import 'dart:async';
// import 'dart:io';
import 'package:logging/logging.dart';
import 'package:sqflite_common_ffi/sqflite_ffi.dart';
import 'mining_task_info.dart';
import '../utils/path_utils.dart';

/// 数据库管理服务
class DatabaseService {
  static final DatabaseService _instance = DatabaseService._internal();
  factory DatabaseService() => _instance;
  DatabaseService._internal();

  final Logger _logger = Logger('DatabaseService');
  Database? _database;

  /// 初始化数据库
  Future<void> initialize() async {
    try {
      // Windows/Desktop: 使用 sqflite_common_ffi
      sqfliteFfiInit();
      databaseFactory = databaseFactoryFfi;

      // 与 Go 版一致，尽量落到 ./bin/mining_task.db
      final dbPath = PathUtils.binFile('mining_task.db');
      
      _database = await databaseFactory.openDatabase(
        dbPath,
        options: OpenDatabaseOptions(
          version: 1,
          onCreate: (db, version) async {
          await db.execute('''
            CREATE TABLE mining_tasks (
              id INTEGER PRIMARY KEY AUTOINCREMENT,
              coin TEXT NOT NULL,
              algo TEXT NOT NULL,
              pool TEXT NOT NULL,
              pool_url TEXT NOT NULL,
              wallet_address TEXT NOT NULL,
              worker_id TEXT NOT NULL,
              pool_user TEXT,
              wallet_mining INTEGER NOT NULL,
              end_timestamp INTEGER NOT NULL,
              miner TEXT NOT NULL,
              status TEXT NOT NULL,
              created_at INTEGER NOT NULL,
              updated_at INTEGER NOT NULL
            )
          ''');
          },
        ),
      );

      _logger.info('数据库初始化成功');
    } catch (e) {
      _logger.severe('数据库初始化失败: $e');
      rethrow;
    }
  }

  /// 插入挖矿任务
  Future<int> insertMiningTask(MiningTaskInfo task) async {
    if (_database == null) {
      await initialize();
    }

    try {
      final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
      return await _database!.insert(
        'mining_tasks',
        {
          'coin': task.coin,
          'algo': task.algo,
          'pool': task.pool,
          'pool_url': task.poolUrl,
          'wallet_address': task.walletAddress,
          'worker_id': task.workerId,
          'pool_user': task.poolUser,
          'wallet_mining': task.walletMining ? 1 : 0,
          'end_timestamp': task.endTimestamp,
          'miner': task.miner,
          'status': 'running',
          'created_at': now,
          'updated_at': now,
        },
      );
    } catch (e) {
      _logger.severe('插入挖矿任务失败: $e');
      rethrow;
    }
  }

  /// 完成挖矿任务
  Future<void> finishMiningTask(int taskId) async {
    if (_database == null) {
      await initialize();
    }

    try {
      final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
      await _database!.update(
        'mining_tasks',
        {
          'status': 'finished',
          'updated_at': now,
        },
        where: 'id = ?',
        whereArgs: [taskId],
      );
    } catch (e) {
      _logger.severe('完成挖矿任务失败: $e');
    }
  }

  /// 加载未完成的挖矿任务
  Future<MiningTaskInfo?> loadUnfinishedTask() async {
    if (_database == null) {
      await initialize();
    }

    try {
      final results = await _database!.query(
        'mining_tasks',
        where: 'status = ?',
        whereArgs: ['running'],
        orderBy: 'created_at DESC',
        limit: 1,
      );

      if (results.isEmpty) {
        return null;
      }

      final row = results.first;
      final currentTime = DateTime.now().millisecondsSinceEpoch ~/ 1000;
      final endTimestamp = row['end_timestamp'] as int;

      if (currentTime >= endTimestamp) {
        // 任务已过期，标记为完成
        await finishMiningTask(row['id'] as int);
        return null;
      }

      return MiningTaskInfo(
        coin: row['coin'] as String,
        algo: row['algo'] as String,
        pool: row['pool'] as String,
        poolUrl: row['pool_url'] as String,
        walletAddress: row['wallet_address'] as String,
        workerId: row['worker_id'] as String,
        poolUser: row['pool_user'] as String?,
        walletMining: (row['wallet_mining'] as int) == 1,
        endTimestamp: endTimestamp,
        miner: row['miner'] as String,
      );
    } catch (e) {
      _logger.severe('加载挖矿任务失败: $e');
      return null;
    }
  }

  /// 获取任务历史
  Future<List<Map<String, dynamic>>> getTaskHistory({int limit = 100}) async {
    if (_database == null) {
      await initialize();
    }

    try {
      return await _database!.query(
        'mining_tasks',
        orderBy: 'created_at DESC',
        limit: limit,
      );
    } catch (e) {
      _logger.severe('获取任务历史失败: $e');
      return [];
    }
  }

  /// 关闭数据库
  Future<void> close() async {
    await _database?.close();
    _database = null;
  }
}