allow adding / removing rooms from a space

Fixes #140

lib/controllers/via.dart

@@ -7,9 +7,9 @@ import "package:nexus/models/content/power_levels.dart";
 import "package:nexus/models/event.dart";
 import "package:nexus/models/room.dart";
 
-class ViaController(final Room room) extends Notifier<String> {
+class ViaController(final Room room) extends Notifier<ISet<String>> {
   @override
-  String build() {
+  ISet<String> build() {
     final powerLevelUsers =
         switch (room.state[EventType.powerLevels.type]?[""]) {
           final rowId? => switch (room.events[rowId]?.content) {
@@ -35,7 +35,7 @@ class ViaController(final Room room) extends Notifier<String> {
             .nonNulls
             .toIList();
 
-    final servers = [?ref.watch(ClientStateController.provider)?.userId]
+    return [?ref.watch(ClientStateController.provider)?.userId]
         .toIList()
         .addAll(powerLevelUsers)
         .addAll(joinedMembers)
@@ -43,13 +43,16 @@ class ViaController(final Room room) extends Notifier<String> {
         .whereNoDuplicates()
         .take(5)
         .toISet();
-
-    return servers.isEmpty
-        ? ""
-        : "?${servers.map((server) => "via=$server").join("&")}";
   }
 
-  static final provider = NotifierProvider.family<ViaController, String, Room>(
-    ViaController.new,
-  );
+  static final provider =
+      NotifierProvider.family<ViaController, ISet<String>, Room>(
+        ViaController.new,
+      );
+}
+
+extension ViaQuery on ISet<String> {
+  /// These servers as a matrix: URI query, or empty if there are none.
+  String get viaQuery =>
+      isEmpty ? "" : "?${map((server) => "via=$server").join("&")}";
 }

lib/helpers/extensions/build_event_options.dart

@@ -213,7 +213,7 @@ extension BuildEventOptions on Event {
           );
           if (room == null) return;
 
-          final vias = ref.read(ViaController.provider(room));
+          final vias = ref.read(ViaController.provider(room)).viaQuery;
 
           await Clipboard.setData(
             ClipboardData(

lib/models/content/content.dart

@@ -13,6 +13,7 @@ import "package:nexus/models/content/reaction.dart";
 import "package:nexus/models/content/encrypted.dart";
 import "package:nexus/models/content/redaction.dart";
 import "package:nexus/models/content/server_acl.dart";
+import "package:nexus/models/content/space_child.dart";
 import "package:nexus/models/content/topic.dart";
 import "package:nexus/models/content/sticker.dart";
 import "package:nexus/models/content/history_visibility.dart";
@@ -65,6 +66,7 @@ enum EventType(
   tombstone("m.room.tombstone", Content.fromJson),
   reaction("m.reaction", ReactionContent.fromJson),
   pinnedEvents("m.room.pinned_events", PinnedEventsContent.fromJson),
+  spaceChild("m.space.child", SpaceChildContent.fromJson),
   imagePack("m.room.image_pack", ImagePackContent.fromJson),
   legacyImagePack("im.ponies.room_emotes", ImagePackContent.fromJson),
   pollStart("org.matrix.msc3381.poll.start", PollStartContent.fromJson),

lib/models/content/space_child.dart

@@ -0,0 +1,20 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:freezed_annotation/freezed_annotation.dart";
+import "package:nexus/models/content/content.dart";
+
+part "space_child.freezed.dart";
+part "space_child.g.dart";
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable(includeIfNull: false)
+class const SpaceChildContent({
+  final IList<String> via = const .empty(),
+  final String? order,
+  final bool suggested = false,
+}) extends Content with _$SpaceChildContent {
+  @override
+  Map<String, Object?> toJson() => _$SpaceChildContentToJson(this);
+
+  factory SpaceChildContent.fromJson(Map<String, Object?> json) =>
+      _$SpaceChildContentFromJson(json);
+}

