rewrite without retrofit and kotlin-serialization

server/build.gradle.kts

@@ -28,13 +28,6 @@ dependencies {
     implementation("com.squareup.okhttp3:okhttp-dnsoverhttps:$okhttpVersion")
     implementation("com.squareup.okio:okio:2.10.0")
 
-    // Retrofit, used in `ExtensionGithubService`
-    val retrofitVersion = "2.9.0"
-    implementation("com.squareup.retrofit2:retrofit:$retrofitVersion")
-    implementation("com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter:0.8.0")
-    implementation("com.squareup.retrofit2:converter-gson:$retrofitVersion")
-    implementation("com.squareup.retrofit2:adapter-rxjava:$retrofitVersion")
-
     // Javalin api
     implementation("io.javalin:javalin:3.13.6")
     // jackson version is tied to javalin, ref: `io.javalin.core.util.OptionalDependency`
@@ -54,9 +47,6 @@ dependencies {
     implementation("com.dorkbox:SystemTray:4.1")
     implementation("com.dorkbox:Utilities:1.9")
 
-    // misc
-    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.1.0")
-
 
     // dependencies of Tachiyomi extensions, some are duplicate, keeping it here for reference
     implementation("com.github.inorichi.injekt:injekt-core:65b0440")

server/src/main/kotlin/eu/kanade/tachiyomi/extension/api/ExtensionGithubApi.kt

@@ -7,13 +7,12 @@ package eu.kanade.tachiyomi.extension.api
  * 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 com.github.salomonbrys.kotson.int
+import com.github.salomonbrys.kotson.string
+import com.google.gson.JsonArray
 import eu.kanade.tachiyomi.extension.model.Extension
 import eu.kanade.tachiyomi.extension.util.ExtensionLoader
 import ir.armor.tachidesk.model.dataclass.ExtensionDataClass
-import kotlinx.serialization.json.JsonArray
-import kotlinx.serialization.json.int
-import kotlinx.serialization.json.jsonObject
-import kotlinx.serialization.json.jsonPrimitive
 
 object ExtensionGithubApi {
     const val BASE_URL = "https://raw.githubusercontent.com"
@@ -21,19 +20,20 @@ object ExtensionGithubApi {
 
     private fun parseResponse(json: JsonArray): List<Extension.Available> {
         return json
+            .map { it.asJsonObject }
             .filter { element ->
-                val versionName = element.jsonObject["version"]!!.jsonPrimitive.content
+                val versionName = element["version"].string
                 val libVersion = versionName.substringBeforeLast('.').toDouble()
                 libVersion >= ExtensionLoader.LIB_VERSION_MIN && libVersion <= ExtensionLoader.LIB_VERSION_MAX
             }
             .map { element ->
-                val name = element.jsonObject["name"]!!.jsonPrimitive.content.substringAfter("Tachiyomi: ")
+                val name = element["name"].string.substringAfter("Tachiyomi: ")
-                val pkgName = element.jsonObject["pkg"]!!.jsonPrimitive.content
+                val pkgName = element["pkg"].string
-                val apkName = element.jsonObject["apk"]!!.jsonPrimitive.content
+                val apkName = element["apk"].string
-                val versionName = element.jsonObject["version"]!!.jsonPrimitive.content
+                val versionName = element["version"].string
-                val versionCode = element.jsonObject["code"]!!.jsonPrimitive.int
+                val versionCode = element["code"].int
-                val lang = element.jsonObject["lang"]!!.jsonPrimitive.content
+                val lang = element["lang"].string
-                val nsfw = element.jsonObject["nsfw"]!!.jsonPrimitive.int == 1
+                val nsfw = element["nsfw"].int == 1
                 val icon = "$REPO_URL_PREFIX/icon/${apkName.replace(".apk", ".png")}"
 
                 Extension.Available(name, pkgName, versionName, versionCode, lang, nsfw, apkName, icon)
@@ -41,9 +41,8 @@ object ExtensionGithubApi {
     }
 
     suspend fun findExtensions(): List<Extension.Available> {
-        val service: ExtensionGithubService = ExtensionGithubService.create()
 
