feat: import Chinese-localized Buzz source snapshot

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

mobile/lib/shared/theme/community_theme_preference.dart

@@ -0,0 +1,167 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'accent_colors.dart';
+import 'theme_catalog.dart';
+import 'theme_provider.dart' show effectiveTheme, schemeForAppearanceMode;
+
+const communityThemeDTag = 'community-theme';
+const defaultCommunityTheme = CommunityThemePreference(
+  theme: 'buzz',
+  accent: '#3b82f6',
+  followSystem: true,
+);
+
+class CommunityThemePreference {
+  final int version;
+  final String theme;
+  final String accent;
+  final bool followSystem;
+
+  const CommunityThemePreference({
+    this.version = 1,
+    required this.theme,
+    required this.accent,
+    required this.followSystem,
+  });
+
+  factory CommunityThemePreference.fromJson(Map<String, dynamic> json) {
+    if (json['version'] != 1 ||
+        json['theme'] is! String ||
+        findTheme(json['theme'] as String) == null ||
+        json['accent'] is! String ||
+        accentIndexForWireValue(json['accent'] as String) == null ||
+        json['followSystem'] is! bool) {
+      throw const FormatException('Invalid community theme preference');
+    }
+    return CommunityThemePreference(
+      theme: json['theme'] as String,
+      accent: json['accent'] as String,
+      followSystem: json['followSystem'] as bool,
+    );
+  }
+
+  Map<String, dynamic> toJson() => {
+    'version': version,
+    'theme': theme,
+    'accent': accent,
+    'followSystem': followSystem,
+  };
+
+  ThemeMode get mode {
+    if (followSystem) return ThemeMode.system;
+    return findTheme(theme)?.isDark == true ? ThemeMode.dark : ThemeMode.light;
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      other is CommunityThemePreference &&
+      theme == other.theme &&
+      accent == other.accent &&
+      followSystem == other.followSystem;
+
+  @override
+  int get hashCode => Object.hash(theme, accent, followSystem);
+}
+
+class CommunityThemeStorage {
+  static const _prefix = 'buzz-community-theme.v1';
+  static const _outboxPrefix = 'buzz-community-theme-outbox.v1';
+  static const _migrationPrefix = 'buzz-community-theme-migrated.v1';
+  static const _legacyModeKey = 'buzz_theme_mode';
+  static const _legacyAccentKey = 'buzz_accent_color';
+  static const _legacySchemeKey = 'buzz_color_scheme';
+
+  final SharedPreferences prefs;
+
+  const CommunityThemeStorage(this.prefs);
+
+  String key(String pubkey, String relayUrl) =>
+      '$_prefix:$pubkey:${Uri.encodeComponent(normalizeCommunityRelayUrl(relayUrl))}';
+
+  String outboxKey(String pubkey, String relayUrl) =>
+      '$_outboxPrefix:$pubkey:${Uri.encodeComponent(normalizeCommunityRelayUrl(relayUrl))}';
+
+  CommunityThemePreference? _readKey(String storageKey) {
+    try {
+      final raw = prefs.getString(storageKey);
+      if (raw == null) return null;
+      final decoded = jsonDecode(raw);
+      if (decoded is! Map<String, dynamic>) return null;
+      return CommunityThemePreference.fromJson(decoded);
+    } catch (_) {
+      return null;
+    }
+  }
+
+  CommunityThemePreference? read(String pubkey, String relayUrl) =>
+      _readKey(key(pubkey, relayUrl));
+
+  CommunityThemePreference? readOutbox(String pubkey, String relayUrl) =>
+      _readKey(outboxKey(pubkey, relayUrl));
+
+  Future<bool> write(
+    String pubkey,
+    String relayUrl,
+    CommunityThemePreference preference,
+  ) => prefs.setString(key(pubkey, relayUrl), jsonEncode(preference.toJson()));
+
+  Future<bool> writeOutbox(
+    String pubkey,
+    String relayUrl,
+    CommunityThemePreference preference,
+  ) => prefs.setString(
+    outboxKey(pubkey, relayUrl),
+    jsonEncode(preference.toJson()),
+  );
+
+  Future<void> clearOutbox(
+    String pubkey,
+    String relayUrl,
+    CommunityThemePreference acknowledged,
+  ) async {
+    if (readOutbox(pubkey, relayUrl) == acknowledged) {
+      await prefs.remove(outboxKey(pubkey, relayUrl));
+    }
+  }
+
+  bool hasMigrated(String pubkey) =>
+      prefs.getBool('$_migrationPrefix:$pubkey') == true;
+
+  Future<bool> markMigrated(String pubkey) =>
+      prefs.setBool('$_migrationPrefix:$pubkey', true);
+
+  Future<void> writeLegacy(CommunityThemePreference preference) async {
+    await prefs.setString(_legacyModeKey, preference.mode.name);
+    await prefs.setString(_legacySchemeKey, preference.theme);
+    await prefs.setInt(
+      _legacyAccentKey,
+      accentIndexForWireValue(preference.accent) ?? defaultAccentIndex,
+    );
+  }
+
+  CommunityThemePreference legacyPreference() {
+    final modeName = prefs.getString(_legacyModeKey);
+    final mode =
+        ThemeMode.values.where((value) => value.name == modeName).firstOrNull ??
+        ThemeMode.system;
+    final storedTheme = prefs.getString(_legacySchemeKey);
+    final theme = findTheme(storedTheme ?? 'buzz')?.name ?? 'buzz';
+    final legacyAccent = prefs.getInt(_legacyAccentKey);
+    final resolvedTheme = switch (mode) {
+      ThemeMode.system => schemeForAppearanceMode(theme, mode) ?? theme,
+      ThemeMode.light ||
+      ThemeMode.dark => effectiveTheme(theme, mode)?.name ?? theme,
+    };
+    return CommunityThemePreference(
+      theme: resolvedTheme,
+      accent: legacyAccentWireValue(legacyAccent),
+      followSystem: mode == ThemeMode.system,
+    );
+  }
+}
+
+String normalizeCommunityRelayUrl(String relayUrl) =>
+    relayUrl.trim().replaceFirst(RegExp(r'/+$'), '').toLowerCase();