From 7891b4de31a75413563ca7565dfda529e928a7a6 Mon Sep 17 00:00:00 2001
From: arkon <eugcheung94@gmail.com>
Date: Sat, 10 Jul 2021 11:35:43 -0400
Subject: [PATCH] Use jsDelivr as fallback when GitHub can't be reached for
 extensions list (closes #5517)

(cherry picked from commit 24bb2f02dce135e0ceb2856618ecfc0e30dce875)

# Conflicts:
#	app/src/main/java/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt
---
 .../extension/api/ExtensionGithubApi.kt       | 67 +++++++++++++------
 .../ui/browse/extension/ExtensionHolder.kt    |  5 +-
 2 files changed, 48 insertions(+), 24 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt b/app/src/main/java/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt
index 60074ba4c..b0e0ca38a 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt
@@ -23,22 +23,34 @@ internal class ExtensionGithubApi {
     private val networkService: NetworkHelper by injectLazy()
     private val preferences: PreferencesHelper by injectLazy()
 
+    private var requiresFallbackSource = false
+
     suspend fun findExtensions(): List<Extension.Available> {
         return withIOContext {
-            networkService.client
-                .newCall(GET("${REPO_URL_PREFIX}index.min.json"))
-                .await()
-                .parseAs<JsonArray>()
-                .let { parseResponse(it) }
-        } /* SY --> */ + preferences.extensionRepos().get().flatMap { repoPath ->
-            val url = "$BASE_URL$repoPath/repo/"
-            networkService.client
-                .newCall(GET("${url}index.min.json"))
-                .await()
-                .parseAs<JsonArray>()
-                .let {
-                    parseResponse(it, url)
-                }
+            val response = try {
+                networkService.client
+                    .newCall(GET("${REPO_URL_PREFIX}index.min.json"))
+                    .await()
+            } catch (e: Throwable) {
+                requiresFallbackSource = true
+
+                networkService.client
+                    .newCall(GET("${FALLBACK_REPO_URL_PREFIX}index.min.json"))
+                    .await()
+            }
+
+            parseResponse(response.parseAs()) + preferences.extensionRepos().get().flatMap { repoPath ->
+                try {
+                    networkService.client
+                        .newCall(GET("$BASE_URL$repoPath/repo/index.min.json"))
+                        .await()
+                } catch (e: Exception) {
+                    networkService.client
+                        .newCall(GET("$FALLBACK_BASE_URL$repoPath@repo/index.min.json"))
+                        .await()
+                }.parseAs<JsonArray>()
+                    .let { parseResponse(it, getUrlPrefix(repoPath)) }
+            }
         }
         // SY <--
     }
@@ -73,7 +85,7 @@ internal class ExtensionGithubApi {
         return extensionsWithUpdate
     }
 
-    private fun parseResponse(json: JsonArray /* SY --> */, repoUrl: String = REPO_URL_PREFIX /* SY <-- */): List<Extension.Available> {
+    private fun parseResponse(json: JsonArray /* SY --> */, repoUrl: String = getUrlPrefix() /* SY <-- */): List<Extension.Available> {
         return json
             .filter { element ->
                 val versionName = element.jsonObject["version"]!!.jsonPrimitive.content
@@ -97,19 +109,32 @@ internal class ExtensionGithubApi {
     }
 
     fun getApkUrl(extension: Extension.Available): String {
-        return /* SY --> */ "${extension.repoUrl}/apk/${extension.apkName}" /* SY <-- */
+        return /* SY --> */ "${extension.repoUrl}apk/${extension.apkName}" /* SY <-- */
+    }
+
+    private fun getUrlPrefix(): String {
+        return when (requiresFallbackSource) {
+            true -> FALLBACK_REPO_URL_PREFIX
+            false -> REPO_URL_PREFIX
+        }
     }
 
     // SY -->
+    private fun getUrlPrefix(repoUrl: String): String {
+        return when (requiresFallbackSource) {
+            true -> "${FALLBACK_BASE_URL}$repoUrl@repo/"
+            false -> "${BASE_URL}$repoUrl/repo/"
+        }
+    }
+
     private fun Extension.isBlacklisted(
         blacklistEnabled: Boolean = preferences.enableSourceBlacklist().get()
     ): Boolean {
         return pkgName in BlacklistedSources.BLACKLISTED_EXTENSIONS && blacklistEnabled
     }
     // SY <--
-
-    companion object {
-        const val BASE_URL = "https://raw.githubusercontent.com/"
-        const val REPO_URL_PREFIX = "${BASE_URL}tachiyomiorg/tachiyomi-extensions/repo/"
-    }
 }
+const val BASE_URL = "https://raw.githubusercontent.com/"
+const val FALLBACK_BASE_URL = "https://cdn.jsdelivr.net/gh/"
+private const val REPO_URL_PREFIX = "${BASE_URL}tachiyomiorg/tachiyomi-extensions/repo/"
+private const val FALLBACK_REPO_URL_PREFIX = "${FALLBACK_BASE_URL}tachiyomiorg/tachiyomi-extensions@repo/"
diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionHolder.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionHolder.kt
index 52ca2f7dd..7146a1c34 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionHolder.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionHolder.kt
@@ -8,7 +8,6 @@ import eu.davidea.viewholders.FlexibleViewHolder
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.databinding.ExtensionCardItemBinding
-import eu.kanade.tachiyomi.extension.api.ExtensionGithubApi
 import eu.kanade.tachiyomi.extension.model.Extension
 import eu.kanade.tachiyomi.extension.model.InstallStep
 import eu.kanade.tachiyomi.source.ConfigurableSource
@@ -60,8 +59,8 @@ class ExtensionHolder(view: View, val adapter: ExtensionAdapter) :
     // SY -->
     private fun String.plusRepo(extension: Extension): String {
         return if (extension is Extension.Available) {
-            when (extension.repoUrl) {
-                ExtensionGithubApi.REPO_URL_PREFIX -> this
+            when {
+                extension.repoUrl.contains("tachiyomiorg/tachiyomi-extensions") -> this
                 else -> {
                     this + if (this.isEmpty()) {
                         ""