add poll support

Fixes #130

lib/controllers/event.dart

@@ -1,4 +1,3 @@
-import "package:collection/collection.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:nexus/controllers/client.dart";
 import "package:nexus/controllers/rooms.dart";
@@ -10,11 +9,14 @@ class EventController(final GetEventRequest request)
   @override
   Future<Event?> build() async {
     final event = ref.watch(
-      RoomsController.provider.select(
-        (rooms) => rooms[request.roomId]?.events.values.firstWhereOrNull(
-          (event) => event.eventId == request.eventId,
-        ),
-      ),
+      RoomsController.provider.select((rooms) {
+        final room = rooms[request.roomId];
+
+        return switch (room?.eventIds[request.eventId]) {
+          final rowId? => room?.events[rowId],
+          null => null,
+        };
+      }),
     );
 
     if (event != null) return event;

lib/controllers/poll_votes.dart

@@ -0,0 +1,132 @@
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/client.dart";
+import "package:nexus/controllers/room_power_levels.dart";
+import "package:nexus/controllers/rooms.dart";
+import "package:nexus/helpers/extensions/event_id_is_fake.dart";
+import "package:nexus/models/configs/event.dart";
+import "package:nexus/models/content/content.dart";
+import "package:nexus/models/content/encrypted.dart";
+import "package:nexus/models/content/poll_end.dart";
+import "package:nexus/models/content/poll_response.dart";
+import "package:nexus/models/content/poll_start.dart";
+import "package:nexus/models/event.dart";
+import "package:nexus/models/poll_votes.dart";
+
+class PollVotesController(final EventConfig config)
+    extends AsyncNotifier<PollVotes> {
+  @override
+  Future<PollVotes> build() async {
+    // Only what's needed, so e.g. reactions don't cause refetches
+    final (poll, localRelated) = ref.watch(
+      RoomsController.provider.select((rooms) {
+        final room = rooms[config.roomId];
+        final event = room?.events[config.eventRowId];
+        if (room == null || event == null) {
+          return (null, const IList<Event>.empty());
+        }
+
+        final edited = event.lastEditRowId == 0
+            ? null
+            : room.events[event.lastEditRowId];
+
+        return (
+          (
+            eventId: event.eventId,
+            sender: event.sender,
+            // Edits can change the answers
+            content: (edited ?? event).content,
+          ),
+          (room.relations[event.eventId] ?? const ISet<int>.empty())
+              .map((rowId) => room.events[rowId])
+              .nonNulls
+              .where((related) => related.relationType == "m.reference")
+              .toIList(),
+        );
+      }),
+    );
+    final powerLevels = ref.watch(
+      RoomPowerLevelsController.provider(config.roomId),
+    );
+
+    if (poll == null) return const PollVotes();
+    final PollStart(:answers, :selectionLimit) = switch (poll.content) {
+      PollStartContent(:final poll) => poll,
+      _ => const PollStart(),
+    };
+
+    final fetched = await ref
+        .read(ClientController.provider.notifier)
+        .getRelatedEvents(
+          .new(
+            roomId: config.roomId,
+            eventId: poll.eventId,
+            relationType: "m.reference",
+          ),
+        );
+
+    final related =
+        IMap.fromIterable(
+              (fetched ?? const IList.empty()).addAll(localRelated),
+              keyMapper: (event) => event.rowId,
+              valueMapper: (event) => event,
+            ).values
+            // gomuks' database has unsent local echoes too
+            .where((event) => event.redactedBy == null && !event.eventId.isFake)
+            .toIList();
+
+    final end = related
+        .where(
+          (event) =>
+              event.content is PollEndContent &&
+              powerLevels.canEndPoll(event.sender, pollSender: poll.sender),
+        )
+        .sortedBy((event) => event.timestamp)
+        .firstOrNull;
+    final endedAt = end?.timestamp;
+
+    bool beforeEnd(Event event) =>
+        endedAt == null || !event.timestamp.isAfter(endedAt);
+
+    final answerIds = answers.map((answer) => answer.id).toISet();
+
+    return .new(
+      endEventId: end?.eventId,
+      undecryptable: related
+          .where(
+            (event) => event.content is EncryptedContent && beforeEnd(event),
+          )
+          .length,
+      // Each user's latest response before the end counts, even if invalid
+      votes: related
+          .where(
+            (event) =>
+                event.type == EventType.pollResponse.type && beforeEnd(event),
+          )
+          .toIList()
+          .sort((a, b) => a.timestamp.compareTo(b.timestamp))
+          .fold(const .empty(), (votes, event) {
+            // Truncated before removing duplicates, as MSC3381 specifies
+            final picked = switch (event.content) {
+              PollResponseContent(:final answers) =>
+                answers.take(selectionLimit).toISet(),
+              _ => null,
+            };
+
+            return votes.add(
+              event.sender,
+              // Spoiled responses count as no answers
+              picked != null && picked.every(answerIds.contains)
+                  ? picked.toIList()
+                  : const .empty(),
+            );
+          }),
+    );
+  }
+
+  static final provider = AsyncNotifierProvider.family
+      .autoDispose<PollVotesController, PollVotes, EventConfig>(
+        PollVotesController.new,
+      );
+}

