Refactor: Migrate network layer 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 Pixabay
ImageRepository to use the new Ktor-based PixabayService.
- Introduced Result sealed class to handle network responses.
- Updated PhotoDetailViewModel to handle Result.Error state.

data/build.gradle.kts

@@ -25,6 +25,8 @@ android {
 dependencies {
     implementation(libs.androidx.paging.compose)
 
+
+    //Kotlin Serialization
     implementation(libs.kotlinx.serialization.json)
 
     //Ktor

data/src/main/kotlin/dev/adriankuta/pixabay/data/Result.kt

@@ -0,0 +1,8 @@
+package dev.adriankuta.pixabay.data
+
+fun <T> Result<T>.isSuccess() = this is Result.Success<T>
+
+sealed interface Result<out T> {
+    data class Success<out T>(val data: T) : Result<T>
+    data class Error(val exception: Throwable) : Result<Nothing>
+}

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

@@ -31,7 +31,7 @@ internal abstract class NetworkModule {
         @Singleton
         @Provides
         fun provideKtorClient(): HttpClient {
-            val httpClient = HttpClient(Android) {
+            return HttpClient(Android) {
                 install(ContentNegotiation) {
                     json(
                         Json {
@@ -53,8 +53,6 @@ internal abstract class NetworkModule {
                     socketTimeout = 100_000
                 }
             }
-            return httpClient
         }
-
     }
 }

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

@@ -8,7 +8,6 @@ import dagger.hilt.InstallIn
 import dagger.hilt.android.qualifiers.ApplicationContext
 import dagger.hilt.components.SingletonComponent
 import dev.adriankuta.pixabay.data.room.AppDatabase
-import dev.adriankuta.pixabay.data.room.dao.PixabayImagesDao
 import javax.inject.Singleton
 
 @InstallIn(SingletonComponent::class)

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

@@ -1,6 +1,5 @@
 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/repository/ImageRepository.kt

@@ -1,14 +1,15 @@
 package dev.adriankuta.pixabay.data.repository
 
 import androidx.paging.PagingData
+import dev.adriankuta.pixabay.data.Result
 import dev.adriankuta.pixabay.data.model.PixabayImage
 import kotlinx.coroutines.flow.Flow
 
 interface ImageRepository {
 
-    suspend fun searchImageById(id: Int): PixabayImage
+    suspend fun searchImageById(id: Int): Result<PixabayImage>
 
-    suspend fun searchImages(query: String, page: Int, pageSize: Int): List<PixabayImage>
+    suspend fun searchImages(query: String, page: Int, pageSize: Int): Result<List<PixabayImage>>
 
     fun getSearchResultStream(query: String): Flow<PagingData<PixabayImage>>
 }

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

@@ -7,6 +7,7 @@ import androidx.paging.Pager
 import androidx.paging.PagingConfig
 import androidx.paging.PagingData
 import androidx.paging.map
+import dev.adriankuta.pixabay.data.Result
 import dev.adriankuta.pixabay.data.model.PixabayImage
 import dev.adriankuta.pixabay.data.network.PixabayService
 import dev.adriankuta.pixabay.data.paging.PixabayPagingSource
@@ -16,31 +17,38 @@ 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,
     private val pixabayService: PixabayService
 ) : ImageRepository {
 
-    override suspend fun searchImageById(id: Int): PixabayImage {
+    override suspend fun searchImageById(id: Int): Result<PixabayImage> {
         return runCatching {
             pixabayService.searchImageById(id.toString())
         }.mapCatching { response ->
-            PixabayImage(response.hits.first())
+            Result.Success(PixabayImage(response.hits.first()))
         }.onFailure { e ->
             Timber.e(e)
-        }.getOrThrow()
+        }.getOrElse {
+            Result.Error(it)
+        }
     }
 
-    override suspend fun searchImages(query: String, page: Int, pageSize: Int): List<PixabayImage> {
+    override suspend fun searchImages(
+        query: String,
+        page: Int,
+        pageSize: Int
+    ): Result<List<PixabayImage>> {
         return runCatching {
             pixabayService.searchImages(query, page, pageSize)
         }.mapCatching { response ->
-            response.hits.map { PixabayImage(it) }
+            Result.Success(response.hits.map { PixabayImage(it) })
         }.onFailure { e ->
             Timber.e(e)
-        }.getOrThrow()
+        }.getOrElse {
+            Result.Error(it)
+        }
     }
 
     override fun getSearchResultStream(query: String): Flow<PagingData<PixabayImage>> {

data/src/main/kotlin/dev/adriankuta/pixabay/data/room/entity/PixabayImageEntity.kt

@@ -33,7 +33,7 @@ internal data class PixabayImageEntity(
     @ColumnInfo(COLUMN_USER) val user: String,
     @ColumnInfo(COLUMN_USER_IMAGE_URL) val userImageURL: String,
 
-) {
+    ) {
     constructor(pixabayImageResponse: PixabayImageResponse, queryUsed: String) :
             this(
                 id = pixabayImageResponse.id,