ДЗ Coroutines

app/build.gradle

@@ -42,4 +42,10 @@ dependencies {
     implementation 'com.google.android.material:material:1.3.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
     implementation 'com.squareup.picasso:picasso:2.71828'
+
+//coroutine retrofit
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlin_coroutines"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$kotlin_coroutines"
+    implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.0.0'
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1"
 }

app/src/main/java/otus/homework/coroutines/CatsPresenter.kt

@@ -1,28 +1,42 @@
 package otus.homework.coroutines
 
-import retrofit2.Call
-import retrofit2.Callback
+import android.util.Log
+import kotlinx.coroutines.*
 import retrofit2.Response
+import java.net.SocketTimeoutException
+import kotlin.coroutines.CoroutineContext
 
 class CatsPresenter(
-    private val catsService: CatsService
+    private val catsServiceFact: CatsService,
+    private val catsServiceImage: CatsService
 ) {
 
     private var _catsView: ICatsView? = null
+    private val presenterScope =
+        PresenterScope(Dispatchers.Main, CoroutineName("CatsCoroutine"))
 
     fun onInitComplete() {
-        catsService.getCatFact().enqueue(object : Callback<Fact> {
-
-            override fun onResponse(call: Call<Fact>, response: Response<Fact>) {
-                if (response.isSuccessful && response.body() != null) {
-                    _catsView?.populate(response.body()!!)
+        presenterScope.launch {
+            withContext(Dispatchers.IO) {
+                try {
+                    val factResponse = catsServiceFact.getCatFact()
+                    val imageResponse = catsServiceImage.getCatImage()
+                    val factImage = FactImage(factResponse, imageResponse)
+                    _catsView?.populate(factImage)
+                } catch (e: Exception) {
+                    when (e) {
+                        is SocketTimeoutException -> {
+                            _catsView?.showToast("Не удалось получить ответ от сервером")
+                        }
+                        else -> {
+                            _catsView?.showToast(e.message.toString())
+                            CrashMonitor.trackWarning()
+                            e.printStackTrace()
+                        }
+                    }
                 }
             }
-
-            override fun onFailure(call: Call<Fact>, t: Throwable) {
-                CrashMonitor.trackWarning()
-            }
-        })
+        }
     }
 
     fun attachView(catsView: ICatsView) {
@@ -31,5 +45,14 @@ class CatsPresenter(
 
     fun detachView() {
         _catsView = null
+        presenterScope.cancel()
     }
+}
+
+class PresenterScope(
+    private val dispatchers: CoroutineDispatcher,
+    private val coroutineName: CoroutineName
+) : CoroutineScope {
+    override val coroutineContext: CoroutineContext
+        get() = dispatchers + coroutineName
 }

app/src/main/java/otus/homework/coroutines/CatsService.kt

@@ -1,10 +1,15 @@
 package otus.homework.coroutines
 
+import kotlinx.coroutines.Deferred
 import retrofit2.Call
+import retrofit2.Response
 import retrofit2.http.GET
 
 interface CatsService {
 
     @GET("random?animal_type=cat")
-    fun getCatFact() : Call<Fact>
+    suspend fun getCatFact() : Fact
+
+    @GET("meow")
+    suspend fun getCatImage() : Image
 }

app/src/main/java/otus/homework/coroutines/CatsView.kt

@@ -3,30 +3,48 @@ package otus.homework.coroutines
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.Button
+import android.widget.ImageView
 import android.widget.TextView
+import android.widget.Toast
+import android.widget.Toast.LENGTH_LONG
 import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import com.squareup.picasso.Picasso
 
 class CatsView @JvmOverloads constructor(
     context: Context,
     attrs: AttributeSet? = null,
     defStyleAttr: Int = 0
 ) : ConstraintLayout(context, attrs, defStyleAttr), ICatsView {
 
