Coroutines and flow homework

app/src/main/kotlin/ru/otus/coroutineshomework/ui/login/LoginFragment.kt

@@ -7,6 +7,10 @@ import android.view.ViewGroup
 import androidx.core.view.isVisible
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
+import kotlinx.coroutines.launch
 import ru.otus.coroutineshomework.databinding.ContentBinding
 import ru.otus.coroutineshomework.databinding.FragmentLoginBinding
 import ru.otus.coroutineshomework.databinding.LoadingBinding
@@ -26,7 +30,7 @@ class LoginFragment : Fragment() {
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
-        savedInstanceState: Bundle?
+        savedInstanceState: Bundle?,
     ): View {
         _binding = FragmentLoginBinding.inflate(inflater, container, false)
 
@@ -43,13 +47,18 @@ class LoginFragment : Fragment() {
         setupLogin()
         setupContent()
 
-        loginViewModel.state.observe(viewLifecycleOwner) {
-            when(it) {
-                is LoginViewState.Login -> showLogin(it)
-                LoginViewState.LoggingIn -> showLoggingIn()
-                is LoginViewState.Content -> showContent(it)
-                LoginViewState.LoggingOut -> showLoggingOut()
+        lifecycleScope.launch {
+            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
+                loginViewModel.state.collect {
+                    when (it) {
+                        is LoginViewState.Login -> showLogin(it)
+                        LoginViewState.LoggingIn -> showLoggingIn()
+                        is LoginViewState.Content -> showContent(it)
+                        LoginViewState.LoggingOut -> showLoggingOut()
+                    }
+                }
             }
+
         }
     }
 
@@ -111,4 +120,4 @@ class LoginFragment : Fragment() {
         super.onDestroyView()
         _binding = null
     }
-}
+}

app/src/main/kotlin/ru/otus/coroutineshomework/ui/login/LoginViewModel.kt

@@ -1,27 +1,52 @@
 package ru.otus.coroutineshomework.ui.login
 
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import ru.otus.coroutineshomework.ui.login.data.Credentials
+import ru.otus.coroutineshomework.ui.login.data.User
 
 class LoginViewModel : ViewModel() {
 
-    private val _state = MutableLiveData<LoginViewState>(LoginViewState.Login())
-    val state: LiveData<LoginViewState> = _state
+    private val stateFlow = MutableStateFlow<LoginViewState>(LoginViewState.Login())
+    val state: StateFlow<LoginViewState> = stateFlow
+    private val loginApi = LoginApi()
+    private lateinit var user: User
 
-    /**
-     * Login to the network
-     * @param name user name
-     * @param password user password
-     */
     fun login(name: String, password: String) {
-        // TODO: Implement login
+        stateFlow.value = LoginViewState.LoggingIn
+        viewModelScope.launch {
+            loginFlow(name, password).collect {
+                stateFlow.value = it
+            }
+        }
     }
 
-    /**
-     * Logout from the network
-     */
     fun logout() {
-        // TODO: Implement logout
+        stateFlow.value = LoginViewState.LoggingOut
+        viewModelScope.launch {
+            withContext(Dispatchers.IO) {
+                loginApi.logout()
+            }
+            stateFlow.value = LoginViewState.Login()
+        }
     }
+
+    private fun loginFlow(name: String, password: String): Flow<LoginViewState> = flow {
+        emit(LoginViewState.LoggingIn)
+        try {
+            user = loginApi.login(Credentials(name, password))
+            emit(LoginViewState.Content(user))
+        } catch (e: IllegalArgumentException) {
+            emit(LoginViewState.Login(e))
+
+        }
+    }.flowOn(Dispatchers.IO)
 }

app/src/main/kotlin/ru/otus/coroutineshomework/ui/network/NetworkViewModel.kt

@@ -4,8 +4,11 @@ import android.util.Log
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
 import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlin.random.Random
 
@@ -18,7 +21,21 @@ class NetworkViewModel : ViewModel() {
     val result: LiveData<Long?> = _result
 
     fun startTest(numberOfThreads: Int) {
-        // TODO: Implement the logic
+
+        val resultsList = mutableListOf<Result<Long>>()
+
+        viewModelScope.launch {
+            _running.value = true
+            repeat(numberOfThreads) {
+                resultsList.add(async { emulateBlockingNetworkRequest() }.await())
+            }
+
+            val successResultsList = resultsList.mapNotNull { it.getOrNull() }
+
+            _result.value = successResultsList.average().toLong()
+            _running.value = false
+        }
+
     }
 
     private companion object {

app/src/main/kotlin/ru/otus/coroutineshomework/ui/timer/TimerFragment.kt

@@ -5,10 +5,12 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
-import kotlinx.coroutines.isActive
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.launch
 import ru.otus.coroutineshomework.databinding.FragmentTimerBinding
 import java.util.Locale
@@ -21,9 +23,7 @@ class TimerFragment : Fragment() {
     private var _binding: FragmentTimerBinding? = null
     private val binding get() = _binding!!
 
-    private var time: Duration by Delegates.observable(Duration.ZERO) { _, _, newValue ->
-        binding.time.text = newValue.toDisplayString()
-    }
+    private var timeFlow = MutableStateFlow(Duration.ZERO)
 
     private var started by Delegates.observable(false) { _, _, newValue ->
         setButtonsState(newValue)
@@ -34,6 +34,8 @@ class TimerFragment : Fragment() {
         }
     }
 
+    private var timerJob: Job? = null
+
     private fun setButtonsState(started: Boolean) {
         with(binding) {
             btnStart.isEnabled = !started
@@ -44,7 +46,7 @@ class TimerFragment : Fragment() {
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
-        savedInstanceState: Bundle?
+        savedInstanceState: Bundle?,
     ): View {
         _binding = FragmentTimerBinding.inflate(inflater, container, false)
         return binding.root
@@ -53,12 +55,16 @@ class TimerFragment : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         savedInstanceState?.let {
-            time = it.getLong(TIME).milliseconds
+            timeFlow.value = it.getLong(TIME).milliseconds
             started = it.getBoolean(STARTED)
         }
         setButtonsState(started)
         with(binding) {
-            time.text = this@TimerFragment.time.toDisplayString()
+            lifecycleScope.launch {
+                viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
+                    timeFlow.collect { value -> time.text = value.toDisplayString() }
+                }
+            }
             btnStart.setOnClickListener {
                 started = true
             }
@@ -70,16 +76,21 @@ class TimerFragment : Fragment() {
 
     override fun onSaveInstanceState(outState: Bundle) {
         super.onSaveInstanceState(outState)
-        outState.putLong(TIME, time.inWholeMilliseconds)
+        outState.putLong(TIME, timeFlow.value.inWholeMilliseconds)
         outState.putBoolean(STARTED, started)
     }
 
     private fun startTimer() {
-        // TODO: Start timer
+        timerJob = lifecycleScope.launch {
+            while (started) {
+                delay(2L)
+                timeFlow.emit(timeFlow.value + 2.milliseconds)
+            }
+        }
     }
 
     private fun stopTimer() {
-        // TODO: Stop timer
+        timerJob?.cancel()
     }
 
     override fun onDestroyView() {
@@ -99,4 +110,4 @@ class TimerFragment : Fragment() {
             this.inWholeMilliseconds.toInt()
         )
     }
-}
+}