feat: Random.org dice and daily word matrix, interpreter voices, curated lexicon

Wire cleromancy rolls and the once-per-UTC-day 000-999 word shuffle to RANDOM.ORG JSON-RPC, with a local CSPRNG fallback. Add settings for interpreter personas and a cleaner default oracle prompt. Replace proper names and bureaucratic filler in the 1000-word lexicon with sacred symbols.

lib/services/words_repository.dart

@@ -3,6 +3,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 import '../data/words_data.dart';
 import '../models/history_entry_model.dart';
 import '../models/word_model.dart';
+import 'true_random_service.dart';
 
 class WordsRepository {
   static final WordsRepository _instance = WordsRepository._internal();
@@ -10,43 +11,112 @@ class WordsRepository {
   WordsRepository._internal();
 
   static const String _kHistoryKey = 'oracle_999_sessions_history_v2';
+  static const String _kMappingDateKey = 'oracle_daily_mapping_date_v1';
+  static const String _kMappingOrderKey = 'oracle_daily_mapping_order_v1';
+  static const String _kMappingSourceKey = 'oracle_daily_mapping_source_v1';
 
   List<WordItem> _sessionWords = [];
   final List<OracleSession> _sessions = [];
+  bool _useRemoteShuffle = true;
+  String? _dailyMappingDate;
+  RandomSource _dailyMappingSource = RandomSource.local;
 
   List<WordItem> get allWords => List.unmodifiable(_sessionWords);
   List<OracleSession> get sessions => List.unmodifiable(_sessions);
   List<OracleSession> get history => sessions; // Alias for compatibility
   int get totalWords => _sessionWords.length;
+  String? get dailyMappingDate => _dailyMappingDate;
+  RandomSource get dailyMappingSource => _dailyMappingSource;
 
-  Future<void> init() async {
-    // 1. Initialize random session mapping
-    _initializeSessionMapping();
-
-    // 2. Load stored session history
+  Future<void> init({bool remoteDailyShuffle = true}) async {
+    _useRemoteShuffle = remoteDailyShuffle;
+    await _restoreOrFetchDailyMapping(force: false);
     await _loadHistoryFromPrefs();
   }
 
-  void _initializeSessionMapping() {
-    final list = List<WordItem>.from(kRussianTop1000Words);
-    final random = Random();
+  Future<RandomSource> reshuffleSessionNumbers() {
+    return _restoreOrFetchDailyMapping(force: true);
+  }
 
-    // Fisher-Yates shuffle
-    for (int i = list.length - 1; i > 0; i--) {
-      int n = random.nextInt(i + 1);
-      final temp = list[i];
-      list[i] = list[n];
-      list[n] = temp;
+  Future<RandomSource> _restoreOrFetchDailyMapping({required bool force}) async {
+    final today = utcDateStamp();
+    if (!force) {
+      final restored = await _loadPersistedMapping(today);
+      if (restored) return _dailyMappingSource;
     }
 
-    _sessionWords = [];
-    for (int i = 0; i < list.length; i++) {
-      _sessionWords.add(list[i].copyWith(sessionNumber: i));
+    final lastId = kRussianTop1000Words.length - 1;
+    RangeShuffle shuffle;
+    if (_useRemoteShuffle) {
+      shuffle = await TrueRandomService.instance.permutation(
+        min: 0,
+        max: lastId,
+      );
+    } else {
+      shuffle = RangeShuffle(
+        TrueRandomService.instance.localPermutation(0, lastId),
+        RandomSource.local,
+      );
+    }
+
+    _applyIndexOrder(shuffle.order);
+    _dailyMappingDate = today;
+    _dailyMappingSource = shuffle.source;
+    await _persistMapping(today, shuffle.order, shuffle.source);
+    return shuffle.source;
+  }
+
+  void _applyIndexOrder(List<int> order) {
+    _sessionWords = [
+      for (var i = 0; i < order.length; i++)
+        kRussianTop1000Words[order[i]].copyWith(sessionNumber: i),
+    ];
+  }
+
+  Future<bool> _loadPersistedMapping(String today) async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      final date = prefs.getString(_kMappingDateKey);
+      final stored = prefs.getStringList(_kMappingOrderKey);
+      if (date != today || stored == null) return false;
+      final order = stored.map(int.parse).toList();
+      if (!isPermutation(order, 0, kRussianTop1000Words.length - 1)) {
+        return false;
+      }
+      _applyIndexOrder(order);
+      _dailyMappingDate = date;
+      final sourceName = prefs.getString(_kMappingSourceKey);
+      _dailyMappingSource = sourceName == RandomSource.randomOrg.name
+          ? RandomSource.randomOrg
+          : RandomSource.local;
+      return true;
+    } catch (_) {
+      return false;
     }
   }
 
-  void reshuffleSessionNumbers() {
-    _initializeSessionMapping();
+  Future<void> _persistMapping(
+    String date,
+    List<int> order,
+    RandomSource source,
+  ) async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString(_kMappingDateKey, date);
+      await prefs.setStringList(
+        _kMappingOrderKey,
+        order.map((e) => e.toString()).toList(),
+      );
+      await prefs.setString(_kMappingSourceKey, source.name);
+    } catch (_) {}
+  }
+
+  static String utcDateStamp([DateTime? now]) {
+    final d = (now ?? DateTime.now()).toUtc();
+    final y = d.year.toString().padLeft(4, '0');
+    final m = d.month.toString().padLeft(2, '0');
+    final day = d.day.toString().padLeft(2, '0');
+    return '$y-$m-$day';
   }
 
   WordItem? getWordBySessionNumber(int number) {
@@ -55,7 +125,7 @@ class WordsRepository {
   }
 
   WordItem getRandomWord() {
-    final random = Random();
+    final random = Random.secure();
     final idx = random.nextInt(_sessionWords.length);
     return _sessionWords[idx];
   }