-        val response = service.getRepo()
+        val response = ExtensionGithubService.getRepo()
         return parseResponse(response)
     }
 

server/src/main/kotlin/eu/kanade/tachiyomi/extension/api/ExtensionGithubService.kt

@@ -1,46 +1,74 @@
 package eu.kanade.tachiyomi.extension.api
 
-import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import com.google.gson.JsonParser
 import eu.kanade.tachiyomi.network.NetworkHelper
-import kotlinx.serialization.ExperimentalSerializationApi
+import okhttp3.Headers
-import kotlinx.serialization.json.Json
+import okhttp3.Interceptor
-import kotlinx.serialization.json.JsonArray
+import okhttp3.Interceptor.Chain
-import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.Request
-import retrofit2.Retrofit
+import okhttp3.Response
-import retrofit2.http.GET
+import okhttp3.internal.http.RealResponseBody
+import okio.GzipSource
+import okio.buffer
 import uy.kohesive.injekt.injectLazy
+import java.io.IOException
 
 /**
  * Used to get the extension repo listing from GitHub.
  */
-interface ExtensionGithubService {
+object ExtensionGithubService {
-
+    private val client by lazy {
-    companion object {
+        val network: NetworkHelper by injectLazy()
-        private val client by lazy {
+        network.client.newBuilder()
-            val network: NetworkHelper by injectLazy()
+            .addNetworkInterceptor { chain ->
-            network.client.newBuilder()
+                val originalResponse = chain.proceed(chain.request())
-                .addNetworkInterceptor { chain ->
+                originalResponse.newBuilder()
-                    val originalResponse = chain.proceed(chain.request())
+                    .header("Content-Encoding", "gzip")
-                    originalResponse.newBuilder()
+                    .header("Content-Type", "application/json")
-                        .header("Content-Encoding", "gzip")
+                    .build()
-                        .header("Content-Type", "application/json")
+            }
-                        .build()
+            .addInterceptor(UnzippingInterceptor())
-                }
+            .build()
-                .build()
-        }
-
-        @ExperimentalSerializationApi
-        fun create(): ExtensionGithubService {
-            val adapter = Retrofit.Builder() // TODO: rewrite in order to not depend on retrofit2
-                .baseUrl(ExtensionGithubApi.BASE_URL)
-                .addConverterFactory(Json.asConverterFactory("application/json".toMediaType()))
-                .client(client)
-                .build()
-
-            return adapter.create(ExtensionGithubService::class.java)
-        }
     }
 
-    @GET("${ExtensionGithubApi.REPO_URL_PREFIX}/index.json.gz")
+    suspend fun getRepo(): com.google.gson.JsonArray {
-    suspend fun getRepo(): JsonArray
+        val request = Request.Builder()
+            .url("${ExtensionGithubApi.REPO_URL_PREFIX}/index.json.gz")
+            .build()
+
+        val response = client.newCall(request).execute().use { response -> response.body!!.string() }
+        return JsonParser.parseString(response).asJsonArray
+    }
+}
+
+private class UnzippingInterceptor : Interceptor {
+    @Throws(IOException::class)
+    override fun intercept(chain: Chain): Response {
+        val response: Response = chain.proceed(chain.request())
+        return unzip(response)
+    }
+
+    // ref: https://stackoverflow.com/questions/51901333/okhttp-3-how-to-decompress-gzip-deflate-response-manually-using-java-android
+    @Throws(IOException::class)
+    private fun unzip(response: Response): Response {
+        if (response.body == null) {
+            return response
+        }
+
+        // check if we have gzip response
+        val contentEncoding: String? = response.headers["Content-Encoding"]
+
+        // this is used to decompress gzipped responses
+        return if (contentEncoding != null && contentEncoding == "gzip") {
+            val body = response.body!!
+            val contentLength: Long = body.contentLength()
+            val responseBody = GzipSource(body.source())
+            val strippedHeaders: Headers = response.headers.newBuilder().build()
+            response.newBuilder().headers(strippedHeaders)
+                .body(RealResponseBody(body.contentType().toString(), contentLength, responseBody.buffer()))
+                .build()
+        } else {
+            response
+        }
+    }
 }