feat: add in-memory dice roll history (Closes #17) (#74)

sharedUI/src/commonMain/kotlin/org/shahondin1624/App.kt

@@ -3,6 +3,7 @@ package org.shahondin1624
 import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.DarkMode
+import androidx.compose.material.icons.filled.History
 import androidx.compose.material.icons.filled.LightMode
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Person
@@ -12,6 +13,8 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
@@ -29,6 +32,8 @@ import org.jetbrains.compose.ui.tooling.preview.Preview
 import org.shahondin1624.lib.components.TestTags
 import org.shahondin1624.lib.components.UiConstants
 import org.shahondin1624.lib.components.charactermodel.CharacterSheetPage
+import org.shahondin1624.lib.components.charactermodel.DiceRollHistoryDialog
+import org.shahondin1624.lib.functions.DiceRollHistory
 import org.shahondin1624.lib.components.settings.SettingsPage
 import org.shahondin1624.navigation.AppRoutes
 import org.shahondin1624.theme.AppTheme
@@ -248,6 +253,26 @@ private fun MainScaffold(
     val currentRoute = currentRoute(navController)
     val character by characterViewModel.character.collectAsState()
 
+    // Dice roll history (in-memory, not persisted)
+    val diceRollHistory = remember { DiceRollHistory() }
+    var showHistoryDialog by remember { mutableStateOf(false) }
+    // Trigger recomposition when history changes
+    var historyVersion by remember { mutableStateOf(0) }
+
+    if (showHistoryDialog) {
+        // Read historyVersion to trigger recomposition when entries change
+        @Suppress("UNUSED_EXPRESSION")
+        historyVersion
+        DiceRollHistoryDialog(
+            entries = diceRollHistory.entries,
+            onClear = {
+                diceRollHistory.clear()
+                historyVersion++
+            },
+            onDismiss = { showHistoryDialog = false }
+        )
+    }
+
     val topBarTitle = when (currentRoute) {
         AppRoutes.CHARACTER_SHEET -> character.characterData.name
         AppRoutes.SETTINGS -> "Settings"
@@ -271,6 +296,12 @@ private fun MainScaffold(
                     }
                 },
                 actions = {
+                    IconButton(
+                        onClick = { showHistoryDialog = true },
+                        modifier = Modifier.testTag(TestTags.DICE_HISTORY_BUTTON)
+                    ) {
+                        Icon(Icons.Default.History, contentDescription = "Roll History")
+                    }
                     IconButton(
                         onClick = {
                             val newPref = if (isDark) ThemePreference.Light else ThemePreference.Dark
@@ -316,6 +347,10 @@ private fun MainScaffold(
                         contentPadding = contentPadding,
                         onUpdateCharacter = { transform ->
                             characterViewModel.updateCharacter(transform)
+                        },
+                        onRecordRoll = { roll, label ->
+                            diceRollHistory.record(label, roll)
+                            historyVersion++
                         }
                     )
                 }

sharedUI/src/commonMain/kotlin/org/shahondin1624/lib/components/TestTags.kt

@@ -96,6 +96,14 @@ object TestTags {
     const val IMPORT_DISMISS = "import_dismiss"
     const val IMPORT_ERROR = "import_error"
 
+    // --- Dice roll history ---
+    const val DICE_HISTORY_BUTTON = "dice_history_button"
+    const val DICE_HISTORY_DIALOG = "dice_history_dialog"
+    const val DICE_HISTORY_EMPTY = "dice_history_empty"
+    const val DICE_HISTORY_DISMISS = "dice_history_dismiss"
+    const val DICE_HISTORY_CLEAR = "dice_history_clear"
+    fun diceHistoryEntry(index: Int): String = "dice_history_entry_$index"
+
     // --- Top app bar ---
     const val TOP_APP_BAR = "top_app_bar"
     const val THEME_TOGGLE = "theme_toggle"

sharedUI/src/commonMain/kotlin/org/shahondin1624/lib/components/charactermodel/CharacterSheetPage.kt

@@ -38,7 +38,8 @@ private enum class CharacterTab(val title: String) {
 fun CharacterSheetPage(
     character: ShadowrunCharacter,
     contentPadding: Dp,
-    onUpdateCharacter: ((ShadowrunCharacter) -> ShadowrunCharacter) -> Unit = {}
+    onUpdateCharacter: ((ShadowrunCharacter) -> ShadowrunCharacter) -> Unit = {},
+    onRecordRoll: ((DiceRoll, String) -> Unit)? = null
 ) {
     val windowSizeClass = LocalWindowSizeClass.current
     var selectedTab by remember { mutableStateOf(CharacterTab.Overview) }
@@ -51,6 +52,7 @@ fun CharacterSheetPage(
     val onDiceRoll: (DiceRoll, String) -> Unit = { roll, label ->
         pendingRoll = roll
         pendingRollLabel = label
+        onRecordRoll?.invoke(roll, label)
     }
 
