Add timer

commonUI/src/commonMain/kotlin/ch/dissem/yaep/ui/common/App.kt

@@ -18,6 +18,7 @@ import androidx.compose.material3.OutlinedCard
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -58,12 +59,26 @@ class DisplayClue<C : Clue>(val clue: C) {
 
 @Composable
 fun App(modifier: Modifier = Modifier, game: Game = remember { generateGame() }) {
-    val horizontalClues = remember { game.horizontalClues.map { DisplayClue(it) } }
-    val verticalClues = remember { game.verticalClues.map { DisplayClue(it) } }
-    val time = "00:00:00" // TODO
+    val horizontalClues = remember(game) { game.horizontalClues.map { DisplayClue(it) } }
+    val verticalClues = remember(game) { game.verticalClues.map { DisplayClue(it) } }
+    val timer = remember(game) { GameTimer() }
+    val time by timer.elapsedTime.collectAsState("00:00")
+    LaunchedEffect(game) {
+        game.onStart {
+            timer.start()
+        }
+
+        game.onSolved {
+            timer.stop()
+        }
+    }
+
     Row(modifier = modifier) {
         PuzzleGrid(
-            modifier = Modifier.aspectRatio(1f).weight(0.6f).fillMaxHeight(),
+            modifier = Modifier
+                .aspectRatio(1f)
+                .weight(0.6f)
+                .fillMaxHeight(),
             grid = game.grid,
             onUpdate = {
                 horizontalClues.forEach { it.update(game.grid) }

commonUI/src/commonMain/kotlin/ch/dissem/yaep/ui/common/GameTimer.kt

@@ -0,0 +1,57 @@
+package ch.dissem.yaep.ui.common
+
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
+
+class GameTimer {
+
+    private var startTime: Long = 0L
+    private var stopTime: Long = 0L
+
+    val isRunning: Boolean
+        get() = startTime != 0L && stopTime == 0L
+
+    val elapsedSeconds: Flow<Long> = flow {
+        emit(0L)
+        while (startTime == 0L) {
+            delay(100)
+        }
+        var previousSeconds = 0L
+        while (stopTime == 0L) {
+            val elapsedSeconds = System.currentTimeMillis() / 1000 - startTime
+            if (elapsedSeconds != previousSeconds) {
+                emit(elapsedSeconds)
+            }
+            delay(100)
+            previousSeconds = elapsedSeconds
+        }
+        emit(stopTime - startTime)
+    }
+
+    val elapsedTime: Flow<String> = elapsedSeconds.map { seconds ->
+        val minutes = seconds / 60
+        val hours = minutes / 60
+        val remainingMinutes = minutes % 60
+        val remainingSeconds = seconds % 60
+        if (hours == 0L) {
+            "%02d:%02d".format(minutes, remainingSeconds)
+        } else {
+            "%02d:%02d:%02d".format(hours, remainingMinutes, remainingSeconds)
+        }
+    }
+
+    fun start() {
+        if (startTime == 0L) {
+            startTime = System.currentTimeMillis() / 1000
+        }
+    }
+
+    fun stop() {
+        if (isRunning) {
+            stopTime = System.currentTimeMillis() / 1000
+        }
+    }
+
+}