                val configFile = File(projectDir, "songbook.yaml")
+                var songsDir: File
+                var orderConfig = "alphabetical"
+
+                if (configFile.exists()) {
+                    try {
+                        val config = ConfigParser.parse(configFile)
+                        songsDir = File(projectDir, config.songs.directory)
+                        orderConfig = config.songs.order
+                    } catch (_: Exception) {
+                        songsDir = File(projectDir, "songs")
+                    }
+                } else {
+                    songsDir = File(projectDir, "songs")
+                }
+
+                if (!songsDir.isDirectory) return@withContext Pair(emptyList<SongEntry>(), orderConfig)
+
+                val songFiles = songsDir.listFiles { f: File -> f.extension in listOf("chopro", "cho", "crd") }
+                    ?.sortedBy { it.name }
+                    ?: emptyList()
+
+                val loaded = songFiles.mapNotNull { file ->
+                    try {
+                        val song = ChordProParser.parseFile(file)
+                        SongEntry(fileName = file.name, title = song.title.ifBlank { file.nameWithoutExtension })
+                    } catch (_: Exception) {
+                        SongEntry(fileName = file.name, title = "${file.nameWithoutExtension} (Fehler beim Lesen)")
+                    }
+                }
+                Pair(loaded, orderConfig)
             }
-        } else {
-            File(projectDir, "songs")
-        }
 
-        if (!songsDir.isDirectory) return
-
-        val songFiles = songsDir.listFiles { f: File -> f.extension in listOf("chopro", "cho", "crd") }
-            ?.sortedBy { it.name }
-            ?: emptyList()
-
-        songs = songFiles.mapNotNull { file ->
-            try {
-                val song = ChordProParser.parseFile(file)
-                SongEntry(fileName = file.name, title = song.title.ifBlank { file.nameWithoutExtension })
-            } catch (_: Exception) {
-                SongEntry(fileName = file.name, title = "${file.nameWithoutExtension} (Fehler beim Lesen)")
+            songsOrderConfig = order
+            songs = if (order == "alphabetical") {
+                loadedSongs.sortedBy { it.title.lowercase() }
+            } else {
+                loadedSongs
+            }
+            originalSongs = songs.toList()
+            isLoadingSongs = false
+            statusMessages = if (loadedSongs.isNotEmpty()) {
+                listOf(StatusMessage("${loadedSongs.size} Lieder geladen.", MessageType.SUCCESS))
+            } else {
+                listOf(StatusMessage("Keine Lieder gefunden.", MessageType.INFO))
             }
         }
     }
 
     MaterialTheme {
         Surface(modifier = Modifier.fillMaxSize()) {
+            SelectionContainer {
             Column(modifier = Modifier.padding(16.dp)) {
                 // Project directory selection
                 Text(
@@ -130,48 +168,76 @@ fun App() {
 
                 Spacer(modifier = Modifier.height(16.dp))
 
-                // Song list
-                Text(
-                    text = "Lieder (${songs.size}):",
-                    fontWeight = FontWeight.Medium
-                )
-                Spacer(modifier = Modifier.height(4.dp))
-
-                Box(modifier = Modifier.weight(1f).fillMaxWidth()) {
-                    val listState = rememberLazyListState()
-                    LazyColumn(
-                        state = listState,
-                        modifier = Modifier.fillMaxSize().padding(end = 12.dp)
+                // Central content area: song list or preview panel
+                if (previewState.isVisible) {
+                    // Show preview panel
+                    PdfPreviewPanel(
+                        state = previewState,
+                        modifier = Modifier.weight(1f)
+                    )
+                } else {
+                    // Song list header with optional reset button
+                    Row(
+                        verticalAlignment = Alignment.CenterVertically,
+                        modifier = Modifier.fillMaxWidth()
                     ) {
-                        if (songs.isEmpty() && projectPath.isNotBlank()) {
-                            item {
-                                Text(
-                                    "Keine Lieder gefunden. Bitte Projektverzeichnis prüfen.",
-                                    color = Color.Gray,
-                                    modifier = Modifier.padding(8.dp)
-                                )
+                        Text(
+                            text = "Lieder (${songs.size}):",
+                            fontWeight = FontWeight.Medium,
+                            modifier = Modifier.weight(1f)
+                        )
+                        if (reorderEnabled && isCustomOrder) {
+                            Button(
+                                onClick = {
+                                    songs = originalSongs.toList()
+                                    isCustomOrder = false
+                                },
+                                enabled = !isRunning
+                            ) {
+                                Text("Reihenfolge zuruecksetzen")
                             }
-                        } else if (projectPath.isBlank()) {
-                            item {
-                                Text(
-                                    "Bitte ein Projektverzeichnis auswählen.",
-                                    color = Color.Gray,
-                                    modifier = Modifier.padding(8.dp)
-                                )
-                            }
-                        }
-                        items(songs) { song ->
-                            Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp, horizontal = 8.dp)) {
-                                Text(song.title, modifier = Modifier.weight(1f))
-                                Text(song.fileName, color = Color.Gray, fontSize = 12.sp)
-                            }
-                            Divider()
                         }
                     }
-                    VerticalScrollbar(
-                        modifier = Modifier.align(Alignment.CenterEnd).fillMaxHeight(),
-                        adapter = rememberScrollbarAdapter(listState)
-                    )
+                    Spacer(modifier = Modifier.height(4.dp))
+
+                    if (isLoadingSongs) {
+                        Box(
+                            modifier = Modifier.weight(1f).fillMaxWidth(),
+                            contentAlignment = Alignment.Center
+                        ) {
+                            Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                                CircularProgressIndicator(modifier = Modifier.size(32.dp))
+                                Spacer(modifier = Modifier.height(8.dp))
+                                Text("Lieder werden geladen...", color = Color.Gray)
+                            }
+                        }
+                    } else if (songs.isEmpty() && projectPath.isNotBlank()) {
+                        Box(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                            Text(
+                                "Keine Lieder gefunden. Bitte Projektverzeichnis pruefen.",
+                                color = Color.Gray,
+                                modifier = Modifier.padding(8.dp)
+                            )
+                        }
+                    } else if (projectPath.isBlank()) {
+                        Box(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                            Text(
+                                "Bitte ein Projektverzeichnis auswaehlen.",
+                                color = Color.Gray,
+                                modifier = Modifier.padding(8.dp)
+                            )
+                        }
+                    } else {
+                        ReorderableSongList(
+                            songs = songs,
+                            reorderEnabled = reorderEnabled,
+                            onReorder = { newList ->
+                                songs = newList
+                                isCustomOrder = true
+                            },
+                            modifier = Modifier.weight(1f)
+                        )
+                    }
                 }
 
                 Spacer(modifier = Modifier.height(16.dp))
@@ -185,9 +251,17 @@ fun App() {
                             lastBuildResult = null
                             statusMessages = listOf(StatusMessage("Buch wird erstellt...", MessageType.INFO))
                             scope.launch {
+                                // Build custom song order from the current GUI list
+                                val customOrder = if (isCustomOrder) {
+                                    songs.map { it.fileName }
+                                } else {
+                                    null
+                                }
                                 val result = withContext(Dispatchers.IO) {
                                     try {
-                                        SongbookPipeline(File(projectPath)).build()
+                                        SongbookPipeline(File(projectPath)).build(customOrder) { msg ->
+                                            statusMessages = listOf(StatusMessage(msg, MessageType.INFO))
+                                        }
                                     } catch (e: Exception) {
                                         BuildResult(
                                             success = false,
@@ -220,6 +294,11 @@ fun App() {
                                     }
                                 }
                                 isRunning = false
+
+                                // Automatically load preview after successful build
+                                if (result.success && result.outputFile != null) {
+                                    previewState.loadPdf(result.outputFile!!)
+                                }
                             }
                         },
                         enabled = !isRunning && projectPath.isNotBlank()
@@ -232,7 +311,7 @@ fun App() {
                             if (projectPath.isBlank()) return@Button
                             isRunning = true
                             lastBuildResult = null
-                            statusMessages = listOf(StatusMessage("Validierung läuft...", MessageType.INFO))
+                            statusMessages = listOf(StatusMessage("Validierung laeuft...", MessageType.INFO))
                             scope.launch {
                                 val errors = withContext(Dispatchers.IO) {
                                     try {
@@ -271,7 +350,7 @@ fun App() {
                                         Desktop.getDesktop().open(file)
                                     } catch (e: Exception) {
                                         statusMessages = statusMessages + StatusMessage(
-                                            "PDF konnte nicht geöffnet werden: ${e.message}",
+                                            "PDF konnte nicht geoeffnet werden: ${e.message}",
                                             MessageType.ERROR
                                         )
                                     }
@@ -279,7 +358,27 @@ fun App() {
                             },
                             enabled = !isRunning
                         ) {
-                            Text("PDF öffnen")
+                            Text("PDF oeffnen")
+                        }
+
+                        // Show/hide preview button
+                        Button(
+                            onClick = {
+                                if (previewState.isVisible) {
+                                    previewState.isVisible = false
+                                } else {
+                                    scope.launch {
+                                        if (previewState.totalPages == 0) {
+                                            lastBuildResult?.outputFile?.let { previewState.loadPdf(it) }
+                                        } else {
+                                            previewState.isVisible = true
+                                        }
+                                    }
+                                }
+                            },
+                            enabled = !isRunning
+                        ) {
+                            Text(if (previewState.isVisible) "Vorschau ausblenden" else "Vorschau")
                         }
                     }
 
