Refactor error handling of API

blackcandy-org · Mar 12, 2024 · 682debb · 682debb
1 parent f5af4d7
commit 682debb
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Showing 14 changed files with 204 additions and 112 deletions.
diff --git a/app/src/main/java/org/blackcandy/android/api/ApiException.kt b/app/src/main/java/org/blackcandy/android/api/ApiException.kt
@@ -1,3 +1,3 @@
 package org.blackcandy.android.api
 
-class ApiException(message: String?) : Exception(message)
+class ApiException(val code: Int?, message: String?) : Exception(message)
diff --git a/app/src/main/java/org/blackcandy/android/api/ApiResponse.kt b/app/src/main/java/org/blackcandy/android/api/ApiResponse.kt
@@ -0,0 +1,27 @@
+package org.blackcandy.android.api
+
+import org.blackcandy.android.utils.TaskResult
+
+sealed interface ApiResponse<out T> {
+    data class Success<T>(val data: T) : ApiResponse<T>
+
+    data class Failure(val exception: ApiException) : ApiResponse<Nothing>
+
+    fun orNull(): T? =
+        when (this) {
+            is Success -> data
+            is Failure -> null
+        }
+
+    fun orThrow(): T =
+        when (this) {
+            is Success -> data
+            is Failure -> throw exception
+        }
+
+    fun asResult(): TaskResult<T> =
+        when (this) {
+            is Success -> TaskResult.Success(data)
+            is Failure -> TaskResult.Failure(exception.message)
+        }
+}
diff --git a/app/src/main/java/org/blackcandy/android/api/BlackCandyService.kt b/app/src/main/java/org/blackcandy/android/api/BlackCandyService.kt
@@ -20,83 +20,107 @@ import org.blackcandy.android.models.SystemInfo
 import org.blackcandy.android.models.User
 
 interface BlackCandyService {
-    suspend fun getSystemInfo(): SystemInfo
+    suspend fun getSystemInfo(): ApiResponse<SystemInfo>
 
     suspend fun createAuthentication(
         email: String,
         password: String,
-    ): AuthenticationResponse
+    ): ApiResponse<AuthenticationResponse>
 
-    suspend fun destroyAuthentication()
+    suspend fun destroyAuthentication(): ApiResponse<Unit>
 
-    suspend fun getSongsFromCurrentPlaylist(): List<Song>
+    suspend fun getSongsFromCurrentPlaylist(): ApiResponse<List<Song>>
 
-    suspend fun addSongToFavorite(songId: Int): Song
+    suspend fun addSongToFavorite(songId: Int): ApiResponse<Song>
 
-    suspend fun deleteSongFromFavorite(songId: Int): Song
+    suspend fun deleteSongFromFavorite(songId: Int): ApiResponse<Song>
 }
 
 class BlackCandyServiceImpl(
     private val client: HttpClient,
 ) : BlackCandyService {
-    override suspend fun getSystemInfo(): SystemInfo {
-        return client.get("system").body()
+    override suspend fun getSystemInfo(): ApiResponse<SystemInfo> {
+        return handleResponse {
+            client.get("system").body()
+        }
     }
 