     // Attribute edit dialog state

sharedUI/src/commonMain/kotlin/org/shahondin1624/lib/components/charactermodel/DiceRollHistoryDialog.kt

@@ -0,0 +1,135 @@
+package org.shahondin1624.lib.components.charactermodel
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import org.shahondin1624.lib.components.TestTags
+import org.shahondin1624.lib.functions.DiceRollHistoryEntry
+
+/**
+ * Dialog displaying the dice roll history in reverse chronological order.
+ */
+@Composable
+fun DiceRollHistoryDialog(
+    entries: List<DiceRollHistoryEntry>,
+    onClear: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        modifier = Modifier.testTag(TestTags.DICE_HISTORY_DIALOG),
+        title = { Text("Roll History") },
+        text = {
+            if (entries.isEmpty()) {
+                Box(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .heightIn(min = 100.dp),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Text(
+                        text = "No rolls yet",
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.testTag(TestTags.DICE_HISTORY_EMPTY)
+                    )
+                }
+            } else {
+                LazyColumn(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .heightIn(max = 400.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp)
+                ) {
+                    itemsIndexed(entries) { index, entry ->
+                        DiceRollHistoryItem(
+                            entry = entry,
+                            rollNumber = entries.size - index,
+                            modifier = Modifier.testTag(TestTags.diceHistoryEntry(index))
+                        )
+                    }
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = onDismiss,
+                modifier = Modifier.testTag(TestTags.DICE_HISTORY_DISMISS)
+            ) {
+                Text("Close")
+            }
+        },
+        dismissButton = {
+            if (entries.isNotEmpty()) {
+                TextButton(
+                    onClick = onClear,
+                    modifier = Modifier.testTag(TestTags.DICE_HISTORY_CLEAR)
+                ) {
+                    Text("Clear")
+                }
+            }
+        }
+    )
+}
+
+@Composable
+private fun DiceRollHistoryItem(
+    entry: DiceRollHistoryEntry,
+    rollNumber: Int,
+    modifier: Modifier = Modifier
+) {
+    Card(modifier = modifier.fillMaxWidth()) {
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(12.dp)
+        ) {
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween,
+                verticalAlignment = Alignment.CenterVertically
+            ) {
+                Text(
+                    text = entry.label,
+                    style = MaterialTheme.typography.titleSmall,
+                    fontWeight = FontWeight.Bold
+                )
+                Text(
+                    text = "#$rollNumber",
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+            }
+            Spacer(Modifier.height(4.dp))
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.SpaceBetween
+            ) {
+                Text(
+                    text = "Pool: ${entry.poolSize}d6",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant
+                )
+                Text(
+                    text = "${entry.successes} hit${if (entry.successes != 1) "s" else ""}",
+                    style = MaterialTheme.typography.bodySmall,
+                    fontWeight = FontWeight.SemiBold,
+                    color = MaterialTheme.colorScheme.primary
+                )
+            }
+            Spacer(Modifier.height(4.dp))
+            Text(
+                text = entry.results.joinToString(", ") { "[$it]" },
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
+        }
+    }
+}

sharedUI/src/commonMain/kotlin/org/shahondin1624/lib/functions/DiceRollHistory.kt

@@ -0,0 +1,55 @@
+package org.shahondin1624.lib.functions
+
+/**
+ * A single entry in the dice roll history log.
+ */
+data class DiceRollHistoryEntry(
+    /** What was rolled (e.g., "Body", "Firearms") */
+    val label: String,
+    /** Pool size (number of dice) */
+    val poolSize: Int,
+    /** Individual die results */
+    val results: List<Int>,
+    /** Number of successes (hits) */
+    val successes: Int,
+    /** Monotonic sequence number for ordering (higher = more recent) */
+    val sequenceNumber: Long
+)
+
+/**
+ * In-memory dice roll history holding the last [maxEntries] rolls.
+ * Not persisted across app restarts. Entries are in reverse chronological order.
+ */
+class DiceRollHistory(private val maxEntries: Int = 20) {
+    private val _entries = mutableListOf<DiceRollHistoryEntry>()
+    private var nextSequence = 1L
+
+    /** Current history entries in reverse chronological order (most recent first). */
+    val entries: List<DiceRollHistoryEntry> get() = _entries.toList()
+
+    /** Number of entries currently stored. */
+    val size: Int get() = _entries.size
+
+    /**
+     * Record a dice roll to history.
+     * Oldest entries are dropped when capacity is exceeded.
+     */
+    fun record(label: String, roll: DiceRoll) {
+        val entry = DiceRollHistoryEntry(
+            label = label,
+            poolSize = roll.numberOfDice,
+            results = roll.result,
+            successes = roll.numberOfSuccesses,
+            sequenceNumber = nextSequence++
+        )
+        _entries.add(0, entry) // Add to front for reverse chronological
+        if (_entries.size > maxEntries) {
+            _entries.removeAt(_entries.lastIndex)
+        }
+    }
+
+    /** Clear all history. */
+    fun clear() {
+        _entries.clear()
+    }
+}