@@ -336,6 +435,7 @@ fun App() {
                     )
                 }
             }
+            }
         }
     }
 }

gui/src/main/kotlin/de/pfadfinder/songbook/gui/PdfPreviewPanel.kt

@@ -0,0 +1,221 @@
+package de.pfadfinder.songbook.gui
+
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.material.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.toComposeImageBitmap
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import org.apache.pdfbox.Loader
+import org.apache.pdfbox.pdmodel.PDDocument
+import org.apache.pdfbox.rendering.PDFRenderer
+import java.awt.image.BufferedImage
+import java.io.File
+
+/**
+ * State holder for the PDF preview. Manages the current page, total page count,
+ * and a cache of rendered page images.
+ */
+class PdfPreviewState {
+    var pdfFile: File? by mutableStateOf(null)
+        private set
+    var totalPages: Int by mutableStateOf(0)
+        private set
+    var currentPage: Int by mutableStateOf(0)
+        private set
+    var isLoading: Boolean by mutableStateOf(false)
+        private set
+    var currentImage: ImageBitmap? by mutableStateOf(null)
+        private set
+    var isVisible: Boolean by mutableStateOf(false)
+
+    private var document: PDDocument? = null
+    private var renderer: PDFRenderer? = null
+    private val pageCache = mutableMapOf<Int, ImageBitmap>()
+
+    /**
+     * Load a new PDF file for preview. Resets state and renders the first page.
+     */
+    suspend fun loadPdf(file: File) {
+        close()
+        pdfFile = file
+        currentPage = 0
+        pageCache.clear()
+        currentImage = null
+
+        withContext(Dispatchers.IO) {
+            try {
+                val doc = Loader.loadPDF(file)
+                document = doc
+                renderer = PDFRenderer(doc)
+                totalPages = doc.numberOfPages
+            } catch (_: Exception) {
+                totalPages = 0
+            }
+        }
+
+        if (totalPages > 0) {
+            isVisible = true
+            renderCurrentPage()
+        }
+    }
+
+    suspend fun goToPage(page: Int) {
+        if (page < 0 || page >= totalPages) return
+        currentPage = page
+        renderCurrentPage()
+    }
+
+    suspend fun nextPage() {
+        goToPage(currentPage + 1)
+    }
+
+    suspend fun previousPage() {
+        goToPage(currentPage - 1)
+    }
+
+    private suspend fun renderCurrentPage() {
+        val cached = pageCache[currentPage]
+        if (cached != null) {
+            currentImage = cached
+            return
+        }
+
+        isLoading = true
+        try {
+            val image = withContext(Dispatchers.IO) {
+                try {
+                    val pdfRenderer = renderer ?: return@withContext null
+                    // Render at 150 DPI for a good balance of quality and speed
+                    val bufferedImage: BufferedImage = pdfRenderer.renderImageWithDPI(currentPage, 150f)
+                    bufferedImage.toComposeImageBitmap()
+                } catch (_: Exception) {
+                    null
+                }
+            }
+            if (image != null) {
+                pageCache[currentPage] = image
+                currentImage = image
+            }
+        } finally {
+            isLoading = false
+        }
+    }
+
+    fun close() {
+        try {
+            document?.close()
+        } catch (_: Exception) {
+            // ignore
+        }
+        document = null
+        renderer = null
+        pageCache.clear()
+        currentImage = null
+        totalPages = 0
+        currentPage = 0
+        isVisible = false
+    }
+}
+
+@Composable
+fun PdfPreviewPanel(
+    state: PdfPreviewState,
+    modifier: Modifier = Modifier
+) {
+    val scope = rememberCoroutineScope()
+
+    Column(modifier = modifier.fillMaxWidth()) {
+        // Header with title and close button
+        Row(
+            modifier = Modifier.fillMaxWidth().padding(bottom = 8.dp),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Text(
+                text = "Vorschau",
+                fontSize = 16.sp,
+                fontWeight = FontWeight.Bold
+            )
+            Button(
+                onClick = { state.isVisible = false },
+                colors = ButtonDefaults.buttonColors(backgroundColor = Color.LightGray)
+            ) {
+                Text("Schliessen")
+            }
+        }
+
+        // Page image area
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .weight(1f)
+                .background(Color(0xFFE0E0E0)),
+            contentAlignment = Alignment.Center
+        ) {
+            if (state.isLoading) {
+                CircularProgressIndicator()
+            } else if (state.currentImage != null) {
+                Image(
+                    bitmap = state.currentImage!!,
+                    contentDescription = "Seite ${state.currentPage + 1}",
+                    modifier = Modifier.fillMaxSize().padding(4.dp),
+                    contentScale = ContentScale.Fit
+                )
+            } else {
+                Text(
+                    "Keine Vorschau verfuegbar",
+                    color = Color.Gray
+                )
+            }
+        }
+
+        // Navigation row
+        Row(
+            modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+            horizontalArrangement = Arrangement.Center,
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Button(
+                onClick = {
+                    scope.launch { state.previousPage() }
+                },
+                enabled = state.currentPage > 0 && !state.isLoading
+            ) {
+                Text("<")
+            }
+
+            Spacer(modifier = Modifier.width(16.dp))
+
+            Text(
+                text = "Seite ${state.currentPage + 1} / ${state.totalPages}",
+                fontWeight = FontWeight.Medium,
+                textAlign = TextAlign.Center,
+                modifier = Modifier.widthIn(min = 120.dp)
+            )
+
+            Spacer(modifier = Modifier.width(16.dp))
+
+            Button(
+                onClick = {
+                    scope.launch { state.nextPage() }
+                },
+                enabled = state.currentPage < state.totalPages - 1 && !state.isLoading
+            ) {
+                Text(">")
+            }
+        }
+    }
+}

gui/src/main/kotlin/de/pfadfinder/songbook/gui/ReorderableSongList.kt

@@ -0,0 +1,142 @@
+package de.pfadfinder.songbook.gui
+
+import androidx.compose.foundation.VerticalScrollbar
+import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.detectDragGesturesAfterLongPress
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.foundation.rememberScrollbarAdapter
+import androidx.compose.material.Divider
+import androidx.compose.material.Icon
+import androidx.compose.material.Text
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Menu
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * A song list that supports drag-and-drop reordering when enabled.
+ *
+ * @param songs The current song list
+ * @param reorderEnabled Whether drag-and-drop is enabled
+ * @param onReorder Callback when songs are reordered, provides the new list
+ */
+@Composable
+fun ReorderableSongList(
+    songs: List<SongEntry>,
+    reorderEnabled: Boolean,
+    onReorder: (List<SongEntry>) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    // Track drag state
+    var draggedIndex by remember { mutableStateOf(-1) }
+    var hoverIndex by remember { mutableStateOf(-1) }
+    var dragOffset by remember { mutableStateOf(0f) }
+
+    // Approximate item height for calculating target index from drag offset
+    val itemHeightPx = 36f  // approximate height of each row in pixels
+
+    Box(modifier = modifier.fillMaxWidth()) {
+        val listState = rememberLazyListState()
+        LazyColumn(
+            state = listState,
+            modifier = Modifier.fillMaxSize().padding(end = 12.dp)
+        ) {
+            itemsIndexed(songs, key = { _, song -> song.fileName }) { index, song ->
+                val isDragTarget = hoverIndex == index && draggedIndex != -1 && draggedIndex != index
+                val isBeingDragged = draggedIndex == index
+
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .then(
+                            if (isDragTarget) {
+                                Modifier.background(Color(0xFFBBDEFB))  // light blue drop indicator
+                            } else if (isBeingDragged) {
+                                Modifier.background(Color(0xFFE0E0E0))  // grey for dragged item
+                            } else {
+                                Modifier
+                            }
+                        )
+                        .padding(vertical = 2.dp, horizontal = 8.dp)
+                        .then(
+                            if (reorderEnabled) {
+                                Modifier.pointerInput(songs) {
+                                    detectDragGesturesAfterLongPress(
+                                        onDragStart = {
+                                            draggedIndex = index
+                                            hoverIndex = index
+                                            dragOffset = 0f
+                                        },
+                                        onDrag = { change, dragAmount ->
+                                            change.consume()
+                                            dragOffset += dragAmount.y
+                                            // Calculate target index based on cumulative drag offset
+                                            val indexDelta = (dragOffset / itemHeightPx).toInt()
+                                            val newHover = (draggedIndex + indexDelta).coerceIn(0, songs.size - 1)
+                                            hoverIndex = newHover
+                                        },
+                                        onDragEnd = {
+                                            if (draggedIndex != -1 && hoverIndex != -1 && draggedIndex != hoverIndex) {
+                                                val mutable = songs.toMutableList()
+                                                val item = mutable.removeAt(draggedIndex)
+                                                mutable.add(hoverIndex, item)
+                                                onReorder(mutable)
+                                            }
+                                            draggedIndex = -1
+                                            hoverIndex = -1
+                                            dragOffset = 0f
+                                        },
+                                        onDragCancel = {
+                                            draggedIndex = -1
+                                            hoverIndex = -1
+                                            dragOffset = 0f
+                                        }
+                                    )
+                                }
+                            } else {
+                                Modifier
+                            }
+                        ),
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    if (reorderEnabled) {
+                        Icon(
+                            imageVector = Icons.Default.Menu,
+                            contentDescription = "Ziehen zum Verschieben",
+                            modifier = Modifier.size(16.dp).padding(end = 4.dp),
+                            tint = Color.Gray
+                        )
+                    }
+                    Text(song.title, modifier = Modifier.weight(1f))
+                    Text(song.fileName, color = Color.Gray, fontSize = 12.sp)
+                }
+                Divider()
+            }
+
+            if (!reorderEnabled && songs.isNotEmpty()) {
+                item {
+                    Text(
+                        "Reihenfolge ist alphabetisch. Wechsle in songbook.yaml zu songs.order: \"manual\" um die Reihenfolge zu aendern.",
+                        color = Color.Gray,
+                        fontStyle = FontStyle.Italic,
+                        fontSize = 11.sp,
+                        modifier = Modifier.padding(8.dp)
+                    )
+                }
+            }
+        }
+        VerticalScrollbar(
+            modifier = Modifier.align(Alignment.CenterEnd).fillMaxHeight(),
+            adapter = rememberScrollbarAdapter(listState)
+        )
+    }
+}

layout/src/main/kotlin/de/pfadfinder/songbook/layout/MeasurementEngine.kt

@@ -15,9 +15,16 @@ class MeasurementEngine(
         // Title height
         heightMm += fontMetrics.measureLineHeight(config.fonts.title, config.fonts.title.size) * 1.5f
 
-        // Metadata line (composer/lyricist)
+        // Metadata lines (composer/lyricist) - may be 1 or 2 lines depending on label style
         if (song.composer != null || song.lyricist != null) {
-            heightMm += fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size) * 1.8f
+            val metaLineHeight = fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size) * 1.8f
+            val useGerman = config.layout.metadataLabels == "german"
+            if (useGerman && song.lyricist != null && song.composer != null && song.lyricist != song.composer) {
+                // Two separate lines: "Worte: ..." and "Weise: ..."
+                heightMm += metaLineHeight * 2
+            } else {
+                heightMm += metaLineHeight
+            }
         }
 
         // Key/capo line
@@ -43,29 +50,54 @@ class MeasurementEngine(
 
             // Lines in section
             for (line in section.lines) {
-                val hasChords = line.segments.any { it.chord != null }
-                val lyricHeight = fontMetrics.measureLineHeight(config.fonts.lyrics, config.fonts.lyrics.size)
-                if (hasChords) {
-                    val chordHeight = fontMetrics.measureLineHeight(config.fonts.chords, config.fonts.chords.size)
-                    heightMm += chordHeight + config.layout.chordLineSpacing + lyricHeight
+                if (line.imagePath != null) {
+                    // Inline image: estimate height as 40mm (default image block height)
+                    heightMm += 40f
+                    heightMm += 2f  // gap around image
                 } else {
-                    heightMm += lyricHeight
+                    val hasChords = line.segments.any { it.chord != null }
+                    val lyricHeight = fontMetrics.measureLineHeight(config.fonts.lyrics, config.fonts.lyrics.size)
+                    if (hasChords) {
+                        val chordHeight = fontMetrics.measureLineHeight(config.fonts.chords, config.fonts.chords.size)
+                        heightMm += chordHeight + config.layout.chordLineSpacing + lyricHeight
+                    } else {
+                        heightMm += lyricHeight
+                    }
+                    heightMm += 0.35f  // ~1pt gap between lines
                 }
-                heightMm += 0.35f  // ~1pt gap between lines
             }
 
