lots of background work for manga extensions

app/src/main/java/eu/kanade/tachiyomi/source/MangaSource.kt

@@ -0,0 +1,85 @@
+package eu.kanade.tachiyomi.source
+
+import eu.kanade.tachiyomi.source.model.Page
+import eu.kanade.tachiyomi.source.model.SChapter
+import eu.kanade.tachiyomi.source.model.SManga
+import eu.kanade.tachiyomi.util.lang.awaitSingle
+import rx.Observable
+
+/**
+ * A basic interface for creating a source. It could be an online source, a local source, etc.
+ */
+interface MangaSource {
+
+    /**
+     * ID for the source. Must be unique.
+     */
+    val id: Long
+
+    /**
+     * Name of the source.
+     */
+    val name: String
+
+    val lang: String
+        get() = ""
+
+    /**
+     * Returns an observable with the updated details for a manga.
+     *
+     * @param manga the manga to update.
+     */
+    @Deprecated(
+        "Use the 1.x API instead",
+        ReplaceWith("getMangaDetails"),
+    )
+    fun fetchMangaDetails(manga: SManga): Observable<SManga> = throw IllegalStateException("Not used")
+
+    /**
+     * Returns an observable with all the available chapters for a manga.
+     *
+     * @param manga the manga to update.
+     */
+    @Deprecated(
+        "Use the 1.x API instead",
+        ReplaceWith("getChapterList"),
+    )
+    fun fetchChapterList(manga: SManga): Observable<List<SChapter>> = throw IllegalStateException("Not used")
+
+    /**
+     * Returns an observable with the list of pages a chapter has. Pages should be returned
+     * in the expected order; the index is ignored.
+     *
+     * @param chapter the chapter.
+     */
+    @Deprecated(
+        "Use the 1.x API instead",
+        ReplaceWith("getPageList"),
+    )
+    fun fetchPageList(chapter: SChapter): Observable<List<Page>> = Observable.empty()
+
+    /**
+     * [1.x API] Get the updated details for a manga.
+     */
+    @Suppress("DEPRECATION")
+    suspend fun getMangaDetails(manga: SManga): SManga {
+        return fetchMangaDetails(manga).awaitSingle()
+    }
+
+    /**
+     * [1.x API] Get all the available chapters for a manga.
+     */
+    @Suppress("DEPRECATION")
+    suspend fun getChapterList(manga: SManga): List<SChapter> {
+        return fetchChapterList(manga).awaitSingle()
+    }
+
+    /**
+     * [1.x API] Get the list of pages a chapter has. Pages should be returned
+     * in the expected order; the index is ignored.
+     */
+    @Suppress("DEPRECATION")
+    suspend fun getPageList(chapter: SChapter): List<Page> {
+        return fetchPageList(chapter).awaitSingle()
+    }
+}