import AsyncStorage from '@/utils/kvStore';

interface LogEntry {
  id: string;
  timestamp: number;
  level: 'DEBUG' | 'INFO' | 'WARN' | 'ERROR';
  message: string;
  data?: any;
}

class Logger {
  private static instance: Logger;
  private readonly maxLogs = 1000; // 最多保存1000条日志
  private readonly storageKey = '@app_logs';

  static getInstance(): Logger {
    if (!Logger.instance) {
      Logger.instance = new Logger();
    }
    return Logger.instance;
  }

  private async getLogs(): Promise<LogEntry[]> {
    try {
      const logsJson = await AsyncStorage.getItem(this.storageKey);
      return logsJson ? JSON.parse(logsJson) : [];
    } catch (error) {
      console.error('Failed to get logs from storage:', error);
      return [];
    }
  }

  private async saveLogs(logs: LogEntry[]): Promise<void> {
    try {
      // 只保留最新的maxLogs条日志
      const trimmedLogs = logs.slice(-this.maxLogs);
      await AsyncStorage.setItem(this.storageKey, JSON.stringify(trimmedLogs));
    } catch (error) {
      console.error('Failed to save logs to storage:', error);
    }
  }

  private async addLog(level: LogEntry['level'], message: string, data?: any): Promise<void> {
    const logEntry: LogEntry = {
      id: Date.now().toString() + Math.random().toString(36).substr(2, 9),
      timestamp: Date.now(),
      level,
      message,
      data
    };

    // 同时在控制台输出
    const logMethod = level === 'ERROR' ? console.error : 
                     level === 'WARN' ? console.warn : 
                     level === 'INFO' ? console.info : console.log;
    
    logMethod(`[${level}] ${message}`, data || '');

    try {
      const logs = await this.getLogs();
      logs.push(logEntry);
      await this.saveLogs(logs);
    } catch (error) {
      console.error('Failed to add log:', error);
    }
  }

  async debug(message: string, data?: any): Promise<void> {
    await this.addLog('DEBUG', message, data);
  }

  async info(message: string, data?: any): Promise<void> {
    await this.addLog('INFO', message, data);
  }

  async warn(message: string, data?: any): Promise<void> {
    await this.addLog('WARN', message, data);
  }

  async error(message: string, data?: any): Promise<void> {
    await this.addLog('ERROR', message, data);
  }

  async getAllLogs(): Promise<LogEntry[]> {
    return await this.getLogs();
  }

  async clearLogs(): Promise<void> {
    try {
      await AsyncStorage.removeItem(this.storageKey);
    } catch (error) {
      console.error('Failed to clear logs:', error);
    }
  }

  async exportLogs(): Promise<string> {
    const logs = await this.getLogs();
    return JSON.stringify(logs, null, 2);
  }
}

// 导出全局日志实例和便捷函数
export const logger = Logger.getInstance();

// 便捷的全局日志函数
export const log = {
  debug: (message: string, data?: any) => logger.debug(message, data),
  info: (message: string, data?: any) => logger.info(message, data),
  warn: (message: string, data?: any) => logger.warn(message, data),
  error: (message: string, data?: any) => logger.error(message, data),
};

export type { LogEntry };