(Almost) Full OkHTTP implementation

app/src/main/java/xyz/quaver/pupil/services/DownloadService.kt

@@ -0,0 +1,155 @@
+/*
+ *     Pupil, Hitomi.la viewer for Android
+ *     Copyright (C) 2020  tom5079
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package xyz.quaver.pupil.services
+
+import android.app.Service
+import android.content.Context
+import android.content.ContextWrapper
+import android.content.Intent
+import android.os.Binder
+import android.os.IBinder
+import android.util.SparseArray
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationManagerCompat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import okhttp3.Interceptor
+import okhttp3.ResponseBody
+import okio.*
+import xyz.quaver.pupil.R
+
+private typealias ProgressListener = (Any?, Long, Long, Boolean) -> Unit
+
+class Cache(context: Context) : ContextWrapper(context) {
+
+
+
+}
+
+class DownloadService : Service() {
+
+    //region Notification
+    private val notificationManager by lazy {
+        NotificationManagerCompat.from(this)
+    }
+
+    private val serviceNotification by lazy {
+        NotificationCompat.Builder(this, "downloader")
+            .setContentTitle(getString(R.string.downloader_running))
+            .setProgress(0, 0, false)
+            .setSmallIcon(R.drawable.ic_notification)
+            .setOngoing(true)
+    }
+    //endregion
+
+    //region ProgressListener
+    @Suppress("UNCHECKED_CAST")
+    private val progressListener: ProgressListener = listener@{ tag, bytesRead, contentLength, done ->
+            val (galleryID, index) = (tag as? Pair<Int, Int>) ?: return@listener
+
+            if (!done && progress[galleryID]?.get(index)?.isFinite() == true)
+                progress[galleryID]?.set(index, bytesRead * 100F / contentLength)
+    }
+
+    private class ProgressResponseBody(
+        val tag: Any?,
+        val responseBody: ResponseBody,
+        val progressListener : ProgressListener
+    ) : ResponseBody() {
+        private var bufferedSource : BufferedSource? = null
+
+        override fun contentLength() = responseBody.contentLength()
+        override fun contentType() = responseBody.contentType()
+
+        override fun source(): BufferedSource {
+            if (bufferedSource == null)
+                bufferedSource = Okio.buffer(source(responseBody.source()))
+
+            return bufferedSource!!
+        }
+
+        private fun source(source: Source) = object: ForwardingSource(source) {
+            var totalBytesRead = 0L
+
+            override fun read(sink: Buffer, byteCount: Long): Long {
+                val bytesRead = super.read(sink, byteCount)
+
+                totalBytesRead += if (bytesRead == -1L) 0L else bytesRead
+                progressListener.invoke(tag, totalBytesRead, responseBody.contentLength(), bytesRead == -1L)
+
+                return bytesRead
+            }
+        }
+    }
+
+    val interceptor = Interceptor { chain ->
+        val request = chain.request()
+        var response = chain.proceed(request)
+
+        var retry = 5
+        while (!response.isSuccessful && retry > 0) {
+            response = chain.proceed(request)
+            retry--
+        }
+
+        response.newBuilder()
+            .body(response.body()?.let {
+                ProgressResponseBody(request.tag(), it, progressListener)
+            }).build()
+    }
+    //endregion
+
+    /**
+    * KEY
+    *  primary galleryID
+    *  secondary index
+    * PRIMARY VALUE
+    *  MutableList -> Download in progress
+    *  null -> Loading / Gallery doesn't exist
+    * SECONDARY VALUE
+    *  0 <= value < 100 -> Download in progress
+    *  Float.POSITIVE_INFINITY -> Download completed
+    */
+    val progress = SparseArray<MutableList<Float>?>()
+
+    override fun onCreate() {
+        startForeground(R.id.downloader_notification_id, serviceNotification.build())
+    }
+
+    override fun onDestroy() {
+
+    }
+
+
+    inner class Binder : android.os.Binder() {
+        val service = this@DownloadService
+    }
+
+    private val binder = Binder()
+    override fun onBind(p0: Intent?) = binder
+
+    fun load(galleryID: Int) {
+        
+    }
+
+    fun download(galleryID: Int) = CoroutineScope(Dispatchers.IO).launch {
+
+    }
+}