RxJava HomeWork

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

@@ -5,40 +5,59 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
+import io.reactivex.Flowable
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.disposables.CompositeDisposable
+import io.reactivex.schedulers.Schedulers
 import retrofit2.Call
 import retrofit2.Callback
 import retrofit2.Response
+import java.util.concurrent.TimeUnit
 
 class CatsViewModel(
-    catsService: CatsService,
-    localCatFactsGenerator: LocalCatFactsGenerator,
-    context: Context
+    private val catsService: CatsService,
+    private val localCatFactsGenerator: LocalCatFactsGenerator,
+    private val context: Context
 ) : ViewModel() {
 
     private val _catsLiveData = MutableLiveData<Result>()
     val catsLiveData: LiveData<Result> = _catsLiveData
 
-    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 {
+    private val compositeDisposable = CompositeDisposable()
+
+    fun getFacts() {
+        compositeDisposable.clear()
+
+        val disposable = Flowable.interval(2000, TimeUnit.MILLISECONDS)
+            .flatMapSingle { _ ->
+                catsService.getCatFact()
+                    .subscribeOn(Schedulers.io())
+                    .onErrorResumeNext { throwable ->
+                        localCatFactsGenerator.generateCatFact()
+                            .subscribeOn(Schedulers.io())
+                    }
+            }
+            .subscribeOn(Schedulers.io())
+            .observeOn(AndroidSchedulers.mainThread())
+            .subscribe(
+                { fact ->
+                    _catsLiveData.value = Success(fact)
+                },
+                { error ->
                     _catsLiveData.value = Error(
-                        response.errorBody()?.string() ?: context.getString(
-                            R.string.default_error_text
-                        )
+                        error.message ?: context.getString(R.string.default_error_text)
                     )
                 }
-            }
+            )
 
-            override fun onFailure(call: Call<Fact>, t: Throwable) {
-                _catsLiveData.value = ServerError
-            }
-        })
+        compositeDisposable.add(disposable)
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        compositeDisposable.clear()
     }
 
-    fun getFacts() {}
 }
 
 class CatsViewModelFactory(

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 {
@@ -11,6 +12,7 @@ class DiContainer {
             //.baseUrl("https://cat-fact.herokuapp.com/facts/")
             .baseUrl("https://catfact.ninja/")
             .addConverterFactory(GsonConverterFactory.create())
+            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
             .build()
     }
 

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

@@ -3,28 +3,30 @@ 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
 ) {
 
-    /**
-     * 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()
+        return Single.just(newCatFact())
     }
 
-    /**
-     * 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()
+        return Flowable.interval(2000, TimeUnit.MILLISECONDS)
+            .map {
+                newCatFact()
+            }
+            .distinctUntilChanged { oldFact, newFact ->
+                oldFact.fact == newFact.fact
+            }
+    }
+
+    private fun newCatFact(): Fact {
+        val factsArray = context.resources.getStringArray(R.array.local_cat_facts)
+        val randomIndex = Random.nextInt(factsArray.size)
+        return Fact(factsArray[randomIndex])
     }
 }

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

@@ -22,6 +22,7 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
+        catsViewModel.getFacts()
         catsViewModel.catsLiveData.observe(this) { result ->
             when (result) {
                 is Success -> view.populate(result.fact)

gradle/libs.versions.toml

@@ -30,12 +30,13 @@ okhttp = { group = "com.squareup.okhttp3", name = "okhttp", version.ref = "okhtt
 okhttp-logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-interceptor", version.ref = "okhttp" }
 picasso = { module = "com.squareup.picasso:picasso", version.ref = "picasso" }
 retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
+retrofit-rxjava = { group = "com.squareup.retrofit2", name = "adapter-rxjava2", version.ref = "retrofit" }
 retrofit-converter-gson = { group = "com.squareup.retrofit2", name = "converter-gson", version.ref = "retrofit" }
 rxandroid = { module = "io.reactivex.rxjava2:rxandroid", version.ref = "rxandroid" }
 rxjava = { module = "io.reactivex.rxjava2:rxjava", version.ref = "rxjava" }
 
 [bundles]
-network = ["okhttp", "okhttp-logging-interceptor", "retrofit", "retrofit-converter-gson"]
+network = ["okhttp", "okhttp-logging-interceptor", "retrofit", "retrofit-converter-gson", "retrofit-rxjava"]
 
 [plugins]
 androidApplication = { id = "com.android.application", version.ref = "agp" }