lib/widgets/add_space_rooms_sheet.dart

@@ -0,0 +1,178 @@
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_hooks/flutter_hooks.dart";
+import "package:hooks_riverpod/hooks_riverpod.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/controllers/client.dart";
+import "package:nexus/controllers/client_state.dart";
+import "package:nexus/controllers/rooms.dart";
+import "package:nexus/controllers/space_hierarchy.dart";
+import "package:nexus/controllers/via.dart";
+import "package:nexus/helpers/extensions/get_localpart.dart";
+import "package:nexus/helpers/extensions/with_progress_snackbar.dart";
+import "package:nexus/main.dart";
+import "package:nexus/models/content/content.dart";
+import "package:nexus/models/content/space_child.dart";
+import "package:nexus/widgets/avatar_or_hash.dart";
+import "package:nexus/widgets/settings/search_chooser.dart";
+import "package:nexus/widgets/sheet_layout.dart";
+
+/// Chooses rooms to add to the space [spaceId], then adds them.
+class const AddSpaceRoomsSheet(
+  final String spaceId, {
+  required final String spaceName,
+
+  /// The rooms already in the space, which aren't offered.
+  required final ISet<String> existing,
+  super.key,
+}) extends HookConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final chosen = useState(const ISet<String>.empty());
+    final error = useState<String?>(null);
+    final resolving = useState(false);
+    final controller = useTextEditingController();
+    final rooms = ref.watch(
+      RoomsController.provider.select(
+        (rooms) => IMap.fromEntries(
+          rooms.values
+              .map((room) => room.metadata)
+              .nonNulls
+              .map(
+                (metadata) => MapEntry(metadata.id, (
+                  name: metadata.name,
+                  avatar: metadata.avatar,
+                )),
+              ),
+        ),
+      ),
+    );
+
+    String nameOf(String id) => rooms[id]?.name ?? id;
+
+    final suggestions = rooms.entries
+        .where((entry) => entry.key != spaceId && !existing.contains(entry.key))
+        .sortedBy((entry) => entry.value.name?.toLowerCase() ?? "")
+        .map((entry) => entry.key)
+        .toIList();
+
+    void add(String id) {
+      if (id == spaceId) {
+        error.value = "A space can't contain itself";
+        return;
+      }
+      if (existing.contains(id)) {
+        error.value = "This room is already in the space";
+        return;
+      }
+      if (!chosen.value.contains(id)) chosen.value = chosen.value.add(id);
+      controller.clear();
+    }
+
+    Future<void> addRoom(String text) async {
+      if (text.startsWith("!")) return add(text);
+
+      resolving.value = true;
+      try {
+        final id = await ref
+            .read(ClientController.provider.notifier)
+            .resolveAlias(text);
+
+        if (!context.mounted) return;
+
+        if (id == null) {
+          error.value = "No room has this alias";
+        } else {
+          add(id);
+        }
+      } finally {
+        if (context.mounted) resolving.value = false;
+      }
+    }
+
+    // Runs after the sheet closes, so it can't use [ref]
+    Future<void> save(ProviderContainer container, ISet<String> roomIds) async {
+      final client = container.read(ClientController.provider.notifier);
+      final joined = container.read(RoomsController.provider);
+      final ownServer = container
+          .read(ClientStateController.provider)
+          ?.userId
+          ?.serverName;
+
+      await Future.wait(
+        roomIds.map(
+          (roomId) => client.setState(
+            .new(
+              roomId: spaceId,
+              type: EventType.spaceChild.type,
+              stateKey: roomId,
+              content: SpaceChildContent(
+                via: switch (joined[roomId]) {
+                  final room? => container.read(ViaController.provider(room)),
+                  // Rooms the user isn't in can only be routed through their
+                  // own server
+                  null => ISet([?ownServer]),
+                }.toIList(),
+              ),
+            ),
+          ),
+        ),
+      );
+      container.invalidate(SpaceHierarchyController.provider(spaceId));
+    }
+
+    return SheetLayout(
+      title: Text("Add Rooms"),
+      actions: [
+        TextButton(onPressed: Navigator.of(context).pop, child: Text("Cancel")),
+        TextButton(
+          onPressed: chosen.value.isEmpty
+              ? null
+              : () {
+                  final container = ProviderScope.containerOf(context);
+                  final roomIds = chosen.value;
+                  context.withProgressSnackbar(
+                    "Adding ${roomIds.length == 1 ? nameOf(roomIds.single) : "${roomIds.length} rooms"} to $spaceName...",
+                    () => save(container, roomIds),
+                  );
+                  Navigator.of(context).pop();
+                },
+          child: Text("Add"),
+        ),
+      ],
+      children: [
+        Text("Choose rooms to add to \"$spaceName\"."),
+        SearchChooser(
+          controller: controller,
+          chosen: chosen.value,
+          options: suggestions,
+          nameOf: nameOf,
+          avatarOf: (id) => AvatarOrHash(
+            rooms[id]?.avatar,
+            nameOf(id),
+            fallback: Icon(Icons.numbers),
+          ),
+          subtitleOf: (id) => rooms[id]?.name == null ? null : id,
+          onAdded: add,
+          onRemoved: (id) => chosen.value = chosen.value.remove(id),
+          onSubmitted: (text, topMatch) {
+            if (text.startsWith(RegExp("[!#]"))) {
+              addRoom(text).onError(showError);
+            } else if (topMatch != null) {
+              add(topMatch);
+            } else {
+              error.value = "Enter a room ID or alias";
+            }
+          },
+          onChanged: (_) => error.value = null,
+          label: "Add room",
+          hint: "Search, or enter a room ID or alias",
+          removeTooltip: "Remove room",
+          error: error.value,
+          loading: resolving.value,
+          autofocus: true,
+        ),
+      ],
+    );
+  }
+}

