change(room permissions): user can edit only roles <= to his own role

features/rolesandpermissions/impl/src/main/kotlin/io/element/android/features/rolesandpermissions/impl/permissions/ChangeRoomPermissionsPresenter.kt

@@ -10,6 +10,7 @@ package io.element.android.features.rolesandpermissions.impl.permissions
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
@@ -20,9 +21,11 @@ import dev.zacsweers.metro.Inject
 import io.element.android.features.rolesandpermissions.impl.analytics.trackPermissionChangeAnalytics
 import io.element.android.libraries.architecture.AsyncAction
 import io.element.android.libraries.architecture.Presenter
+import io.element.android.libraries.core.coroutine.mapState
 import io.element.android.libraries.matrix.api.room.JoinedRoom
 import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.room.powerlevels.RoomPowerLevelsValues
+import io.element.android.libraries.matrix.ui.model.powerLevelOf
 import io.element.android.services.analytics.api.AnalyticsService
 import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.toImmutableMap
@@ -89,6 +92,10 @@ class ChangeRoomPermissionsPresenter(
             derivedStateOf { initialPermissions != currentPermissions }
         }
 
+        val ownPowerLevel by remember {
+            room.roomInfoFlow.mapState { it.powerLevelOf(room.sessionId) }
+        }.collectAsState()
+
         fun handleEvent(event: ChangeRoomPermissionsEvent) {
             when (event) {
                 is ChangeRoomPermissionsEvent.ChangeMinimumRoleForAction -> {
@@ -123,6 +130,7 @@ class ChangeRoomPermissionsPresenter(
             }
         }
         return ChangeRoomPermissionsState(
+            ownPowerLevel = ownPowerLevel,
             currentPermissions = currentPermissions,
             itemsBySection = itemsBySection,
             hasChanges = hasChanges,

features/rolesandpermissions/impl/src/main/kotlin/io/element/android/features/rolesandpermissions/impl/permissions/ChangeRoomPermissionsState.kt

@@ -18,34 +18,55 @@ import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.room.powerlevels.RoomPowerLevelsValues
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.ImmutableMap
+import kotlinx.collections.immutable.persistentListOf
 
 data class ChangeRoomPermissionsState(
+    private val ownPowerLevel: Long,
     val currentPermissions: RoomPowerLevelsValues?,
     val itemsBySection: ImmutableMap<RoomPermissionsSection, ImmutableList<RoomPermissionType>>,
     val hasChanges: Boolean,
     val saveAction: AsyncAction<Boolean>,
     val eventSink: (ChangeRoomPermissionsEvent) -> Unit,
 ) {
+    private val ownRole = RoomMember.Role.forPowerLevel(ownPowerLevel)
+
+    // Roles that the user can select based on their own role
+    val selectableRoles: ImmutableList<SelectableRole> = when (ownRole) {
+        is RoomMember.Role.Owner,
+        RoomMember.Role.Admin -> persistentListOf(SelectableRole.Admin, SelectableRole.Moderator, SelectableRole.Everyone)
+        RoomMember.Role.Moderator -> persistentListOf(SelectableRole.Moderator, SelectableRole.Everyone)
+        RoomMember.Role.User -> persistentListOf(SelectableRole.Everyone)
+    }
+
     fun selectedRoleForType(type: RoomPermissionType): SelectableRole? {
-        if (currentPermissions == null) return null
-        val role = when (type) {
-            RoomPermissionType.BAN -> RoomMember.Role.forPowerLevel(currentPermissions.ban)
-            RoomPermissionType.INVITE -> RoomMember.Role.forPowerLevel(currentPermissions.invite)
-            RoomPermissionType.KICK -> RoomMember.Role.forPowerLevel(currentPermissions.kick)
-            RoomPermissionType.SEND_EVENTS -> RoomMember.Role.forPowerLevel(currentPermissions.eventsDefault)
-            RoomPermissionType.REDACT_EVENTS -> RoomMember.Role.forPowerLevel(currentPermissions.redactEvents)
-            RoomPermissionType.ROOM_NAME -> RoomMember.Role.forPowerLevel(currentPermissions.roomName)
-            RoomPermissionType.ROOM_AVATAR -> RoomMember.Role.forPowerLevel(currentPermissions.roomAvatar)
-            RoomPermissionType.ROOM_TOPIC -> RoomMember.Role.forPowerLevel(currentPermissions.roomTopic)
-            RoomPermissionType.SPACE_MANAGE_ROOMS -> RoomMember.Role.forPowerLevel(currentPermissions.spaceChild)
-        }
-        return when (role) {
+        val powerLevel = currentPowerLevelForType(type = type) ?: return null
+        return when (RoomMember.Role.forPowerLevel(powerLevel)) {
             is RoomMember.Role.Owner,
             RoomMember.Role.Admin -> SelectableRole.Admin
             RoomMember.Role.Moderator -> SelectableRole.Moderator
             RoomMember.Role.User -> SelectableRole.Everyone
         }
     }
+
+    fun canChangePermission(type: RoomPermissionType): Boolean {
+        val currentPowerLevel = currentPowerLevelForType(type) ?: return false
+        return ownPowerLevel >= currentPowerLevel
+    }
+
+    private fun currentPowerLevelForType(type: RoomPermissionType): Long? {
+        if (currentPermissions == null) return null
+        return when (type) {
+            RoomPermissionType.BAN -> currentPermissions.ban
+            RoomPermissionType.INVITE -> currentPermissions.invite
+            RoomPermissionType.KICK -> currentPermissions.kick
+            RoomPermissionType.SEND_EVENTS -> currentPermissions.eventsDefault
+            RoomPermissionType.REDACT_EVENTS -> currentPermissions.redactEvents
+            RoomPermissionType.ROOM_NAME -> currentPermissions.roomName
+            RoomPermissionType.ROOM_AVATAR -> currentPermissions.roomAvatar
+            RoomPermissionType.ROOM_TOPIC -> currentPermissions.roomTopic
+            RoomPermissionType.SPACE_MANAGE_ROOMS -> currentPermissions.spaceChild
+        }
+    }
 }
 