lib/controllers/reactions.dart

@@ -2,10 +2,10 @@ import "package:fast_immutable_collections/fast_immutable_collections.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:nexus/controllers/client.dart";
 import "package:nexus/controllers/rooms.dart";
-import "package:nexus/models/configs/reactions.dart";
+import "package:nexus/models/configs/event.dart";
 import "package:nexus/models/content/reaction.dart";
 
-class ReactionsController(final ReactionsConfig config)
+class ReactionsController(final EventConfig config)
     extends AsyncNotifier<IMap<String, IList<String>>> {
   @override
   Future<IMap<String, IList<String>>> build() async {
@@ -48,6 +48,6 @@ class ReactionsController(final ReactionsConfig config)
       AsyncNotifierProvider.family<
         ReactionsController,
         IMap<String, IList<String>>,
-        ReactionsConfig
+        EventConfig
       >(ReactionsController.new);
 }

lib/controllers/room_chat.dart

@@ -8,8 +8,12 @@ import "package:fluttertagger/fluttertagger.dart";
 import "package:nexus/controllers/attachment.dart";
 import "package:nexus/controllers/client.dart";
 import "package:nexus/controllers/rooms.dart";
+import "package:nexus/helpers/extensions/send_failed.dart";
 import "package:nexus/models/content/content.dart";
 import "package:nexus/models/content/image_pack.dart";
+import "package:nexus/models/content/poll_end.dart";
+import "package:nexus/models/content/poll_response.dart";
+import "package:nexus/models/content/poll_start.dart";
 import "package:nexus/models/content/reaction.dart";
 import "package:nexus/models/content/sticker.dart";
 import "package:nexus/models/direction.dart";
@@ -340,10 +344,10 @@ class RoomChatController(final ChatParams info)
     );
   }
 
-  /// Sends [image] as a sticker, as a reply to [repliedEventRowId] if set.
-  Future<void> sendSticker(
-    String shortcode,
-    PackImage image, {
+  /// Sends [content], as a reply to [repliedEventRowId] if set.
+  Future<void> sendWithReply(
+    EventType type,
+    Content content, {
     bool shouldMention = true,
     int? repliedEventRowId,
   }) async {
@@ -360,12 +364,8 @@ class RoomChatController(final ChatParams info)
         .sendEvent(
           .new(
             roomId: info.roomId,
-            type: EventType.sticker.type,
-            content: StickerContent(
-              body: image.body ?? shortcode,
-              info: image.info ?? const .new(),
-              url: image.url,
-            ),
+            type: type.type,
+            content: content,
             mentions: Mentions(
               userIds: [
                 if (shouldMention && repliedEvent != null) repliedEvent.sender,
@@ -387,6 +387,70 @@ class RoomChatController(final ChatParams info)
         );
   }
 
+  /// Sends [image] as a sticker, as a reply to [repliedEventRowId] if set.
+  Future<void> sendSticker(
+    String shortcode,
+    PackImage image, {
+    bool shouldMention = true,
+    int? repliedEventRowId,
+  }) => sendWithReply(
+    .sticker,
+    StickerContent(
+      body: image.body ?? shortcode,
+      info: image.info ?? const .new(),
+      url: image.url,
+    ),
+    shouldMention: shouldMention,
+    repliedEventRowId: repliedEventRowId,
+  );
+
+  Future<void> sendPoll(
+    PollStart poll, {
+    bool shouldMention = true,
+    int? repliedEventRowId,
+  }) => sendWithReply(
+    .pollStart,
+    PollStartContent(poll: poll),
+    shouldMention: shouldMention,
+    repliedEventRowId: repliedEventRowId,
+  );
+
+  /// Completes once the event has come down sync.
+  Future<void> sendPollReference(
+    Event poll,
+    EventType type,
+    Content content,
+  ) async {
+    final event = await ref
+        .read(ClientController.provider.notifier)
+        .sendEvent(
+          .new(
+            roomId: info.roomId,
+            type: type.type,
+            content: content,
+            relatesTo: poll.eventId,
+            relationType: "m.reference",
+            synchronous: true,
+          ),
+        );
+
+    if (event.sendFailed) throw Exception(event.sendError);
+
+    await ref
+        .read(RoomsController.provider.notifier)
+        .awaitEvent(info.roomId, event.eventId);
+  }
+
+  /// An empty [answers] removes the vote.
+  Future<void> votePoll(Event poll, IList<String> answers) => sendPollReference(
+    poll,
+    .pollResponse,
+    PollResponseContent(answers: answers),
+  );
+
+  Future<void> endPoll(Event poll) =>
+      sendPollReference(poll, .pollEnd, const PollEndContent());
+
   static final provider = AsyncNotifierProvider.family
       .autoDispose<RoomChatController, RoomChat?, ChatParams>(
         RoomChatController.new,