     override suspend fun createAuthentication(
         email: String,
         password: String,
-    ): AuthenticationResponse {
-        val response: HttpResponse =
-            client.submitForm(
-                url = "authentication",
-                formParameters =
-                    parameters {
-                        append("with_cookie", "true")
-                        append("session[email]", email)
-                        append("session[password]", password)
-                    },
+    ): ApiResponse<AuthenticationResponse> {
+        return handleResponse {
+            val response: HttpResponse =
+                client.submitForm(
+                    url = "authentication",
+                    formParameters =
+                        parameters {
+                            append("with_cookie", "true")
+                            append("session[email]", email)
+                            append("session[password]", password)
+                        },
+                )
+
+            val userElement = Json.parseToJsonElement(response.bodyAsText()).jsonObject["user"]!!
+
+            val token = userElement.jsonObject["api_token"]?.jsonPrimitive.toString()
+            val id = userElement.jsonObject["id"]?.jsonPrimitive?.int!!
+            val userEmail = userElement.jsonObject["email"]?.jsonPrimitive.toString()
+            val isAdmin = userElement.jsonObject["is_admin"]?.jsonPrimitive?.boolean!!
+            val cookies = response.headers.getAll(HttpHeaders.SetCookie)!!
+
+            AuthenticationResponse(
+                token = token,
+                user =
+                    User(
+                        id = id,
+                        email = userEmail,
+                        isAdmin = isAdmin,
+                    ),
+                cookies = cookies,
             )
+        }
+    }
 
-        val userElement = Json.parseToJsonElement(response.bodyAsText()).jsonObject["user"]!!
-
-        val token = userElement.jsonObject["api_token"]?.jsonPrimitive.toString()
-        val id = userElement.jsonObject["id"]?.jsonPrimitive?.int!!
-        val userEmail = userElement.jsonObject["email"]?.jsonPrimitive.toString()
-        val isAdmin = userElement.jsonObject["is_admin"]?.jsonPrimitive?.boolean!!
-        val cookies = response.headers.getAll(HttpHeaders.SetCookie)!!
-
-        return AuthenticationResponse(
-            token = token,
-            user =
-                User(
-                    id = id,
-                    email = userEmail,
-                    isAdmin = isAdmin,
-                ),
-            cookies = cookies,
-        )
+    override suspend fun destroyAuthentication(): ApiResponse<Unit> {
+        return handleResponse {
+            client.delete("authentication").body()
+        }
     }
 
-    override suspend fun destroyAuthentication() {
-        client.delete("authentication")
+    override suspend fun getSongsFromCurrentPlaylist(): ApiResponse<List<Song>> {
+        return handleResponse {
+            client.get("current_playlist/songs").body()
+        }
     }
 
-    override suspend fun getSongsFromCurrentPlaylist(): List<Song> {
-        return client.get("current_playlist/songs").body()
+    override suspend fun addSongToFavorite(songId: Int): ApiResponse<Song> {
+        return handleResponse {
+            client.submitForm(
+                url = "favorite_playlist/songs",
+                formParameters =
+                    parameters {
+                        append("song_id", songId.toString())
+                    },
+            ).body()
+        }
     }
 
-    override suspend fun addSongToFavorite(songId: Int): Song {
-        return client.submitForm(
-            url = "favorite_playlist/songs",
-            formParameters =
-                parameters {
-                    append("song_id", songId.toString())
-                },
-        ).body()
+    override suspend fun deleteSongFromFavorite(songId: Int): ApiResponse<Song> {
+        return handleResponse {
+            client.delete("favorite_playlist/songs/$songId").body()
+        }
     }
 
-    override suspend fun deleteSongFromFavorite(songId: Int): Song {
-        return client.delete("favorite_playlist/songs/$songId").body()
+    private suspend fun <T> handleResponse(request: suspend () -> T): ApiResponse<T> {
+        try {
+            return ApiResponse.Success(request())
+        } catch (e: ApiException) {
+            if (e.code == 204) {
+                return ApiResponse.Success(Unit as T)
+            }
+
+            return ApiResponse.Failure(e)
+        }
     }
 }
diff --git a/app/src/main/java/org/blackcandy/android/data/CurrentPlaylistRepository.kt b/app/src/main/java/org/blackcandy/android/data/CurrentPlaylistRepository.kt
@@ -2,11 +2,12 @@ package org.blackcandy.android.data
 
 import org.blackcandy.android.api.BlackCandyService
 import org.blackcandy.android.models.Song
+import org.blackcandy.android.utils.TaskResult
 