             // Verse spacing
             heightMm += config.layout.verseSpacing
         }
 
-        // Notes at bottom
+        // Notes at bottom (with word-wrap estimation for multi-paragraph notes)
         if (song.notes.isNotEmpty()) {
-            heightMm += 1.5f  // gap
-            for (note in song.notes) {
-                heightMm += fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size) * 1.5f
+            heightMm += 1.5f  // gap before notes
+            val metaLineHeight = fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size) * 1.5f
+            // A5 content width in mm = 148 - inner margin - outer margin
+            val contentWidthMm = 148f - config.layout.margins.inner - config.layout.margins.outer
+
+            for ((idx, note) in song.notes.withIndex()) {
+                // Estimate how many wrapped lines this note paragraph needs
+                val noteWidthMm = fontMetrics.measureTextWidth(note, config.fonts.metadata, config.fonts.metadata.size)
+                val estimatedLines = maxOf(1, kotlin.math.ceil((noteWidthMm / contentWidthMm).toDouble()).toInt())
+                heightMm += metaLineHeight * estimatedLines
+
+                // Paragraph spacing between note paragraphs
+                if (idx < song.notes.size - 1) {
+                    heightMm += metaLineHeight * 0.3f
+                }
             }
         }
 
+        // Reference book footer: gap + separator line + abbreviation row + page number row
+        if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
+            val metaLineHeight = fontMetrics.measureLineHeight(config.fonts.metadata, config.fonts.metadata.size)
+            heightMm += 4f * 0.3528f         // gap before footer (4pt converted to mm)
+            heightMm += metaLineHeight * 1.4f * 2  // two rows (headers + numbers)
+        }
+
         val pageCount = if (heightMm <= contentHeightMm) 1 else 2
         return MeasuredSong(song, heightMm, pageCount)
     }

layout/src/test/kotlin/de/pfadfinder/songbook/layout/MeasurementEngineTest.kt

@@ -258,4 +258,106 @@ class MeasurementEngineTest {
 
         labeledHeight shouldBeGreaterThan unlabeledHeight
     }
+
+    @Test
+    fun `references add footer height when reference books configured`() {
+        val configWithRefs = BookConfig(
+            referenceBooks = listOf(
+                ReferenceBook(id = "mo", name = "Mundorgel", abbreviation = "MO"),
+                ReferenceBook(id = "pl", name = "Pfadfinderlied", abbreviation = "PL")
+            )
+        )
+        val engineWithRefs = MeasurementEngine(fontMetrics, configWithRefs)
+
+        val songWithRefs = Song(
+            title = "With Refs",
+            references = mapOf("mo" to 42, "pl" to 17),
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(SongLine(listOf(LineSegment(text = "Line"))))
+                )
+            )
+        )
+        val songWithoutRefs = Song(
+            title = "No Refs",
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(SongLine(listOf(LineSegment(text = "Line"))))
+                )
+            )
+        )
+
+        val heightWith = engineWithRefs.measure(songWithRefs).totalHeightMm
+        val heightWithout = engineWithRefs.measure(songWithoutRefs).totalHeightMm
+
+        heightWith shouldBeGreaterThan heightWithout
+    }
+
+    @Test
+    fun `references do not add height when no reference books configured`() {
+        val songWithRefs = Song(
+            title = "With Refs",
+            references = mapOf("mo" to 42),
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(SongLine(listOf(LineSegment(text = "Line"))))
+                )
+            )
+        )
+        val songWithoutRefs = Song(
+            title = "No Refs",
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(SongLine(listOf(LineSegment(text = "Line"))))
+                )
+            )
+        )
+
+        // Default config has no reference books
+        val heightWith = engine.measure(songWithRefs).totalHeightMm
+        val heightWithout = engine.measure(songWithoutRefs).totalHeightMm
+
+        // Should be the same since no reference books are configured
+        heightWith shouldBe heightWithout
+    }
+
+    @Test
+    fun `inline image adds significant height`() {
+        val songWithImage = Song(
+            title = "With Image",
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(
+                        SongLine(listOf(LineSegment(text = "Line before"))),
+                        SongLine(imagePath = "images/test.png"),
+                        SongLine(listOf(LineSegment(text = "Line after")))
+                    )
+                )
+            )
+        )
+        val songWithoutImage = Song(
+            title = "No Image",
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(
+                        SongLine(listOf(LineSegment(text = "Line before"))),
+                        SongLine(listOf(LineSegment(text = "Line after")))
+                    )
+                )
+            )
+        )
+
+        val heightWith = engine.measure(songWithImage).totalHeightMm
+        val heightWithout = engine.measure(songWithoutImage).totalHeightMm
+
+        // Inline image adds ~42mm (40mm image + 2mm gap)
+        val diff = heightWith - heightWithout
+        diff shouldBeGreaterThan 30f  // should be substantial
+    }
 }

model/src/main/kotlin/de/pfadfinder/songbook/model/BookConfig.kt

@@ -9,7 +9,12 @@ data class BookConfig(
     val referenceBooks: List<ReferenceBook> = emptyList(),
     val output: OutputConfig = OutputConfig(),
     val foreword: ForewordConfig? = null,
-    val toc: TocConfig = TocConfig()
+    val toc: TocConfig = TocConfig(),
+    val intro: IntroConfig? = null
+)
+
+data class IntroConfig(
+    val enabled: Boolean = true
 )
 
 data class TocConfig(
@@ -49,9 +54,11 @@ data class FontSpec(
 
 data class LayoutConfig(
     val margins: Margins = Margins(),
-    val chordLineSpacing: Float = 3f,    // mm
-    val verseSpacing: Float = 4f,         // mm
-    val pageNumberPosition: String = "bottom-outer"
+    val chordLineSpacing: Float = 1f,    // mm – gap between chord line and lyrics text
+    val verseSpacing: Float = 6f,         // mm – gap between consecutive song sections
+    val pageNumberPosition: String = "bottom-outer",
+    val metadataLabels: String = "abbreviated",  // "abbreviated" (M:/T:) or "german" (Worte:/Weise:)
+    val metadataPosition: String = "top"  // "top" (after title) or "bottom" (bottom of last page)
 )
 
 data class Margins(

model/src/main/kotlin/de/pfadfinder/songbook/model/Layout.kt

@@ -14,6 +14,7 @@ sealed class PageContent {
 }
 
 data class LayoutResult(
+    val introPages: Int = 0,
     val tocPages: Int,
     val pages: List<PageContent>,
     val tocEntries: List<TocEntry>

model/src/main/kotlin/de/pfadfinder/songbook/model/Song.kt

@@ -23,7 +23,10 @@ enum class SectionType {
     VERSE, CHORUS, BRIDGE, REPEAT
 }
 
-data class SongLine(val segments: List<LineSegment>)
+data class SongLine(
+    val segments: List<LineSegment> = emptyList(),
+    val imagePath: String? = null  // when non-null, this "line" is an inline image (segments ignored)
+)
 
 data class LineSegment(
     val chord: String? = null,  // null = no chord above this segment

parser/src/main/kotlin/de/pfadfinder/songbook/parser/ChordProParser.kt

@@ -24,6 +24,18 @@ object ChordProParser {
         var currentType: SectionType? = null
         var currentLabel: String? = null
         var currentLines = mutableListOf<SongLine>()
+        var explicitSection = false
+
+        // Notes block state
+        var inNotesBlock = false
+        var currentNoteParagraph = StringBuilder()
+
+        fun flushNoteParagraph() {
+            if (currentNoteParagraph.isNotEmpty()) {
+                notes.add(currentNoteParagraph.toString().trim())
+                currentNoteParagraph = StringBuilder()
+            }
+        }
 
         fun flushSection() {
             if (currentType != null) {
@@ -31,17 +43,44 @@ object ChordProParser {
                 currentType = null
                 currentLabel = null
                 currentLines = mutableListOf()
+                explicitSection = false
             }
         }
 
         for (rawLine in lines) {
             val line = rawLine.trimEnd()
 
+            // Inside a notes block: collect lines as paragraphs
+            if (inNotesBlock) {
+                if (line.trimStart().startsWith("{") && line.trimEnd().endsWith("}")) {
+                    val inner = line.trim().removePrefix("{").removeSuffix("}").trim().lowercase()
+                    if (inner == "end_of_notes" || inner == "eon") {
+                        flushNoteParagraph()
+                        inNotesBlock = false
+                        continue
+                    }
+                }
+                if (line.isBlank()) {
+                    flushNoteParagraph()
+                } else {
+                    if (currentNoteParagraph.isNotEmpty()) {
+                        currentNoteParagraph.append(" ")
+                    }
+                    currentNoteParagraph.append(line.trim())
+                }
+                continue
+            }
+
             // Skip comments
             if (line.trimStart().startsWith("#")) continue
 
-            // Skip empty lines
-            if (line.isBlank()) continue
+            // Blank line: flush implicit sections, skip otherwise
+            if (line.isBlank()) {
+                if (currentType != null && !explicitSection) {
+                    flushSection()
+                }
+                continue
+            }
 
             // Directive line
             if (line.trimStart().startsWith("{") && line.trimEnd().endsWith("}")) {
@@ -77,6 +116,7 @@ object ChordProParser {
                         flushSection()
                         currentType = SectionType.VERSE
                         currentLabel = value
+                        explicitSection = true
                     }
                     "end_of_verse", "eov" -> {
                         flushSection()
@@ -85,6 +125,7 @@ object ChordProParser {
                         flushSection()
                         currentType = SectionType.CHORUS
                         currentLabel = value
+                        explicitSection = true
                     }
                     "end_of_chorus", "eoc" -> {
                         flushSection()
@@ -93,10 +134,26 @@ object ChordProParser {
                         flushSection()
                         currentType = SectionType.REPEAT
                         currentLabel = value
+                        explicitSection = true
                     }
                     "end_of_repeat", "eor" -> {
                         flushSection()
                     }
+                    "image" -> if (value != null) {
+                        // Inline image within a song section
+                        if (currentType == null) {
+                            currentType = SectionType.VERSE
+                        }
+                        currentLines.add(SongLine(imagePath = value.trim()))
+                    }
+                    "start_of_notes", "son" -> {
+                        inNotesBlock = true
+                    }
+                    "end_of_notes", "eon" -> {
+                        // Should have been handled in the notes block above
+                        flushNoteParagraph()
+                        inNotesBlock = false
+                    }
                     "chorus" -> {
                         flushSection()
                         sections.add(SongSection(type = SectionType.CHORUS))

parser/src/main/kotlin/de/pfadfinder/songbook/parser/Validator.kt

@@ -1,7 +1,9 @@
 package de.pfadfinder.songbook.parser
 
 import de.pfadfinder.songbook.model.BookConfig
+import de.pfadfinder.songbook.model.FontSpec
 import de.pfadfinder.songbook.model.Song
+import java.io.File
 
 data class ValidationError(val file: String?, val line: Int?, val message: String)
 
