Home task implement

app/build.gradle

@@ -46,5 +46,6 @@ dependencies {
     implementation libs.gson
     implementation libs.picasso
     implementation libs.rxjava
+    implementation libs.retrofit.rxjava
     implementation libs.rxandroid
 }

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

@@ -1,11 +1,11 @@
 package otus.homework.reactivecats
 
-import retrofit2.Call
+import io.reactivex.Single
 import retrofit2.http.GET
 
 interface CatsService {
 
     //@GET("random?animal_type=cat")
     @GET("fact")
-    fun getCatFact(): Call<Fact>
+    fun getCatFact(): Single<Fact>
 }

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

@@ -1,55 +1,68 @@
 package otus.homework.reactivecats
 
-import android.content.Context
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
-import retrofit2.Call
-import retrofit2.Callback
-import retrofit2.Response
+import io.reactivex.Flowable
+import io.reactivex.Single
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.disposables.CompositeDisposable
+
 
 class CatsViewModel(
-    catsService: CatsService,
-    localCatFactsGenerator: LocalCatFactsGenerator,
-    context: Context
+    private val catsService: CatsService,
+    private val localCatFactsGenerator: LocalCatFactsGenerator,
 ) : ViewModel() {
 
     private val _catsLiveData = MutableLiveData<Result>()
     val catsLiveData: LiveData<Result> = _catsLiveData
 
+    private val disposable = CompositeDisposable()
+
     init {
-        catsService.getCatFact().enqueue(object : Callback<Fact> {
-            override fun onResponse(call: Call<Fact>, response: Response<Fact>) {
-                if (response.isSuccessful && response.body() != null) {
-                    _catsLiveData.value = Success(response.body()!!)
-                } else {
-                    _catsLiveData.value = Error(
-                        response.errorBody()?.string() ?: context.getString(
-                            R.string.default_error_text
-                        )
-                    )
-                }
-            }
-
-            override fun onFailure(call: Call<Fact>, t: Throwable) {
-                _catsLiveData.value = ServerError
-            }
-        })
+        getFacts()
+    }
+
+    private fun getFacts() {
+        disposable.add(
+            localCatFactsGenerator.generateCatFactPeriodically()
+                .flatMap(::handleFactRequest)
+                .distinctUntilChanged()
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(::onFactSuccess, ::onFactError)
+        )
+    }
+
+    private fun handleFactRequest(localFact: Fact): Flowable<Fact> {
+        return catsService.getCatFact()
+            .onErrorResumeNext { Single.just(localFact) }
+            .toFlowable()
     }
 
-    fun getFacts() {}
+    private fun onFactSuccess(fact: Fact) {
+        _catsLiveData.value = Success(fact)
+    }
+
+    private fun onFactError(throwable: Throwable) {
+        _catsLiveData.value = Error(throwable.message!!)
+    }
+
+
+    override fun onCleared() {
+        super.onCleared()
+        disposable.clear()
+    }
 }
 
 class CatsViewModelFactory(
     private val catsRepository: CatsService,
     private val localCatFactsGenerator: LocalCatFactsGenerator,
-    private val context: Context
 ) :
     ViewModelProvider.NewInstanceFactory() {
 
     override fun <T : ViewModel> create(modelClass: Class<T>): T =
-        CatsViewModel(catsRepository, localCatFactsGenerator, context) as T
+        CatsViewModel(catsRepository, localCatFactsGenerator) as T
 }
 
 sealed class Result

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

@@ -2,6 +2,7 @@ package otus.homework.reactivecats
 
 import android.content.Context
 import retrofit2.Retrofit
+import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory
 import retrofit2.converter.gson.GsonConverterFactory
 
 class DiContainer {
@@ -11,10 +12,11 @@ class DiContainer {
             //.baseUrl("https://cat-fact.herokuapp.com/facts/")
             .baseUrl("https://catfact.ninja/")
             .addConverterFactory(GsonConverterFactory.create())
+            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
             .build()
     }
 