lib/controllers/rooms.dart

@@ -82,6 +82,35 @@ class RoomsController extends Notifier<IMap<String, Room>> {
     ),
   );
 
+  static IMap<String, ISet<int>> addRelations(
+    IMap<String, ISet<int>> relations,
+    Iterable<Event> events,
+  ) => events.fold(
+    relations,
+    (acc, event) => switch (event.relatesTo) {
+      final relatesTo? => acc.update(
+        relatesTo,
+        (rowIds) => rowIds.add(event.rowId),
+        ifAbsent: () => .new([event.rowId]),
+      ),
+      null => acc,
+    },
+  );
+
+  /// IDs replace previous ones for the same row, e.g. once a local echo is sent.
+  static IMap<String, int> addEventIds(
+    IMap<String, int> eventIds,
+    IMap<int, Event> existing,
+    Iterable<Event> events,
+  ) => events.fold(eventIds, (acc, event) {
+    final previousId = existing[event.rowId]?.eventId;
+
+    return (previousId != null && previousId != event.eventId
+            ? acc.remove(previousId)
+            : acc)
+        .add(event.eventId, event.rowId);
+  });
+
   void update(
     IMap<String, Room> rooms, [
     ISet<String> leftRooms = const .empty(),
@@ -109,6 +138,15 @@ class RoomsController extends Notifier<IMap<String, Room>> {
               events: incoming.events.isEmpty
                   ? existing.events
                   : existing.events.addAll(incoming.events),
+              relations: addRelations(
+                existing.relations,
+                incoming.events.values,
+              ),
+              eventIds: addEventIds(
+                existing.eventIds,
+                existing.events,
+                incoming.events.values,
+              ),
               state: incoming.state.entries.fold(
                 existing.state,
                 (previousValue, event) => previousValue.add(
@@ -129,6 +167,12 @@ class RoomsController extends Notifier<IMap<String, Room>> {
             ) ??
             incoming.copyWith(
               receipts: mergeReceipts(const .empty(), incoming.receipts),
+              relations: addRelations(const .empty(), incoming.events.values),
+              eventIds: addEventIds(
+                const .empty(),
+                const .empty(),
+                incoming.events.values,
+              ),
             ),
       );
     });
@@ -144,12 +188,19 @@ class RoomsController extends Notifier<IMap<String, Room>> {
     String type,
     String eventId, {
     String stateKey = "",
-  }) {
-    bool arrived(IMap<String, Room> rooms) =>
-        switch (rooms[roomId]?.state[type]?[stateKey]) {
-          final rowId? => rooms[roomId]?.events[rowId]?.eventId == eventId,
-          null => false,
-        };
+  }) => awaitRooms(
+    (rooms) => switch (rooms[roomId]?.state[type]?[stateKey]) {
+      final rowId? => rooms[roomId]?.events[rowId]?.eventId == eventId,
+      null => false,
+    },
+  );
+
+  /// Waits for a sent event to come down sync, giving up after a while.
+  Future<void> awaitEvent(String roomId, String eventId) => awaitRooms(
+    (rooms) => rooms[roomId]?.eventIds.containsKey(eventId) ?? false,
+  );
+
+  Future<void> awaitRooms(bool Function(IMap<String, Room> rooms) arrived) {
     if (arrived(state)) return .value();
 
     final completer = Completer<void>();

lib/helpers/extensions/is_shown_as_message.dart

@@ -1,15 +1,19 @@
 import "package:nexus/models/content/encrypted.dart";
 import "package:nexus/models/content/message.dart";
+import "package:nexus/models/content/poll_start.dart";
 import "package:nexus/models/content/sticker.dart";
 import "package:nexus/models/event.dart";
 