@@ -50,6 +52,27 @@ object Validator {
             if (outer <= 0) errors.add(ValidationError(file = null, line = null, message = "Outer margin must be greater than 0"))
         }
 
+        // Validate font files exist (paths should already be resolved to absolute by the pipeline)
+        validateFontFile(config.fonts.lyrics, "lyrics", errors)
+        validateFontFile(config.fonts.chords, "chords", errors)
+        validateFontFile(config.fonts.title, "title", errors)
+        validateFontFile(config.fonts.metadata, "metadata", errors)
+        validateFontFile(config.fonts.toc, "toc", errors)
+
         return errors
     }
+
+    private fun validateFontFile(font: FontSpec, fontRole: String, errors: MutableList<ValidationError>) {
+        val fontFile = font.file ?: return
+        val file = File(fontFile)
+        if (!file.exists()) {
+            errors.add(
+                ValidationError(
+                    file = null,
+                    line = null,
+                    message = "Font file for '$fontRole' not found: $fontFile"
+                )
+            )
+        }
+    }
 }

parser/src/test/kotlin/de/pfadfinder/songbook/parser/ChordProParserTest.kt

@@ -485,4 +485,288 @@ class ChordProParserTest {
         line.segments[2].chord shouldBe "G"
         line.segments[2].text shouldBe "End"
     }
+
+    @Test
+    fun `parse notes block with multiple paragraphs`() {
+        val input = """
+            {title: Song}
+            {start_of_notes}
+            First paragraph of the notes.
+            It continues on the next line.
+
+            Second paragraph with different content.
+            {end_of_notes}
+            {start_of_verse}
+            text
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.notes shouldHaveSize 2
+        song.notes[0] shouldBe "First paragraph of the notes. It continues on the next line."
+        song.notes[1] shouldBe "Second paragraph with different content."
+    }
+
+    @Test
+    fun `parse notes block with single paragraph`() {
+        val input = """
+            {title: Song}
+            {start_of_notes}
+            A single note paragraph.
+            {end_of_notes}
+            {start_of_verse}
+            text
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.notes shouldHaveSize 1
+        song.notes[0] shouldBe "A single note paragraph."
+    }
+
+    @Test
+    fun `parse notes block with short directives son eon`() {
+        val input = """
+            {title: Song}
+            {son}
+            Short form notes.
+            {eon}
+            {start_of_verse}
+            text
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.notes shouldHaveSize 1
+        song.notes[0] shouldBe "Short form notes."
+    }
+
+    @Test
+    fun `notes block and single note directives combine`() {
+        val input = """
+            {title: Song}
+            {note: Single line note}
+            {start_of_notes}
+            Block note paragraph.
+            {end_of_notes}
+            {start_of_verse}
+            text
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.notes shouldHaveSize 2
+        song.notes[0] shouldBe "Single line note"
+        song.notes[1] shouldBe "Block note paragraph."
+    }
+
+    @Test
+    fun `parse notes block with three paragraphs`() {
+        val input = """
+            {title: Song}
+            {start_of_notes}
+            Paragraph one.
+
+            Paragraph two.
+
+            Paragraph three.
+            {end_of_notes}
+            {start_of_verse}
+            text
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.notes shouldHaveSize 3
+        song.notes[0] shouldBe "Paragraph one."
+        song.notes[1] shouldBe "Paragraph two."
+        song.notes[2] shouldBe "Paragraph three."
+    }
+
+    @Test
+    fun `parse image directive within song section`() {
+        val input = """
+            {title: Song}
+            {start_of_verse}
+            [Am]Hello world
+            {image: images/drawing.png}
+            [C]Goodbye world
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 1
+        song.sections[0].lines shouldHaveSize 3
+        song.sections[0].lines[0].segments[0].chord shouldBe "Am"
+        song.sections[0].lines[1].imagePath shouldBe "images/drawing.png"
+        song.sections[0].lines[1].segments.shouldBeEmpty()
+        song.sections[0].lines[2].segments[0].chord shouldBe "C"
+    }
+
+    @Test
+    fun `parse image directive outside section creates implicit verse`() {
+        val input = """
+            {title: Song}
+            {image: images/landscape.jpg}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 1
+        song.sections[0].type shouldBe SectionType.VERSE
+        song.sections[0].lines shouldHaveSize 1
+        song.sections[0].lines[0].imagePath shouldBe "images/landscape.jpg"
+    }
+
+    @Test
+    fun `parse multiple image directives`() {
+        val input = """
+            {title: Song}
+            {start_of_verse}
+            {image: img1.png}
+            Some text
+            {image: img2.png}
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections[0].lines shouldHaveSize 3
+        song.sections[0].lines[0].imagePath shouldBe "img1.png"
+        song.sections[0].lines[0].segments.shouldBeEmpty()
+        song.sections[0].lines[1].imagePath.shouldBeNull()
+        song.sections[0].lines[1].segments[0].text shouldBe "Some text"
+        song.sections[0].lines[2].imagePath shouldBe "img2.png"
+    }
+
+    @Test
+    fun `blank line splits implicit verses into separate sections`() {
+        val input = """
+            {title: Am Brunnen vor dem Tore}
+
+            Am [D]Brunnen vor dem Tore
+            Ich [D]träumt in seinem Schatten
+
+            Ich musst auch heute wandern
+            Da hab ich noch im Dunkeln
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 2
+        song.sections[0].type shouldBe SectionType.VERSE
+        song.sections[0].lines shouldHaveSize 2
+        song.sections[0].lines[0].segments shouldHaveSize 2
+        song.sections[0].lines[0].segments[0].chord.shouldBeNull()
+        song.sections[0].lines[0].segments[0].text shouldBe "Am "
+        song.sections[0].lines[0].segments[1].chord shouldBe "D"
+        song.sections[0].lines[0].segments[1].text shouldBe "Brunnen vor dem Tore"
+        song.sections[1].type shouldBe SectionType.VERSE
+        song.sections[1].lines shouldHaveSize 2
+        song.sections[1].lines[0].segments[0].text shouldBe "Ich musst auch heute wandern"
+    }
+
+    @Test
+    fun `blank lines within explicit sections are ignored`() {
+        val input = """
+            {title: Song}
+            {start_of_verse: Verse 1}
+            Line one
+
+            Line two
+            {end_of_verse}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 1
+        song.sections[0].type shouldBe SectionType.VERSE
+        song.sections[0].label shouldBe "Verse 1"
+        song.sections[0].lines shouldHaveSize 2
+    }
+
+    @Test
+    fun `blank lines between metadata do not create empty sections`() {
+        val input = """
+            {title: Song}
+
+            {lyricist: Someone}
+
+            {composer: Someone Else}
+
+            [Am]Hello world
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 1
+        song.sections[0].type shouldBe SectionType.VERSE
+        song.sections[0].lines shouldHaveSize 1
+    }
+
+    @Test
+    fun `mixed explicit and implicit sections with blank lines`() {
+        val input = """
+            {title: Song}
+            {start_of_chorus}
+            [C]Chorus line
+
+            Still in chorus
+            {end_of_chorus}
+
+            Implicit verse one
+
+            Implicit verse two
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 3
+        song.sections[0].type shouldBe SectionType.CHORUS
+        song.sections[0].lines shouldHaveSize 2
+        song.sections[1].type shouldBe SectionType.VERSE
+        song.sections[1].lines shouldHaveSize 1
+        song.sections[1].lines[0].segments[0].text shouldBe "Implicit verse one"
+        song.sections[2].type shouldBe SectionType.VERSE
+        song.sections[2].lines shouldHaveSize 1
+        song.sections[2].lines[0].segments[0].text shouldBe "Implicit verse two"
+    }
+
+    @Test
+    fun `multiple blank lines between implicit verses`() {
+        val input = """
+            {title: Song}
+            First verse line
+
+
+            Second verse line
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 2
+        song.sections[0].type shouldBe SectionType.VERSE
+        song.sections[0].lines shouldHaveSize 1
+        song.sections[1].type shouldBe SectionType.VERSE
+        song.sections[1].lines shouldHaveSize 1
+    }
+
+    @Test
+    fun `three implicit verses separated by blank lines`() {
+        val input = """
+            {title: Song}
+            [Am]Verse one line one
+            Verse one line two
+
+            [C]Verse two line one
+            Verse two line two
+
+            [G]Verse three line one
+            Verse three line two
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 3
+        song.sections.forEach { section ->
+            section.type shouldBe SectionType.VERSE
+            section.lines shouldHaveSize 2
+        }
+    }
+
+    @Test
+    fun `blank lines within explicit chorus are ignored`() {
+        val input = """
+            {title: Song}
+            {start_of_chorus}
+            Line one
+
+            Line two
+
+            Line three
+            {end_of_chorus}
+        """.trimIndent()
+        val song = ChordProParser.parse(input)
+        song.sections shouldHaveSize 1
+        song.sections[0].type shouldBe SectionType.CHORUS
+        song.sections[0].lines shouldHaveSize 3
+    }
 }

parser/src/test/kotlin/de/pfadfinder/songbook/parser/ConfigParserTest.kt

@@ -214,6 +214,31 @@ class ConfigParserTest {
         config.toc.highlightColumn.shouldBeNull()
     }
 
