HW kotlin flow

flowcats/src/main/java/otus/homework/flowcats/CatsService.kt

@@ -4,6 +4,6 @@ import retrofit2.http.GET
 
 interface CatsService {
 
-    @GET("random?animal_type=cat")
+    @GET("fact")
     suspend fun getCatFact(): Fact
 }

flowcats/src/main/java/otus/homework/flowcats/CatsView.kt

@@ -11,12 +11,12 @@ class CatsView @JvmOverloads constructor(
     defStyleAttr: Int = 0
 ) : ConstraintLayout(context, attrs, defStyleAttr), ICatsView {
 
-    override fun populate(fact: Fact) {
-        findViewById<TextView>(R.id.fact_textView).text = fact.text
+    override fun populate(fact: Fact?) {
+        findViewById<TextView>(R.id.fact_textView).text = fact?.text
     }
 }
 
 interface ICatsView {
 
-    fun populate(fact: Fact)
+    fun populate(fact: Fact?)
 }

flowcats/src/main/java/otus/homework/flowcats/CatsViewModel.kt

@@ -1,7 +1,13 @@
 package otus.homework.flowcats
 
-import androidx.lifecycle.*
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -10,22 +16,26 @@ class CatsViewModel(
     private val catsRepository: CatsRepository
 ) : ViewModel() {
 
-    private val _catsLiveData = MutableLiveData<Fact>()
-    val catsLiveData: LiveData<Fact> = _catsLiveData
+    private val _stateFlow = MutableStateFlow<Result>(Result.Initial)
+    val stateFlow: StateFlow<Result> = _stateFlow
 
     init {
         viewModelScope.launch {
             withContext(Dispatchers.IO) {
-                catsRepository.listenForCatFacts().collect {
-                    _catsLiveData.value = it
-                }
+                catsRepository.listenForCatFacts()
+                    .catch {
+                        _stateFlow.emit(Result.Error(it.message))
+                    }
+                    .collect {
+                        _stateFlow.emit(Result.Success(it))
+                    }
             }
         }
     }
 }
 
 class CatsViewModelFactory(private val catsRepository: CatsRepository) :
     ViewModelProvider.NewInstanceFactory() {
-    override fun <T : ViewModel?> create(modelClass: Class<T>): T =
+    override fun <T : ViewModel> create(modelClass: Class<T>): T =
         CatsViewModel(catsRepository) as T
 }

flowcats/src/main/java/otus/homework/flowcats/DiContainer.kt

@@ -7,7 +7,7 @@ class DiContainer {
 
     private val retrofit by lazy {
         Retrofit.Builder()
-            .baseUrl("https://cat-fact.herokuapp.com/facts/")
+            .baseUrl("https://catfact.ninja/")
             .addConverterFactory(GsonConverterFactory.create())
             .build()
     }

flowcats/src/main/java/otus/homework/flowcats/Fact.kt

@@ -3,22 +3,6 @@ package otus.homework.flowcats
 import com.google.gson.annotations.SerializedName
 
 data class Fact(
-	@field:SerializedName("createdAt")
-	val createdAt: String,
-	@field:SerializedName("deleted")
-	val deleted: Boolean,
-	@field:SerializedName("_id")
-	val id: String,
-	@field:SerializedName("text")
-	val text: String,
-	@field:SerializedName("source")
-	val source: String,
-	@field:SerializedName("used")
-	val used: Boolean,
-	@field:SerializedName("type")
-	val type: String,
-	@field:SerializedName("user")
-	val user: String,
-	@field:SerializedName("updatedAt")
-	val updatedAt: String
+    @field:SerializedName("fact")
+    val text: String
 )

flowcats/src/main/java/otus/homework/flowcats/MainActivity.kt

@@ -1,8 +1,13 @@
 package otus.homework.flowcats
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.util.Log
+import android.widget.Toast
 import androidx.activity.viewModels
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
 
@@ -14,8 +19,22 @@ class MainActivity : AppCompatActivity() {
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
 
-        catsViewModel.catsLiveData.observe(this){
-            view.populate(it)
+        lifecycleScope.launch {
+            catsViewModel.stateFlow.collect { state ->
+                when (state) {
+                    is Result.Success -> {
+                        view.populate(state.fact)
+                    }
+
+                    is Result.Error -> {
+                        Toast.makeText(baseContext, state.msg, Toast.LENGTH_SHORT).show()
+                    }
+
+                    Result.Initial -> Unit
+                }
+
+            }
         }
+
     }
 }

flowcats/src/main/java/otus/homework/flowcats/Result.kt

@@ -0,0 +1,7 @@
+package otus.homework.flowcats
+
+sealed interface Result {
+    data class Success(val fact: Fact?) : Result
+    data class Error(val msg: String?) : Result
+    data object Initial : Result
+}

operators/src/main/java/otus/homework/flow/SampleInteractor.kt

@@ -1,7 +1,14 @@
 package otus.homework.flow
 
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onCompletion
+import kotlinx.coroutines.flow.take
+import kotlinx.coroutines.flow.transform
+import kotlinx.coroutines.flow.zip
 
 @ExperimentalCoroutinesApi
 class SampleInteractor(
@@ -18,7 +25,11 @@ class SampleInteractor(
      * 6) возвращает результат
      */
     fun task1(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .map { it * 5 }
+            .filter { it > 20 && it % 2 != 0 }
+            .map { "$it won" }
+            .take(3)
     }
 
     /**
@@ -29,7 +40,15 @@ class SampleInteractor(
      * Если число не делится на 3,5,15 - эмитим само число
      */
     fun task2(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .transform {
+                emit(it.toString())
+                when {
+                    it % 15 == 0 -> emit("FizzBuzz")
+                    it % 3 == 0 -> emit("Fizz")
+                    it % 5 == 0 -> emit("Buzz")
+                }
+            }
     }
 
     /**
@@ -38,7 +57,8 @@ class SampleInteractor(
      * Если айтемы в одно из флоу кончились то результирующий флоу также должен закончится
      */
     fun task3(): Flow<Pair<String, String>> {
-        return flowOf()
+        return sampleRepository.produceColors()
+            .zip(sampleRepository.produceForms()) { t1, t2 -> Pair(t1, t2) }
     }
 
     /**
@@ -48,6 +68,12 @@ class SampleInteractor(
      * При любом исходе, будь то выброс исключения или успешная отработка функции вызовите метод dotsRepository.completed()
      */
     fun task4(): Flow<Int> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .catch {
+                if (it is IllegalArgumentException) {
+                    emit(-1)
+                } else throw it
+            }
+            .onCompletion { sampleRepository.completed() }
     }
 }