sharedUI/src/commonTest/kotlin/org/shahondin1624/DiceRollHistoryTest.kt

@@ -0,0 +1,119 @@
+package org.shahondin1624
+
+import org.shahondin1624.lib.functions.DiceRoll
+import org.shahondin1624.lib.functions.DiceRollHistory
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class DiceRollHistoryTest {
+
+    private fun makeRoll(dice: Int = 6, results: List<Int> = listOf(5, 3, 6, 1, 2, 4), successes: Int = 2): DiceRoll {
+        return DiceRoll(
+            numberOfDice = dice,
+            result = results,
+            numberOfSuccesses = successes
+        )
+    }
+
+    @Test
+    fun emptyHistoryHasNoEntries() {
+        val history = DiceRollHistory()
+        assertTrue(history.entries.isEmpty())
+        assertEquals(0, history.size)
+    }
+
+    @Test
+    fun recordAddsEntry() {
+        val history = DiceRollHistory()
+        history.record("Body", makeRoll())
+        assertEquals(1, history.size)
+        assertEquals("Body", history.entries[0].label)
+    }
+
+    @Test
+    fun entriesAreInReverseChronologicalOrder() {
+        val history = DiceRollHistory()
+        history.record("Body", makeRoll())
+        history.record("Agility", makeRoll())
+        history.record("Strength", makeRoll())
+
+        assertEquals("Strength", history.entries[0].label) // most recent first
+        assertEquals("Agility", history.entries[1].label)
+        assertEquals("Body", history.entries[2].label)
+    }
+
+    @Test
+    fun sequenceNumbersAreIncreasing() {
+        val history = DiceRollHistory()
+        history.record("First", makeRoll())
+        history.record("Second", makeRoll())
+        history.record("Third", makeRoll())
+
+        // Most recent first, so highest sequence number first
+        assertTrue(history.entries[0].sequenceNumber > history.entries[1].sequenceNumber)
+        assertTrue(history.entries[1].sequenceNumber > history.entries[2].sequenceNumber)
+    }
+
+    @Test
+    fun entryContainsCorrectData() {
+        val history = DiceRollHistory()
+        val roll = DiceRoll(
+            numberOfDice = 8,
+            result = listOf(5, 6, 3, 1, 4, 5, 2, 6),
+            numberOfSuccesses = 4
+        )
+        history.record("Firearms", roll)
+
+        val entry = history.entries[0]
+        assertEquals("Firearms", entry.label)
+        assertEquals(8, entry.poolSize)
+        assertEquals(listOf(5, 6, 3, 1, 4, 5, 2, 6), entry.results)
+        assertEquals(4, entry.successes)
+    }
+
+    @Test
+    fun maxEntriesIsRespected() {
+        val history = DiceRollHistory(maxEntries = 3)
+        history.record("Roll 1", makeRoll())
+        history.record("Roll 2", makeRoll())
+        history.record("Roll 3", makeRoll())
+        history.record("Roll 4", makeRoll())
+
+        assertEquals(3, history.size)
+        // Oldest (Roll 1) should have been dropped
+        assertEquals("Roll 4", history.entries[0].label)
+        assertEquals("Roll 3", history.entries[1].label)
+        assertEquals("Roll 2", history.entries[2].label)
+    }
+
+    @Test
+    fun defaultMaxIs20() {
+        val history = DiceRollHistory()
+        repeat(25) { i ->
+            history.record("Roll $i", makeRoll())
+        }
+        assertEquals(20, history.size)
+    }
+
+    @Test
+    fun clearRemovesAllEntries() {
+        val history = DiceRollHistory()
+        history.record("Roll 1", makeRoll())
+        history.record("Roll 2", makeRoll())
+        history.clear()
+        assertTrue(history.entries.isEmpty())
+        assertEquals(0, history.size)
+    }
+
+    @Test
+    fun entriesListIsDefensiveCopy() {
+        val history = DiceRollHistory()
+        history.record("Roll 1", makeRoll())
+        val snapshot = history.entries
+        history.record("Roll 2", makeRoll())
+        // Original snapshot should not have changed
+        assertEquals(1, snapshot.size)
+        assertEquals(2, history.entries.size)
+    }
+}