-    var presenter :CatsPresenter? = null
+    var presenter: CatsPresenter? = null
+    private var refreshLayout: SwipeRefreshLayout? = null
+
 
     override fun onFinishInflate() {
         super.onFinishInflate()
         findViewById<Button>(R.id.button).setOnClickListener {
             presenter?.onInitComplete()
         }
+        refreshLayout = findViewById<SwipeRefreshLayout>(R.id.swipe)
+        refreshLayout?.setOnRefreshListener {
+            presenter?.onInitComplete()
+        }
+    }
+
+    override fun populate(factImage: FactImage) {
+        refreshLayout?.isRefreshing = false
+        findViewById<TextView>(R.id.fact_textView).text = factImage.fact.text
+        Picasso.get().load(factImage.image.file).into(findViewById<ImageView>(R.id.iv_image))
     }
 
-    override fun populate(fact: Fact) {
-        findViewById<TextView>(R.id.fact_textView).text = fact.text
+    override fun showToast(message: String) {
+        Toast.makeText(context, message, LENGTH_LONG).show()
     }
 }
 
 interface ICatsView {
 
-    fun populate(fact: Fact)
+    fun populate(factImage: FactImage)
+    fun showToast(message: String)
 }

app/src/main/java/otus/homework/coroutines/CatsViewModel.kt

@@ -0,0 +1,70 @@
+package otus.homework.coroutines
+
+import android.util.Log
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.CoroutineExceptionHandler
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
+import java.net.SocketTimeoutException
+
+class CatsViewModel(
+    private val catsService: CatsService
+) : ViewModel() {
+    private var _catsResponse = MutableLiveData<Result<FactImage>>()
+    val catsResponse: LiveData<Result<FactImage>>
+        get() = _catsResponse
+
+    fun getCatFactImage() {
+        viewModelScope.launch(CoroutineExceptionHandler { coroutineContext, throwable ->
+            CrashMonitor.trackWarning()
+        }) {
+            try {
+                val factResponseDeferred = async {catsService.getCatFact()}
+                val imageResponseDeferred = async {catsService.getCatImage()}
+
+                val factResponse = factResponseDeferred.await()
+                val imageResponse = imageResponseDeferred.await()
+
+                /**
+                 * antonkazakov: ... Используй async чтобы распараллелить
+                 * Вопрос: изначально я сделал без async чтобы они выполнялись полседовательно
+                 * чтобы два результата использовать при создании объекта
+                 * FactImage(factResponse, imageResponse)
+                 * теперь при использовании async как это будет работать?
+                 * допустим получаем результат factResponse, imageResponse - неодновременно
+                 * FactImage(factResponse, imageResponse) будет создан из того что пришло первым,
+                 * а второй параметр "уйдет" пустым
+                 * или
+                 * родительская корутину (которая запускает launch)
+                 * "дождется" всех и только потом создаст FactImage(factResponse, imageResponse) ?
+                 */
+                val factImage = FactImage(factResponse, imageResponse)
+                _catsResponse.value = Result.Success(factImage)
+
+            } catch (e: Exception) {
+                when (e) {
+                    is SocketTimeoutException -> {
+                        _catsResponse.value =
+                            Result.Error("Не удалось получить ответ от сервером", e)
+                    }
+                    else -> {
+                        _catsResponse.value = Result.Error(e.message.toString(), e)
+                        e.printStackTrace()
+                    }
+                }
+            }
+        }
+    }
+}
+
+sealed class Result<out T> {
+    data class Success<out R>(val value: R) : Result<R>()
+    data class Error(
+        val message: String,
+        val throwable: Throwable?
+    ) : Result<Nothing>()
+}

app/src/main/java/otus/homework/coroutines/CatsViewModelFactory.kt

@@ -0,0 +1,8 @@
+package otus.homework.coroutines
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+
+class CatsViewModelFactory(private val catsService: CatsService): ViewModelProvider.NewInstanceFactory() {
+    override fun <T : ViewModel?> create(modelClass: Class<T>): T = CatsViewModel(catsService) as T
+}

app/src/main/java/otus/homework/coroutines/DiContainer.kt

@@ -3,14 +3,22 @@ package otus.homework.coroutines
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
 