 enum class RoomPermissionsSection {

features/rolesandpermissions/impl/src/main/kotlin/io/element/android/features/rolesandpermissions/impl/permissions/ChangeRoomPermissionsStateProvider.kt

@@ -19,6 +19,7 @@ class ChangeRoomPermissionsStateProvider : PreviewParameterProvider<ChangeRoomPe
     override val values: Sequence<ChangeRoomPermissionsState>
         get() = sequenceOf(
             aChangeRoomPermissionsState(),
+            aChangeRoomPermissionsState(ownPowerLevel = RoomMember.Role.Moderator.powerLevel),
             aChangeRoomPermissionsState(hasChanges = true),
             aChangeRoomPermissionsState(hasChanges = true, saveAction = AsyncAction.Loading),
             aChangeRoomPermissionsState(
@@ -31,12 +32,14 @@ class ChangeRoomPermissionsStateProvider : PreviewParameterProvider<ChangeRoomPe
 }
 
 internal fun aChangeRoomPermissionsState(
+    ownPowerLevel: Long = RoomMember.Role.Admin.powerLevel,
     currentPermissions: RoomPowerLevelsValues = previewPermissions(),
     itemsBySection: Map<RoomPermissionsSection, ImmutableList<RoomPermissionType>> = ChangeRoomPermissionsPresenter.buildItems(false),
     hasChanges: Boolean = false,
     saveAction: AsyncAction<Boolean> = AsyncAction.Uninitialized,
     eventSink: (ChangeRoomPermissionsEvent) -> Unit = {},
 ) = ChangeRoomPermissionsState(
+    ownPowerLevel = ownPowerLevel,
     currentPermissions = currentPermissions,
     itemsBySection = itemsBySection.toImmutableMap(),
     hasChanges = hasChanges,

features/rolesandpermissions/impl/src/main/kotlin/io/element/android/features/rolesandpermissions/impl/permissions/ChangeRoomPermissionsView.kt

