update

app/frontend/src/main/java/com/youtubeapp/data/ApiClient.kt

@@ -5,7 +5,7 @@ import retrofit2.converter.gson.GsonConverterFactory
 
 object ApiClient {
     // Server-IP hier anpassen
-    const val BASE_URL = "http://192.168.178.92:8000/"
+    const val BASE_URL = "http://marha.local:8000/"
 
     val api: VideoApi by lazy {
         Retrofit.Builder()

app/frontend/src/main/java/com/youtubeapp/ui/navigation/AppNavigation.kt

@@ -157,7 +157,7 @@ fun AppNavigation() {
                 arguments = listOf(navArgument("videoId") { type = NavType.IntType })
             ) { backStackEntry ->
                 val videoId = backStackEntry.arguments?.getInt("videoId") ?: return@composable
-                VideoPlayerScreen(videoId = videoId, viewModel = viewModel)
+                VideoPlayerScreen(videoId = videoId, viewModel = viewModel, onBack = { navController.popBackStack() })
             }
         }
     }

app/frontend/src/main/java/com/youtubeapp/ui/screens/VideoPlayerScreen.kt

@@ -2,12 +2,21 @@ package com.youtubeapp.ui.screens
 
 import android.app.Activity
 import android.view.LayoutInflater
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.unit.dp
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.view.WindowCompat
 import androidx.core.view.WindowInsetsCompat
@@ -20,7 +29,7 @@ import com.youtubeapp.ui.viewmodel.VideoViewModel
 
 @Composable
 @androidx.annotation.OptIn(androidx.media3.common.util.UnstableApi::class)
-fun VideoPlayerScreen(videoId: Int, viewModel: VideoViewModel) {
+fun VideoPlayerScreen(videoId: Int, viewModel: VideoViewModel, onBack: () -> Unit) {
     val context = LocalContext.current
     val playbackUri = viewModel.getPlaybackUri(videoId)
 
@@ -49,15 +58,29 @@ fun VideoPlayerScreen(videoId: Int, viewModel: VideoViewModel) {
         }
     }
 
-    AndroidView(
-        factory = { ctx ->
-            val view = LayoutInflater.from(ctx).inflate(R.layout.player_view, null) as PlayerView
-            view.player = exoPlayer
-            view
-        },
-        update = { view ->
-            view.player = exoPlayer
-        },
-        modifier = Modifier.fillMaxSize()
-    )
+    Box(modifier = Modifier.fillMaxSize()) {
+        AndroidView(
+            factory = { ctx ->
+                val view = LayoutInflater.from(ctx).inflate(R.layout.player_view, null) as PlayerView
+                view.player = exoPlayer
+                view
+            },
+            update = { view ->
+                view.player = exoPlayer
+            },
+            modifier = Modifier.fillMaxSize()
+        )
+        IconButton(
+            onClick = onBack,
+            modifier = Modifier
+                .align(Alignment.TopStart)
+                .padding(16.dp)
+        ) {
+            Icon(
+                imageVector = Icons.AutoMirrored.Filled.ArrowBack,
+                contentDescription = "Zurück",
+                tint = Color.White
+            )
+        }
+    }
 }

app/frontend/src/main/java/com/youtubeapp/ui/viewmodel/VideoViewModel.kt

@@ -195,6 +195,10 @@ class VideoViewModel : ViewModel() {
 
     fun getPlaybackUri(videoId: Int): String {
         val localFile = localStorage?.getLocalFile(videoId)
-        return localFile?.toURI()?.toString() ?: repository.getStreamUrl(videoId)
+        return if (localFile != null) {
+            android.net.Uri.fromFile(localFile).toString()
+        } else {
+            repository.getStreamUrl(videoId)
+        }
     }
 }