Refactor: Migrate from Retrofit to Ktor

This commit migrates the network layer from Retrofit to Ktor.

Specific changes include:

- Replaced Retrofit
 with Ktor for network requests.
- Updated dependencies to include Ktor libraries.
- Refactored network service and data classes to use Ktor's API.
- Removed Retrofit-specific code and dependencies.
- Adjusted network module to provide Ktor client and services.
- Updated PixabayImageRepository
 to use the new Ktor-based PixabayService.

data/build.gradle.kts

@@ -23,16 +23,19 @@ android {
 }
 
 dependencies {
-    implementation(libs.retrofit)
-
-    implementation(platform(libs.okhttp.bom))
-    implementation(libs.okhttp)
-    implementation(libs.logging.interceptor)
-
     implementation(libs.androidx.paging.compose)
 
     implementation(libs.kotlinx.serialization.json)
-    implementation(libs.retrofit2.kotlinx.serialization.converter)
+
+    //Ktor
+    implementation(libs.ktor.client.android)
+    implementation(libs.ktor.client.resources)
+    implementation(libs.ktor.client.content.negotiation)
+    implementation(libs.ktor.client.logging)
+    implementation(libs.ktor.serialization.kotlinx.json)
+
+    //Logging
+    implementation(libs.slf4j.android)
 
     implementation(libs.androidx.room.runtime)
     ksp(libs.androidx.room.compiler)

data/src/main/kotlin/dev/adriankuta/pixabay/data/di/NetworkModule.kt

@@ -1,52 +1,60 @@
 package dev.adriankuta.pixabay.data.di
 
-import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import dagger.Binds
 import dagger.Module
 import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
 import dev.adriankuta.pixabay.data.BuildConfig
+import dev.adriankuta.pixabay.data.network.KtorPixabayService
 import dev.adriankuta.pixabay.data.network.PixabayService
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.android.Android
+import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.client.plugins.defaultRequest
+import io.ktor.client.plugins.logging.Logging
+import io.ktor.client.plugins.resources.Resources
+import io.ktor.http.URLProtocol
+import io.ktor.serialization.kotlinx.json.json
 import kotlinx.serialization.json.Json
-import okhttp3.MediaType.Companion.toMediaType
-import okhttp3.OkHttpClient
-import okhttp3.logging.HttpLoggingInterceptor
-import retrofit2.Retrofit
 import javax.inject.Singleton
 
 @InstallIn(SingletonComponent::class)
 @Module
-internal class NetworkModule {
-    @Singleton
-    @Provides
-    fun provideHttpLoggingInterceptor(): HttpLoggingInterceptor {
-        val logging = HttpLoggingInterceptor()
-        logging.level =
-            if (BuildConfig.DEBUG) HttpLoggingInterceptor.Level.BODY else HttpLoggingInterceptor.Level.NONE
-        return logging
-    }
+internal abstract class NetworkModule {
 
     @Singleton
-    @Provides
-    fun provideOkHttpClient(
-        httpLoggingInterceptor: HttpLoggingInterceptor
-    ): OkHttpClient {
-        return OkHttpClient.Builder()
-            .addInterceptor(httpLoggingInterceptor)
-            .build()
-    }
+    @Binds
+    abstract fun provideKtorApi(ktorPixabayService: KtorPixabayService): PixabayService
+
+    companion object {
+        @Singleton
+        @Provides
+        fun provideKtorClient(): HttpClient {
+            val httpClient = HttpClient(Android) {
+                install(ContentNegotiation) {
+                    json(
+                        Json {
+                            ignoreUnknownKeys = true
+                        }
+                    )
+                }
+                install(Resources)
+                install(Logging)
+                defaultRequest {
+                    url {
+                        protocol = URLProtocol.HTTP
+                        host = "pixabay.com"
+                        parameters.append("key", BuildConfig.PIXABAY_API_KEY)
+                    }
+                }
+                engine {
+                    connectTimeout = 100_000
+                    socketTimeout = 100_000
+                }
+            }
+            return httpClient
+        }
 
-    @Singleton
-    @Provides
-    fun providePixabayApi(
-        okHttpClient: OkHttpClient
-    ): PixabayService {
-        val networkJson = Json { ignoreUnknownKeys = true }
-        return Retrofit.Builder()
-            .client(okHttpClient)
-            .baseUrl("https://pixabay.com/")
-            .addConverterFactory(networkJson.asConverterFactory("application/json".toMediaType()))
-            .build()
-            .create(PixabayService::class.java)
     }
 }

data/src/main/kotlin/dev/adriankuta/pixabay/data/dto/request/PixabayImages.kt

@@ -0,0 +1,12 @@
+package dev.adriankuta.pixabay.data.dto.request
+
+import io.ktor.resources.Resource
+import kotlinx.serialization.SerialName
+
+@Resource("/api")
+internal class PixabayImages(
+    @SerialName("q")
+    val query: String,
+    val page: Int,
+    val pageSize: Int
+)

data/src/main/kotlin/dev/adriankuta/pixabay/data/dto/request/PixabayImagesById.kt

