feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

mobile/lib/features/channels/send_message_provider.dart

@@ -0,0 +1,201 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import '../../shared/relay/relay.dart';
+import '../channels/channel_management_provider.dart';
+import '../profile/user_cache_provider.dart';
+import '../profile/user_profile.dart';
+import 'channel_messages_provider.dart';
+
+/// Sends messages by signing an event with the user's nsec and publishing it
+/// over the relay's NIP-42-authenticated WebSocket session.
+class SendMessage {
+  final SignedEventRelay _signedEventRelay;
+  final Future<List<ChannelMember>> Function(String channelId) _fetchMembers;
+  final Map<String, UserProfile> Function() _readUserCache;
+  final void Function(String channelId, NostrEvent event) _addLocalMessage;
+  final void Function(String channelId, String eventId) _completeLocalMessage;
+  final void Function(String channelId, String eventId) _removeLocalMessage;
+  final bool Function()? _isDeliveryValid;
+
+  SendMessage({
+    required SignedEventRelay signedEventRelay,
+    required Future<List<ChannelMember>> Function(String channelId)
+    fetchMembers,
+    required Map<String, UserProfile> Function() readUserCache,
+    required void Function(String channelId, NostrEvent event) addLocalMessage,
+    required void Function(String channelId, String eventId)
+    completeLocalMessage,
+    required void Function(String channelId, String eventId) removeLocalMessage,
+    bool Function()? isDeliveryValid,
+  }) : _signedEventRelay = signedEventRelay,
+       _fetchMembers = fetchMembers,
+       _readUserCache = readUserCache,
+       _addLocalMessage = addLocalMessage,
+       _completeLocalMessage = completeLocalMessage,
+       _removeLocalMessage = removeLocalMessage,
+       _isDeliveryValid = isDeliveryValid;
+
+  /// Send a text message to a channel.
+  ///
+  /// For thread replies, pass [parentEventId] and optionally [rootEventId].
+  /// If [rootEventId] is null it defaults to [parentEventId] (direct reply to
+  /// thread head). Tags are built to match the desktop's `buildReplyTags`
+  /// convention with `root` / `reply` markers. Pass [mediaTags] to append
+  /// relay-validated `imeta` tags and NIP-30 `emoji` tags.
+  Future<void> call({
+    required String channelId,
+    required String content,
+    String? parentEventId,
+    String? rootEventId,
+    List<String>? mentionPubkeys,
+    List<List<String>> mediaTags = const [],
+  }) async {
+    _ensureDeliveryValid();
+    // Use explicitly passed pubkeys, or resolve @mentions against
+    // channel members to avoid matching the wrong user.
+    final resolvedMentions =
+        mentionPubkeys ?? await _resolveMentions(content, channelId);
+    final authorPubkey = _signedEventRelay.pubkey;
+
+    // Normalize mentions: lowercase, deduplicate, exclude self (matching
+    // the desktop's normalizeMentionPubkeys).
+    final selfLower = authorPubkey?.toLowerCase();
+    final seenMentions = <String>{?selfLower};
+    final normalizedMentions = <String>[
+      for (final pk in resolvedMentions)
+        if (seenMentions.add(pk.toLowerCase())) pk,
+    ];
+
+    final tags = <List<String>>[
+      ['h', channelId],
+      if (parentEventId != null) ..._buildReplyTags(parentEventId, rootEventId),
+      for (final pk in normalizedMentions) ['p', pk],
+      ...mediaTags,
+    ];
+
+    _ensureDeliveryValid();
+    NostrEvent? localMessage;
+    try {
+      await _signedEventRelay.submit(
+        kind: EventKind.streamMessage,
+        content: content,
+        tags: tags,
+        onSigned: (event) {
+          localMessage = event;
+          _addLocalMessage(channelId, event);
+        },
+      );
+      final event = localMessage;
+      if (event != null) _completeLocalMessage(channelId, event.id);
+    } catch (_) {
+      final event = localMessage;
+      if (event != null) _removeLocalMessage(channelId, event.id);
+      rethrow;
+    }
+  }
+
+  void _ensureDeliveryValid() {
+    if (_isDeliveryValid?.call() == false) {
+      throw StateError(
+        'Message delivery cancelled because the active community changed',
+      );
+    }
+  }
+
+  /// Resolve @mentions to pubkeys, scoped to channel members.