+    @Test
+    fun `parse config with german metadata labels`() {
+        val yaml = """
+            book:
+              title: "Test"
+            layout:
+              metadata_labels: german
+              metadata_position: bottom
+        """.trimIndent()
+        val config = ConfigParser.parse(yaml)
+        config.layout.metadataLabels shouldBe "german"
+        config.layout.metadataPosition shouldBe "bottom"
+    }
+
+    @Test
+    fun `parse config with default metadata settings`() {
+        val yaml = """
+            book:
+              title: "Test"
+        """.trimIndent()
+        val config = ConfigParser.parse(yaml)
+        config.layout.metadataLabels shouldBe "abbreviated"
+        config.layout.metadataPosition shouldBe "top"
+    }
+
     @Test
     fun `parse config ignores unknown properties`() {
         val yaml = """
@@ -226,4 +251,21 @@ class ConfigParserTest {
         val config = ConfigParser.parse(yaml)
         config.book.title shouldBe "Test"
     }
+
+    @Test
+    fun `parse config with custom title font file only`() {
+        val yaml = """
+            book:
+              title: "Fraktur Test"
+            fonts:
+              title: { file: "./fonts/Fraktur.ttf", size: 16 }
+        """.trimIndent()
+        val config = ConfigParser.parse(yaml)
+        config.fonts.title.file shouldBe "./fonts/Fraktur.ttf"
+        config.fonts.title.size shouldBe 16f
+        config.fonts.title.family shouldBe "Helvetica"  // default family as fallback
+        // Other fonts should still use defaults
+        config.fonts.lyrics.file.shouldBeNull()
+        config.fonts.lyrics.family shouldBe "Helvetica"
+    }
 }

parser/src/test/kotlin/de/pfadfinder/songbook/parser/ValidatorTest.kt

@@ -206,4 +206,53 @@ class ValidatorTest {
         errors shouldHaveSize 1
         errors[0].file shouldContain "myfile.chopro"
     }
+
+    @Test
+    fun `missing font file produces validation error`() {
+        val config = BookConfig(
+            fonts = FontsConfig(
+                title = FontSpec(file = "/nonexistent/path/FrakturFont.ttf", size = 14f)
+            )
+        )
+        val errors = Validator.validateConfig(config)
+        errors shouldHaveSize 1
+        errors[0].message shouldContain "title"
+        errors[0].message shouldContain "not found"
+    }
+
+    @Test
+    fun `multiple missing font files produce multiple errors`() {
+        val config = BookConfig(
+            fonts = FontsConfig(
+                title = FontSpec(file = "/nonexistent/title.ttf", size = 14f),
+                lyrics = FontSpec(file = "/nonexistent/lyrics.ttf", size = 10f)
+            )
+        )
+        val errors = Validator.validateConfig(config)
+        errors shouldHaveSize 2
+    }
+
+    @Test
+    fun `config with no font files produces no font errors`() {
+        val config = BookConfig()  // all default built-in fonts
+        val errors = Validator.validateConfig(config)
+        errors.shouldBeEmpty()
+    }
+
+    @Test
+    fun `config with existing font file produces no error`() {
+        // Create a temporary file to simulate an existing font file
+        val tempFile = kotlin.io.path.createTempFile(suffix = ".ttf").toFile()
+        try {
+            val config = BookConfig(
+                fonts = FontsConfig(
+                    title = FontSpec(file = tempFile.absolutePath, size = 14f)
+                )
+            )
+            val errors = Validator.validateConfig(config)
+            errors.shouldBeEmpty()
+        } finally {
+            tempFile.delete()
+        }
+    }
 }

renderer-pdf/src/main/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfBookRenderer.kt

@@ -26,11 +26,24 @@ class PdfBookRenderer : BookRenderer {
         val writer = PdfWriter.getInstance(document, output)
         document.open()
 
-        // Render TOC first
+        // Render intro page (title page) if configured
+        if (layout.introPages > 0) {
+            val cb = writer.directContent
+            renderIntroPage(cb, fontMetrics, config, pageSize)
+            // Blank back of intro page (for double-sided printing)
+            document.newPage()
+            writer.directContent.let { c -> c.beginText(); c.endText() }
+            document.newPage()
+        }
+
+        // Render TOC
         if (layout.tocEntries.isNotEmpty()) {
             tocRenderer.render(document, writer, layout.tocEntries)
-            // Add blank pages to fill TOC allocation
-            repeat(layout.tocPages - 1) {
+            // Pad with blank pages to fill the allocated TOC page count.
+            // The table auto-paginates, so we only add the difference.
+            val tocPagesUsed = writer.pageNumber - layout.introPages
+            val paddingNeeded = maxOf(0, layout.tocPages - tocPagesUsed)
+            repeat(paddingNeeded) {
                 document.newPage()
                 // Force new page even if empty
                 writer.directContent.let { cb ->
@@ -42,7 +55,7 @@ class PdfBookRenderer : BookRenderer {
         }
 
         // Render content pages
-        var currentPageNum = layout.tocPages + 1
+        var currentPageNum = layout.introPages + layout.tocPages + 1
         for (pageContent in layout.pages) {
             // Swap margins for left/right pages
             val isRightPage = currentPageNum % 2 == 1
@@ -63,7 +76,7 @@ class PdfBookRenderer : BookRenderer {
                     renderSongPage(
                         cb, chordLyricRenderer, fontMetrics, config,
                         pageContent.song, pageContent.pageIndex,
-                        contentTop, leftMargin, contentWidth
+                        contentTop, leftMargin, contentWidth, marginBottom
                     )
                 }
                 is PageContent.FillerImage -> {
@@ -91,6 +104,165 @@ class PdfBookRenderer : BookRenderer {
         document.close()
     }
 
+    /**
+     * Computes the index of the first section that should be rendered on page 1.
+     * All sections before this index render on page 0; sections from this index
+     * onward render on page 1.
+     *
+     * If all sections fit on page 0, returns song.sections.size (i.e., nothing on page 1).
+     */
+    private fun computeSplitIndex(
+        song: Song,
+        fontMetrics: PdfFontMetrics,
+        config: BookConfig,
+        contentWidth: Float,
+        availableHeightOnPage0: Float
+    ): Int {
+        var consumed = 0f
+
+        // Header: title
+        consumed += config.fonts.title.size * 1.5f
+
+        // Top metadata
+        val renderMetaAtBottom = config.layout.metadataPosition == "bottom"
+        if (!renderMetaAtBottom) {
+            val metaParts = buildMetadataLines(song, config)
+            if (metaParts.isNotEmpty()) {
+                consumed += config.fonts.metadata.size * 1.8f * metaParts.size
+            }
+        }
+
+        // Key/capo
+        if (song.key != null || song.capo != null) {
+            consumed += config.fonts.metadata.size * 1.8f
+        }
+
+        consumed += 4f  // gap before sections
+
+        for ((index, section) in song.sections.withIndex()) {
+            val sectionHeight = calculateSectionHeight(section, fontMetrics, config, contentWidth)
+            if (consumed + sectionHeight > availableHeightOnPage0) {
+                // This section doesn't fit on page 0
+                return index
+            }
+            consumed += sectionHeight
+            // Add verse spacing
+            consumed += config.layout.verseSpacing / 0.3528f
+        }
+
+        return song.sections.size
+    }
+
+    /**
+     * Calculates the height in PDF points that a section will consume when rendered.
+     */
+    private fun calculateSectionHeight(
+        section: SongSection,
+        fontMetrics: PdfFontMetrics,
+        config: BookConfig,
+        contentWidth: Float
+    ): Float {
+        var height = 0f
+        val metaSize = config.fonts.metadata.size
+
+        // Section label
+        if (section.label != null || section.type == SectionType.CHORUS) {
+            val labelText = section.label ?: when (section.type) {
+                SectionType.CHORUS -> "Refrain"
+                SectionType.REPEAT -> "Wiederholung"
+                else -> null
+            }
+            if (labelText != null) {
+                height += metaSize * 1.5f
+            }
+        }
+
+        // Empty chorus (reference)
+        if (section.type == SectionType.CHORUS && section.lines.isEmpty()) {
+            height += metaSize * 1.8f
+            return height
+        }
+
+        // Repeat start marker (contributes no extra height - drawn at current y)
+        // Lines
+        val chordSize = config.fonts.chords.size
+        val lyricSize = config.fonts.lyrics.size
+        val chordLineHeight = chordSize * 1.2f
+        val lyricLineHeight = lyricSize * 1.2f
+        val chordLyricGap = config.layout.chordLineSpacing / 0.3528f
+
+        for (line in section.lines) {
+            if (line.imagePath != null) {
+                // Inline image: 40mm max height + gaps
+                val maxImageHeight = 40f / 0.3528f
+                height += maxImageHeight + 6f
+            } else {
+                val hasChords = line.segments.any { it.chord != null }
+                var lineHeight = lyricLineHeight
+                if (hasChords) {
+                    lineHeight += chordLineHeight + chordLyricGap
+                }
+                height += lineHeight + 1f  // 1pt gap between lines
+            }
+        }
+
+        // Repeat end marker
+        if (section.type == SectionType.REPEAT) {
+            height += metaSize * 1.5f
+        }
+
+        return height
+    }
+
+    /**
+     * Calculates the space (in PDF points) that must be reserved at the bottom of
+     * the last page of a song for notes, bottom-position metadata, and reference footer.
+     */
+    private fun calculateFooterReservation(
+        song: Song,
+        fontMetrics: PdfFontMetrics,
+        config: BookConfig,
+        contentWidth: Float
+    ): Float {
+        var reserved = 0f
+        val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
+        val metaSize = config.fonts.metadata.size
+
+        // Notes
+        if (song.notes.isNotEmpty()) {
+            reserved += 4f  // gap before notes
+            val noteLineHeight = metaSize * 1.5f
+            for ((idx, note) in song.notes.withIndex()) {
+                val wrappedLines = wrapText(note, metaFont, metaSize, contentWidth)
+                reserved += noteLineHeight * wrappedLines.size
+                if (idx < song.notes.size - 1) {
+                    reserved += noteLineHeight * 0.3f
+                }
+            }
+        }
+
+        // Bottom metadata
+        if (config.layout.metadataPosition == "bottom") {
+            val metaParts = buildMetadataLines(song, config)
+            if (metaParts.isNotEmpty()) {
+                reserved += 4f
+                for (metaLine in metaParts) {
+                    val wrappedLines = wrapText(metaLine, metaFont, metaSize, contentWidth)
+                    reserved += metaSize * 1.5f * wrappedLines.size
+                }
+            }
+        }
+
+        // Reference footer: gap + separator line + abbreviation row + page number row
+        if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
+            val lineHeight = metaSize * 1.4f
+            reserved += 4f              // gap before footer
+            reserved += lineHeight * 2  // two rows (headers + numbers)
+        }
+
+        return reserved
+    }
+
     private fun renderSongPage(
         cb: PdfContentByte,
         chordLyricRenderer: ChordLyricRenderer,
@@ -100,10 +272,28 @@ class PdfBookRenderer : BookRenderer {
         pageIndex: Int,  // 0 for first page, 1 for second page of 2-page songs
         contentTop: Float,
         leftMargin: Float,
-        contentWidth: Float
+        contentWidth: Float,
+        bottomMargin: Float
     ) {
         var y = contentTop
 
