feat: import Chinese-localized Buzz source snapshot

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

mobile/lib/features/search/search_provider.dart

@@ -0,0 +1,218 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+import '../../shared/relay/relay.dart';
+import '../channels/channel.dart';
+import '../channels/channel_management_provider.dart';
+import '../channels/channels_provider.dart';
+
+@immutable
+class SearchHit {
+  final String eventId;
+  final String content;
+  final int kind;
+  final String pubkey;
+  final String? channelId;
+  final String? channelName;
+  final int createdAt;
+  final double score;
+  final List<List<String>> tags;
+
+  const SearchHit({
+    required this.eventId,
+    required this.content,
+    required this.kind,
+    required this.pubkey,
+    this.channelId,
+    this.channelName,
+    required this.createdAt,
+    required this.score,
+    this.tags = const [],
+  });
+
+  factory SearchHit.fromJson(Map<String, dynamic> json) => SearchHit(
+    eventId: json['event_id'] as String,
+    content: json['content'] as String? ?? '',
+    kind: json['kind'] as int? ?? 9,
+    pubkey: json['pubkey'] as String,
+    channelId: json['channel_id'] as String?,
+    channelName: json['channel_name'] as String?,
+    createdAt: json['created_at'] as int? ?? 0,
+    score: (json['score'] as num?)?.toDouble() ?? 0.0,
+    tags:
+        (json['tags'] as List<dynamic>?)
+            ?.map((t) => (t as List<dynamic>).map((e) => e as String).toList())
+            .toList() ??
+        const [],
+  );
+}
+
+@immutable
+class SearchState {
+  final String query;
+  final List<SearchHit> messageResults;
+  final List<DirectoryUser> userResults;
+  final List<Channel> channelResults;
+  final bool isLoading;
+  final String? error;
+
+  const SearchState({
+    this.query = '',
+    this.messageResults = const [],
+    this.userResults = const [],
+    this.channelResults = const [],
+    this.isLoading = false,
+    this.error,
+  });
+
+  const SearchState.initial()
+    : query = '',
+      messageResults = const [],
+      userResults = const [],
+      channelResults = const [],
+      isLoading = false,
+      error = null;
+
+  SearchState copyWith({
+    String? query,
+    List<SearchHit>? messageResults,
+    List<DirectoryUser>? userResults,
+    List<Channel>? channelResults,
+    bool? isLoading,
+    String? error,
+  }) => SearchState(
+    query: query ?? this.query,
+    messageResults: messageResults ?? this.messageResults,
+    userResults: userResults ?? this.userResults,
+    channelResults: channelResults ?? this.channelResults,
+    isLoading: isLoading ?? this.isLoading,
+    error: error ?? this.error,
+  );
+}
+
+class SearchNotifier extends Notifier<SearchState> {
+  Timer? _debounce;
+
+  @override
+  SearchState build() {
+    // Watch relayConfig so search state resets on community switch.
+    ref.watch(relayConfigProvider);
+    ref.onDispose(() {
+      _debounce?.cancel();
+    });
+    return const SearchState.initial();
+  }
+
+  void search(String query) {
+    _debounce?.cancel();
+
+    final trimmed = query.trim();
+    if (trimmed.isEmpty) {
+      state = const SearchState.initial();
+      return;
+    }
+
+    state = SearchState(query: trimmed, isLoading: true);
+
+    _debounce = Timer(const Duration(milliseconds: 300), () {
+      _executeSearch(trimmed);
+    });
+  }
+
+  Future<void> _executeSearch(String query) async {
+    // If the query changed while debouncing, bail out.
+    if (state.query != query) return;
+
+    // Fire all three lookups in parallel.
+    _searchMessages(query);
+    _searchUsers(query);
+    _searchChannels(query);
+  }
+
+  Future<void> _searchMessages(String query) async {
+    try {
+      final session = ref.read(relaySessionProvider.notifier);
+      final events = await session.fetchHistory(
+        NostrFilter(
+          kinds: const [9, 40002, 45001, 45003],
+          search: query,
+          limit: 20,
+        ),
+      );
+
+      // Channel-name lookup from the cached channels list — not all hits
+      // will have a known channel (e.g. ones we're not a member of).
+      final channelsById = {
+        for (final c in ref.read(channelsProvider).value ?? const <Channel>[])
+          c.id: c.name,
+      };
+
+      final hits = events
+          .map(
+            (e) => SearchHit(
+              eventId: e.id,
+              content: e.content,
+              kind: e.kind,
+              pubkey: e.pubkey,
+              channelId: e.channelId,
+              channelName: e.channelId != null
+                  ? channelsById[e.channelId!]
+                  : null,
+              createdAt: e.createdAt,
+              score: 0.0,
+              tags: e.tags,
+            ),
+          )
+          .toList();
+
+      if (state.query != query) return;
+      state = state.copyWith(messageResults: hits, isLoading: false);
+    } catch (e) {
+      if (state.query != query) return;
+      state = state.copyWith(isLoading: false, error: e.toString());
+    }
+  }
+
+  Future<void> _searchUsers(String query) async {
+    try {
+      final users = await ref
+          .read(channelActionsProvider)
+          .searchUsers(query, limit: 8);
+
+      if (state.query != query) return;
+      state = state.copyWith(
+        userResults: users,
+        isLoading: state.messageResults.isEmpty && state.channelResults.isEmpty,
+      );
+    } catch (_) {
+      // User search failure is non-critical — keep existing results.
+    }
+  }
+
+  void _searchChannels(String query) {
+    final channels = ref.read(channelsProvider).value ?? [];
+    final lowerQuery = query.toLowerCase();
+    final matches = channels.where((c) {
+      if (c.isDm) return false;
+      return c.name.toLowerCase().contains(lowerQuery) ||
+          c.description.toLowerCase().contains(lowerQuery);
+    }).toList();
+
+    if (state.query != query) return;
+    state = state.copyWith(
+      channelResults: matches,
+      isLoading: state.messageResults.isEmpty && state.userResults.isEmpty,
+    );
+  }
+
+  void clear() {
+    _debounce?.cancel();
+    state = const SearchState.initial();
+  }
+}
+
+final searchProvider = NotifierProvider<SearchNotifier, SearchState>(
+  SearchNotifier.new,
+);