 extension IsShownAsMessage on Event {
+  /// Whether this is a message, sticker or poll.
+  bool get hasMessageContent => switch (content) {
+    MessageContent() || StickerContent() || PollStartContent() => true,
+    _ => false,
+  };
+
   /// Whether this is shown in the timeline as a message, with MessageRenderer.
   bool get isShownAsMessage =>
       redactedBy == null &&
       relationType != "m.replace" &&
-      switch (content) {
-        MessageContent() || EncryptedContent() || StickerContent() => true,
-        _ => false,
-      };
+      (hasMessageContent || content is EncryptedContent);
 }

lib/helpers/extensions/send_failed.dart

@@ -0,0 +1,6 @@
+import "package:nexus/models/event.dart";
+
+extension SendFailed on Event {
+  /// gomuks marks events that are still sending as "not sent" (and often forgets to clear it at all)
+  bool get sendFailed => sendError != null && sendError != "not sent";
+}

lib/models/configs/event.dart

@@ -0,0 +1,16 @@
+import "package:freezed_annotation/freezed_annotation.dart";
+
+part "event.freezed.dart";
+part "event.g.dart";
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable()
+class const EventConfig({
+  required final String roomId,
+  required final int eventRowId,
+}) with _$EventConfig {
+  Map<String, Object?> toJson() => _$EventConfigToJson(this);
+
+  factory EventConfig.fromJson(Map<String, Object?> json) =>
+      _$EventConfigFromJson(json);
+}

lib/models/configs/reactions.dart

@@ -1,16 +0,0 @@
-import "package:freezed_annotation/freezed_annotation.dart";
-
-part "reactions.freezed.dart";
-part "reactions.g.dart";
-
-@Freezed(toJson: false, fromJson: false)
-@JsonSerializable()
-class const ReactionsConfig({
-  required final String roomId,
-  required final int eventRowId,
-}) with _$ReactionsConfig {
-  Map<String, Object?> toJson() => _$ReactionsConfigToJson(this);
-
-  factory ReactionsConfig.fromJson(Map<String, Object?> json) =>
-      _$ReactionsConfigFromJson(json);
-}

lib/models/content/content.dart

@@ -17,6 +17,9 @@ import "package:nexus/models/content/topic.dart";
 import "package:nexus/models/content/sticker.dart";
 import "package:nexus/models/content/history_visibility.dart";
 import "package:nexus/models/content/image_pack.dart";
+import "package:nexus/models/content/poll_end.dart";
+import "package:nexus/models/content/poll_response.dart";
+import "package:nexus/models/content/poll_start.dart";
 
 class const Content({final String? parseError, final StackTrace? stackTrace}) {
   factory Content.fromJson(Map<String, dynamic> json) => const Content();
@@ -64,5 +67,11 @@ enum EventType(
   pinnedEvents("m.room.pinned_events", PinnedEventsContent.fromJson),
   imagePack("m.room.image_pack", ImagePackContent.fromJson),
   legacyImagePack("im.ponies.room_emotes", ImagePackContent.fromJson),
+  pollStart("org.matrix.msc3381.poll.start", PollStartContent.fromJson),
+  pollResponse(
+    "org.matrix.msc3381.poll.response",
+    PollResponseContent.fromJson,
+  ),
+  pollEnd("org.matrix.msc3381.poll.end", PollEndContent.fromJson),
   message("m.room.message", MessageContent.fromJson),
 }

lib/models/content/poll_end.dart

@@ -0,0 +1,12 @@
+import "package:nexus/models/content/content.dart";
+
+class const PollEndContent() extends Content {
+  factory PollEndContent.fromJson(Map<String, dynamic> json) =>
+      const PollEndContent();
+
+  @override
+  Map<String, dynamic> toJson() => {
+    "org.matrix.msc3381.poll.end": {},
+    "org.matrix.msc1767.text": "Ended the poll",
+  };
+}

lib/models/content/poll_response.dart

@@ -0,0 +1,23 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:freezed_annotation/freezed_annotation.dart";
+import "package:nexus/models/content/content.dart";
+part "poll_response.freezed.dart";
+part "poll_response.g.dart";
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable(createToJson: false)
+class const PollResponseContent({
+  @JsonKey(readValue: PollResponseContent.answersFromJson)
+  final IList<String> answers = const .empty(),
+}) extends Content with _$PollResponseContent {
+  static List<dynamic>? answersFromJson(Map<dynamic, dynamic> json, _) =>
+      json["org.matrix.msc3381.poll.response"]?["answers"];
+
+  @override
+  Map<String, Object?> toJson() => {
+    "org.matrix.msc3381.poll.response": {"answers": answers.toList()},
+  };
+
+  factory PollResponseContent.fromJson(Map<String, Object?> json) =>
+      _$PollResponseContentFromJson(json);
+}