 class CurrentPlaylistRepository(
     private val service: BlackCandyService,
 ) {
-    suspend fun getSongs(): List<Song> {
-        return service.getSongsFromCurrentPlaylist()
+    suspend fun getSongs(): TaskResult<List<Song>> {
+        return service.getSongsFromCurrentPlaylist().asResult()
     }
 }
diff --git a/app/src/main/java/org/blackcandy/android/data/FavoritePlaylistRepository.kt b/app/src/main/java/org/blackcandy/android/data/FavoritePlaylistRepository.kt
@@ -2,15 +2,13 @@ package org.blackcandy.android.data
 
 import org.blackcandy.android.api.BlackCandyService
 import org.blackcandy.android.models.Song
+import org.blackcandy.android.utils.TaskResult
 
 class FavoritePlaylistRepository(
     private val service: BlackCandyService,
 ) {
-    suspend fun addSong(songId: Int): Song {
-        return service.addSongToFavorite(songId)
-    }
-
-    suspend fun deleteSong(songId: Int): Song {
-        return service.deleteSongFromFavorite(songId)
+    suspend fun toggleSong(song: Song): TaskResult<Song> {
+        val response = if (song.isFavorited) service.deleteSongFromFavorite(song.id) else service.addSongToFavorite(song.id)
+        return response.asResult()
     }
 }
diff --git a/app/src/main/java/org/blackcandy/android/data/SystemInfoRepository.kt b/app/src/main/java/org/blackcandy/android/data/SystemInfoRepository.kt
@@ -2,11 +2,12 @@ package org.blackcandy.android.data
 
 import org.blackcandy.android.api.BlackCandyService
 import org.blackcandy.android.models.SystemInfo
+import org.blackcandy.android.utils.TaskResult
 
 class SystemInfoRepository(
     private val service: BlackCandyService,
 ) {
-    suspend fun getSystemInfo(): SystemInfo {
-        return service.getSystemInfo()
+    suspend fun getSystemInfo(): TaskResult<SystemInfo> {
+        return service.getSystemInfo().asResult()
     }
 }
diff --git a/app/src/main/java/org/blackcandy/android/data/UserRepository.kt b/app/src/main/java/org/blackcandy/android/data/UserRepository.kt
@@ -2,11 +2,17 @@ package org.blackcandy.android.data
 
 import android.webkit.CookieManager
 import androidx.datastore.core.DataStore
+import io.ktor.client.HttpClient
+import io.ktor.client.plugins.auth.Auth
+import io.ktor.client.plugins.auth.providers.BearerAuthProvider
+import io.ktor.client.plugins.plugin
 import kotlinx.coroutines.flow.Flow
 import org.blackcandy.android.api.BlackCandyService
 import org.blackcandy.android.models.User
+import org.blackcandy.android.utils.TaskResult
 
 class UserRepository(
+    private val httpClient: HttpClient,
     private val service: BlackCandyService,
     private val cookieManager: CookieManager,
     private val userDataStore: DataStore<User?>,
@@ -16,24 +22,35 @@ class UserRepository(
     suspend fun login(
         email: String,
         password: String,
-    ) {
-        val response = service.createAuthentication(email, password)
-        val serverAddress = preferencesDataSource.getServerAddress()
+    ): TaskResult<Unit> {
+        try {
+            val response = service.createAuthentication(email, password).orThrow()
+            val serverAddress = preferencesDataSource.getServerAddress()
 
-        response.cookies.forEach {
-            cookieManager.setCookie(serverAddress, it)
-        }
+            response.cookies.forEach {
+                cookieManager.setCookie(serverAddress, it)
+            }
+
+            cookieManager.flush()
+            userDataStore.updateData { response.user }
+            encryptedPreferencesDataSource.updateApiToken(response.token)
 
