Test homework

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

@@ -1,7 +1,10 @@
 package otus.homework.flowcats
 
-import androidx.lifecycle.*
+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.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -10,14 +13,18 @@ class CatsViewModel(
     private val catsRepository: CatsRepository
 ) : ViewModel() {
 
-    private val _catsLiveData = MutableLiveData<Fact>()
-    val catsLiveData: LiveData<Fact> = _catsLiveData
+    val cats = MutableStateFlow<Result>(Result.Success(Fact("", 0)))
 
     init {
         viewModelScope.launch {
             withContext(Dispatchers.IO) {
-                catsRepository.listenForCatFacts().collect {
-                    _catsLiveData.value = it
+                try {
+                    catsRepository.listenForCatFacts()
+                        .collect {
+                            cats.value = Result.Success(it)
+                        }
+                } catch (t: Throwable) {
+                    cats.value = Result.Error
                 }
             }
         }

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

@@ -2,7 +2,11 @@ package otus.homework.flowcats
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.widget.Toast
 import androidx.activity.viewModels
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
 
@@ -14,8 +18,19 @@ 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.cats.collect {
+                when (it) {
+                    Result.Error -> {
+                        Toast.makeText(this@MainActivity, "Error", Toast.LENGTH_SHORT).show()
+                    }
+                    is Result.Success<*> -> {
+                        if (it.res is Fact) {
+                            view.populate(it.res)
+                        }
+                    }
+                }
+            }
         }
     }
 }

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

@@ -0,0 +1,6 @@
+package otus.homework.flowcats
+
+sealed class Result {
+    data class Success<T>(val res: T): Result()
+    data object Error: Result()
+}

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

@@ -18,7 +18,12 @@ class SampleInteractor(
      * 6) возвращает результат
      */
     fun task1(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .map { it * 5 }
+            .filter { it > 20 }
+            .filter { it % 2 != 0 }
+            .map { "$it won" }
+            .take(3)
     }
 
     /**
@@ -29,7 +34,19 @@ class SampleInteractor(
      * Если число не делится на 3,5,15 - эмитим само число
      */
     fun task2(): Flow<String> {
-        return flowOf()
+        return flow {
+            sampleRepository.produceNumbers().collect { num ->
+                val results = when {
+                    num % 15 == 0 -> listOf("$num", "FizzBuzz")
+                    num % 3 == 0  -> listOf("$num", "Fizz")
+                    num % 5 == 0  -> listOf("$num", "Buzz")
+                    else          -> listOf("$num")
+                }
+                for (item in results) {
+                    emit(item)
+                }
+            }
+        }
     }
 
     /**
@@ -38,7 +55,18 @@ class SampleInteractor(
      * Если айтемы в одно из флоу кончились то результирующий флоу также должен закончится
      */
     fun task3(): Flow<Pair<String, String>> {
-        return flowOf()
+        return flow {
+            val colors = mutableListOf<String>()
+            val forms = mutableListOf<String>()
+
+            sampleRepository.produceColors().collect { colors.add(it) }
+            sampleRepository.produceForms().collect { forms.add(it) }
+
+            val size = minOf(colors.size, forms.size)
+            for (i in 0 until size) {
+                emit(colors[i] to forms[i])
+            }
+        }
     }
 
     /**
@@ -48,6 +76,11 @@ 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 { cause: Throwable ->
+                if (cause is IllegalArgumentException) emit(-1)
+                else throw cause
+            }
+            .onCompletion { sampleRepository.completed() }
     }
 }