lib/models/content/poll_start.dart

@@ -0,0 +1,90 @@
+import "dart:math";
+
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:freezed_annotation/freezed_annotation.dart";
+import "package:nexus/models/content/content.dart";
+part "poll_start.freezed.dart";
+part "poll_start.g.dart";
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable(createToJson: false)
+class const PollStartContent({
+  @JsonKey(name: "org.matrix.msc3381.poll.start") required final PollStart poll,
+}) extends Content with _$PollStartContent {
+  @override
+  Map<String, Object?> toJson() => {
+    "org.matrix.msc3381.poll.start": poll.toJson(),
+    // Shown by clients without poll support
+    "org.matrix.msc1767.text": [
+      poll.question,
+      ...poll.answers.mapIndexed(
+        (index, answer) => "${index + 1}. ${answer.text}",
+      ),
+    ].join("\n"),
+  };
+
+  factory PollStartContent.fromJson(Map<String, Object?> json) =>
+      _$PollStartContentFromJson(json);
+}
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable()
+class const PollStart({
+  @JsonKey(readValue: PollStart.questionFromJson) final String question = "",
+  final int? maxSelections,
+  @JsonKey(readValue: PollStart.answersFromJson)
+  final IList<PollAnswer> answers = const .empty(),
+}) with _$PollStart {
+  static const maxAnswers = 20;
+
+  static String? extensibleTextFromJson(Object? json) => switch (json) {
+    {"org.matrix.msc1767.text": final String text} => text,
+    {"body": final String body} => body,
+    {"org.matrix.msc1767.message": final List message} =>
+      message
+          .whereType<Map>()
+          .map((part) => part["body"])
+          .whereType<String>()
+          .firstOrNull,
+    _ => null,
+  };
+
+  static String? questionFromJson(Map<dynamic, dynamic> json, String key) =>
+      PollStart.extensibleTextFromJson(json[key]);
+
+  static List<dynamic>? answersFromJson(
+    Map<dynamic, dynamic> json,
+    String key,
+  ) => (json[key] as List?)?.take(maxAnswers).toList();
+
+  /// [maxSelections], defaulting to 1, and at most the number of answers
+  int get selectionLimit =>
+      (maxSelections ?? 1).clamp(1, max(answers.length, 1));
+
+  Map<String, Object?> toJson() => {
+    ..._$PollStartToJson(this),
+    // We don't allow undisclosed polls as they make no sense
+    "kind": "org.matrix.msc3381.poll.disclosed",
+    "question": {"org.matrix.msc1767.text": question},
+    "answers": answers.map((answer) => answer.toJson()).toList(),
+  };
+
+  factory PollStart.fromJson(Map<String, Object?> json) =>
+      _$PollStartFromJson(json);
+}
+
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable(createToJson: false)
+class const PollAnswer({
+  required final String id,
+  @JsonKey(readValue: PollAnswer.textFromJson) final String text = "",
+}) with _$PollAnswer {
+  static String? textFromJson(Map<dynamic, dynamic> json, _) =>
+      PollStart.extensibleTextFromJson(json);
+
+  Map<String, Object?> toJson() => {"id": id, "org.matrix.msc1767.text": text};
+
+  factory PollAnswer.fromJson(Map<String, Object?> json) =>
+      _$PollAnswerFromJson(json);
+}

lib/models/poll_votes.dart

@@ -0,0 +1,25 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+
+class const PollVotes({
+  /// Each user's answers, by user ID
+  final IMap<String, IList<String>> votes = const .empty(),
+  final String? endEventId,
+  final int undecryptable = 0,
+}) {
+  bool get hasEnded => endEventId != null;
+
+  IMap<String, IList<String>> get votersByAnswer => votes.entries.fold(
+    const .empty(),
+    (acc, entry) => entry.value.fold(
+      acc,
+      (acc, answer) => acc.update(
+        answer,
+        (voters) => voters.add(entry.key),
+        ifAbsent: () => .new([entry.key]),
+      ),
+    ),
+  );
+
+  int get voterCount =>
+      votes.values.where((answers) => answers.isNotEmpty).length;
+}

lib/models/room.dart

@@ -24,6 +24,14 @@ class const Room({
   @JsonKey(fromJson: Room.eventsJsonToIMap)
   final IMap<int, Event> events = const .empty(),
 
