add network for external camera with retrofit [#35]

- 임시로 `http` 사용 가능하도록 설정
- 일부 `data` 모듈에서 사용할 예정인 공용 코드는 `util`에 구현

app/src/main/AndroidManifest.xml

@@ -9,7 +9,9 @@
         android:name=".MainApplication"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
-        android:roundIcon="@mipmap/ic_launcher_round" />
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:usesCleartextTraffic="true" />
+    <!-- TODO: temporary add usesCleartextTraffic. remove later -->
 
 <!--    TODO: support back-up-->
 <!--    android:allowBackup="true"-->

domain/src/main/java/com/foke/together/domain/output/ExternalCameraRepositoryInterface.kt

@@ -0,0 +1,9 @@
+package com.foke.together.domain.output
+
+import android.graphics.Bitmap
+
+interface ExternalCameraRepositoryInterface {
+    fun setCameraSourceUrl(url: String)
+    suspend fun capture(): Result<Bitmap>
+    fun getPreviewUrl(): String
+}

external/build.gradle.kts

@@ -15,6 +15,12 @@ dependencies {
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
 
+    // retrofit
+    implementation(libs.ok.http.base)
+    implementation(libs.retrofit.base)
+    implementation(libs.retrofit.gson)
+    implementation(libs.google.gson)
+
     // module dependency
     implementation(project(":domain"))
 

external/src/main/java/com/foke/together/external/network/ExternalCameraApi.kt

@@ -0,0 +1,12 @@
+package com.foke.together.external.network
+
+import okhttp3.ResponseBody
+import retrofit2.http.GET
+import retrofit2.http.Query
+
+interface ExternalCameraApi {
+    @GET("/capture")
+    suspend fun capture(
+        @Query("timeout") timeout: Int? = null
+    ): Result<ResponseBody>
+}

external/src/main/java/com/foke/together/external/network/ExternalCameraDataSource.kt

@@ -0,0 +1,21 @@
+package com.foke.together.external.network
+
+import com.foke.together.external.network.interceptor.BaseUrlInterceptor
+import okhttp3.ResponseBody
+import javax.inject.Inject
+
+class ExternalCameraDataSource @Inject constructor(
+    private val externalCameraApi: ExternalCameraApi,
+    private val baseUrlInterceptor: BaseUrlInterceptor
+){
+    fun setBaseUrl(url: String) {
+        baseUrlInterceptor.setBaseUrl(url)
+    }
+
+    suspend fun capture(timeout: Int? = null): Result<ResponseBody> {
+        return externalCameraApi.capture(timeout)
+    }
+
+    fun getPreviewUrl(): String =
+        "${baseUrlInterceptor.getBaseUrl()}/preview"
+}

external/src/main/java/com/foke/together/external/network/ExternalCameraModule.kt

@@ -0,0 +1,61 @@
+package com.foke.together.external.network
+
+import com.foke.together.external.network.interceptor.BaseUrlInterceptor
+import com.foke.together.util.AppPolicy
+import com.foke.together.util.retrofit.NetworkCallAdapterFactory
+import com.google.gson.GsonBuilder
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
+import java.util.concurrent.TimeUnit
+import javax.inject.Named
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object ExternalCameraModule {
+
+    @Provides
+    @Named("cameraIPUrl")
+    // TODO: need to check in phase3; is it valid injection?
+    fun provideCameraIPUrl(): String = AppPolicy.EXTERNAL_CAMERA_DEFAULT_SERVER_URL
+
+    @Provides
+    @Singleton
+    fun provideBaseUrlInterceptor() = BaseUrlInterceptor()
+
+    @Singleton
+    @Provides
+    fun provideOkHttpClient(
+        baseUrlInterceptor: BaseUrlInterceptor
+    ) = OkHttpClient.Builder()
+        .connectTimeout(AppPolicy.EXTERNAL_CAMERA_CONNECT_TIMEOUT, TimeUnit.SECONDS)
+        .readTimeout(AppPolicy.EXTERNAL_CAMERA_READ_TIMEOUT, TimeUnit.SECONDS)
+        .writeTimeout(AppPolicy.EXTERNAL_CAMERA_WRITE_TIMEOUT, TimeUnit.SECONDS)
+        // .addInterceptor(MockInterceptor()) // TODO: add mock code for test
+        .addInterceptor(baseUrlInterceptor)
+        .build()
+
+    @Singleton
+    @Provides
+    fun provideExternalCameraServerRetrofit(
+        okHttpClient: OkHttpClient,
+        @Named("cameraIPUrl") cameraIPUrl: String
+    ) = Retrofit.Builder()
+        .baseUrl(cameraIPUrl)
+        .addConverterFactory(GsonConverterFactory.create(
+            GsonBuilder().setLenient().create()
+        ))
+        .addCallAdapterFactory(NetworkCallAdapterFactory())
+        .client(okHttpClient)
+        .build()
+
+    @Singleton
+    @Provides
+    fun provideApiService(retrofit: Retrofit): ExternalCameraApi =
+        retrofit.create(ExternalCameraApi::class.java)
+}