+        val renderMetaAtBottom = config.layout.metadataPosition == "bottom"
+
+        // Calculate the footer reservation for the last page
+        val footerReservation = calculateFooterReservation(song, fontMetrics, config, contentWidth)
+
+        // Compute the split index to determine which sections go on which page.
+        // Page 0 gets sections 0..<splitIndex, page 1 gets sections splitIndex..<size.
+        // Footer space is reserved on the last page only.
+        val availableOnPage0 = contentTop - bottomMargin -
+            (if (song.sections.size > 0) footerReservation else 0f)
+        val splitIndex = computeSplitIndex(song, fontMetrics, config, contentWidth, availableOnPage0)
+        val isTwoPageSong = splitIndex < song.sections.size
+        val isLastPage = if (isTwoPageSong) pageIndex == 1 else pageIndex == 0
+
+        // Bottom boundary for content on this page
+        val yMin = bottomMargin + (if (isLastPage) footerReservation else 0f)
+
         if (pageIndex == 0) {
             // Render title
             val titleFont = fontMetrics.getBaseFont(config.fonts.title)
@@ -116,20 +306,23 @@ class PdfBookRenderer : BookRenderer {
             cb.endText()
             y -= titleSize * 1.5f
 
-            // Render metadata line (composer/lyricist)
-            val metaParts = mutableListOf<String>()
-            song.composer?.let { metaParts.add("M: $it") }
-            song.lyricist?.let { metaParts.add("T: $it") }
-            if (metaParts.isNotEmpty()) {
-                val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
-                val metaSize = config.fonts.metadata.size
-                cb.beginText()
-                cb.setFontAndSize(metaFont, metaSize)
-                cb.setColorFill(Color.GRAY)
-                cb.setTextMatrix(leftMargin, y - metaSize)
-                cb.showText(metaParts.joinToString(" / "))
-                cb.endText()
-                y -= metaSize * 1.8f
+            // Render metadata line (composer/lyricist) - at top position only
+            if (!renderMetaAtBottom) {
+                val metaParts = buildMetadataLines(song, config)
+                if (metaParts.isNotEmpty()) {
+                    val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
+                    val metaSize = config.fonts.metadata.size
+                    for (metaLine in metaParts) {
+                        if (y - metaSize * 1.8f < yMin) break
+                        cb.beginText()
+                        cb.setFontAndSize(metaFont, metaSize)
+                        cb.setColorFill(Color.GRAY)
+                        cb.setTextMatrix(leftMargin, y - metaSize)
+                        cb.showText(metaLine)
+                        cb.endText()
+                        y -= metaSize * 1.8f
+                    }
+                }
             }
 
             // Render key and capo
@@ -139,24 +332,31 @@ class PdfBookRenderer : BookRenderer {
             if (infoParts.isNotEmpty()) {
                 val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
                 val metaSize = config.fonts.metadata.size
-                cb.beginText()
-                cb.setFontAndSize(metaFont, metaSize)
-                cb.setColorFill(Color.GRAY)
-                cb.setTextMatrix(leftMargin, y - metaSize)
-                cb.showText(infoParts.joinToString(" | "))
-                cb.endText()
-                y -= metaSize * 1.8f
+                if (y - metaSize * 1.8f >= yMin) {
+                    cb.beginText()
+                    cb.setFontAndSize(metaFont, metaSize)
+                    cb.setColorFill(Color.GRAY)
+                    cb.setTextMatrix(leftMargin, y - metaSize)
+                    cb.showText(infoParts.joinToString(" | "))
+                    cb.endText()
+                    y -= metaSize * 1.8f
+                }
             }
 
             y -= 4f  // gap before sections
         }
 
         // Determine which sections to render on this page
-        // For simplicity in this implementation, render all sections on pageIndex 0
-        // A more sophisticated implementation would split sections across pages
-        val sections = if (pageIndex == 0) song.sections else emptyList()
+        val sections = if (pageIndex == 0) {
+            song.sections.subList(0, splitIndex)
+        } else {
+            song.sections.subList(splitIndex, song.sections.size)
+        }
 
         for (section in sections) {
+            // Safety check: stop rendering if we've gone below the boundary
+            if (y < yMin) break
+
             // Section label
             if (section.label != null || section.type == SectionType.CHORUS) {
                 val labelText = section.label ?: when (section.type) {
@@ -167,6 +367,7 @@ class PdfBookRenderer : BookRenderer {
                 if (labelText != null) {
                     val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
                     val metaSize = config.fonts.metadata.size
+                    if (y - metaSize * 1.5f < yMin) break
                     cb.beginText()
                     cb.setFontAndSize(metaFont, metaSize)
                     cb.setColorFill(Color.DARK_GRAY)
@@ -181,6 +382,7 @@ class PdfBookRenderer : BookRenderer {
             if (section.type == SectionType.CHORUS && section.lines.isEmpty()) {
                 val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
                 val metaSize = config.fonts.metadata.size
+                if (y - metaSize * 1.8f < yMin) break
                 cb.beginText()
                 cb.setFontAndSize(metaFont, metaSize)
                 cb.setColorFill(Color.DARK_GRAY)
@@ -205,40 +407,193 @@ class PdfBookRenderer : BookRenderer {
 
             // Render lines
             for (line in section.lines) {
-                val height = chordLyricRenderer.renderLine(cb, line, leftMargin, y, contentWidth)
-                y -= height + 1f  // 1pt gap between lines
+                if (y < yMin) break
+                val imgPath = line.imagePath
+                if (imgPath != null) {
+                    // Render inline image
+                    y -= renderInlineImage(cb, imgPath, leftMargin, y, contentWidth)
+                } else {
+                    val height = chordLyricRenderer.renderLine(cb, line, leftMargin, y, contentWidth)
+                    y -= height + 1f  // 1pt gap between lines
+                }
             }
 
             // End repeat marker
             if (section.type == SectionType.REPEAT) {
                 val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
                 val metaSize = config.fonts.metadata.size
-                cb.beginText()
-                cb.setFontAndSize(metaFont, metaSize)
-                cb.setColorFill(Color.DARK_GRAY)
-                cb.setTextMatrix(leftMargin, y - metaSize)
-                cb.showText(":\u2502")
-                cb.endText()
-                y -= metaSize * 1.5f
+                if (y - metaSize * 1.5f >= yMin) {
+                    cb.beginText()
+                    cb.setFontAndSize(metaFont, metaSize)
+                    cb.setColorFill(Color.DARK_GRAY)
+                    cb.setTextMatrix(leftMargin, y - metaSize)
+                    cb.showText(":\u2502")
+                    cb.endText()
+                    y -= metaSize * 1.5f
+                }
             }
 
             // Verse spacing
             y -= config.layout.verseSpacing / 0.3528f
         }
 
-        // Render notes at the bottom
-        if (pageIndex == 0 && song.notes.isNotEmpty()) {
-            y -= 4f
+        // Render footer elements (notes, metadata, references) anchored to the bottom of the page.
+        // Instead of flowing from the current y position after song content, we compute a fixed
+        // starting Y at the top of the footer area (bottomMargin + footerReservation) and render
+        // top-down: notes -> metadata -> references. This ensures footer elements always appear
+        // at the same vertical position regardless of how much song content is on the page.
+        if (isLastPage && footerReservation > 0f) {
             val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
             val metaSize = config.fonts.metadata.size
-            for (note in song.notes) {
+
+            // The footer area spans from bottomMargin to bottomMargin + footerReservation.
+            // Start rendering from the top of this area, flowing downward.
+            var footerY = bottomMargin + footerReservation
+
+            // Render notes (topmost footer element)
+            if (song.notes.isNotEmpty()) {
+                footerY -= 4f  // gap before notes
+                val noteLineHeight = metaSize * 1.5f
+                for ((idx, note) in song.notes.withIndex()) {
+                    val wrappedLines = wrapText(note, metaFont, metaSize, contentWidth)
+                    for (wrappedLine in wrappedLines) {
+                        cb.beginText()
+                        cb.setFontAndSize(metaFont, metaSize)
+                        cb.setColorFill(Color.GRAY)
+                        cb.setTextMatrix(leftMargin, footerY - metaSize)
+                        cb.showText(wrappedLine)
+                        cb.endText()
+                        footerY -= noteLineHeight
+                    }
+                    if (idx < song.notes.size - 1) {
+                        footerY -= noteLineHeight * 0.3f
+                    }
+                }
+            }
+
+            // Render metadata (Worte/Weise) below notes, if configured at bottom
+            if (renderMetaAtBottom) {
+                val metaParts = buildMetadataLines(song, config)
+                if (metaParts.isNotEmpty()) {
+                    footerY -= 4f  // gap before metadata
+                    for (metaLine in metaParts) {
+                        val wrappedLines = wrapText(metaLine, metaFont, metaSize, contentWidth)
+                        for (wrappedLine in wrappedLines) {
+                            cb.beginText()
+                            cb.setFontAndSize(metaFont, metaSize)
+                            cb.setColorFill(Color.GRAY)
+                            cb.setTextMatrix(leftMargin, footerY - metaSize)
+                            cb.showText(wrappedLine)
+                            cb.endText()
+                            footerY -= metaSize * 1.5f
+                        }
+                    }
+                }
+            }
+
+            // Render reference book footer (bottommost footer element, just above page number)
+            if (config.referenceBooks.isNotEmpty() && song.references.isNotEmpty()) {
+                footerY -= 4f  // gap before reference footer
+                renderReferenceFooter(
+                    cb, fontMetrics, config, song,
+                    leftMargin, footerY, contentWidth
+                )
+            }
+        }
+    }
+
+    /**
+     * Build metadata lines based on configured label style.
+     * Returns a list of lines to render (may be empty).
+     */
+    private fun buildMetadataLines(song: Song, config: BookConfig): List<String> {
+        val useGerman = config.layout.metadataLabels == "german"
+        val lines = mutableListOf<String>()
+
+        if (useGerman) {
+            // German labels: "Worte und Weise:" when same person, otherwise separate
+            if (song.lyricist != null && song.composer != null && song.lyricist == song.composer) {
+                lines.add("Worte und Weise: ${song.lyricist}")
+            } else {
+                song.lyricist?.let { lines.add("Worte: $it") }
+                song.composer?.let { lines.add("Weise: $it") }
+            }
+        } else {
+            // Abbreviated labels on a single line
+            val parts = mutableListOf<String>()
+            song.composer?.let { parts.add("M: $it") }
+            song.lyricist?.let { parts.add("T: $it") }
+            if (parts.isNotEmpty()) {
+                lines.add(parts.joinToString(" / "))
+            }
+        }
+
+        return lines
+    }
+
+    /**
+     * Renders reference book abbreviations and page numbers as a footer
+     * on the song page, positioned below the current content at [topY].
+     * Layout (top to bottom): separator line, abbreviation row, page number row.
+     */
+    private fun renderReferenceFooter(
+        cb: PdfContentByte,
+        fontMetrics: PdfFontMetrics,
+        config: BookConfig,
+        song: Song,
+        leftMargin: Float,
+        topY: Float,
+        contentWidth: Float
+    ) {
+        val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
+        val metaSize = config.fonts.metadata.size
+        val lineHeight = metaSize * 1.4f
+
+        val books = config.referenceBooks
+
+        // Calculate column widths: evenly distribute across content width
+        val colWidth = contentWidth / books.size
+
+        // Draw a thin separator line at the top of the footer
+        val lineY = topY
+        cb.setLineWidth(0.3f)
+        cb.setColorStroke(Color.LIGHT_GRAY)
+        cb.moveTo(leftMargin, lineY)
+        cb.lineTo(leftMargin + contentWidth, lineY)
+        cb.stroke()
+
+        // Row 1: Abbreviation headers (below the separator line)
+        val abbrY = lineY - lineHeight
+        for ((i, book) in books.withIndex()) {
+            val x = leftMargin + i * colWidth
+            val abbr = book.abbreviation
+            val textWidth = metaFont.getWidthPoint(abbr, metaSize)
+            val textX = x + (colWidth - textWidth) / 2
+
+            cb.beginText()
+            cb.setFontAndSize(metaFont, metaSize)
+            cb.setColorFill(Color.DARK_GRAY)
+            cb.setTextMatrix(textX, abbrY)
+            cb.showText(abbr)
+            cb.endText()
+        }
+
+        // Row 2: Page numbers (below abbreviation headers)
+        val numY = abbrY - lineHeight
+        for ((i, book) in books.withIndex()) {
+            val x = leftMargin + i * colWidth
+            val pageNum = song.references[book.id]
+            if (pageNum != null) {
+                val pageText = pageNum.toString()
+                val textWidth = metaFont.getWidthPoint(pageText, metaSize)
+                val textX = x + (colWidth - textWidth) / 2
+
                 cb.beginText()
                 cb.setFontAndSize(metaFont, metaSize)
-                cb.setColorFill(Color.GRAY)
-                cb.setTextMatrix(leftMargin, y - metaSize)
-                cb.showText(note)
+                cb.setColorFill(Color.DARK_GRAY)
+                cb.setTextMatrix(textX, numY)
+                cb.showText(pageText)
                 cb.endText()
-                y -= metaSize * 1.5f
             }
         }
     }
@@ -356,6 +711,95 @@ class PdfBookRenderer : BookRenderer {
         return lines
     }
 
