Move current user listening logic out of UserModule and into a new CurrentUserProvider

Signed-off-by: Álvaro Brey <alvaro.brey@nextcloud.com>

app/src/main/java/com/nextcloud/talk/ui/theme/ServerThemeProviderImpl.kt

@@ -23,7 +23,6 @@
 
 package com.nextcloud.talk.ui.theme
 
-import android.annotation.SuppressLint
 import com.nextcloud.talk.data.user.model.User
 import com.nextcloud.talk.models.json.capabilities.Capabilities
 import com.nextcloud.talk.utils.database.user.CurrentUserProviderNew
@@ -37,25 +36,6 @@ internal class ServerThemeProviderImpl @Inject constructor(
 
     private val themeCache: ConcurrentHashMap<String, ServerTheme> = ConcurrentHashMap()
 
-    // TODO move this logic to currentUserProvider or something
-    private var _currentUser: User? = null
-    private val currentUser: User?
-        @SuppressLint("CheckResult")
-        get() {
-            return when (_currentUser) {
-                null -> {
-                    // immediately get a result synchronously
-                    _currentUser = userProvider.currentUser.blockingGet()
-                    // start observable for auto-updates
-                    userProvider.currentUserObservable.subscribe { _currentUser = it }
-                    _currentUser
-                }
-                else -> {
-                    _currentUser
-                }
-            }
-        }
-
     override fun getServerThemeForUser(user: User?): ServerTheme {
         val url: String = if (user?.baseUrl != null) {
             user.baseUrl!!
@@ -71,7 +51,7 @@ internal class ServerThemeProviderImpl @Inject constructor(
     }
 
     override fun getServerThemeForCurrentUser(): ServerTheme {
-        return getServerThemeForUser(currentUser)
+        return getServerThemeForUser(userProvider.currentUser.blockingGet())
     }
 
     override fun getServerThemeForCapabilities(capabilities: Capabilities?): ServerTheme {

app/src/main/java/com/nextcloud/talk/users/UserManager.kt

@@ -28,25 +28,24 @@ import com.nextcloud.talk.data.user.model.User
 import com.nextcloud.talk.models.ExternalSignalingServer
 import com.nextcloud.talk.models.json.capabilities.Capabilities
 import com.nextcloud.talk.models.json.push.PushConfigurationState
-import com.nextcloud.talk.utils.database.user.CurrentUserProviderNew
 import io.reactivex.Maybe
 import io.reactivex.Observable
 import io.reactivex.Single
 
 @Suppress("TooManyFunctions")
-class UserManager internal constructor(private val userRepository: UsersRepository) : CurrentUserProviderNew {
+class UserManager internal constructor(private val userRepository: UsersRepository) {
     val users: Single<List<User>>
         get() = userRepository.getUsers()
 
     val usersScheduledForDeletion: Single<List<User>>
         get() = userRepository.getUsersScheduledForDeletion()
 
-    override val currentUser: Maybe<User>
+    val currentUser: Maybe<User>
         get() {
             return userRepository.getActiveUser()
         }
 
-    override val currentUserObservable: Observable<User>
+    val currentUserObservable: Observable<User>
         get() {
             return userRepository.getActiveUserObservable()
         }

app/src/main/java/com/nextcloud/talk/utils/database/user/CurrentUserProviderImpl.kt

@@ -0,0 +1,49 @@
+/*
+ * Nextcloud Talk application
+ *
+ * @author Álvaro Brey
+ * Copyright (C) 2022 Álvaro Brey
+ * Copyright (C) 2022 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.nextcloud.talk.utils.database.user
+
+import com.nextcloud.talk.data.user.model.User
+import com.nextcloud.talk.users.UserManager
+import io.reactivex.Maybe
+import io.reactivex.disposables.Disposable
+import javax.inject.Inject
+
+/**
+ * Listens to changes in the database and provides the current user without needing to query the database everytime.
+ */
+class CurrentUserProviderImpl @Inject constructor(private val userManager: UserManager) : CurrentUserProviderNew {
+    private var _currentUser: User? = null
+    private var currentUserObserver: Disposable? = null
+
+    override val currentUser: Maybe<User>
+        get() {
+            if (_currentUser == null) {
+                // immediately get a result synchronously
+                _currentUser = userManager.currentUser.blockingGet()
+                if (currentUserObserver == null) {
+                    // start observable for auto-updates
+                    currentUserObserver = userManager.currentUserObservable.subscribe { _currentUser = it }
+                }
+            }
+            return _currentUser?.let { Maybe.just(it) } ?: Maybe.empty()
+        }
+}

app/src/main/java/com/nextcloud/talk/utils/database/user/CurrentUserProviderNew.kt

@@ -22,9 +22,7 @@ package com.nextcloud.talk.utils.database.user
 
 import com.nextcloud.talk.data.user.model.User
 import io.reactivex.Maybe
-import io.reactivex.Observable
 
 interface CurrentUserProviderNew {
     val currentUser: Maybe<User>
-    val currentUserObservable: Observable<User>
 }

app/src/main/java/com/nextcloud/talk/utils/database/user/UserModule.kt

@@ -30,7 +30,7 @@ import dagger.Provides
 abstract class UserModule {
 
     @Binds
-    abstract fun bindCurrentUserProviderNew(userManager: UserManager): CurrentUserProviderNew
+    abstract fun bindCurrentUserProviderNew(currentUserProviderImpl: CurrentUserProviderImpl): CurrentUserProviderNew
 
     companion object {
         @Provides