Introduce AppNavigationStateService.

services/appnavstate/api/build.gradle.kts

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+/*
+ * Copyright (c) 2022 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// TODO: Remove once https://youtrack.jetbrains.com/issue/KTIJ-19369 is fixed
+@Suppress("DSL_SCOPE_VIOLATION")
+plugins {
+    id("io.element.android-library")
+}
+
+android {
+    namespace = "io.element.android.services.appnavstate.api"
+}
+
+dependencies {
+    implementation(libs.coroutines.core)
+    implementation(projects.libraries.matrix.api)
+}

services/appnavstate/api/src/main/kotlin/io/element/android/services/appnavstate/api/AppNavigationState.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.services.appnavstate.api
+
+import io.element.android.libraries.matrix.api.core.RoomId
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.api.core.SpaceId
+import io.element.android.libraries.matrix.api.core.ThreadId
+
+sealed interface AppNavigationState {
+    object Root : AppNavigationState
+
+    data class Session(
+        val sessionId: SessionId,
+    ) : AppNavigationState
+
+    data class Space(
+        // Can be fake value, if no space is selected
+        val spaceId: SpaceId,
+        val parentSession: Session,
+    ) : AppNavigationState
+
+    data class Room(
+        val roomId: RoomId,
+        val parentSpace: Space,
+    ) : AppNavigationState
+
+    data class Thread(
+        val threadId: ThreadId,
+        val parentRoom: Room,
+    ) : AppNavigationState
+}

services/appnavstate/api/src/main/kotlin/io/element/android/services/appnavstate/api/AppNavigationStateService.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.services.appnavstate.api
+
+import io.element.android.libraries.matrix.api.core.RoomId
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.api.core.SpaceId
+import io.element.android.libraries.matrix.api.core.ThreadId
+import kotlinx.coroutines.flow.StateFlow
+
+interface AppNavigationStateService {
+    val appNavigationStateFlow: StateFlow<AppNavigationState>
+
+    fun onNavigateToSession(sessionId: SessionId)
+    fun onLeavingSession()
+
+    fun onNavigateToSpace(spaceId: SpaceId)
+    fun onLeavingSpace()
+
+    fun onNavigateToRoom(roomId: RoomId)
+    fun onLeavingRoom()
+
+    fun onNavigateToThread(threadId: ThreadId)
+    fun onLeavingThread()
+}

services/appnavstate/impl/build.gradle.kts

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+/*
+ * Copyright (c) 2022 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// TODO: Remove once https://youtrack.jetbrains.com/issue/KTIJ-19369 is fixed
+@Suppress("DSL_SCOPE_VIOLATION")
+plugins {
+    id("io.element.android-library")
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.anvil)
+}
+
+anvil {
+    generateDaggerFactories.set(true)
+}
+
+android {
+    namespace = "io.element.android.services.appnavstate.impl"
+}
+
+dependencies {
+    anvil(projects.anvilcodegen)
+    implementation(libs.dagger)
+    implementation(projects.libraries.core)
+    implementation(projects.libraries.di)
+    implementation(projects.libraries.matrix.api)
+    implementation(projects.anvilannotations)
+
+    implementation(libs.coroutines.core)
+    implementation(libs.androidx.corektx)
+
+    api(projects.services.appnavstate.api)
+
+    testImplementation(libs.test.junit)
+    testImplementation(libs.coroutines.test)
+    testImplementation(libs.test.truth)
+    testImplementation(projects.libraries.matrix.test)
+}