external/src/main/java/com/foke/together/external/network/interceptor/BaseUrlInterceptor.kt

@@ -0,0 +1,61 @@
+package com.foke.together.external.network.interceptor
+
+import com.foke.together.util.AppLog
+import com.foke.together.util.AppPolicy
+import okhttp3.Interceptor
+import okhttp3.Response
+
+class BaseUrlInterceptor: Interceptor {
+    @Volatile
+    private var baseUrl: String? = null
+    @Volatile
+    private var scheme: String? = null
+    @Volatile
+    private var host: String? = null
+    @Volatile
+    private var port: Int? = null
+
+    fun getBaseUrl() = baseUrl ?: AppPolicy.EXTERNAL_CAMERA_DEFAULT_SERVER_URL
+
+    fun setBaseUrl(newBaseUrl: String) {
+        baseUrl = newBaseUrl
+        try {
+            val sep = newBaseUrl.indexOf("://")
+            scheme = newBaseUrl.substring(0, sep)
+            val newHost = newBaseUrl.substring(sep + 3, newBaseUrl.length)
+
+            val pSep = newHost.lastIndexOf(":")
+            port = if (pSep != -1) {
+                host = newHost.substring(0, pSep)
+                newHost.substring(pSep + 1, newHost.length).toInt()
+            } else {
+                host = newHost
+                null
+            }
+        } catch (e: Exception) {
+            AppLog.e(TAG, "setBaseUrl", "cannot parse newBaseUrl")
+        }
+    }
+
+    override fun intercept(chain: Interceptor.Chain): Response {
+        var request = chain.request()
+        scheme?.let { s ->
+            host?.let { h ->
+                val newUrl = request.url.newBuilder().run {
+                    scheme(s)
+                    host(h)
+                    port?.let { port(it) }
+                    build()
+                }
+                request = request.newBuilder()
+                    .url(newUrl)
+                    .build()
+            }
+        }
+        return chain.proceed(request)
+    }
+
+    companion object {
+        private val TAG: String = BaseUrlInterceptor::class.java.simpleName
+    }
+}

external/src/main/java/com/foke/together/external/network/interceptor/MockInterceptor.kt

@@ -0,0 +1,15 @@
+package com.foke.together.external.network.interceptor
+
+import okhttp3.Interceptor
+import okhttp3.Protocol
+import okhttp3.Response
+
+class MockInterceptor: Interceptor {
+    override fun intercept(chain: Interceptor.Chain): Response {
+        // TODO: make mock for test
+        return Response.Builder()
+            .request(chain.request())
+            .protocol(Protocol.HTTP_2)
+            .build()
+    }
+}

external/src/main/java/com/foke/together/external/repository/ExternalCameraRepository.kt

@@ -0,0 +1,29 @@
+package com.foke.together.external.repository
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import com.foke.together.domain.output.ExternalCameraRepositoryInterface
+import com.foke.together.external.network.ExternalCameraDataSource
+import javax.inject.Inject
+
+class ExternalCameraRepository @Inject constructor(
+    private val externalCameraDataSource: ExternalCameraDataSource
+): ExternalCameraRepositoryInterface {
+    override fun setCameraSourceUrl(url: String) {
+        externalCameraDataSource.setBaseUrl(url)
+    }
+
+    override suspend fun capture(): Result<Bitmap> {
+        return externalCameraDataSource.capture()
+            .map { responseBody ->
+                BitmapFactory.decodeStream(responseBody.byteStream())
+            }
+    }
+
+    override fun getPreviewUrl() =
+        externalCameraDataSource.getPreviewUrl()
+
+    companion object {
+        private val TAG = ExternalCameraRepository::class.java.simpleName
+    }
+}

external/src/main/java/com/foke/together/external/repository/di/RepositoryModule.kt