-        cookieManager.flush()
-        userDataStore.updateData { response.user }
-        encryptedPreferencesDataSource.updateApiToken(response.token)
+            // Clear previous cached auth token in http client
+            httpClient.plugin(Auth).providers
+                .filterIsInstance<BearerAuthProvider>()
+                .first().clearToken()
+
+            return TaskResult.Success(Unit)
+        } catch (e: Exception) {
+            return TaskResult.Failure(e.message)
+        }
     }
 
     suspend fun logout() {
         service.destroyAuthentication()
-        userDataStore.updateData { null }
-        cookieManager.removeAllCookies(null)
         encryptedPreferencesDataSource.removeApiToken()
+        cookieManager.removeAllCookies(null)
+        userDataStore.updateData { null }
     }
 
     fun getCurrentUserFlow(): Flow<User?> {

diff --git a/app/src/main/java/org/blackcandy/android/di/AppModule.kt b/app/src/main/java/org/blackcandy/android/di/AppModule.kt
@@ -79,7 +79,7 @@ val appModule =
         single { MusicServiceController(androidContext()) }
         single { ServerAddressRepository(get()) }
         single { SystemInfoRepository(get()) }
-        single { UserRepository(get(), get(), get(named("UserDataStore")), get(), get()) }
+        single { UserRepository(get(), get(), get(), get(named("UserDataStore")), get(), get()) }
         single { CurrentPlaylistRepository(get()) }
         single { FavoritePlaylistRepository(get()) }
 
@@ -132,23 +132,40 @@ private fun provideHttpClient(
         }
 
         HttpResponseValidator {
+            validateResponse { response ->
+                val statusCode = response.status.value
+
+                if (statusCode == 204) {
+                    throw ApiException(
+                        code = statusCode,
+                        message = null,
+                    )
+                }
+            }
+
             handleResponseExceptionWithRequest { exception, _ ->
                 when (exception) {
                     is ClientRequestException -> {
-                        val responseText = exception.response.bodyAsText()
+                        val response = exception.response
 
                         val apiError =
                             try {
-                                json.decodeFromString<ApiError>(responseText)
+                                json.decodeFromString<ApiError>(response.bodyAsText())
                             } catch (e: Exception) {
                                 null
                             }
 
-                        throw ApiException(apiError?.message ?: exception.message)
+                        throw ApiException(
+                            code = response.status.value,
+                            message = apiError?.message ?: exception.message,
+                        )
                     }
 
                     else -> {
-                        throw ApiException(exception.message)
+                        throw ApiException(
+                            code = null,
+                            message = exception.message,
+                        )
                     }
                 }
             }

diff --git a/app/src/main/java/org/blackcandy/android/models/AlertMessage.kt b/app/src/main/java/org/blackcandy/android/models/AlertMessage.kt
@@ -3,7 +3,7 @@ package org.blackcandy.android.models
 import androidx.annotation.StringRes
 
 sealed class AlertMessage {
-    data class String(val value: kotlin.String) : AlertMessage()
+    data class String(val value: kotlin.String?) : AlertMessage()
 
     data class StringResource(
         @StringRes val value: Int,

diff --git a/app/src/main/java/org/blackcandy/android/utils/SnackbarUtil.kt b/app/src/main/java/org/blackcandy/android/utils/SnackbarUtil.kt
@@ -18,7 +18,7 @@ class SnackbarUtil {
                 when (message) {
                     is AlertMessage.String -> message.value
                     is AlertMessage.StringResource -> stringResource(message.value)
-                }
+                } ?: return
 
             LaunchedEffect(state) {
                 state.showSnackbar(snackbarText)

diff --git a/app/src/main/java/org/blackcandy/android/utils/TaskResult.kt b/app/src/main/java/org/blackcandy/android/utils/TaskResult.kt
@@ -0,0 +1,7 @@
+package org.blackcandy.android.utils
+
+sealed interface TaskResult<out T> {
+    data class Success<T>(val data: T) : TaskResult<T>
+
+    data class Failure(val message: String?) : TaskResult<Nothing>
+}