import '../database/app_usage_dao.dart';
import '../database/daily_stats_dao.dart';
import '../theme/app_theme.dart';

class ExportService {
  final AppUsageDao _appUsageDao = AppUsageDao();
  final DailyStatsDao _dailyStatsDao = DailyStatsDao();

  /// 导出 CSV 格式数据
  Future<String> exportToCSV({
    required DateTime startDate,
    required DateTime endDate,
  }) async {
    final appUsages = await _appUsageDao.getAppUsages(
      startTime: startDate,
      endTime: endDate,
    );

    final buffer = StringBuffer();
    
    // CSV 头部
    buffer.writeln('应用名称,包名,开始时间,结束时间,使用时长(秒),使用时长(格式化),分类');

    // 数据行
    for (final usage in appUsages) {
      buffer.writeln([
        _escapeCsvField(usage.appName),
        _escapeCsvField(usage.packageName),
        usage.startTime.toIso8601String(),
        usage.endTime.toIso8601String(),
        usage.duration.toString(),
        usage.formattedDuration,
        AppTheme.getCategoryName(usage.category),
      ].join(','));
    }

    return buffer.toString();
  }

  /// 导出统计报告（文本格式）
  Future<String> exportStatsReport({
    required DateTime startDate,
    required DateTime endDate,
  }) async {
    final stats = await _dailyStatsDao.getStatsRange(
      startDate: startDate,
      endDate: endDate,
    );

    final buffer = StringBuffer();
    
    buffer.writeln('=== AutoTime Tracker 统计报告 ===');
    buffer.writeln('报告时间: ${startDate.toString().split(' ')[0]} 至 ${endDate.toString().split(' ')[0]}');
    buffer.writeln('');
    buffer.writeln('日期统计:');
    buffer.writeln('');

    int totalWorkTime = 0;
    int totalStudyTime = 0;
    int totalEntertainmentTime = 0;
    int totalSocialTime = 0;
    int totalToolTime = 0;
    int totalTime = 0;

    for (final stat in stats) {
      buffer.writeln('${stat.date.toString().split(' ')[0]}:');
      buffer.writeln('  总时长: ${stat.formattedTotalTime}');
      buffer.writeln('  工作: ${_formatTime(stat.workTime)}');
      buffer.writeln('  学习: ${_formatTime(stat.studyTime)}');
      buffer.writeln('  娱乐: ${_formatTime(stat.entertainmentTime)}');
      buffer.writeln('  社交: ${_formatTime(stat.socialTime)}');
      buffer.writeln('  工具: ${_formatTime(stat.toolTime)}');
      if (stat.efficiencyScore != null) {
        buffer.writeln('  效率评分: ${stat.efficiencyScore}%');
      }
      buffer.writeln('');

      totalWorkTime += stat.workTime;
      totalStudyTime += stat.studyTime;
      totalEntertainmentTime += stat.entertainmentTime;
      totalSocialTime += stat.socialTime;
      totalToolTime += stat.toolTime;
      totalTime += stat.totalTime;
    }

    buffer.writeln('总计:');
    buffer.writeln('  总时长: ${_formatTime(totalTime)}');
    buffer.writeln('  工作: ${_formatTime(totalWorkTime)} (${(totalWorkTime / totalTime * 100).toStringAsFixed(1)}%)');
    buffer.writeln('  学习: ${_formatTime(totalStudyTime)} (${(totalStudyTime / totalTime * 100).toStringAsFixed(1)}%)');
    buffer.writeln('  娱乐: ${_formatTime(totalEntertainmentTime)} (${(totalEntertainmentTime / totalTime * 100).toStringAsFixed(1)}%)');
    buffer.writeln('  社交: ${_formatTime(totalSocialTime)} (${(totalSocialTime / totalTime * 100).toStringAsFixed(1)}%)');
    buffer.writeln('  工具: ${_formatTime(totalToolTime)} (${(totalToolTime / totalTime * 100).toStringAsFixed(1)}%)');

    return buffer.toString();
  }

  /// 导出今日报告
  Future<String> exportTodayReport() async {
    final today = DateTime.now();
    final startOfDay = DateTime(today.year, today.month, today.day);
    final endOfDay = startOfDay.add(const Duration(days: 1));

    final stats = await _dailyStatsDao.getTodayStats();
    final topApps = await _appUsageDao.getTopApps(
      startTime: startOfDay,
      endTime: endOfDay,
      limit: 10,
    );

    final buffer = StringBuffer();
    
    buffer.writeln('=== AutoTime Tracker 今日报告 ===');
    buffer.writeln('日期: ${today.toString().split(' ')[0]}');
    buffer.writeln('');

    if (stats != null) {
      buffer.writeln('总时长: ${stats.formattedTotalTime}');
      buffer.writeln('工作: ${_formatTime(stats.workTime)}');
      buffer.writeln('学习: ${_formatTime(stats.studyTime)}');
      buffer.writeln('娱乐: ${_formatTime(stats.entertainmentTime)}');
      buffer.writeln('社交: ${_formatTime(stats.socialTime)}');
      buffer.writeln('工具: ${_formatTime(stats.toolTime)}');
      if (stats.efficiencyScore != null) {
        buffer.writeln('效率评分: ${stats.efficiencyScore}%');
      }
      buffer.writeln('');
    }

    if (topApps.isNotEmpty) {
      buffer.writeln('Top 应用:');
      for (int i = 0; i < topApps.length; i++) {
        final app = topApps[i];
        buffer.writeln('${i + 1}. ${app.appName}: ${app.formattedDuration} (${AppTheme.getCategoryName(app.category)})');
      }
    }

    return buffer.toString();
  }

  String _escapeCsvField(String field) {
    if (field.contains(',') || field.contains('"') || field.contains('\n')) {
      return '"${field.replaceAll('"', '""')}"';
    }
    return field;
  }

  String _formatTime(int seconds) {
    final hours = seconds ~/ 3600;
    final minutes = (seconds % 3600) ~/ 60;
    if (hours > 0) {
      return '${hours}h ${minutes}m';
    }
    return '${minutes}m';
  }
}