-    val service by lazy { retrofit.create(CatsService::class.java) }
+    val service: CatsService by lazy { retrofit.create(CatsService::class.java) }
 
     fun localCatFactsGenerator(context: Context) = LocalCatFactsGenerator(context)
 }

app/src/main/java/otus/homework/reactivecats/LocalCatFactsGenerator.kt

@@ -3,28 +3,32 @@ package otus.homework.reactivecats
 import android.content.Context
 import io.reactivex.Flowable
 import io.reactivex.Single
+import java.util.concurrent.TimeUnit
 import kotlin.random.Random
 
 class LocalCatFactsGenerator(
     private val context: Context
 ) {
 
+    private val localFactsArray by lazy { context.resources.getStringArray(R.array.local_cat_facts) }
+    private val localFactsSize by lazy { localFactsArray.size }
+
     /**
-     * Реализуйте функцию otus.homework.reactivecats.LocalCatFactsGenerator#generateCatFact так,
-     * чтобы она возвращала Fact со случайной строкой  из массива строк R.array.local_cat_facts
+     * Реализуйте функцию [otus.homework.reactivecats.LocalCatFactsGenerator.generateCatFact] так,
+     * чтобы она возвращала Fact со случайной строкой из массива строк R.array.local_cat_facts
      * обернутую в подходящий стрим(Flowable/Single/Observable и т.п)
      */
-    fun generateCatFact(): Single<Fact> {
-        return Single.never()
+    private fun generateCatFact() = Single.fromCallable {
+        Fact(localFactsArray[Random.nextInt(localFactsSize)])
     }
 
     /**
-     * Реализуйте функцию otus.homework.reactivecats.LocalCatFactsGenerator#generateCatFactPeriodically так,
+     * Реализуйте функцию [otus.homework.reactivecats.LocalCatFactsGenerator.generateCatFactPeriodically] так,
      * чтобы она эмитила Fact со случайной строкой из массива строк R.array.local_cat_facts каждые 2000 миллисекунд.
      * Если вновь заэмиченный Fact совпадает с предыдущим - пропускаем элемент.
      */
-    fun generateCatFactPeriodically(): Flowable<Fact> {
-        val success = Fact(context.resources.getStringArray(R.array.local_cat_facts)[Random.nextInt(5)])
-        return Flowable.empty()
-    }
+    fun generateCatFactPeriodically(): Flowable<Fact> =
+        Flowable.interval(2000, TimeUnit.MILLISECONDS)
+            .flatMap { generateCatFact().toFlowable() }
+            .distinctUntilChanged()
 }

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

@@ -1,10 +1,9 @@
 package otus.homework.reactivecats
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.widget.Toast
 import androidx.activity.viewModels
-import androidx.lifecycle.lifecycleScope
+import androidx.appcompat.app.AppCompatActivity
 import com.google.android.material.snackbar.Snackbar
 
 class MainActivity : AppCompatActivity() {
@@ -14,7 +13,6 @@ class MainActivity : AppCompatActivity() {
         CatsViewModelFactory(
             diContainer.service,
             diContainer.localCatFactsGenerator(applicationContext),
-            applicationContext
         )
     }
 

gradle/libs.versions.toml

@@ -31,6 +31,7 @@ okhttp-logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-i
 picasso = { module = "com.squareup.picasso:picasso", version.ref = "picasso" }
 retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
 retrofit-converter-gson = { group = "com.squareup.retrofit2", name = "converter-gson", version.ref = "retrofit" }
+retrofit-rxjava= { group = "com.squareup.retrofit2", name = "adapter-rxjava2", version.ref = "retrofit" }
 rxandroid = { module = "io.reactivex.rxjava2:rxandroid", version.ref = "rxandroid" }
 rxjava = { module = "io.reactivex.rxjava2:rxjava", version.ref = "rxjava" }