+  /// [relations] is an IMap of event ID to the eventRowIds relating to it
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  final IMap<String, ISet<int>> relations = const .empty(),
+
+  /// [eventIds] is an IMap of event ID to eventRowId
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  final IMap<String, int> eventIds = const .empty(),
+
   final bool reset = false,
   @JsonKey(includeFromJson: false, includeToJson: false)
   final bool resetClientSticky = false,

lib/models/room_power_levels.dart

@@ -8,4 +8,7 @@ class const RoomPowerLevels({
   double levelOf(String userId) => creators.contains(userId)
       ? double.infinity
       : (content.users[userId] ?? content.usersDefault).toDouble();
+
+  bool canEndPoll(String userId, {required String pollSender}) =>
+      userId == pollSender || levelOf(userId) >= content.redact;
 }

lib/widgets/composer/composer.dart

@@ -20,9 +20,11 @@ import "package:nexus/controllers/power_level.dart";
 import "package:nexus/controllers/image_packs.dart";
 import "package:nexus/models/content/image_pack.dart";
 import "package:nexus/models/content/message.dart";
+import "package:nexus/models/content/poll_start.dart";
 import "package:nexus/models/image_pack.dart";
 import "package:nexus/widgets/mxc_emoji.dart";
 import "package:nexus/widgets/sticker_picker.dart";
+import "package:nexus/widgets/create_poll_sheet.dart";
 import "package:nexus/models/relation_type.dart";
 import "package:nexus/widgets/composer/overlays/tagger_overlay.dart";
 import "package:nexus/widgets/composer/paste_files_action.dart";
@@ -30,6 +32,7 @@ import "package:pasteboard/pasteboard.dart";
 import "package:path/path.dart";
 import "package:path_provider/path_provider.dart";
 import "package:nexus/widgets/composer/relation_preview.dart";
+import "package:nexus/widgets/composer/composer_replacement.dart";
 import "package:nexus/main.dart";
 
 class const Composer(
@@ -49,6 +52,11 @@ class const Composer(
     required bool shouldMention,
   })
   onSendSticker,
+  required final Future<void> Function(
+    PollStart poll, {
+    required bool shouldMention,
+  })
+  onSendPoll,
   final FocusNode? node,
   super.key,
 }) extends HookConsumerWidget {
@@ -70,6 +78,11 @@ class const Composer(
                 .value
                 ?.any((pack) => pack.stickers.isNotEmpty) ??
             false);
+    final canSendPolls = ref.watch(
+      PowerLevelController.provider(
+        .new(eventType: .pollStart, roomId: roomId),
+      ),
+    );
     final relatedEvent = this.relatedEvent == null
         ? null
         : ref.watch(
@@ -95,15 +108,24 @@ class const Composer(
     /// The sticker to send, which replaces the text field until it is sent or
     /// removed, as stickers can't have a caption
     final sticker = useState<(String, PackImage)?>(null);
+
+    final poll = useState<PollStart?>(null);
     useEffect(() {
       sticker.value = null;
+      poll.value = null;
       return null;
     }, [roomId]);
 
+    final hasReplacement = sticker.value != null || poll.value != null;
+
+    // The relation type stays as edit after cancelling an edit
+    final isEditing = relationType == .edit && relatedEvent != null;
+
     useEffect(() {
       if (relationType == .edit && relatedEvent != null) {
         textBefore.value ??= controller.text;
         sticker.value = null;
+        poll.value = null;
 
         final text =
             relatedEvent.localContent?.editSource ??
@@ -216,11 +238,16 @@ class const Composer(
     }
 
