feat(ui):优化ohos日志

@@ -7,7 +7,7 @@ import 'package:path_provider/path_provider.dart';
 
 import 'app_logger.dart';
 
-/// Persists a compact, privacy-safe timeline of the OHOS health data pipeline.
+/// Persists a privacy-safe timeline of the OHOS health data pipeline.
 ///
 /// Writes are queued and intentionally fire-and-forget so health callbacks,
 /// calculation, and push delivery are never blocked by file I/O. Call
@@ -18,9 +18,10 @@ class OhosHealthFlowLogStore {
 
   static final OhosHealthFlowLogStore instance = OhosHealthFlowLogStore();
 
-  static const fileName = 'ohos_health_flow_events.json';
-  static const _retention = Duration(days: 7);
-  static const _maxEventCount = 1000;
+  static const _fileNamePrefix = 'ohos_health_flow_events_';
+  static const _fileNameSuffix = '.json';
+  static const _legacyFileName = 'ohos_health_flow_events.json';
+  static const _retainedDays = 7;
 
   final Directory? _rootDirectory;
   Future<void> _writeQueue = Future<void>.value();
@@ -49,18 +50,15 @@ class OhosHealthFlowLogStore {
           if (details != null && details.isNotEmpty)
             'details': _sanitizeMap(details),
         };
-        final file = await _file();
-        await file.parent.create(recursive: true);
-        final cutoff = now.subtract(_retention);
-        final events = (await _readEvents(file))
-            .where((item) => _isWithinRetention(item, cutoff))
-            .toList()
-          ..add(event);
-        final retained = events.length > _maxEventCount
-            ? events.sublist(events.length - _maxEventCount)
-            : events;
+        final root = await _root();
+        await root.create(recursive: true);
+        await _migrateLegacyFile(root, now);
+        await _deleteExpiredDailyFiles(root, now);
+        final file = _fileFor(root, now);
+        final events = await _readEvents(file);
+        events.add(event);
         await file.writeAsString(
-          const JsonEncoder.withIndent('  ').convert(retained),
+          const JsonEncoder.withIndent('  ').convert(events),
           flush: true,
         );
       } catch (error, stackTrace) {
@@ -77,7 +75,7 @@ class OhosHealthFlowLogStore {
   /// Returns the complete file after all previously queued writes finish.
   Future<Uint8List> readBytes() async {
     await _writeQueue;
-    final file = await _file();
+    final file = _fileFor(await _root(), DateTime.now());
     if (!await file.exists()) {
       return Uint8List.fromList(
         utf8.encode('[{"message":"No OHOS health flow logs found"}]'),
@@ -86,11 +84,79 @@ class OhosHealthFlowLogStore {
     return file.readAsBytes();
   }
 
-  Future<File> _file() async {
-    final root = _rootDirectory ?? await getApplicationDocumentsDirectory();
-    return File('${root.path}/$fileName');
+  Future<Directory> _root() {
+    return _rootDirectory == null
+        ? getApplicationDocumentsDirectory()
+        : Future<Directory>.value(_rootDirectory);
   }
 
+  File _fileFor(Directory root, DateTime date) {
+    return File('${root.path}/${_fileNameFor(date)}');
+  }
+
+  static String _fileNameFor(DateTime date) {
+    final day = '${date.year.toString().padLeft(4, '0')}'
+        '${date.month.toString().padLeft(2, '0')}'
+        '${date.day.toString().padLeft(2, '0')}';
+    return '$_fileNamePrefix$day$_fileNameSuffix';
+  }
+
+  Future<void> _deleteExpiredDailyFiles(Directory root, DateTime now) async {
+    final earliestRetainedDay = DateTime(now.year, now.month, now.day)
+        .subtract(const Duration(days: _retainedDays - 1));
+    await for (final entity in root.list(followLinks: false)) {
+      if (entity is! File) continue;
+      final date = _dateFromFileName(entity.uri.pathSegments.last);
+      if (date != null && date.isBefore(earliestRetainedDay)) {
+        await entity.delete();
+      }
+    }
+  }
+
+  Future<void> _migrateLegacyFile(Directory root, DateTime now) async {
+    final legacyFile = File('${root.path}/$_legacyFileName');
+    if (!await legacyFile.exists()) return;
+
+    final earliestRetainedDay = DateTime(now.year, now.month, now.day)
+        .subtract(const Duration(days: _retainedDays - 1));
+    final eventsByDay = <String, List<Map<String, Object?>>>{};
+    for (final event in await _readEvents(legacyFile)) {
+      final timestamp = event['timestamp'];
+      final date = timestamp is String ? DateTime.tryParse(timestamp) : null;
+      if (date == null || _dayOf(date).isBefore(earliestRetainedDay)) continue;
+      eventsByDay.putIfAbsent(_fileNameFor(date), () => []).add(event);
+    }
+
+    try {
+      for (final entry in eventsByDay.entries) {
+        final file = File('${root.path}/${entry.key}');
+        final events = await _readEvents(file);
+        events.addAll(entry.value);
+        await file.writeAsString(
+          const JsonEncoder.withIndent('  ').convert(events),
+          flush: true,
+        );
+      }
+      await legacyFile.delete();
+    } catch (_) {
+      // Keep the legacy file for the next write if migration cannot finish.
+    }
+  }
+
+  static DateTime? _dateFromFileName(String fileName) {
+    final match =
+        RegExp(r'^ohos_health_flow_events_(\d{8})\.json$').firstMatch(fileName);
+    if (match == null) return null;
+    final day = match.group(1)!;
+    final date = DateTime.tryParse(
+      '${day.substring(0, 4)}-${day.substring(4, 6)}-${day.substring(6, 8)}',
+    );
+    return date != null && _fileNameFor(date) == fileName ? date : null;
+  }
+
+  static DateTime _dayOf(DateTime date) =>
+      DateTime(date.year, date.month, date.day);
+
   Future<List<Map<String, Object?>>> _readEvents(File file) async {
     if (!await file.exists()) return <Map<String, Object?>>[];
     try {
@@ -127,14 +193,4 @@ class OhosHealthFlowLogStore {
 
   static String _limit(String value) =>
       value.length <= 2000 ? value : '${value.substring(0, 2000)}…';
-
-  static bool _isWithinRetention(
-    Map<String, Object?> event,
-    DateTime cutoff,
-  ) {
-    final timestamp = event['timestamp'];
-    if (timestamp is! String) return false;
-    final recordedAt = DateTime.tryParse(timestamp);
-    return recordedAt != null && !recordedAt.isBefore(cutoff);
-  }
 }