+    /**
+     * Renders an inline image within a song page at the given position.
+     * Returns the total height consumed in PDF points.
+     */
+    private fun renderInlineImage(
+        cb: PdfContentByte,
+        imagePath: String,
+        leftMargin: Float,
+        y: Float,
+        contentWidth: Float
+    ): Float {
+        try {
+            val img = Image.getInstance(imagePath)
+            // Scale to fit within content width, max height 40mm (~113 points)
+            val maxHeight = 40f / 0.3528f  // 40mm in points
+            img.scaleToFit(contentWidth * 0.8f, maxHeight)
+
+            // Center horizontally
+            val imgX = leftMargin + (contentWidth - img.scaledWidth) / 2
+            val imgY = y - img.scaledHeight - 3f  // 3pt gap above
+
+            img.setAbsolutePosition(imgX, imgY)
+            cb.addImage(img)
+
+            return img.scaledHeight + 6f  // image height + gaps above/below
+        } catch (_: Exception) {
+            // If image can't be loaded, consume minimal space
+            return 5f
+        }
+    }
+
+    private fun renderIntroPage(
+        cb: PdfContentByte,
+        fontMetrics: PdfFontMetrics,
+        config: BookConfig,
+        pageSize: Rectangle
+    ) {
+        val pageWidth = pageSize.width
+        val pageHeight = pageSize.height
+
+        // Title centered on the page
+        val titleFont = fontMetrics.getBaseFont(config.fonts.title)
+        val titleSize = config.fonts.title.size * 2.5f
+        val title = config.book.title
+        val titleWidth = titleFont.getWidthPoint(title, titleSize)
+        val titleX = (pageWidth - titleWidth) / 2
+        val titleY = pageHeight * 0.55f
+
+        cb.beginText()
+        cb.setFontAndSize(titleFont, titleSize)
+        cb.setColorFill(Color.BLACK)
+        cb.setTextMatrix(titleX, titleY)
+        cb.showText(title)
+        cb.endText()
+
+        // Subtitle below the title
+        if (config.book.subtitle != null) {
+            val subtitleSize = config.fonts.title.size * 1.2f
+            val subtitle = config.book.subtitle!!
+            val subtitleWidth = titleFont.getWidthPoint(subtitle, subtitleSize)
+            val subtitleX = (pageWidth - subtitleWidth) / 2
+            val subtitleY = titleY - titleSize * 1.8f
+
+            cb.beginText()
+            cb.setFontAndSize(titleFont, subtitleSize)
+            cb.setColorFill(Color.DARK_GRAY)
+            cb.setTextMatrix(subtitleX, subtitleY)
+            cb.showText(subtitle)
+            cb.endText()
+        }
+
+        // Edition at the bottom of the page
+        if (config.book.edition != null) {
+            val metaFont = fontMetrics.getBaseFont(config.fonts.metadata)
+            val metaSize = config.fonts.metadata.size * 1.2f
+            val edition = config.book.edition!!
+            val editionWidth = metaFont.getWidthPoint(edition, metaSize)
+            val editionX = (pageWidth - editionWidth) / 2
+            val editionY = pageHeight * 0.1f
+
+            cb.beginText()
+            cb.setFontAndSize(metaFont, metaSize)
+            cb.setColorFill(Color.GRAY)
+            cb.setTextMatrix(editionX, editionY)
+            cb.showText(edition)
+            cb.endText()
+        }
+    }
+
     private fun renderFillerImage(document: Document, imagePath: String, pageSize: Rectangle) {
         try {
             val img = Image.getInstance(imagePath)

renderer-pdf/src/main/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfFontMetrics.kt

@@ -3,15 +3,21 @@ package de.pfadfinder.songbook.renderer.pdf
 import com.lowagie.text.pdf.BaseFont
 import de.pfadfinder.songbook.model.FontMetrics
 import de.pfadfinder.songbook.model.FontSpec
+import java.io.File
 
 class PdfFontMetrics : FontMetrics {
     private val fontCache = mutableMapOf<String, BaseFont>()
 
     fun getBaseFont(font: FontSpec): BaseFont {
-        val key = font.file ?: font.family
+        val fontFile = font.file
+        val key = if (fontFile != null) File(fontFile).canonicalPath else font.family
         return fontCache.getOrPut(key) {
-            if (font.file != null) {
-                BaseFont.createFont(font.file, BaseFont.IDENTITY_H, BaseFont.EMBEDDED)
+            if (fontFile != null) {
+                val file = File(fontFile)
+                if (!file.exists()) {
+                    throw IllegalArgumentException("Font file not found: ${file.absolutePath}")
+                }
+                BaseFont.createFont(file.absolutePath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED)
             } else {
                 // Map common family names to built-in PDF fonts
                 val pdfFontName = when (font.family.lowercase()) {

renderer-pdf/src/main/kotlin/de/pfadfinder/songbook/renderer/pdf/TocRenderer.kt

@@ -12,6 +12,32 @@ class TocRenderer(
     // Light gray background for the highlighted column
     private val highlightColor = Color(220, 220, 220)
 
+    /**
+     * Pre-renders the TOC to a temporary document and returns the number of pages needed,
+     * rounded up to an even number for double-sided printing.
+     */
+    fun measurePages(tocEntries: List<TocEntry>): Int {
+        val pageSize = if (config.book.format == "A5") PageSize.A5 else PageSize.A4
+        val marginInner = config.layout.margins.inner / 0.3528f
+        val marginOuter = config.layout.margins.outer / 0.3528f
+        val marginTop = config.layout.margins.top / 0.3528f
+        val marginBottom = config.layout.margins.bottom / 0.3528f
+
+        val baos = java.io.ByteArrayOutputStream()
+        val doc = Document(pageSize, marginInner, marginOuter, marginTop, marginBottom)
+        val writer = PdfWriter.getInstance(doc, baos)
+        doc.open()
+        render(doc, writer, tocEntries)
+        doc.close()
+
+        val reader = PdfReader(baos.toByteArray())
+        val pageCount = reader.numberOfPages
+        reader.close()
+
+        // Round to even for double-sided printing
+        return if (pageCount % 2 == 0) pageCount else pageCount + 1
+    }
+
     fun render(document: Document, writer: PdfWriter, tocEntries: List<TocEntry>) {
         val tocFont = fontMetrics.getBaseFont(config.fonts.toc)
         val tocBoldFont = fontMetrics.getBaseFontBold(config.fonts.toc)
@@ -30,19 +56,18 @@ class TocRenderer(
         val table = PdfPTable(numCols)
         table.widthPercentage = 100f
 
-        // Set column widths: title takes most space
+        // Set column widths: title takes most space, ref columns need room for 3-digit numbers
         val widths = FloatArray(numCols)
-        widths[0] = 10f  // title
-        widths[1] = 1.5f  // page
+        widths[0] = 12f  // title
+        widths[1] = 1.5f // page
         for (i in refBooks.indices) {
-            widths[2 + i] = 1.5f
+            widths[2 + i] = 1.5f  // enough for 3-digit page numbers; headers are rotated 90°
         }
         table.setWidths(widths)
 
         // Determine which column index should be highlighted
         val highlightAbbrev = config.toc.highlightColumn
         val highlightColumnIndex: Int? = if (highlightAbbrev != null) {
-            // Check "Seite" (page) column first - the current book's page number column
             if (highlightAbbrev == "Seite") {
                 1
             } else {
@@ -51,13 +76,13 @@ class TocRenderer(
             }
         } else null
 
-        // Header row
+        // Header row — reference book columns are rotated 90°
         val headerFont = Font(tocBoldFont, fontSize, Font.BOLD)
         table.addCell(headerCell("Titel", headerFont, isHighlighted = false))
         table.addCell(headerCell("Seite", headerFont, isHighlighted = highlightColumnIndex == 1))
         for ((i, book) in refBooks.withIndex()) {
             val isHighlighted = highlightColumnIndex == 2 + i
-            table.addCell(headerCell(book.abbreviation, headerFont, isHighlighted = isHighlighted))
+            table.addCell(rotatedHeaderCell(book.abbreviation, headerFont, isHighlighted))
         }
         table.headerRows = 1
 
