Coroutines Homework by Diana

app/build.gradle

@@ -41,4 +41,6 @@ dependencies {
     implementation 'com.google.android.material:material:1.11.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
     implementation 'com.squareup.picasso:picasso:2.71828'
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.6.2"
+    implementation("androidx.activity:activity-ktx:1.8.0")
 }

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

@@ -0,0 +1,9 @@
+package otus.homework.coroutines
+
+import retrofit2.http.GET
+
+interface CatsImageService {
+
+    @GET("v1/images/search")
+    suspend fun getCatImage(): List<Image>
+}

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

@@ -1,28 +1,48 @@
 package otus.homework.coroutines
 
-import retrofit2.Call
-import retrofit2.Callback
-import retrofit2.Response
+import android.content.Context
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.async
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.supervisorScope
+import java.net.SocketTimeoutException
 
 class CatsPresenter(
-    private val catsService: CatsService
+    private val catsService: CatsService,
+    private val catsImageService: CatsImageService,
+    val context: Context
 ) {
-
     private var _catsView: ICatsView? = null
+    private val presenterScope =
+        CoroutineScope(Dispatchers.Main + Job() + 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.coroutineContext[Job]?.cancel()
+        presenterScope.launch {
+            try {
+                supervisorScope {
+                    val factDeferred = async { catsService.getCatFact() }
+                    val imageDeferred = async { catsImageService.getCatImage() }
+                    val factResponse = factDeferred.await()
+                    val imageResponse = imageDeferred.await()
+
+                    _catsView?.populate(
+                        PresentationFact(factResponse.fact, imageResponse.first().imageUrl)
+                    )
+                }
+            } catch (e: Exception) {
+                if (e is SocketTimeoutException) {
+                    _catsView?.showToast(context.getString(R.string.server_error))
+                } else {
+                    _catsView?.showToast(e.message ?: context.getString(R.string.error))
+                    CrashMonitor.trackWarning()
                 }
             }
-
-            override fun onFailure(call: Call<Fact>, t: Throwable) {
-                CrashMonitor.trackWarning()
-            }
-        })
+        }
     }
 
     fun attachView(catsView: ICatsView) {
@@ -32,4 +52,8 @@ class CatsPresenter(
     fun detachView() {
         _catsView = null
     }
+
+    fun cancel() {
+        presenterScope.cancel()
+    }
 }

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

@@ -1,10 +1,9 @@
 package otus.homework.coroutines
 
-import retrofit2.Call
 import retrofit2.http.GET
 
 interface CatsService {
 
     @GET("fact")
-    fun getCatFact() : Call<Fact>
+    suspend fun getCatFact(): Fact
 }

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

@@ -3,30 +3,42 @@ 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 androidx.constraintlayout.widget.ConstraintLayout
+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
+    var viewModel: CatsViewModel? = null
 
     override fun onFinishInflate() {
         super.onFinishInflate()
         findViewById<Button>(R.id.button).setOnClickListener {
-            presenter?.onInitComplete()
+            viewModel?.onInitComplete()
         }
     }
 
-    override fun populate(fact: Fact) {
+    override fun populate(fact: PresentationFact) {
         findViewById<TextView>(R.id.fact_textView).text = fact.fact
+        Picasso
+            .get()
+            .load(fact.imageUrl)
+            .into(findViewById<ImageView>(R.id.fact_image))
+    }
+
+    override fun showToast(text: String) {
+        Toast.makeText(context, text, Toast.LENGTH_SHORT).show()
     }
 }
 
 interface ICatsView {
-
-    fun populate(fact: Fact)
+    fun populate(fact: PresentationFact)
+    fun showToast(text: String)
 }

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

@@ -0,0 +1,41 @@
+package otus.homework.coroutines
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.CoroutineExceptionHandler
+import kotlinx.coroutines.async
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
+
+class CatsViewModel(
+    private val catsService: CatsService,
+    private val catsImageService: CatsImageService
+) : ViewModel() {
+    val handler = CoroutineExceptionHandler { _, exception ->
+        _factState.value = Result.Error(exception)
+        CrashMonitor.trackWarning()
+    }
+    private val _factState = MutableStateFlow<Result>(Result.Loading)
+    val factState: StateFlow<Result> = _factState
+
+    fun onInitComplete() {
+        _factState.value = Result.Loading
+        viewModelScope.launch(handler) {
+            val factDeferred = async { catsService.getCatFact() }
+            val imageDeferred = async { catsImageService.getCatImage() }
+            val factResponse = factDeferred.await()
+            val imageResponse = imageDeferred.await()
+
+            _factState.value = Result.Success(
+                PresentationFact(factResponse.fact, imageResponse.first().imageUrl)
+            )
+        }
+    }
+}
+
+sealed class Result() {
+    data class Success(val data: PresentationFact) : Result()
+    data class Error(val exception: Throwable) : Result()
+    object Loading : Result()
+}