lib/widgets/composer/overlays/room_overlay.dart

@@ -39,7 +39,9 @@ class const RoomOverlay(
                       ? null
                       : Text(room.metadata!.topic!, maxLines: 1),
                   onTap: () {
-                    final vias = ref.watch(ViaController.provider(room));
+                    final vias = ref
+                        .watch(ViaController.provider(room))
+                        .viaQuery;
                     addTag(
                       id: "[#$name](matrix:roomid/${room.metadata?.id.substring(1)}$vias)",
                       name:

lib/widgets/room_menu_button.dart

@@ -42,7 +42,7 @@ final class const RoomMenuButton(
         if (room != null) ...[
           PopupMenuItem(
             onTap: () async {
-              final vias = ref.read(ViaController.provider(room!));
+              final vias = ref.read(ViaController.provider(room!)).viaQuery;
 
               await Clipboard.setData(
                 .new(

lib/widgets/space_hierarchy_sheet.dart

@@ -3,15 +3,20 @@ import "package:fast_immutable_collections/fast_immutable_collections.dart";
 import "package:flutter_hooks/flutter_hooks.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:material_ui/material_ui.dart";
+import "package:nexus/controllers/client.dart";
+import "package:nexus/controllers/power_level.dart";
 import "package:nexus/controllers/rooms.dart";
 import "package:nexus/controllers/space_hierarchy.dart";
 import "package:nexus/helpers/extensions/better_when.dart";
 import "package:nexus/helpers/extensions/join_room.dart";
 import "package:nexus/helpers/extensions/show_adaptive_sheet.dart";
 import "package:nexus/helpers/extensions/show_leave_room_sheet.dart";
+import "package:nexus/helpers/extensions/with_progress_snackbar.dart";
 import "package:nexus/main.dart";
+import "package:nexus/models/content/content.dart";
 import "package:nexus/models/content/create.dart";
 import "package:nexus/models/space_hierarchy.dart";
+import "package:nexus/widgets/add_space_rooms_sheet.dart";
 import "package:nexus/widgets/avatar_or_hash.dart";
 import "package:nexus/widgets/expandable_image.dart";
 import "package:nexus/widgets/knock_sheet.dart";
@@ -64,6 +69,60 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
             child: const Text("Join"),
           );
 
+    Widget removeButton(
+      String spaceId,
+      String roomId, {
+      required String name,
+      required String spaceName,
+    }) => IconButton(
+      tooltip: "Remove from space",
+      icon: const Icon(Icons.remove_circle_outline),
+      onPressed: () => context.showAdaptiveSheet(
+        (context) => SheetLayout(
+          title: const Text("Remove Room"),
+          actions: [
+            TextButton(
+              onPressed: Navigator.of(context).pop,
+              child: const Text("Cancel"),
+            ),
+            TextButton(
+              onPressed: () {
+                final container = ProviderScope.containerOf(context);
+                context.withProgressSnackbar(
+                  "Removing $name from $spaceName...",
+                  () async {
+                    await container
+                        .read(ClientController.provider.notifier)
+                        .setState(
+                          .new(
+                            roomId: spaceId,
+                            type: EventType.spaceChild.type,
+                            stateKey: roomId,
+                            content: const Content(),
+                          ),
+                        );
+                    container.invalidate(
+                      SpaceHierarchyController.provider(spaceId),
+                    );
+                  },
+                );
+                Navigator.of(context).pop();
+              },
+              style: TextButton.styleFrom(
+                foregroundColor: Theme.of(context).colorScheme.error,
+              ),
+              child: const Text("Remove"),
+            ),
+          ],
+          children: [
+            Text(
+              "Are you sure you want to remove \"$name\" from \"$spaceName\"? Its members will stay in it.",
+            ),
+          ],
+        ),
+      ),
+    );
+
     Widget level(
       String spaceId,
       SpaceHierarchy hierarchy,
@@ -71,11 +130,20 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
     ) => HookConsumer(
       builder: (context, ref, _) {
         final loadingMore = useState(false);
+        final canManage = ref.watch(
+          PowerLevelController.provider(
+            .state(eventType: .spaceChild, roomId: spaceId),
+          ),
+        );
 