@@ -0,0 +1,8 @@
+package dev.adriankuta.pixabay.data.dto.request
+
+import io.ktor.resources.Resource
+
+@Resource("/api")
+internal class PixabayImagesById(
+    val id: String,
+)

data/src/main/kotlin/dev/adriankuta/pixabay/data/dto/response/SearchPixabayImagesResponse.kt

@@ -1,5 +1,6 @@
 package dev.adriankuta.pixabay.data.dto.response
 
+import io.ktor.resources.Resource
 import kotlinx.serialization.Serializable
 
 @Serializable

data/src/main/kotlin/dev/adriankuta/pixabay/data/network/KtorPixabayService.kt

@@ -0,0 +1,26 @@
+package dev.adriankuta.pixabay.data.network
+
+import dev.adriankuta.pixabay.data.dto.request.PixabayImages
+import dev.adriankuta.pixabay.data.dto.request.PixabayImagesById
+import dev.adriankuta.pixabay.data.dto.response.SearchPixabayImagesResponse
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.plugins.resources.get
+import javax.inject.Inject
+
+internal class KtorPixabayService @Inject constructor(
+    private val client: HttpClient,
+) : PixabayService {
+
+    override suspend fun searchImages(
+        query: String,
+        page: Int,
+        pageSize: Int
+    ): SearchPixabayImagesResponse {
+        return client.get(PixabayImages(query, page, pageSize)).body()
+    }
+
+    override suspend fun searchImageById(id: String): SearchPixabayImagesResponse {
+        return client.get(PixabayImagesById(id)).body()
+    }
+}

data/src/main/kotlin/dev/adriankuta/pixabay/data/network/PixabayService.kt

@@ -1,23 +1,16 @@
 package dev.adriankuta.pixabay.data.network
 
-import dev.adriankuta.pixabay.data.BuildConfig
 import dev.adriankuta.pixabay.data.dto.response.SearchPixabayImagesResponse
-import retrofit2.http.GET
-import retrofit2.http.Query
 
 internal interface PixabayService {
 
-    @GET("api")
     suspend fun searchImages(
-        @Query("q") query: String,
-        @Query("page") page: Int,
-        @Query("per_page") pageSize: Int,
-        @Query("key") key: String = BuildConfig.PIXABAY_API_KEY
+        query: String,
+        page: Int,
+        pageSize: Int
     ): SearchPixabayImagesResponse
 
-    @GET("api")
     suspend fun searchImageById(
-        @Query("id") query: String,
-        @Query("key") key: String = BuildConfig.PIXABAY_API_KEY
+        id: String,
     ): SearchPixabayImagesResponse
 }

data/src/main/kotlin/dev/adriankuta/pixabay/data/paging/PixabayPagingSource.kt

@@ -5,7 +5,6 @@ import androidx.paging.PagingState
 import dev.adriankuta.pixabay.data.model.PixabayImage
 import dev.adriankuta.pixabay.data.network.PixabayService
 import dev.adriankuta.pixabay.data.repository.PixabayImageRepository.Companion.NETWORK_PAGE_SIZE
-import retrofit2.HttpException
 import java.io.IOException
 
 private const val STARTING_PAGE_INDEX = 1
@@ -34,8 +33,6 @@ internal class PixabayPagingSource(
             )
         } catch (exception: IOException) {
             return LoadResult.Error(exception)
-        } catch (exception: HttpException) {
-            return LoadResult.Error(exception)
         }
     }
 

data/src/main/kotlin/dev/adriankuta/pixabay/data/paging/PixabayRemoteMediator.kt

@@ -7,12 +7,10 @@ import androidx.paging.LoadType
 import androidx.paging.PagingState
 import androidx.paging.RemoteMediator
 import androidx.room.withTransaction
-import dev.adriankuta.pixabay.data.model.PixabayImage
 import dev.adriankuta.pixabay.data.network.PixabayService
 import dev.adriankuta.pixabay.data.room.AppDatabase
 import dev.adriankuta.pixabay.data.room.entity.PixabayImageEntity
 import dev.adriankuta.pixabay.data.room.entity.RemoteKeys
-import retrofit2.HttpException
 import java.io.IOException
 
 private const val STARTING_PAGE_INDEX = 1
@@ -78,8 +76,6 @@ internal class PixabayRemoteMediator(
             return MediatorResult.Success(endOfPaginationReached = endOfPaginationReached)
         } catch (exception: IOException) {
             return MediatorResult.Error(exception)
-        } catch (exception: HttpException) {
-            return MediatorResult.Error(exception)
         }
     }
 

data/src/main/kotlin/dev/adriankuta/pixabay/data/repository/PixabayImageRepository.kt

@@ -16,6 +16,7 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import timber.log.Timber
 import javax.inject.Inject
+import javax.inject.Named
 
 internal class PixabayImageRepository @Inject constructor(
     private val database: AppDatabase,
@@ -75,6 +76,6 @@ internal class PixabayImageRepository @Inject constructor(
 
     companion object {
         const val NETWORK_PAGE_SIZE = 30
-        const val USE_CACHE_PAGER = true
+        const val USE_CACHE_PAGER = false
     }
 }