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

@@ -0,0 +1,16 @@
+package otus.homework.coroutines
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+
+class CatsViewModelFactory(
+    private val catsService: CatsService,
+    private val catImagesService: CatsImageService
+) : ViewModelProvider.Factory {
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        if (modelClass.isAssignableFrom(CatsViewModel::class.java)) {
+            return CatsViewModel(catsService, catImagesService) as T
+        }
+        throw IllegalArgumentException("Unknown ViewModel class")
+    }
+}

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

@@ -5,12 +5,18 @@ import retrofit2.converter.gson.GsonConverterFactory
 
 class DiContainer {
 
-    private val retrofit by lazy {
+    private val catsRetrofit by lazy {
         Retrofit.Builder()
             .baseUrl("https://catfact.ninja/")
             .addConverterFactory(GsonConverterFactory.create())
             .build()
     }
-
-    val service by lazy { retrofit.create(CatsService::class.java) }
+    private val catsImageRetrofit by lazy {
+        Retrofit.Builder()
+            .baseUrl("https://api.thecatapi.com/")
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+    }
+    val catsImageservice by lazy { catsImageRetrofit.create(CatsImageService::class.java) }
+    val catsService by lazy { catsRetrofit.create(CatsService::class.java) }
 }

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("url")
+    val imageUrl: String?
+)

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

@@ -1,30 +1,48 @@
 package otus.homework.coroutines
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.activity.viewModels
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.launch
+import java.net.SocketTimeoutException
 
 class MainActivity : AppCompatActivity() {
 
-    lateinit var catsPresenter: CatsPresenter
-
     private val diContainer = DiContainer()
 
+    private val viewModel: CatsViewModel by viewModels {
+        CatsViewModelFactory(
+            catsService = diContainer.catsService,
+            catImagesService = diContainer.catsImageservice
+        )
+    }
+
     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()
-    }
-
-    override fun onStop() {
-        if (isFinishing) {
-            catsPresenter.detachView()
+        view.viewModel = viewModel
+        viewModel.onInitComplete()
+
+        lifecycleScope.launch {
+            viewModel.factState.collect { result ->
+                when (result) {
+                    is Result.Success -> view.populate(result.data)
+
+                    is Result.Error -> {
+                        if (result.exception is SocketTimeoutException) {
+                            view.showToast(getString(R.string.server_error))
+                        } else {
+                            view.showToast(result.exception.message ?: getString(R.string.error))
+                        }
+                    }
+
+                    is Result.Loading -> {}
+                }
+            }
         }
-        super.onStop()
     }
 }

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

@@ -0,0 +1,6 @@
+package otus.homework.coroutines
+
+data class PresentationFact(
+    val fact: String?,
+    val imageUrl: String?
+)

app/src/main/res/layout/activity_main.xml

@@ -3,16 +3,26 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:padding="16dp"
     android:layout_height="match_parent"
+    android:padding="16dp"
     tools:context=".MainActivity">
 
+    <ImageView
+        android:id="@+id/fact_image"
+        android:layout_width="wrap_content"
+        android:layout_height="200dp"
+        android:contentDescription=""
+        android:scaleType="fitCenter"
+        app:layout_constraintBottom_toTopOf="@id/fact_textView"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent" />
+
     <TextView
         android:id="@+id/fact_textView"
-        android:textColor="@color/black"
-        android:textSize="24sp"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:textColor="@color/black"
+        android:textSize="24sp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"

app/src/main/res/values/strings.xml

@@ -1,4 +1,7 @@
 <resources>
     <string name="app_name">Cat Facts </string>
     <string name="more_facts">More Facts</string>
+    <string name="server_error">Не удалось получить ответ от сервера</string>
+    <string name="error">Что-то пошло не так</string>
+    <string name="cat_image">Фото кота</string>
 </resources>