-class DiContainer {
+class DiContainer() {
 
-    private val retrofit by lazy {
+    private val retrofitFact by lazy {
         Retrofit.Builder()
             .baseUrl("https://cat-fact.herokuapp.com/facts/")
             .addConverterFactory(GsonConverterFactory.create())
             .build()
     }
 
-    val service by lazy { retrofit.create(CatsService::class.java) }
+    private val retrofitImage by lazy {
+        Retrofit.Builder()
+            .baseUrl("https://aws.random.cat/")
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+    }
+
+    val service by lazy { retrofitFact.create(CatsService::class.java) }
+
 }

app/src/main/java/otus/homework/coroutines/FactImage.kt

@@ -0,0 +1,8 @@
+package otus.homework.coroutines
+
+import com.google.gson.annotations.SerializedName
+
+data class FactImage(
+	val fact: Fact,
+	val image: Image
+)

app/src/main/java/otus/homework/coroutines/FactImageResponse.kt

@@ -0,0 +1,10 @@
+package otus.homework.coroutines
+
+import com.google.gson.annotations.SerializedName
+
+data class FactImageResponse(
+	val fact: Fact? = null,
+	val image: Image? = null,
+	var isSuccessful: Boolean? = true,
+	var errorMessage: String? = null
+)

app/src/main/java/otus/homework/coroutines/Image.kt

@@ -0,0 +1,8 @@
+package otus.homework.coroutines
+
+import com.google.gson.annotations.SerializedName
+
+data class Image(
+	@field:SerializedName("file")
+	val file: String
+)

app/src/main/java/otus/homework/coroutines/MainActivity.kt

@@ -2,23 +2,63 @@ package otus.homework.coroutines
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.widget.ImageView
+import android.widget.TextView
+import android.widget.Toast
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProvider
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import com.squareup.picasso.Picasso
 
 class MainActivity : AppCompatActivity() {
 
     lateinit var catsPresenter: CatsPresenter
 
     private val diContainer = DiContainer()
+    private lateinit var viewModel: CatsViewModel
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
 
-        catsPresenter = CatsPresenter(diContainer.service)
-        view.presenter = catsPresenter
-        catsPresenter.attachView(view)
-        catsPresenter.onInitComplete()
+        /*
+            ### Реализовать решение ViewModel
+         */
+        val viewModelFactory = CatsViewModelFactory(diContainer.service)
+        viewModel = ViewModelProvider(this, viewModelFactory).get(CatsViewModel::class.java)
+
+        viewModel.getCatFactImage()
+
+        val refreshLayout = findViewById<SwipeRefreshLayout>(R.id.swipe)
+        refreshLayout?.setOnRefreshListener {
+            viewModel.getCatFactImage()
+        }
+
+        viewModel.catsResponse.observe(this, Observer { factImage ->
+            refreshLayout.isRefreshing = false
+            when (factImage) {
+                is Result.Success -> {
+                    findViewById<TextView>(R.id.fact_textView).text = factImage.value.fact?.text
+                    Picasso.get().load(factImage.value.image?.file)
+                        .into(findViewById<ImageView>(R.id.iv_image))
+                }
+                is Result.Error -> {
+                    Toast.makeText(this, factImage.message, Toast.LENGTH_LONG).show()
+                }
+            }
+        })
+
+        /*
+            ### Перейти с коллбеков на саспенд функции и корутины
+            ### Добавить к запросу фактов запрос рандомных картинок с [https://aws.random.cat/meow](https://aws.random.cat/meow)
+         */
+//        catsPresenter = CatsPresenter(diContainer.serviceFact, diContainer.serviceImage)
+//        view.presenter = catsPresenter
+//        catsPresenter.attachView(view)
+//        catsPresenter.onInitComplete()
+
     }
 
     override fun onStop() {