move all packages to 'suwayomi.tachidesk'

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/DownloadManager.kt

@@ -0,0 +1,129 @@
+package suwayomi.tachidesk.manga.impl.download
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+import io.javalin.websocket.WsContext
+import io.javalin.websocket.WsMessageContext
+import org.jetbrains.exposed.sql.and
+import org.jetbrains.exposed.sql.select
+import org.jetbrains.exposed.sql.transactions.transaction
+import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Downloading
+import suwayomi.tachidesk.manga.impl.download.model.DownloadStatus
+import suwayomi.tachidesk.manga.model.table.ChapterTable
+import suwayomi.tachidesk.manga.model.table.toDataClass
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.CopyOnWriteArrayList
+
+object DownloadManager {
+    private val clients = ConcurrentHashMap<String, WsContext>()
+    private val downloadQueue = CopyOnWriteArrayList<DownloadChapter>()
+    private var downloader: Downloader? = null
+
+    fun addClient(ctx: WsContext) {
+        clients[ctx.sessionId] = ctx
+    }
+
+    fun removeClient(ctx: WsContext) {
+        clients.remove(ctx.sessionId)
+    }
+
+    fun notifyClient(ctx: WsContext) {
+        ctx.send(
+            getStatus()
+        )
+    }
+
+    fun handleRequest(ctx: WsMessageContext) {
+        when (ctx.message()) {
+            "STATUS" -> notifyClient(ctx)
+            else -> ctx.send(
+                """
+                        |Invalid command.
+                        |Supported commands are:
+                        |    - STATUS
+                        |       sends the current download status
+                        |""".trimMargin()
+            )
+        }
+    }
+
+    private fun notifyAllClients() {
+        val status = getStatus()
+        clients.forEach {
+            it.value.send(status)
+        }
+    }
+
+    private fun getStatus(): DownloadStatus {
+        return DownloadStatus(
+            if (downloader == null ||
+                downloadQueue.none { it.state == Downloading }
+            ) "Stopped" else "Started",
+            downloadQueue
+        )
+    }
+
+    fun enqueue(chapterIndex: Int, mangaId: Int) {
+        if (downloadQueue.none { it.mangaId == mangaId && it.chapterIndex == chapterIndex }) {
+            downloadQueue.add(
+                DownloadChapter(
+                    chapterIndex,
+                    mangaId,
+                    chapter = ChapterTable.toDataClass(
+                        transaction {
+                            ChapterTable.select { (ChapterTable.manga eq mangaId) and (ChapterTable.chapterIndex eq chapterIndex) }
+                                .first()
+                        }
+                    )
+                )
+            )
+            start()
+        }
+        notifyAllClients()
+    }
+
+    fun unqueue(chapterIndex: Int, mangaId: Int) {
+        downloadQueue.removeIf { it.mangaId == mangaId && it.chapterIndex == chapterIndex }
+        notifyAllClients()
+    }
+
+    fun start() {
+        if (downloader != null && !downloader?.isAlive!!) // doesn't exist or is dead
+            downloader = null
+
+        if (downloader == null) {
+            downloader = Downloader(downloadQueue) { notifyAllClients() }
+            downloader!!.start()
+        }
+
+        notifyAllClients()
+    }
+
+    fun stop() {
+        downloader?.let {
+            synchronized(it.shouldStop) {
+                it.shouldStop = true
+            }
+        }
+        downloader = null
+        notifyAllClients()
+    }
+
+    fun clear() {
+        stop()
+        downloadQueue.clear()
+        notifyAllClients()
+    }
+}
+
+enum class DownloaderState(val state: Int) {
+    Stopped(0),
+    Running(1),
+    Paused(2),
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/Downloader.kt

@@ -0,0 +1,81 @@
+package suwayomi.tachidesk.manga.impl.download
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+import kotlinx.coroutines.runBlocking
+import org.jetbrains.exposed.sql.and
+import org.jetbrains.exposed.sql.transactions.transaction
+import org.jetbrains.exposed.sql.update
+import suwayomi.tachidesk.manga.impl.Chapter.getChapter
+import suwayomi.tachidesk.manga.impl.Page.getPageImage
+import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Downloading
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Error
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Finished
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Queued
+import suwayomi.tachidesk.manga.model.table.ChapterTable
+import java.util.concurrent.CopyOnWriteArrayList
+
+class Downloader(private val downloadQueue: CopyOnWriteArrayList<DownloadChapter>, val notifier: () -> Unit) : Thread() {
+    var shouldStop: Boolean = false
+
+    class DownloadShouldStopException : Exception()
+
+    fun step() {
+        notifier()
+        synchronized(shouldStop) {
+            if (shouldStop) throw DownloadShouldStopException()
+        }
+    }
+
+    override fun run() {
+        do {
+            val download = downloadQueue.firstOrNull {
+                it.state == Queued ||
+                    (it.state == Error && it.tries < 3) // 3 re-tries per download
+            } ?: break
+
+            try {
+                download.state = Downloading
+                step()
+
+                download.chapter = runBlocking { getChapter(download.chapterIndex, download.mangaId) }
+                step()
+
+                val pageCount = download.chapter!!.pageCount
+                for (pageNum in 0 until pageCount) {
+                    runBlocking { getPageImage(download.mangaId, download.chapterIndex, pageNum) }
+                    // TODO: retry on error with 2,4,8 seconds of wait
+                    // TODO: download multiple pages at once, possible solution: rx observer's strategy is used in Tachiyomi
+                    // TODO: fine grained download percentage
+                    download.progress = (pageNum + 1).toFloat() / pageCount
+                    step()
+                }
+                download.state = Finished
+                transaction {
+                    ChapterTable.update({ (ChapterTable.manga eq download.mangaId) and (ChapterTable.chapterIndex eq download.chapterIndex) }) {
+                        it[isDownloaded] = true
+                    }
+                }
+                step()
+
+                downloadQueue.removeIf { it.mangaId == download.mangaId && it.chapterIndex == download.chapterIndex }
+                step()
+            } catch (e: DownloadShouldStopException) {
+                println("Downloader was stopped")
+                downloadQueue.filter { it.state == Downloading }.forEach { it.state = Queued }
+            } catch (e: Exception) {
+                println("Downloader faced an exception")
+                downloadQueue.filter { it.state == Downloading }.forEach { it.state = Error; it.tries++ }
+                e.printStackTrace()
+            } finally {
+                notifier()
+            }
+        } while (!shouldStop)
+    }
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/model/DownloadChapter.kt

@@ -0,0 +1,20 @@
+package suwayomi.tachidesk.manga.impl.download.model
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+import suwayomi.tachidesk.manga.impl.download.model.DownloadState.Queued
+import suwayomi.tachidesk.manga.model.dataclass.ChapterDataClass
+
+class DownloadChapter(
+    val chapterIndex: Int,
+    val mangaId: Int,
+    var state: DownloadState = Queued,
+    var progress: Float = 0f,
+    var tries: Int = 0,
+    var chapter: ChapterDataClass? = null,
+)

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/model/DownloadState.kt

@@ -0,0 +1,15 @@
+package suwayomi.tachidesk.manga.impl.download.model
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+enum class DownloadState(val state: Int) {
+    Queued(0),
+    Downloading(1),
+    Finished(2),
+    Error(3),
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/model/DownloadStatus.kt

@@ -0,0 +1,13 @@
+package suwayomi.tachidesk.manga.impl.download.model
+
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+data class DownloadStatus(
+    val status: String,
+    val queue: List<DownloadChapter>,
+)