fix(android): include mpv end-file diagnostics

android/app/src/main/kotlin/com/edde746/plezy/mpv/MpvEndFileDiagnostics.kt

@@ -0,0 +1,35 @@
+package com.edde746.plezy.mpv
+
+import dev.jdtech.mpv.EndFileReason
+import dev.jdtech.mpv.LogLevel
+import dev.jdtech.mpv.LogMessage
+import dev.jdtech.mpv.MpvEvent
+
+/** Adds the native diagnostic that libmpv-android exposes separately via logFlow. */
+internal class MpvEndFileDiagnostics {
+  private var errorMessage: String? = null
+
+  fun onStartFile() {
+    errorMessage = null
+  }
+
+  fun onLogMessage(message: LogMessage) {
+    if (message.level == LogLevel.Fatal || message.level == LogLevel.Error) {
+      errorMessage = message.text.takeIf { it.isNotBlank() }
+    }
+  }
+
+  fun onEndFile(event: MpvEvent.EndFile): Map<String, Any>? {
+    val reason = event.reason
+    if (reason == null) {
+      errorMessage = null
+      return null
+    }
+    val data = mutableMapOf<String, Any>("reason" to reason.id)
+    if (reason == EndFileReason.Error) {
+      errorMessage?.let { data["message"] = it }
+    }
+    errorMessage = null
+    return data
+  }
+}

android/app/src/main/kotlin/com/edde746/plezy/mpv/MpvPlayerCore.kt

@@ -73,6 +73,7 @@ class MpvPlayerCore(
 
   @Volatile private var player: MpvPlayer? = null
   private var scope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
+  private val endFileDiagnostics = MpvEndFileDiagnostics()
 
   // mpv writes must stay off the main thread but run in submission order:
   // setupMpvFallback sets vo/ao/hwdec immediately before the loadfile command,
@@ -184,6 +185,7 @@ class MpvPlayerCore(
 
     try {
       disposing = false
+      endFileDiagnostics.onStartFile()
       cachedPaused = true
       pausedForSurfaceLoss = false
       pendingSurface = null
@@ -361,9 +363,9 @@ class MpvPlayerCore(
       p.eventFlow.collect { event ->
         when (event) {
           is MpvEvent.EndFile -> {
-            val data = event.reason?.let { mapOf("reason" to it.id) }
-            delegate?.onEvent("end-file", data)
+            delegate?.onEvent("end-file", endFileDiagnostics.onEndFile(event))
           }
+          is MpvEvent.StartFile -> endFileDiagnostics.onStartFile()
           is MpvEvent.FileLoaded -> delegate?.onEvent("file-loaded", null)
           is MpvEvent.PlaybackRestart -> delegate?.onEvent("playback-restart", null)
           else -> {}
@@ -397,6 +399,7 @@ class MpvPlayerCore(
   private fun collectLogMessages(p: MpvPlayer) {
     scope.launch(start = CoroutineStart.UNDISPATCHED) {
       p.logFlow.collect { msg ->
+        endFileDiagnostics.onLogMessage(msg)
         emitLog(msg.level.name.lowercase(), msg.prefix, msg.text)
       }
     }

android/app/src/test/kotlin/com/edde746/plezy/mpv/MpvPlayerPluginTest.kt

@@ -1,5 +1,10 @@
 package com.edde746.plezy.mpv
 
+import dev.jdtech.mpv.EndFileReason
+import dev.jdtech.mpv.LogLevel
+import dev.jdtech.mpv.LogMessage
+import dev.jdtech.mpv.MpvEvent
+import io.flutter.plugin.common.EventChannel
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import org.junit.Assert.assertEquals
@@ -37,6 +42,59 @@ class MpvPlayerPluginTest {
     assertNull(result.successValue)
   }
 
+  @Test
+  fun endFileDiagnosticsPreserveReasonIdAndExposeDependencyErrorLog() {
+    val diagnostics = MpvEndFileDiagnostics()
+    diagnostics.onStartFile()
+    diagnostics.onLogMessage(LogMessage("ffmpeg", LogLevel.Error, "Invalid data found when processing input"))
+
+    assertEquals(
+      mapOf(
+        "reason" to 4,
+        "message" to "Invalid data found when processing input"
+      ),
+      diagnostics.onEndFile(MpvEvent.EndFile(EndFileReason.Error))
+    )
+  }
+
+  @Test
+  fun endFileDiagnosticsDoNotAttachStaleOrInventedDetails() {
+    val diagnostics = MpvEndFileDiagnostics()
+    diagnostics.onLogMessage(LogMessage("ffmpeg", LogLevel.Error, "old failure"))
+    diagnostics.onStartFile()
+
+    assertEquals(mapOf("reason" to 0), diagnostics.onEndFile(MpvEvent.EndFile(EndFileReason.Eof)))
+    assertEquals(mapOf("reason" to 4), diagnostics.onEndFile(MpvEvent.EndFile(EndFileReason.Error)))
+    assertNull(diagnostics.onEndFile(MpvEvent.EndFile(null)))
+  }
+
+  @Test
+  fun endFileEventChannelPayloadKeepsExistingEnvelopeAndAddsMessage() {
+    val sink = RecordingEventSink()
+    val plugin = MpvPlayerPlugin()
+    plugin.onListen(null, sink)
+
+    plugin.onEvent(
+      "end-file",
+      mapOf(
+        "reason" to 4,
+        "message" to "Failed to open stream"
+      )
+    )
+
+    assertEquals(
+      mapOf(
+        "type" to "event",
+        "name" to "end-file",
+        "data" to mapOf(
+          "reason" to 4,
+          "message" to "Failed to open stream"
+        )
+      ),
+      sink.successValue
+    )
+  }
+
   private class RecordingResult : MethodChannel.Result {
     var successValue: Any? = null
     var errorCode: String? = null
@@ -51,4 +109,16 @@ class MpvPlayerPluginTest {
 
     override fun notImplemented() = Unit
   }
+
+  private class RecordingEventSink : EventChannel.EventSink {
+    var successValue: Any? = null
+
+    override fun success(event: Any?) {
+      successValue = event
+    }
+
+    override fun error(errorCode: String, errorMessage: String?, errorDetails: Any?) = Unit
+
+    override fun endOfStream() = Unit
+  }
 }