+  ///
+  /// Fetches channel members from the relay and matches @names only
+  /// against members of that channel. Falls back to the full user cache
+  /// if the member fetch fails.
+  Future<List<String>> _resolveMentions(
+    String content,
+    String channelId,
+  ) async {
+    final mentionPattern = RegExp(r'@(\w+)');
+    final matches = mentionPattern.allMatches(content);
+    if (matches.isEmpty) return const [];
+
+    // Try to get channel member pubkeys for scoped resolution.
+    Set<String>? memberPubkeys;
+    try {
+      final members = await _fetchMembers(channelId);
+      memberPubkeys = {for (final m in members) m.pubkey.toLowerCase()};
+    } catch (_) {
+      // Non-fatal — fall through to unscoped cache lookup.
+    }
+
+    final cache = _readUserCache();
+    final pubkeys = <String>{};
+
+    for (final match in matches) {
+      final name = match.group(1)?.toLowerCase();
+      if (name == null || name.isEmpty) continue;
+
+      for (final profile in cache.values) {
+        final displayName = profile.displayName?.toLowerCase();
+        if (displayName == null) continue;
+
+        // Match against full display name or first word.
+        final firstName = displayName.split(RegExp(r'\s+')).first;
+        if (displayName != name && firstName != name) continue;
+
+        // If we have channel members, only match members of this channel.
+        if (memberPubkeys != null &&
+            !memberPubkeys.contains(profile.pubkey.toLowerCase())) {
+          continue;
+        }
+
+        pubkeys.add(profile.pubkey);
+        break;
+      }
+    }
+
+    return pubkeys.toList();
+  }
+
+  /// Build `e`-tags for a thread reply, matching the desktop convention:
+  /// - Direct reply to thread head: `["e", id, "", "reply"]`
+  /// - Nested reply: `["e", rootId, "", "root"]` + `["e", parentId, "", "reply"]`
+  static List<List<String>> _buildReplyTags(
+    String parentEventId,
+    String? rootEventId,
+  ) {
+    final root = rootEventId ?? parentEventId;
+    if (parentEventId == root) {
+      return [
+        ['e', root, '', 'reply'],
+      ];
+    }
+    return [
+      ['e', root, '', 'root'],
+      ['e', parentEventId, '', 'reply'],
+    ];
+  }
+}
+
+final sendMessageProvider = Provider<SendMessage>((ref) {
+  final config = ref.watch(relayConfigProvider);
+  return SendMessage(
+    signedEventRelay: SignedEventRelay(
+      session: ref.read(relaySessionProvider.notifier),
+      nsec: config.nsec,
+    ),
+    fetchMembers: (channelId) =>
+        ref.read(channelMembersProvider(channelId).future),
+    readUserCache: () => ref.read(userCacheProvider),
+    addLocalMessage: (channelId, event) => ref
+        .read(channelMessagesProvider(channelId).notifier)
+        .addLocalMessage(event),
+    completeLocalMessage: (channelId, eventId) => ref
+        .read(channelMessagesProvider(channelId).notifier)
+        .completeLocalMessage(eventId),
+    removeLocalMessage: (channelId, eventId) => ref
+        .read(channelMessagesProvider(channelId).notifier)
+        .removeLocalMessage(eventId),
+    isDeliveryValid: () {
+      final currentConfig = ref.read(relayConfigProvider);
+      return currentConfig.baseUrl == config.baseUrl &&
+          currentConfig.nsec == config.nsec;
+    },
+  );
+});