@@ -74,7 +74,8 @@ fun ChangeRoomPermissionsView(
                         PreferenceDropdown(
                             title = titleForType(permissionType),
                             selectedOption = state.selectedRoleForType(permissionType),
-                            options = SelectableRole.entries.toImmutableList(),
+                            options = state.selectableRoles,
+                            enabled = state.canChangePermission(permissionType),
                             onSelectOption = { role ->
                                 state.eventSink(
                                     ChangeRoomPermissionsEvent.ChangeMinimumRoleForAction(

features/rolesandpermissions/impl/src/test/kotlin/io/element/android/features/rolesandpermissions/impl/permissions/ChangeRoomPermissionsPresenterTest.kt

@@ -16,13 +16,18 @@ import app.cash.turbine.test
 import com.google.common.truth.Truth.assertThat
 import im.vector.app.features.analytics.plan.RoomModeration
 import io.element.android.libraries.architecture.AsyncAction
+import io.element.android.libraries.matrix.api.room.RoomMember
 import io.element.android.libraries.matrix.api.room.RoomMember.Role.Admin
 import io.element.android.libraries.matrix.api.room.RoomMember.Role.Moderator
+import io.element.android.libraries.matrix.api.room.powerlevels.RoomPowerLevels
 import io.element.android.libraries.matrix.api.room.powerlevels.RoomPowerLevelsValues
+import io.element.android.libraries.matrix.test.A_SESSION_ID
 import io.element.android.libraries.matrix.test.room.FakeBaseRoom
 import io.element.android.libraries.matrix.test.room.FakeJoinedRoom
+import io.element.android.libraries.matrix.test.room.aRoomInfo
 import io.element.android.libraries.matrix.test.room.defaultRoomPowerLevelValues
 import io.element.android.services.analytics.test.FakeAnalyticsService
+import kotlinx.collections.immutable.persistentMapOf
 import kotlinx.coroutines.test.runTest
 import org.junit.Test
 
@@ -70,6 +75,28 @@ class ChangeRoomPermissionsPresenterTest {
         }
     }
 
+    @Test
+    fun `present - check canChangePermissions and selectableOptions for moderator`() = runTest {
+        val room = FakeJoinedRoom(
+            baseRoom = FakeBaseRoom(
+                initialRoomInfo = initialRoomInfo(role = Moderator),
+                powerLevelsResult = { Result.success(defaultPermissions()) }
+            ),
+        )
+        val presenter = createChangeRoomPermissionsPresenter(room = room)
+        moleculeFlow(RecompositionMode.Immediate) {
+            presenter.present()
+        }.test {
+            val state = awaitUpdatedItem()
+            assertThat(state.selectableRoles).containsExactly(SelectableRole.Moderator, SelectableRole.Everyone)
+            for (sectionItems in state.itemsBySection.values) {
+                for (permissionType in sectionItems) {
+                    assertThat(state.canChangePermission(permissionType)).isTrue()
+                }
+            }
+        }
+    }
+
     @Test
     fun `present - ChangeMinimumRoleForAction updates the current permissions and hasChanges`() = runTest {
         val presenter = createChangeRoomPermissionsPresenter()
@@ -266,7 +293,9 @@ class ChangeRoomPermissionsPresenterTest {
 
     private fun createChangeRoomPermissionsPresenter(
         room: FakeJoinedRoom = FakeJoinedRoom(
-            baseRoom = FakeBaseRoom(powerLevelsResult = { Result.success(defaultPermissions()) }),
+            baseRoom = FakeBaseRoom(
+                initialRoomInfo = initialRoomInfo(),
+                powerLevelsResult = { Result.success(defaultPermissions()) }),
         ),
         analyticsService: FakeAnalyticsService = FakeAnalyticsService(),
     ) = ChangeRoomPermissionsPresenter(
@@ -274,6 +303,13 @@ class ChangeRoomPermissionsPresenterTest {
         analyticsService = analyticsService,
     )
 
+    private fun initialRoomInfo(role: RoomMember.Role = Admin) = aRoomInfo(
+        roomPowerLevels = RoomPowerLevels(
+            values = defaultPermissions(),
+            users = persistentMapOf(A_SESSION_ID to role.powerLevel),
+        )
+    )
+
     private fun defaultPermissions() = defaultRoomPowerLevelValues()
 
     private suspend fun TurbineTestContext<ChangeRoomPermissionsState>.awaitUpdatedItem(): ChangeRoomPermissionsState {