MatrixClientHolders: some more cleanup

appnav/src/main/kotlin/io/element/android/appnav/di/MatrixClientsHolder.kt

@@ -22,9 +22,9 @@ import com.squareup.anvil.annotations.ContributesBinding
 import io.element.android.libraries.di.AppScope
 import io.element.android.libraries.di.SingleIn
 import io.element.android.libraries.matrix.api.MatrixClient
+import io.element.android.libraries.matrix.api.MatrixClientProvider
 import io.element.android.libraries.matrix.api.auth.MatrixAuthenticationService
 import io.element.android.libraries.matrix.api.core.SessionId
-import io.element.android.libraries.matrix.api.MatrixClientProvider
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
@@ -36,7 +36,7 @@ private const val SAVE_INSTANCE_KEY = "io.element.android.x.di.MatrixClientsHold
 
 @SingleIn(AppScope::class)
 @ContributesBinding(AppScope::class)
-class MatrixClientsHolder @Inject constructor(private val authenticationService: MatrixAuthenticationService): MatrixClientProvider {
+class MatrixClientsHolder @Inject constructor(private val authenticationService: MatrixAuthenticationService) : MatrixClientProvider {
 
     private val sessionIdsToMatrixClient = ConcurrentHashMap<SessionId, MatrixClient>()
     private val restoreMutex = Mutex()
@@ -49,15 +49,13 @@ class MatrixClientsHolder @Inject constructor(private val authenticationService:
         sessionIdsToMatrixClient.remove(sessionId)
     }
 
-    fun isEmpty(): Boolean = sessionIdsToMatrixClient.isEmpty()
-
     fun getOrNull(sessionId: SessionId): MatrixClient? {
         return sessionIdsToMatrixClient[sessionId]
     }
 
     override suspend fun getOrRestore(sessionId: SessionId): Result<MatrixClient> {
         return restoreMutex.withLock {
-            when (val matrixClient = sessionIdsToMatrixClient[sessionId]) {
+            when (val matrixClient = getOrNull(sessionId)) {
                 null -> restore(sessionId)
                 else -> Result.success(matrixClient)
             }
@@ -97,5 +95,4 @@ class MatrixClientsHolder @Inject constructor(private val authenticationService:
                 Timber.e("Fail to restore session")
             }
     }
-
 }

appnav/src/main/kotlin/io/element/android/appnav/root/RootNavState.kt

@@ -16,7 +16,17 @@
 
 package io.element.android.appnav.root
 
+/**
+ * [RootNavState] produced by [RootNavStateFlowFactory].
+ */
 data class RootNavState(
+    /**
+     * This value is incremented when a clear cache is done.
+     * Can be useful to track to force ui state to re-render
+     */
     val cacheIndex: Int,
+    /**
+     * true if we are currently loggedIn.
+     */
     val isLoggedIn: Boolean
 )

appnav/src/main/kotlin/io/element/android/appnav/root/RootNavStateFlowFactory.kt

@@ -31,6 +31,10 @@ import javax.inject.Inject
 
 private const val SAVE_INSTANCE_KEY = "io.element.android.x.RootNavStateFlowFactory.SAVE_INSTANCE_KEY"
 
+/**
+ * This class is responsible for creating a flow of [RootNavState].
+ * It gathers data from multiple datasource and creates a unique one.
+ */
 class RootNavStateFlowFactory @Inject constructor(
     private val authenticationService: MatrixAuthenticationService,
     private val cacheService: CacheService,
@@ -41,11 +45,24 @@ class RootNavStateFlowFactory @Inject constructor(
     private var currentCacheIndex = 0
 
     fun create(savedStateMap: SavedStateMap?): Flow<RootNavState> {
-        /**
+        return combine(
-         * A flow of integer, where each time a clear cache is done, we have a new incremented value.
+            cacheIndexFlow(savedStateMap),
-         */
+            isUserLoggedInFlow(),
+        ) { cacheIndex, isLoggedIn ->
+            RootNavState(cacheIndex = cacheIndex, isLoggedIn = isLoggedIn)
+        }
+    }
+
+    fun saveIntoSavedState(stateMap: MutableSavedStateMap) {
+        stateMap[SAVE_INSTANCE_KEY] = currentCacheIndex
+    }
+
+    /**
+     * @return a flow of integer, where each time a clear cache is done, we have a new incremented value.
+     */
+    private fun cacheIndexFlow(savedStateMap: SavedStateMap?): Flow<Int> {
         val initialCacheIndex = savedStateMap.getCacheIndexOrDefault()
-        val cacheIndexFlow = cacheService.clearedCacheEventFlow
+        return cacheService.clearedCacheEventFlow
             .onEach { sessionId ->
                 matrixClientsHolder.remove(sessionId)
             }
@@ -53,17 +70,6 @@ class RootNavStateFlowFactory @Inject constructor(
             .onEach { cacheIndex ->
                 currentCacheIndex = cacheIndex
             }
-
-        return combine(
-            cacheIndexFlow,
-            isUserLoggedInFlow(),
-        ) { navId, isLoggedIn ->
-            RootNavState(navId, isLoggedIn)
-        }
-    }
-
-    fun saveIntoSavedState(stateMap: MutableSavedStateMap) {
-        stateMap[SAVE_INSTANCE_KEY] = currentCacheIndex
     }
 
     private fun isUserLoggedInFlow(): Flow<Boolean> {
@@ -76,6 +82,9 @@ class RootNavStateFlowFactory @Inject constructor(
             .distinctUntilChanged()
     }
 
+    /**
+     * @return a flow of integer that increments the value by one each time a new element is emitted upstream.
+     */
     private fun Flow<Any>.toIndexFlow(initialValue: Int): Flow<Int> = flow {
         var index = initialValue
         emit(initialValue)