services/appnavstate/impl/src/main/kotlin/io/element/android/services/appnavstate/impl/DefaultAppNavigationStateService.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.services.appnavstate.impl
+
+import com.squareup.anvil.annotations.ContributesBinding
+import io.element.android.libraries.core.log.logger.LoggerTag
+import io.element.android.libraries.di.AppScope
+import io.element.android.libraries.di.SingleIn
+import io.element.android.libraries.matrix.api.core.RoomId
+import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.api.core.SpaceId
+import io.element.android.libraries.matrix.api.core.ThreadId
+import io.element.android.services.appnavstate.api.AppNavigationState
+import io.element.android.services.appnavstate.api.AppNavigationStateService
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import timber.log.Timber
+import javax.inject.Inject
+
+private val loggerTag = LoggerTag("Navigation")
+
+/**
+ * TODO This will maybe not support properly navigation using permalink.
+ */
+@ContributesBinding(AppScope::class)
+@SingleIn(AppScope::class)
+class DefaultAppNavigationStateService @Inject constructor() : AppNavigationStateService {
+
+    private val currentAppNavigationState = MutableStateFlow<AppNavigationState>(AppNavigationState.Root)
+
+    override val appNavigationStateFlow: StateFlow<AppNavigationState> = currentAppNavigationState
+
+    override fun onNavigateToSession(sessionId: SessionId) {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Navigating to session $sessionId. Current state: $currentValue")
+        val newValue: AppNavigationState.Session = when (currentValue) {
+            is AppNavigationState.Session,
+            is AppNavigationState.Space,
+            is AppNavigationState.Room,
+            is AppNavigationState.Thread,
+            AppNavigationState.Root -> AppNavigationState.Session(sessionId)
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onNavigateToSpace(spaceId: SpaceId) {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Navigating to space $spaceId. Current state: $currentValue")
+        val newValue: AppNavigationState.Space = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> AppNavigationState.Space(spaceId, currentValue)
+            is AppNavigationState.Space -> AppNavigationState.Space(spaceId, currentValue.parentSession)
+            is AppNavigationState.Room -> AppNavigationState.Space(spaceId, currentValue.parentSpace.parentSession)
+            is AppNavigationState.Thread -> AppNavigationState.Space(spaceId, currentValue.parentRoom.parentSpace.parentSession)
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onNavigateToRoom(roomId: RoomId) {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Navigating to room $roomId. Current state: $currentValue")
+        val newValue: AppNavigationState.Room = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> error("onNavigateToSpace() must be called first")
+            is AppNavigationState.Space -> AppNavigationState.Room(roomId, currentValue)
+            is AppNavigationState.Room -> AppNavigationState.Room(roomId, currentValue.parentSpace)
+            is AppNavigationState.Thread -> AppNavigationState.Room(roomId, currentValue.parentRoom.parentSpace)
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onNavigateToThread(threadId: ThreadId) {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Navigating to thread $threadId. Current state: $currentValue")
+        val newValue: AppNavigationState.Thread = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> error("onNavigateToSpace() must be called first")
+            is AppNavigationState.Space -> error("onNavigateToRoom() must be called first")
+            is AppNavigationState.Room -> AppNavigationState.Thread(threadId, currentValue)
+            is AppNavigationState.Thread -> AppNavigationState.Thread(threadId, currentValue.parentRoom)
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onLeavingThread() {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Leaving thread. Current state: $currentValue")
+        val newValue: AppNavigationState.Room = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> error("onNavigateToSpace() must be called first")
+            is AppNavigationState.Space -> error("onNavigateToRoom() must be called first")
+            is AppNavigationState.Room -> error("onNavigateToThread() must be called first")
+            is AppNavigationState.Thread -> currentValue.parentRoom
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onLeavingRoom() {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Leaving room. Current state: $currentValue")
+        val newValue: AppNavigationState.Space = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> error("onNavigateToSpace() must be called first")
+            is AppNavigationState.Space -> error("onNavigateToRoom() must be called first")
+            is AppNavigationState.Room -> currentValue.parentSpace
+            is AppNavigationState.Thread -> currentValue.parentRoom.parentSpace
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onLeavingSpace() {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Leaving space. Current state: $currentValue")
+        val newValue: AppNavigationState.Session = when (currentValue) {
+            AppNavigationState.Root -> error("onNavigateToSession() must be called first")
+            is AppNavigationState.Session -> error("onNavigateToSpace() must be called first")
+            is AppNavigationState.Space -> currentValue.parentSession
+            is AppNavigationState.Room -> currentValue.parentSpace.parentSession
+            is AppNavigationState.Thread -> currentValue.parentRoom.parentSpace.parentSession
+        }
+        currentAppNavigationState.value = newValue
+    }
+
+    override fun onLeavingSession() {
+        val currentValue = currentAppNavigationState.value
+        Timber.tag(loggerTag.value).d("Leaving session. Current state: $currentValue")
+        currentAppNavigationState.value = AppNavigationState.Root
+    }
+}

services/appnavstate/impl/src/test/kotlin/io/element/android/services/appnavstate/impl/DefaultAppNavigationStateServiceTest.kt

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+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@file:OptIn(ExperimentalCoroutinesApi::class)
+
+package io.element.android.services.appnavstate.impl
+
+import com.google.common.truth.Truth.assertThat
+import io.element.android.libraries.matrix.test.A_ROOM_ID
+import io.element.android.libraries.matrix.test.A_SESSION_ID
+import io.element.android.libraries.matrix.test.A_SPACE_ID
+import io.element.android.libraries.matrix.test.A_THREAD_ID
+import io.element.android.services.appnavstate.api.AppNavigationState
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertThrows
+import org.junit.Test
+
+class DefaultAppNavigationStateServiceTest {
+
+    @Test
+    fun testNavigation() = runTest {
+        val service = DefaultAppNavigationStateService()
+        service.onNavigateToSession(A_SESSION_ID)
+        service.onNavigateToSpace(A_SPACE_ID)
+        service.onNavigateToRoom(A_ROOM_ID)
+        service.onNavigateToThread(A_THREAD_ID)
+        assertThat(service.appNavigationStateFlow.first()).isEqualTo(
+            AppNavigationState.Thread(
+                A_THREAD_ID,
+                AppNavigationState.Room(
+                    A_ROOM_ID,
+                    AppNavigationState.Space(
+                        A_SPACE_ID,
+                        AppNavigationState.Session(
+                            A_SESSION_ID
+                        )
+                    )
+                )
+            )
+        )
+    }
+
+    @Test
+    fun testFailure() = runTest {
+        val service = DefaultAppNavigationStateService()
+        assertThrows(IllegalStateException::class.java) { service.onNavigateToSpace(A_SPACE_ID) }
+    }
+}