[feat] Complete video caching system

app/src/main/java/com/acitelight/aether/service/FetchManager.kt

@@ -1,6 +1,7 @@
 package com.acitelight.aether.service
 
 import android.content.Context
+import androidx.compose.runtime.mutableStateOf
 import com.acitelight.aether.Screen
 import com.acitelight.aether.model.Video
 import com.acitelight.aether.service.ApiClient.createOkHttp
@@ -13,7 +14,18 @@ import com.tonyodev.fetch2.Status
 import com.tonyodev.fetch2core.Extras
 import com.tonyodev.fetch2okhttp.OkHttpDownloader
 import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.Json
+import okhttp3.OkHttpClient
 import java.io.File
+import java.io.IOException
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -23,21 +35,25 @@ class FetchManager @Inject constructor(
 ) {
     private var fetch: Fetch? = null
     private var listener: FetchListener? = null
+    private var client: OkHttpClient? = null
+    val configured = MutableStateFlow(false)
 
     fun init()
     {
+        client = createOkHttp()
         val fetchConfiguration = FetchConfiguration.Builder(context)
             .setDownloadConcurrentLimit(8)
-            .setHttpDownloader(OkHttpDownloader(createOkHttp()))
+            .setHttpDownloader(OkHttpDownloader(client))
             .build()
 
-         fetch = Fetch.Impl.getInstance(fetchConfiguration)
+        fetch = Fetch.Impl.getInstance(fetchConfiguration)
+        configured.update { true }
     }
 
     // listener management
-    fun setListener(l: FetchListener) {
-        if (fetch == null)
-            return
+    suspend fun setListener(l: FetchListener) {
+        configured.filter { it }.first()
+
         listener?.let { fetch?.removeListener(it) }
         listener = l
         fetch?.addListener(l)
@@ -51,14 +67,24 @@ class FetchManager @Inject constructor(
     }
 
     // query downloads
-    fun getAllDownloads(callback: (List<Download>) -> Unit) {
-        if (fetch == null) init()
+    suspend fun getAllDownloads(callback: (List<Download>) -> Unit) {
+        configured.filter { it }.first()
         fetch?.getDownloads { list -> callback(list) } ?: callback(emptyList())
     }
 
-    fun getDownloadsByStatus(status: Status, callback: (List<Download>) -> Unit) {
-        if (fetch == null) init()
-        fetch?.getDownloadsWithStatus(status) { list -> callback(list) } ?: callback(emptyList())
+    suspend fun getAllDownloadsAsync(): List<Download>
+    {
+        configured.filter { it }.first()
+        val completed = MutableStateFlow(false)
+        var r = listOf<Download>()
+
+        fetch?.getDownloads { list ->
+            r = list
+            completed.update { true }
+        }
+
+        completed.filter { it }.first()
+        return r
     }
 
     // operations
@@ -80,13 +106,13 @@ class FetchManager @Inject constructor(
         } ?: callback?.invoke()
     }
 
-    private fun enqueue(request: Request, onEnqueued: ((Request) -> Unit)? = null, onError: ((com.tonyodev.fetch2.Error) -> Unit)? = null) {
-        if (fetch == null) init()
+    private suspend fun enqueue(request: Request, onEnqueued: ((Request) -> Unit)? = null, onError: ((com.tonyodev.fetch2.Error) -> Unit)? = null) {
+        configured.filter { it }.first()
         fetch?.enqueue(request, { r -> onEnqueued?.invoke(r) }, { e -> onError?.invoke(e) })
     }
 
     private fun getVideosDirectory() {
-        val appFilesDir = context.filesDir
+        val appFilesDir = context.getExternalFilesDir(null)
         val videosDir = File(appFilesDir, "videos")
 
         if (!videosDir.exists()) {
@@ -94,12 +120,52 @@ class FetchManager @Inject constructor(
         }
     }
 
-    fun startVideoDownload(video: Video)
+    suspend fun downloadFile(
+        client: OkHttpClient,
+        url: String,
+        destFile: File
+    ): Result<Unit> = withContext(Dispatchers.IO) {
+        try {
+            val request = okhttp3.Request.Builder().url(url).build()
+            client.newCall(request).execute().use { response ->
+                if (!response.isSuccessful) {
+                    return@withContext Result.failure(IOException("Unexpected code $response"))
+                }
+
+                destFile.parentFile?.mkdirs()
+                response.body.byteStream().use { input ->
+                    destFile.outputStream().use { output ->
+                        input.copyTo(output)
+                    }
+                }
+            }
+            Result.success(Unit)
+        } catch (e: Exception) {
+            Result.failure(e)
+        }
+    }
+
+    suspend fun startVideoDownload(video: Video)
     {
-        val path = File(context.filesDir, "videos/${video.klass}/${video.id}/video.mp4")
+        val path = File(context.getExternalFilesDir(null), "videos/${video.klass}/${video.id}/video.mp4")
         val request = Request(video.getVideo(), path.path).apply {
             extras = Extras(mapOf("name" to video.video.name, "id" to video.id, "class" to video.klass))
         }
+
+        downloadFile(
+            client!!,
+            video.getCover(),
+            File(context.getExternalFilesDir(null), "videos/${video.klass}/${video.id}/cover.jpg"))
+
         enqueue(request)
+        File(context.getExternalFilesDir(null), "videos/${video.klass}/${video.id}/summary.json").writeText(Json.encodeToString(video))
+
+        for(p in video.getGallery())
+        {
+            downloadFile(
+                client!!,
+                p.url,
+                File(context.getExternalFilesDir(null), "videos/${video.klass}/${video.id}/gallery/${p.name}"))
+        }
     }
 }