Implement observing authentication statuses

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthModule.kt

@@ -7,8 +7,10 @@ import dagger.hilt.components.SingletonComponent
 import gq.kirmanak.mealie.data.auth.impl.AuthDataSourceImpl
 import gq.kirmanak.mealie.data.auth.impl.AuthRepoImpl
 import gq.kirmanak.mealie.data.auth.impl.AuthStorageImpl
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.serialization.ExperimentalSerializationApi
 
+@ExperimentalCoroutinesApi
 @ExperimentalSerializationApi
 @Module
 @InstallIn(SingletonComponent::class)

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthRepo.kt

@@ -1,11 +1,13 @@
 package gq.kirmanak.mealie.data.auth
 
-interface AuthRepo {
+import kotlinx.coroutines.flow.Flow
-    suspend fun isAuthenticated(): Boolean
 
+interface AuthRepo {
     suspend fun authenticate(username: String, password: String, baseUrl: String)
 
     suspend fun getBaseUrl(): String?
 
     suspend fun getToken(): String?
+
+    fun authenticationStatuses(): Flow<Boolean>
 }

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthStorage.kt

@@ -1,9 +1,13 @@
 package gq.kirmanak.mealie.data.auth
 
+import kotlinx.coroutines.flow.Flow
+
 interface AuthStorage {
     suspend fun storeAuthData(token: String, baseUrl: String)
 
     suspend fun getBaseUrl(): String?
 
     suspend fun getToken(): String?
+
+    fun tokenObservable(): Flow<String?>
 }

app/src/main/java/gq/kirmanak/mealie/data/auth/impl/AuthRepoImpl.kt

@@ -3,6 +3,8 @@ package gq.kirmanak.mealie.data.auth.impl
 import gq.kirmanak.mealie.data.auth.AuthDataSource
 import gq.kirmanak.mealie.data.auth.AuthRepo
 import gq.kirmanak.mealie.data.auth.AuthStorage
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import timber.log.Timber
 import javax.inject.Inject
 
@@ -10,13 +12,6 @@ class AuthRepoImpl @Inject constructor(
     private val dataSource: AuthDataSource,
     private val storage: AuthStorage
 ) : AuthRepo {
-    override suspend fun isAuthenticated(): Boolean {
-        Timber.v("isAuthenticated")
-        val authenticated = getToken() != null
-        Timber.d("isAuthenticated() response $authenticated")
-        return authenticated
-    }
-
     override suspend fun authenticate(
         username: String,
         password: String,
@@ -38,4 +33,9 @@ class AuthRepoImpl @Inject constructor(
         Timber.v("getToken() called")
         return storage.getToken()
     }
+
+    override fun authenticationStatuses(): Flow<Boolean> {
+        Timber.v("authenticationStatuses() called")
+        return storage.tokenObservable().map { it != null }
+    }
 }

app/src/main/java/gq/kirmanak/mealie/data/auth/impl/AuthStorageImpl.kt

@@ -6,6 +6,12 @@ import androidx.preference.PreferenceManager
 import dagger.hilt.android.qualifiers.ApplicationContext
 import gq.kirmanak.mealie.data.auth.AuthStorage
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.channels.onFailure
+import kotlinx.coroutines.channels.trySendBlocking
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
 import kotlinx.coroutines.withContext
 import timber.log.Timber
 import javax.inject.Inject
@@ -13,6 +19,7 @@ import javax.inject.Inject
 private const val TOKEN_KEY = "AUTH_TOKEN"
 private const val BASE_URL_KEY = "BASE_URL"
 
+@ExperimentalCoroutinesApi
 class AuthStorageImpl @Inject constructor(@ApplicationContext private val context: Context) :
     AuthStorage {
     private val sharedPreferences: SharedPreferences
@@ -40,6 +47,29 @@ class AuthStorageImpl @Inject constructor(@ApplicationContext private val contex
         return token
     }
 
+    override fun tokenObservable(): Flow<String?> {
+        Timber.v("tokenObservable() called")
+        return callbackFlow {
+            val listener = SharedPreferences.OnSharedPreferenceChangeListener { prefs, key ->
+                Timber.v("tokenObservable: listener called with key $key")
+                val token = when (key) {
+                    null -> null
+                    TOKEN_KEY -> prefs.getString(key, null)
+                    else -> return@OnSharedPreferenceChangeListener
+                }
+                Timber.d("tokenObservable: New token: $token")
+                trySendBlocking(token).onFailure { Timber.e(it, "Can't send new token") }
+            }
+            Timber.v("tokenObservable: registering listener")
+            send(getToken())
+            sharedPreferences.registerOnSharedPreferenceChangeListener(listener)
+            awaitClose {
+                Timber.v("tokenObservable: flow has been closed")
+                sharedPreferences.unregisterOnSharedPreferenceChangeListener(listener)
+            }
+        }
+    }
+
     private suspend fun getString(key: String): String? = withContext(Dispatchers.Default) {
         sharedPreferences.getString(key, null)
     }

app/src/main/java/gq/kirmanak/mealie/ui/auth/AuthenticationFragment.kt

@@ -12,6 +12,7 @@ import androidx.navigation.fragment.findNavController
 import com.google.android.material.textfield.TextInputLayout
 import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealie.databinding.FragmentAuthenticationBinding
+import kotlinx.coroutines.flow.collectLatest
 import timber.log.Timber
 