@@ -0,0 +1,17 @@
+package com.foke.together.external.repository.di
+
+import com.foke.together.domain.output.ExternalCameraRepositoryInterface
+import com.foke.together.external.repository.ExternalCameraRepository
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ViewModelComponent
+
+@Module
+@InstallIn(ViewModelComponent::class)
+abstract class RepositoryModule {
+    @Binds
+    abstract fun bindAppPreferenceRepository(
+        externalCameraRepository: ExternalCameraRepository
+    ): ExternalCameraRepositoryInterface
+}

util/build.gradle.kts

@@ -15,6 +15,12 @@ dependencies {
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
 
+    // retrofit
+    implementation(libs.ok.http.base)
+    implementation(libs.retrofit.base)
+    implementation(libs.retrofit.gson)
+    implementation(libs.google.gson)
+
     // module dependency
     implementation(project(":entity"))
 }

util/src/main/java/com/foke/together/util/AppPolicy.kt

@@ -1,5 +1,13 @@
 package com.foke.together.util
 
 object AppPolicy {
+    const val isDebugMode = true
+
     const val DEFAULT_EXTERNAL_CAMERA_IP = "0.0.0.0"
+
+    // network
+    const val EXTERNAL_CAMERA_DEFAULT_SERVER_URL = "http://0.0.0.0"
+    const val EXTERNAL_CAMERA_CONNECT_TIMEOUT = 10L
+    const val EXTERNAL_CAMERA_READ_TIMEOUT = 10L
+    const val EXTERNAL_CAMERA_WRITE_TIMEOUT = 10L
 }

util/src/main/java/com/foke/together/util/retrofit/NetworkCall.kt

@@ -0,0 +1,81 @@
+package com.foke.together.util.retrofit
+
+import com.foke.together.util.AppLog
+import com.foke.together.util.AppPolicy
+import okhttp3.Request
+import okio.IOException
+import okio.Timeout
+import retrofit2.Call
+import retrofit2.Callback
+import retrofit2.Response
+
+class NetworkCall<T>(
+    private val call: Call<T>,
+): Call<Result<T>> {
+    override fun enqueue(callback: Callback<Result<T>>) {
+        call.enqueue(object: Callback<T> {
+            override fun onResponse(call: Call<T>, response: Response<T>) {
+                if (AppPolicy.isDebugMode) {
+                    AppLog.e(TAG, "onResponse", "success: $response")
+                }
+
+                if (response.isSuccessful) {
+                    // success
+                    callback.onResponse(
+                        this@NetworkCall,
+                        Response.success(Result.success(response.body()!!))
+                    )
+                } else {
+                    // error
+                    callback.onResponse(
+                        this@NetworkCall,
+                        Response.success(
+                            // TODO: change to custom `error type`
+                            Result.failure(Exception())
+                        )
+                    )
+                }
+            }
+
+            override fun onFailure(call: Call<T>, t: Throwable) {
+                if (AppPolicy.isDebugMode) {
+                    AppLog.e(TAG, "onResponse", "failure: $t")
+                }
+
+                when(t) {
+                    // TODO: define each error cases by `error type`
+                    is IOException -> Result.failure<T>(t)
+                    else -> Result.failure<T>(t)
+                }.also {
+                    callback.onResponse(this@NetworkCall, Response.success(it))
+                }
+            }
+        })
+    }
+
+    override fun clone(): Call<Result<T>> =
+        NetworkCall(call.clone())
+
+    override fun execute(): Response<Result<T>> =
+        // TODO: check in case of null body
+        Response.success(Result.success(call.execute().body()!!))
+
+    override fun isExecuted(): Boolean =
+        call.isExecuted
+
+    override fun cancel() =
+        call.cancel()
+
+    override fun isCanceled(): Boolean =
+        call.isCanceled
+
+    override fun request(): Request =
+        call.request()
+
+    override fun timeout(): Timeout =
+        call.timeout()
+
+    companion object {
+        private val TAG: String = NetworkCall::class.java.simpleName
+    }
+}

util/src/main/java/com/foke/together/util/retrofit/NetworkCallAdapter.kt

@@ -0,0 +1,16 @@
+package com.foke.together.util.retrofit
+
+import retrofit2.Call
+import retrofit2.CallAdapter
+import java.lang.reflect.Type
+
+class NetworkCallAdapter<T>(
+    private val responseType: Type
+): CallAdapter<T, Call<Result<T>>> {
+    override fun responseType(): Type =
+        responseType
+
+    override fun adapt(call: Call<T>): Call<Result<T>> =
+        // TODO: add NetworkCall for each web-server and external-camera
+        NetworkCall(call)
+}