Room admins can change user roles (#2423)

Allow Admins to modify room member roles:

- Add a 'roles and permissions' option for each room.
- Allow promoting users to admins, adding or removing moderators, and demote yourself if you're and admin.

---------

Co-authored-by: ElementBot <benoitm+elementbot@element.io>

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/MatrixRoom.kt

@@ -29,12 +29,19 @@ import io.element.android.libraries.matrix.api.media.MediaUploadHandler
 import io.element.android.libraries.matrix.api.media.VideoInfo
 import io.element.android.libraries.matrix.api.poll.PollKind
 import io.element.android.libraries.matrix.api.room.location.AssetType
+import io.element.android.libraries.matrix.api.room.powerlevels.UserRoleChange
 import io.element.android.libraries.matrix.api.timeline.MatrixTimeline
 import io.element.android.libraries.matrix.api.timeline.ReceiptType
 import io.element.android.libraries.matrix.api.widget.MatrixWidgetDriver
 import io.element.android.libraries.matrix.api.widget.MatrixWidgetSettings
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.toPersistentList
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.map
 import java.io.Closeable
 import java.io.File
 
@@ -56,7 +63,7 @@ interface MatrixRoom : Closeable {
     /** Whether the room is a direct message. */
     val isDm: Boolean get() = isDirect && isOneToOne
 
-    val roomInfoFlow: Flow<MatrixRoomInfo>
+    val roomInfoFlow: SharedFlow<MatrixRoomInfo>
     val roomTypingMembersFlow: Flow<List<UserId>>
 
     /**
@@ -91,6 +98,10 @@ interface MatrixRoom : Closeable {
 
     suspend fun unsubscribeFromSync()
 
+    suspend fun userRole(userId: UserId): Result<RoomMember.Role>
+
+    suspend fun updateUsersRoles(changes: List<UserRoleChange>): Result<Unit>
+
     suspend fun userDisplayName(userId: UserId): Result<String?>
 
     suspend fun userAvatarUrl(userId: UserId): Result<String?>
@@ -144,6 +155,18 @@ interface MatrixRoom : Closeable {
     suspend fun canUserJoinCall(userId: UserId): Result<Boolean> =
         canUserSendState(userId, StateEventType.CALL_MEMBER)
 
+    fun usersWithRole(role: RoomMember.Role): Flow<ImmutableList<RoomMember>> {
+        return roomInfoFlow
+            .map { it.userPowerLevels.filter { (_, powerLevel) -> RoomMember.Role.forPowerLevel(powerLevel) == role } }
+            .distinctUntilChanged()
+            .combine(membersStateFlow) { powerLevels, membersState ->
+                membersState.roomMembers()
+                    .orEmpty()
+                    .filter { powerLevels.containsKey(it.userId) }
+                    .toPersistentList()
+            }
+    }
+
     suspend fun updateAvatar(mimeType: String, data: ByteArray): Result<Unit>
 
     suspend fun removeAvatar(): Result<Unit>

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/MatrixRoomInfo.kt

@@ -17,8 +17,10 @@
 package io.element.android.libraries.matrix.api.room
 
 import androidx.compose.runtime.Immutable
+import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.timeline.item.event.EventTimelineItem
 import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.ImmutableMap
 
 @Immutable
 data class MatrixRoomInfo(
@@ -39,6 +41,7 @@ data class MatrixRoomInfo(
     val activeMembersCount: Long,
     val invitedMembersCount: Long,
     val joinedMembersCount: Long,
+    val userPowerLevels: ImmutableMap<UserId, Long>,
     val highlightCount: Long,
     val notificationCount: Long,
     val userDefinedNotificationMode: RoomNotificationMode?,

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/RoomMember.kt

@@ -32,10 +32,20 @@ data class RoomMember(
     /**
      * Role of the RoomMember, based on its [powerLevel].
      */
-    enum class Role {
-        ADMIN,
-        MODERATOR,
-        USER
+    enum class Role(val powerLevel: Long) {
+        ADMIN(100L),
+        MODERATOR(50L),
+        USER(0L);
+
+        companion object {
+            fun forPowerLevel(powerLevel: Long): Role {
+                return when {
+                    powerLevel >= ADMIN.powerLevel -> ADMIN
+                    powerLevel >= MODERATOR.powerLevel -> MODERATOR
+                    else -> USER
+                }
+            }
+        }
     }
 
     /**

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/powerlevels/UserRoleChange.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2024 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.libraries.matrix.api.room.powerlevels
+
+import io.element.android.libraries.matrix.api.core.UserId
+import io.element.android.libraries.matrix.api.room.RoomMember
+
+data class UserRoleChange(
+    val userId: UserId,
+    val role: RoomMember.Role,
+) {
+    val powerLevel: Long = role.powerLevel
+}