Implemented source launching

app/src/main/java/xyz/quaver/pupil/util/ApkDownloadManager.kt

@@ -0,0 +1,88 @@
+/*
+ *     Pupil, Hitomi.la viewer for Android
+ *     Copyright (C) 2021 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 <https://www.gnu.org/licenses/>.
+ */
+
+package xyz.quaver.pupil.util
+
+import android.content.Context
+import android.content.Intent
+import android.util.Log
+import android.webkit.MimeTypeMap
+import androidx.core.content.FileProvider
+import io.ktor.client.*
+import io.ktor.client.call.*
+import io.ktor.client.features.*
+import io.ktor.client.request.*
+import io.ktor.client.statement.*
+import io.ktor.http.*
+import io.ktor.util.cio.*
+import io.ktor.utils.io.*
+import io.ktor.utils.io.core.*
+import io.ktor.utils.io.jvm.javaio.*
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.withContext
+import java.io.File
+import kotlin.io.use
+
+class ApkDownloadManager(private val context: Context, private val client: HttpClient) {
+    fun download(projectName: String, sourceName: String, version: String) = flow {
+        val url = "https://github.com/tom5079/PupilSources/releases/download/$sourceName-$version/$projectName-release.apk"
+
+        val file = File(context.externalCacheDir, "apks/$sourceName-$version.apk").also {
+            it.parentFile?.mkdir()
+            it.delete()
+        }
+
+        client.get<HttpStatement>(url).execute { response ->
+            val channel: ByteReadChannel = response.receive()
+            val contentLength = response.contentLength() ?: -1
+            var readBytes = 0f
+
+            file.outputStream().use { outputStream ->
+                while (!channel.isClosedForRead) {
+                    val packet = channel.readRemaining(DEFAULT_BUFFER_SIZE.toLong())
+                    while (!packet.isEmpty) {
+                        val bytes = packet.readBytes()
+                        outputStream.write(bytes)
+
+                        readBytes += bytes.size
+                        emit(readBytes / contentLength)
+                    }
+                }
+            }
+        }
+
+        emit(Float.POSITIVE_INFINITY)
+
+        val uri = FileProvider.getUriForFile(
+            context,
+            "${context.packageName}.fileprovider",
+            file
+        )
+
+        val intent = Intent(Intent.ACTION_VIEW).apply {
+            flags = Intent.FLAG_ACTIVITY_CLEAR_TOP or
+                    Intent.FLAG_GRANT_READ_URI_PERMISSION or
+                    Intent.FLAG_ACTIVITY_NEW_TASK
+            setDataAndType(uri, MimeTypeMap.getSingleton().getMimeTypeFromExtension("apk"))
+        }
+
+        context.startActivity(intent)
+    }.flowOn(Dispatchers.IO)
+}