         final byId = IMap.fromValues(
           keyMapper: (room) => room.summary.roomId,
           values: hierarchy.rooms,
         );
+        final spaceName =
+            byId[spaceId]?.summary.name ??
+            byId[spaceId]?.summary.canonicalAlias ??
+            "Unnamed Space";
         final children = (byId[spaceId]?.children ?? const .empty())
             .map(
               (child) => switch (byId[child.roomId]) {
@@ -126,7 +194,19 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
                               overflow: .ellipsis,
                             ),
                       onTap: () => showSummary(room, child),
-                      trailing: membershipButton(room, child, name: name),
+                      trailing: Row(
+                        mainAxisSize: .min,
+                        children: [
+                          membershipButton(room, child, name: name),
+                          if (canManage)
+                            removeButton(
+                              spaceId,
+                              summary.roomId,
+                              name: name,
+                              spaceName: spaceName,
+                            ),
+                        ],
+                      ),
                     );
                   },
                 ),
@@ -172,6 +252,13 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
                                   child: const Icon(Icons.expand_more),
                                 ),
                               membershipButton(room, child, name: name),
+                              if (canManage)
+                                removeButton(
+                                  spaceId,
+                                  summary.roomId,
+                                  name: name,
+                                  spaceName: spaceName,
+                                ),
                             ],
                           ),
                         ),
@@ -190,6 +277,7 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
                                         ),
                                       )
                                       .betterWhen(
+                                        skipLoadingOnRefresh: true,
                                         loading: () =>
                                             const Loading(dimension: 24),
                                         data: (hierarchy) => level(
@@ -205,24 +293,43 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
                     );
                   },
                 ),
-            if (hierarchy.nextBatch != null)
-              Center(
-                child: TextButton(
-                  onPressed: loadingMore.value
-                      ? null
-                      : () async {
-                          loadingMore.value = true;
-                          await ref
-                              .read(
-                                SpaceHierarchyController.provider(spaceId)
-                                    .notifier,
-                              )
-                              .loadMore()
-                              .onError(showError);
-                          if (context.mounted) loadingMore.value = false;
-                        },
-                  child: const Text("Load more"),
-                ),
+            if (hierarchy.nextBatch != null || canManage)
+              Row(
+                mainAxisAlignment: .center,
+                spacing: 8,
+                children: [
+                  if (hierarchy.nextBatch != null)
+                    TextButton(
+                      onPressed: loadingMore.value
+                          ? null
+                          : () async {
+                              loadingMore.value = true;
+                              await ref
+                                  .read(
+                                    SpaceHierarchyController.provider(spaceId)
+                                        .notifier,
+                                  )
+                                  .loadMore()
+                                  .onError(showError);
+                              if (context.mounted) loadingMore.value = false;
+                            },
+                      child: const Text("Load more"),
+                    ),
+                  if (canManage)
+                    TextButton.icon(
+                      onPressed: () => context.showAdaptiveSheet(
+                        (_) => AddSpaceRoomsSheet(
+                          spaceId,
+                          spaceName: spaceName,
+                          existing: (byId[spaceId]?.children ?? const .empty())
+                              .map((child) => child.roomId)
+                              .toISet(),
+                        ),
+                      ),
+                      icon: const Icon(Icons.add),
+                      label: const Text("Add rooms"),
+                    ),
+                ],
               ),
           ],
         );
@@ -232,6 +339,7 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
     return ref
         .watch(SpaceHierarchyController.provider(spaceId))
         .betterWhen(
+          skipLoadingOnRefresh: true,
           data: (hierarchy) {
             final space = hierarchy.rooms
                 .where((room) => room.summary.roomId == spaceId)