     void send() {
-      if (sticker.value case (final shortcode, final image)?) {
-        onSendSticker(shortcode, image, shouldMention: shouldMention.value);
+      if (hasReplacement) {
+        if (sticker.value case (final shortcode, final image)?) {
+          onSendSticker(shortcode, image, shouldMention: shouldMention.value);
+        } else if (poll.value case final draft?) {
+          onSendPoll(draft, shouldMention: shouldMention.value);
+        }
         onDismiss();
-        // The draft is kept, so it can still be sent after the sticker
+        // The draft is kept, so it can still be sent after the replacement
         sticker.value = null;
+        poll.value = null;
         node?.requestFocus();
         return;
       }
@@ -302,7 +329,7 @@ class const Composer(
                         )
                         ? [
                             IconButton(
-                              onPressed: sticker.value != null
+                              onPressed: hasReplacement
                                   ? null
                                   : () => context.showAdaptiveSheet(
                                       (context) => EmojiPicker(
@@ -338,8 +365,7 @@ class const Composer(
                             ),
                             AdaptiveMenuButton(
                               tooltip: "Add media",
-                              enabled:
-                                  attachment == null && sticker.value == null,
+                              enabled: attachment == null && !hasReplacement,
                               itemBuilder: (context) => [
                                 for (final (source, title, icon) in [
                                   if (Platform.isAndroid || Platform.isIOS)
@@ -386,7 +412,7 @@ class const Composer(
                                 if (canSendStickers)
                                   PopupMenuItem(
                                     // Stickers can't replace messages
-                                    enabled: relationType != .edit,
+                                    enabled: !isEditing,
                                     onTap: () => context.showAdaptiveSheet(
                                       (context) => StickerPicker(
                                         roomId: roomId,
@@ -401,6 +427,22 @@ class const Composer(
                                       leading: Icon(Icons.sticky_note_2),
                                     ),
                                   ),
+                                if (canSendPolls)
+                                  PopupMenuItem(
+                                    enabled: !isEditing,
+                                    onTap: () => context.showAdaptiveSheet(
+                                      (context) => CreatePollSheet(
+                                        onCreate: (created) {
+                                          Navigator.of(context).pop();
+                                          poll.value = created;
+                                        },
+                                      ),
+                                    ),
+                                    child: ListTile(
+                                      title: Text("Poll"),
+                                      leading: Icon(Icons.poll),
+                                    ),
+                                  ),
                               ],
                               icon: Icon(Icons.add),
                             ),
@@ -409,35 +451,49 @@ class const Composer(
                               child: AnimatedSize(
                                 duration: Durations.short4,
                                 alignment: .bottomCenter,
-                                child: switch (sticker.value) {
-                                  (final shortcode, final image)? => Focus(
-                                    autofocus: true,
+                                child: switch ((sticker.value, poll.value)) {
+                                  (_, final draft?) => ComposerReplacement(
+                                    removeTooltip: "Remove poll",
+                                    onRemove: () {
+                                      poll.value = null;
+                                      node?.requestFocus();
+                                    },
                                     onKeyEvent: sendOnEnter,
-                                    child: Padding(
-                                      padding: .symmetric(vertical: 8),
-                                      child: Row(
-                                        children: [
-                                          ConstrainedBox(
-                                            constraints: .loose(.square(128)),
-                                            child: MxcEmoji(
-                                              image.url,
-                                              label: image.body ?? shortcode,
-                                            ),
-                                          ),
-                                          Spacer(),
-                                          IconButton(
-                                            tooltip: "Remove sticker",
-                                            onPressed: () {
-                                              sticker.value = null;
-                                              node?.requestFocus();
-                                            },
-                                            icon: Icon(Icons.close),
-                                          ),
-                                        ],
+                                    ListTile(
+                                      leading: Icon(
+                                        Icons.poll,
+                                        color: theme.colorScheme.primary,
+                                      ),
+                                      title: Text(draft.question),
+                                      subtitle: Text(
+                                        draft.answers
+                                            .map((answer) => answer.text)
+                                            .join(" · "),
+                                        maxLines: 1,
+                                        overflow: .ellipsis,
                                       ),
                                     ),
                                   ),
-                                  null => FlutterTagger(
+                                  ((final shortcode, final image)?, _) =>
+                                    ComposerReplacement(
+                                      removeTooltip: "Remove sticker",
+                                      onRemove: () {
+                                        sticker.value = null;
+                                        node?.requestFocus();
+                                      },
+                                      onKeyEvent: sendOnEnter,
+                                      Align(
+                                        alignment: .centerLeft,
+                                        child: ConstrainedBox(
+                                          constraints: .loose(.square(128)),
+                                          child: MxcEmoji(
+                                            image.url,
+                                            label: image.body ?? shortcode,
+                                          ),
+                                        ),
+                                      ),
+                                    ),
+                                  (null, null) => FlutterTagger(
                                     triggerStrategy: .eager,
                                     // Characters that continue a search, for
                                     // e.g. :+1, :custom_emoji or @user:server

lib/widgets/composer/composer_replacement.dart

@@ -0,0 +1,30 @@
+import "package:material_ui/material_ui.dart";
+
+/// Replaces the composer's text field with something to send, like a sticker.
+class const ComposerReplacement(
+  final Widget child, {
+  required final String removeTooltip,
+  required final VoidCallback onRemove,
+  final FocusOnKeyEventCallback? onKeyEvent,
+  super.key,
+}) extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) => Focus(
+    autofocus: true,
+    onKeyEvent: onKeyEvent,
+    child: Padding(
+      padding: .symmetric(vertical: 8),
+      child: Row(
+        spacing: 12,
+        children: [
+          Expanded(child: child),
+          IconButton(
+            tooltip: removeTooltip,
+            onPressed: onRemove,
+            icon: Icon(Icons.close),
+          ),
+        ],
+      ),
+    ),
+  );
+}

