feat(player): batch relative seek requests

core/src/main/java/hu/bbara/purefin/player/viewmodel/PlayerViewModel.kt

@@ -49,6 +49,9 @@ class PlayerViewModel @Inject constructor(
     val controlsVisible: StateFlow<Boolean> = _controlsVisible.asStateFlow()
 
     private val controlsAutoHidePolicy = ControlsAutoHidePolicy(DEFAULT_CONTROLS_AUTO_HIDE_MS)
+    private val seekByCollector = SeekByCollector(viewModelScope) { deltaMs ->
+        playerManager.seekBy(deltaMs)
+    }
     private var autoHideJob: Job? = null
     private var dataErrorMessage: String? = null
 
@@ -191,18 +194,21 @@ class PlayerViewModel @Inject constructor(
     }
 
     fun seekTo(positionMs: Long) {
+        seekByCollector.clear()
         playerManager.seekTo(positionMs)
     }
 
     fun seekBy(deltaMs: Long) {
-        playerManager.seekBy(deltaMs)
+        seekByCollector.seekBySoon(deltaMs)
     }
 
     fun seekToLiveEdge() {
+        seekByCollector.clear()
         playerManager.seekToLiveEdge()
     }
 
     fun skipActiveSegment() {
+        seekByCollector.clear()
         playerManager.skipActiveSegment()
     }
 
@@ -240,11 +246,13 @@ class PlayerViewModel @Inject constructor(
     }
 
     fun next(autoHideDelayMs: Long = DEFAULT_CONTROLS_AUTO_HIDE_MS) {
+        seekByCollector.clear()
         playerManager.next()
         showControls(autoHideDelayMs)
     }
 
     fun previous(autoHideDelayMs: Long = DEFAULT_CONTROLS_AUTO_HIDE_MS) {
+        seekByCollector.clear()
         playerManager.previous()
         showControls(autoHideDelayMs)
     }
@@ -258,6 +266,7 @@ class PlayerViewModel @Inject constructor(
     }
 
     fun playQueueItem(id: String) {
+        seekByCollector.clear()
         playerManager.play(id.toUuidOrNull() ?: return)
         showControls()
     }

core/src/main/java/hu/bbara/purefin/player/viewmodel/SeekByCollector.kt

@@ -0,0 +1,48 @@
+package hu.bbara.purefin.player.viewmodel
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+class SeekByCollector(
+    private val scope: CoroutineScope,
+    private val intervalMs: Long = 120,
+    private val seekBy: (Long) -> Unit,
+) {
+    private var pendingSeekMs = 0L
+    private var flushJob: Job? = null
+
+    fun seekBySoon(deltaMs: Long) {
+        pendingSeekMs += deltaMs
+        if (flushJob?.isActive != true) {
+            scheduleFlush()
+        }
+    }
+
+    fun clear() {
+        pendingSeekMs = 0
+        flushJob?.cancel()
+        flushJob = null
+    }
+
+    private fun scheduleFlush() {
+        flushJob = scope.launch {
+            delay(intervalMs)
+            flush()
+        }
+    }
+
+    private fun flush() {
+        val deltaMs = pendingSeekMs
+        pendingSeekMs = 0
+        if (deltaMs != 0L) {
+            seekBy(deltaMs)
+        }
+        if (pendingSeekMs != 0L) {
+            scheduleFlush()
+        } else {
+            flushJob = null
+        }
+    }
+}