 @AndroidEntryPoint
@@ -24,7 +25,17 @@ class AuthenticationFragment : Fragment() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         Timber.v("onCreate() called with: savedInstanceState = $savedInstanceState")
-        checkIfAuthenticatedAlready()
+        listenToAuthenticationStatuses()
+    }
+
+    private fun listenToAuthenticationStatuses() {
+        Timber.d("listenToAuthenticationStatuses() called")
+        lifecycleScope.launchWhenCreated {
+            viewModel.authenticationStatuses().collectLatest {
+                Timber.d("listenToAuthenticationStatuses: new status = $it")
+                if (it) navigateToRecipes()
+            }
+        }
     }
 
     override fun onCreateView(
@@ -43,13 +54,6 @@ class AuthenticationFragment : Fragment() {
         binding.button.setOnClickListener { onLoginClicked() }
     }
 
-    private fun checkIfAuthenticatedAlready() {
-        Timber.v("checkIfAuthenticatedAlready() called")
-        lifecycleScope.launchWhenCreated {
-            if (viewModel.isAuthenticated()) navigateToRecipes()
-        }
-    }
-
     private fun navigateToRecipes() {
         findNavController().navigate(AuthenticationFragmentDirections.actionAuthenticationFragmentToRecipesFragment())
     }
@@ -73,8 +77,6 @@ class AuthenticationFragment : Fragment() {
         lifecycleScope.launchWhenResumed {
             runCatching {
                 viewModel.authenticate(email, pass, url)
-            }.onSuccess {
-                navigateToRecipes()
             }.onFailure {
                 Timber.e(it, "Can't authenticate")
             }

app/src/main/java/gq/kirmanak/mealie/ui/auth/AuthenticationViewModel.kt

@@ -3,6 +3,7 @@ package gq.kirmanak.mealie.ui.auth
 import androidx.lifecycle.ViewModel
 import dagger.hilt.android.lifecycle.HiltViewModel
 import gq.kirmanak.mealie.data.auth.AuthRepo
+import kotlinx.coroutines.flow.Flow
 import timber.log.Timber
 import javax.inject.Inject
 
@@ -14,15 +15,13 @@ class AuthenticationViewModel @Inject constructor(
         Timber.v("constructor called")
     }
 
-    suspend fun isAuthenticated(): Boolean {
-        Timber.v("isAuthenticated() called")
-        val result = authRepo.isAuthenticated()
-        Timber.d("isAuthenticated() returned: $result")
-        return result
-    }
-
     suspend fun authenticate(username: String, password: String, baseUrl: String) {
         Timber.v("authenticate() called with: username = $username, password = $password, baseUrl = $baseUrl")
         authRepo.authenticate(username, password, baseUrl)
     }
+
+    fun authenticationStatuses(): Flow<Boolean> {
+        Timber.v("authenticationStatuses() called")
+        return authRepo.authenticationStatuses()
+    }
 }

app/src/test/java/gq/kirmanak/mealie/data/auth/impl/AuthRepoImplTest.kt

@@ -7,6 +7,7 @@ import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.TEST_TOKEN
 import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.TEST_USERNAME
 import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.enqueueSuccessfulAuthResponse
 import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.enqueueUnsuccessfulAuthResponse
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 import org.junit.Test
 import retrofit2.HttpException
@@ -18,15 +19,15 @@ class AuthRepoImplTest : MockServerTest() {
     lateinit var subject: AuthRepoImpl
 
     @Test
-    fun `when not authenticated then isAuthenticated false`() = runBlocking {
+    fun `when not authenticated then first auth status is false`() = runBlocking {
-        assertThat(subject.isAuthenticated()).isFalse()
+        assertThat(subject.authenticationStatuses().first()).isFalse()
     }
 
     @Test
-    fun `when authenticated then isAuthenticated true`() = runBlocking {
+    fun `when authenticated then first auth status is true`() = runBlocking {
         mockServer.enqueueSuccessfulAuthResponse()
         subject.authenticate(TEST_USERNAME, TEST_PASSWORD, serverUrl)
-        assertThat(subject.isAuthenticated()).isTrue()
+        assertThat(subject.authenticationStatuses().first()).isTrue()
     }
 
     @Test(expected = HttpException::class)

app/src/test/java/gq/kirmanak/mealie/data/auth/impl/AuthStorageImplTest.kt

@@ -4,10 +4,13 @@ import com.google.common.truth.Truth.assertThat
 import dagger.hilt.android.testing.HiltAndroidTest
 import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.TEST_TOKEN
 import gq.kirmanak.mealie.data.auth.impl.AuthImplTestData.TEST_URL
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 import org.junit.Test
 import javax.inject.Inject
 
+@ExperimentalCoroutinesApi
 @HiltAndroidTest
 class AuthStorageImplTest : HiltRobolectricTest() {
     @Inject
@@ -39,4 +42,15 @@ class AuthStorageImplTest : HiltRobolectricTest() {
     fun `when reading url without storing data then returns null`() = runBlocking {
         assertThat(subject.getBaseUrl()).isNull()
     }
+
+    @Test
+    fun `when didn't store auth data then first token is null`() = runBlocking {
+        assertThat(subject.tokenObservable().first()).isNull()
+    }
+
+    @Test
+    fun `when stored auth data then first token is correct`() = runBlocking {
+        subject.storeAuthData(TEST_TOKEN, TEST_URL)
+        assertThat(subject.tokenObservable().first()).isEqualTo(TEST_TOKEN)
+    }
 }