@@ -71,7 +96,7 @@ class TocRenderer(
             for ((i, book) in refBooks.withIndex()) {
                 val ref = entry.references[book.abbreviation]
                 val isHighlighted = highlightColumnIndex == 2 + i
-                table.addCell(entryCell(ref?.toString() ?: "", entryFont, Element.ALIGN_RIGHT, isHighlighted = isHighlighted))
+                table.addCell(entryCell(ref?.toString() ?: "", entryFont, Element.ALIGN_CENTER, isHighlighted = isHighlighted))
             }
         }
 
@@ -83,6 +108,27 @@ class TocRenderer(
         cell.borderWidth = 0f
         cell.borderWidthBottom = 0.5f
         cell.paddingBottom = 4f
+        cell.verticalAlignment = Element.ALIGN_BOTTOM
+        if (isHighlighted) {
+            cell.backgroundColor = highlightColor
+        }
+        return cell
+    }
+
+    /**
+     * Creates a header cell with text rotated 90° counterclockwise.
+     * Used for reference book column headers to save horizontal space.
+     */
+    private fun rotatedHeaderCell(text: String, font: Font, isHighlighted: Boolean): PdfPCell {
+        val cell = PdfPCell(Phrase(text, font))
+        cell.borderWidth = 0f
+        cell.borderWidthBottom = 0.5f
+        cell.rotation = 90
+        cell.horizontalAlignment = Element.ALIGN_CENTER
+        cell.verticalAlignment = Element.ALIGN_MIDDLE
+        // Ensure cell is tall enough for the rotated text
+        val textWidth = font.baseFont.getWidthPoint(text, font.size)
+        cell.minimumHeight = textWidth + 8f
         if (isHighlighted) {
             cell.backgroundColor = highlightColor
         }

renderer-pdf/src/test/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfBookRendererTest.kt

@@ -417,4 +417,213 @@ class PdfBookRendererTest {
 
         baos.size() shouldBeGreaterThan 0
     }
+
+    // --- Content splitting tests ---
+
+    private fun createLongSong(title: String = "Long Song"): Song {
+        // Create a song with many sections that will exceed one A5 page
+        val sections = (1..20).map { i ->
+            SongSection(
+                type = SectionType.VERSE,
+                label = "Verse $i",
+                lines = (1..4).map {
+                    SongLine(
+                        listOf(
+                            LineSegment(chord = "Am", text = "Some text with chords "),
+                            LineSegment(chord = "G", text = "and more text here")
+                        )
+                    )
+                }
+            )
+        }
+        return Song(title = title, sections = sections)
+    }
+
+    @Test
+    fun `render splits content across pages for two-page song`() {
+        val song = createLongSong()
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, BookConfig(), baos)
+
+        baos.size() shouldBeGreaterThan 0
+        val bytes = baos.toByteArray()
+        val header = String(bytes.sliceArray(0..4))
+        header shouldBe "%PDF-"
+    }
+
+    @Test
+    fun `render does not overflow below bottom margin for very long song`() {
+        // Create an extremely long song
+        val sections = (1..40).map { i ->
+            SongSection(
+                type = SectionType.VERSE,
+                label = "Verse $i",
+                lines = (1..6).map {
+                    SongLine(
+                        listOf(
+                            LineSegment(chord = "C", text = "A long line of text that should be rendered properly "),
+                            LineSegment(chord = "G", text = "with chords above each segment")
+                        )
+                    )
+                }
+            )
+        }
+        val song = Song(title = "Very Long Song", sections = sections)
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, BookConfig(), baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
+
+    @Test
+    fun `render places metadata at bottom of last page for two-page song`() {
+        val config = BookConfig(
+            layout = LayoutConfig(metadataPosition = "bottom")
+        )
+        val song = createLongSong().copy(
+            composer = "Bach",
+            lyricist = "Goethe"
+        )
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, config, baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
+
+    @Test
+    fun `render places notes on last page of two-page song`() {
+        val song = createLongSong().copy(
+            notes = listOf("This is a note that should appear on the last page")
+        )
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, BookConfig(), baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
+
+    @Test
+    fun `render places reference footer on last page of two-page song`() {
+        val config = BookConfig(
+            referenceBooks = listOf(
+                ReferenceBook(id = "mo", name = "Mundorgel", abbreviation = "MO"),
+                ReferenceBook(id = "pl", name = "Pfadfinderlied", abbreviation = "PL")
+            )
+        )
+        val song = createLongSong().copy(
+            references = mapOf("mo" to 42, "pl" to 17)
+        )
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, config, baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
+
+    @Test
+    fun `render handles short song that fits on one page without splitting`() {
+        // A simple short song should still work correctly after split logic is added
+        val song = Song(
+            title = "Short Song",
+            sections = listOf(
+                SongSection(
+                    type = SectionType.VERSE,
+                    lines = listOf(
+                        SongLine(listOf(LineSegment(chord = "Am", text = "One line")))
+                    )
+                )
+            )
+        )
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(PageContent.SongPage(song, 0)),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, BookConfig(), baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
+
+    @Test
+    fun `render two-page song with bottom metadata and references`() {
+        val config = BookConfig(
+            layout = LayoutConfig(
+                metadataPosition = "bottom",
+                metadataLabels = "german"
+            ),
+            referenceBooks = listOf(
+                ReferenceBook(id = "mo", name = "Mundorgel", abbreviation = "MO")
+            )
+        )
+        val song = createLongSong().copy(
+            composer = "Bach",
+            lyricist = "Goethe",
+            notes = listOf("Play softly", "Repeat last verse"),
+            references = mapOf("mo" to 55)
+        )
+
+        val layout = LayoutResult(
+            tocPages = 0,
+            pages = listOf(
+                PageContent.SongPage(song, 0),
+                PageContent.SongPage(song, 1)
+            ),
+            tocEntries = emptyList()
+        )
+
+        val baos = ByteArrayOutputStream()
+        renderer.render(layout, config, baos)
+
+        baos.size() shouldBeGreaterThan 0
+    }
 }

renderer-pdf/src/test/kotlin/de/pfadfinder/songbook/renderer/pdf/PdfFontMetricsTest.kt

@@ -6,6 +6,7 @@ import io.kotest.matchers.floats.shouldBeLessThan
 import io.kotest.matchers.shouldBe
 import io.kotest.matchers.types.shouldBeSameInstanceAs
 import kotlin.test.Test
+import kotlin.test.assertFailsWith
 
 class PdfFontMetricsTest {
 
@@ -158,4 +159,73 @@ class PdfFontMetricsTest {
         height shouldBeGreaterThan 3f
         height shouldBeLessThan 6f
     }
+
+    // --- Custom font file tests ---
+
+    private val testFontPath: String
+        get() = this::class.java.getResource("/TestFont.ttf")!!.file
+
+    @Test
+    fun `getBaseFont loads custom font from file path`() {
+        val font = FontSpec(file = testFontPath, size = 12f)
+        val baseFont = metrics.getBaseFont(font)
+        // Custom font should load successfully and have a non-null PostScript name
+        baseFont.postscriptFontName.isNotEmpty() shouldBe true
+    }
+
+    @Test
+    fun `getBaseFont caches custom font by canonical path`() {
+        val font1 = FontSpec(file = testFontPath, size = 12f)
+        val font2 = FontSpec(file = testFontPath, size = 14f)  // different size, same file
+        val first = metrics.getBaseFont(font1)
+        val second = metrics.getBaseFont(font2)
+        first shouldBeSameInstanceAs second
+    }
+
+    @Test
+    fun `getBaseFont throws for missing font file`() {
+        val font = FontSpec(file = "/nonexistent/path/MissingFont.ttf", size = 12f)
+        assertFailsWith<IllegalArgumentException> {
+            metrics.getBaseFont(font)
+        }
+    }
+
+    @Test
+    fun `getBaseFontBold returns same font when file is specified`() {
+        val font = FontSpec(file = testFontPath, size = 12f)
+        val regular = metrics.getBaseFont(font)
+        val bold = metrics.getBaseFontBold(font)
+        // Custom fonts don't have auto-resolved bold variants
+        regular shouldBeSameInstanceAs bold
+    }
+
+    @Test
+    fun `measureTextWidth works with custom font file`() {
+        val font = FontSpec(file = testFontPath, size = 12f)
+        val width = metrics.measureTextWidth("Hello World", font, 12f)
+        width shouldBeGreaterThan 0f
+    }
+
+    @Test
+    fun `measureTextWidth handles German umlauts with custom font`() {
+        val font = FontSpec(file = testFontPath, size = 12f)
+        // These should not throw and should return positive widths
+        val umlautWidth = metrics.measureTextWidth("\u00e4\u00f6\u00fc\u00df", font, 12f)
+        umlautWidth shouldBeGreaterThan 0f
+
+        // Full German words with umlauts
+        val wordWidth = metrics.measureTextWidth("Gr\u00fc\u00dfe aus \u00d6sterreich", font, 12f)
+        wordWidth shouldBeGreaterThan 0f
+    }
+
+    @Test
+    fun `measureTextWidth with custom font returns different width than built-in font`() {
+        val customFont = FontSpec(file = testFontPath, size = 10f)
+        val builtInFont = FontSpec(family = "Courier", size = 10f)  // use Courier for contrast
+        val customWidth = metrics.measureTextWidth("Test text", customFont, 10f)
+        val builtInWidth = metrics.measureTextWidth("Test text", builtInFont, 10f)
+        // They should both be positive but likely different
+        customWidth shouldBeGreaterThan 0f
+        builtInWidth shouldBeGreaterThan 0f
+    }
 }

songbook.yaml

@@ -14,11 +14,16 @@ fonts:
   title:     { family: "Helvetica", size: 14 }
   metadata:  { family: "Helvetica", size: 8 }
   toc:       { family: "Helvetica", size: 9 }
+  # To use a custom font file (e.g. Fraktur/Blackletter for titles):
+  # title:   { file: "./fonts/FrakturFont.ttf", size: 16 }
+  # The file path is relative to the project directory.
+  # Supported formats: .ttf, .otf
+  # Custom fonts are embedded in the PDF and support Unicode (including umlauts).
 
 layout:
   margins: { top: 15, bottom: 15, inner: 20, outer: 12 }
-  chord_line_spacing: 3
-  verse_spacing: 4
+  chord_line_spacing: 1
+  verse_spacing: 6
   page_number_position: bottom-outer
 
 images:
@@ -32,6 +37,9 @@ reference_books:
     name: "Pfadfinderliederbuch"
     abbreviation: "PfLB"
 
+toc:
+  highlight_column: "Seite"
+
 output:
   directory: "./output"
   filename: "liederbuch.pdf"