lib/widgets/create_poll_sheet.dart

@@ -0,0 +1,109 @@
+import "package:collection/collection.dart";
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_hooks/flutter_hooks.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/models/content/poll_start.dart";
+import "package:nexus/widgets/sheet_layout.dart";
+
+class const CreatePollSheet({
+  required final void Function(PollStart poll) onCreate,
+  super.key,
+}) extends HookWidget {
+  @override
+  Widget build(BuildContext context) {
+    final questionController = useTextEditingController();
+    final question = useValueListenable(questionController).text.trim();
+
+    // Keyed by ID, so fields keep their text when one above is removed
+    final nextId = useRef(2);
+    final answers = useState<IMap<int, String>>(.new({0: "", 1: ""}));
+    final filledAnswers = answers.value.entries
+        .map(
+          (answer) =>
+              PollAnswer(id: "${answer.key}", text: answer.value.trim()),
+        )
+        .where((answer) => answer.text.isNotEmpty)
+        .toIList();
+
+    final allowMultiple = useState(false);
+
+    final canCreate = question.isNotEmpty && filledAnswers.length >= 2;
+
+    void submit() => onCreate(
+      .new(
+        question: question,
+        answers: filledAnswers,
+        maxSelections: allowMultiple.value ? filledAnswers.length : 1,
+      ),
+    );
+
+    return SheetLayout(
+      title: const Text("Create a Poll"),
+      actions: [
+        TextButton(
+          onPressed: Navigator.of(context).pop,
+          child: const Text("Cancel"),
+        ),
+        TextButton(
+          onPressed: canCreate ? submit : null,
+          child: const Text("Create"),
+        ),
+      ],
+      children: [
+        TextField(
+          controller: questionController,
+          autofocus: true,
+          textCapitalization: .sentences,
+          decoration: const .new(labelText: "Question"),
+        ),
+        AnimatedSize(
+          duration: Durations.medium2,
+          curve: Curves.easeInOut,
+          alignment: .topCenter,
+          child: Column(
+            spacing: 12,
+            children: answers.value.entries
+                .mapIndexed(
+                  (index, answer) => TextFormField(
+                    key: ValueKey(answer.key),
+                    initialValue: answer.value,
+                    textCapitalization: .sentences,
+                    onChanged: (text) =>
+                        answers.value = answers.value.add(answer.key, text),
+                    decoration: .new(
+                      labelText: "Answer ${index + 1}",
+                      suffixIcon: answers.value.length > 2
+                          ? IconButton(
+                              tooltip: "Remove answer",
+                              icon: const Icon(Icons.close),
+                              onPressed: () => answers.value = answers.value
+                                  .remove(answer.key),
+                            )
+                          : null,
+                    ),
+                  ),
+                )
+                .toList(),
+          ),
+        ),
+        Align(
+          alignment: .centerLeft,
+          child: TextButton.icon(
+            onPressed: answers.value.length < PollStart.maxAnswers
+                ? () => answers.value = answers.value.add(nextId.value++, "")
+                : null,
+            icon: const Icon(Icons.add),
+            label: const Text("Add Answer"),
+          ),
+        ),
+        SwitchListTile(
+          secondary: const Icon(Icons.checklist),
+          title: const Text("Allow multiple answers"),
+          subtitle: const Text("Voters can choose more than one"),
+          value: allowMultiple.value,
+          onChanged: (value) => allowMultiple.value = value,
+        ),
+      ],
+    );
+  }
+}

lib/widgets/event_preview.dart

@@ -1,6 +1,5 @@
 import "package:material_ui/material_ui.dart";
-import "package:nexus/models/content/message.dart";
-import "package:nexus/models/content/sticker.dart";
+import "package:nexus/helpers/extensions/is_shown_as_message.dart";
 import "package:nexus/models/event.dart";
 import "package:nexus/widgets/lazy_loading/message_avatar.dart";
 import "package:nexus/widgets/lazy_loading/message_displayname.dart";
@@ -10,10 +9,7 @@ class const EventPreview(final Event event, {super.key})
     extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    final showSender = switch (event.content) {
-      MessageContent() || StickerContent() => true,
-      _ => false,
-    };
+    final showSender = event.hasMessageContent;
 
     return IgnorePointer(
       child: Padding(