Implement MyAnimeList recommendations (#7)

Co-authored-by: she11sh0cked <she11sh0cked@users.noreply.github.com>

app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/browse/RecommendsPager.kt

@@ -10,6 +10,7 @@ import com.google.gson.JsonParser
 import eu.kanade.tachiyomi.network.asObservableSuccess
 import eu.kanade.tachiyomi.source.model.MangasPage
 import eu.kanade.tachiyomi.source.model.SMangaImpl
+import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
 import okhttp3.MediaType.Companion.toMediaTypeOrNull
 import okhttp3.OkHttpClient
 import okhttp3.Request
@@ -17,10 +18,81 @@ import okhttp3.RequestBody.Companion.toRequestBody
 import rx.Observable
 import rx.schedulers.Schedulers
 
-open class RecommendsPager(val title: String) : Pager() {
+open class RecommendsPager(val title: String, val preferredApi: API = API.MYANIMELIST) : Pager() {
     private val client = OkHttpClient.Builder().build()
 
-    override fun requestNext(): Observable<MangasPage> {
+    private fun myAnimeList(): Observable<List<SMangaImpl>>? {
+        fun getId(): Observable<String> {
+            val endpoint =
+                myAnimeListEndpoint.toHttpUrlOrNull()
+                    ?: throw Exception("Could not convert endpoint url")
+            val urlBuilder = endpoint.newBuilder()
+            urlBuilder.addPathSegment("search")
+            urlBuilder.addPathSegment("manga")
+            urlBuilder.addQueryParameter("q", title)
+            val url = urlBuilder.build().toUrl()
+
+            val request = Request.Builder()
+                .url(url)
+                .get()
+                .build()
+
+            return client.newCall(request)
+                .asObservableSuccess().subscribeOn(Schedulers.io())
+                .map { netResponse ->
+                    val responseBody = netResponse.body?.string().orEmpty()
+                    if (responseBody.isEmpty()) {
+                        throw Exception("Null Response")
+                    }
+                    val response = JsonParser.parseString(responseBody).obj
+                    val results = response["results"].array
+                    val firstResult = results[0].obj
+                    val id = firstResult["mal_id"].string
+                    if (id.isEmpty()) {
+                        throw Exception("Not found")
+                    }
+                    id
+                }
+        }
+
+        return getId().map { id ->
+            val endpoint =
+                myAnimeListEndpoint.toHttpUrlOrNull()
+                    ?: throw Exception("Could not convert endpoint url")
+            val urlBuilder = endpoint.newBuilder()
+            urlBuilder.addPathSegment("manga")
+            urlBuilder.addPathSegment(id)
+            urlBuilder.addPathSegment("recommendations")
+            val url = urlBuilder.build().toUrl()
+
+            val request = Request.Builder()
+                .url(url)
+                .get()
+                .build()
+
+            client.newCall(request)
+                .asObservableSuccess().subscribeOn(Schedulers.io())
+                .map { netResponse ->
+                    val responseBody = netResponse.body?.string().orEmpty()
+                    if (responseBody.isEmpty()) {
+                        throw Exception("Null Response")
+                    }
+                    val response = JsonParser.parseString(responseBody).obj
+                    val recommendations = response["recommendations"].array
+                    recommendations.map { rec ->
+                        Log.d("MYANIMELIST RECOMMEND", "${rec["title"].string}")
+                        SMangaImpl().apply {
+                            this.title = rec["title"].string
+                            this.thumbnail_url = rec["image_url"].string
+                            this.initialized = true
+                            this.url = rec["url"].string
+                        }
+                    }
+                }.toBlocking().first()
+        }
+    }
+
+    private fun anilist(): Observable<List<SMangaImpl>>? {
         val query =
             """
             {
@@ -53,7 +125,7 @@ open class RecommendsPager(val title: String) : Pager() {
         )
         val body = payload.toString().toRequestBody("application/json; charset=utf-8".toMediaTypeOrNull())
         val request = Request.Builder()
-            .url(apiUrl)
+            .url(anilistEndpoint)
             .post(body)
             .build()
 
@@ -71,7 +143,7 @@ open class RecommendsPager(val title: String) : Pager() {
                 val edges = recommendations["edges"].array
                 edges.map {
                     val rec = it["node"]["mediaRecommendation"].obj
-                    Log.d("RECOMMEND", "${rec["title"].obj["romaji"].string}")
+                    Log.d("ANILIST RECOMMEND", "${rec["title"].obj["romaji"].string}")
                     SMangaImpl().apply {
                         this.title = rec["title"].obj["romaji"].string
                         this.thumbnail_url = rec["coverImage"].obj["large"].string
@@ -79,13 +151,39 @@ open class RecommendsPager(val title: String) : Pager() {
                         this.url = rec["siteUrl"].string
                     }
                 }
-            }.map {
-                MangasPage(it, false)
-            }.doOnNext {
-                onPageReceived(it)
             }
     }
+
+    override fun requestNext(): Observable<MangasPage> {
+        val apiList = API.values().toMutableList()
+        apiList.removeAt(apiList.indexOf(preferredApi))
+        apiList.add(0, preferredApi)
+
+        var recommendations: Observable<List<SMangaImpl>>? = null
+        for (api in apiList) {
+            recommendations = when (api) {
+                API.MYANIMELIST -> myAnimeList()
+                API.ANILIST -> anilist()
+            }
+                ?: throw Exception("Could not get recommendations")
+
+            val recommendationsBlocking = recommendations.toBlocking().first()
+            if (recommendationsBlocking.isNotEmpty()) {
+                break
+            }
+        }
+
+        return recommendations!!.map {
+            MangasPage(it, false)
+        }.doOnNext {
+            onPageReceived(it)
+        }
+    }
+
     companion object {
-        const val apiUrl = "https://graphql.anilist.co/"
+        private const val myAnimeListEndpoint = "https://api.jikan.moe/v3/"
+        private const val anilistEndpoint = "https://graphql.anilist.co/"
+
+        enum class API { MYANIMELIST, ANILIST }
     }
 }