import { IPC_EVENTS } from '@runtime/lib/constants';
import { promisify } from 'util';
import { ipcMain } from 'electron';
import log from 'electron-log';
import * as path from 'path';
import * as fs from 'fs';
import { getUserDataDir } from '@electron/utils/paths';

// 转换为Promise形式的fs方法
const readdirAsync = promisify(fs.readdir);
const statAsync = promisify(fs.stat);
const unlinkAsync = promisify(fs.unlink);

class LogService {
  private static _instance: LogService;
  private readonly logDirPath: string;

  // 日志保留天数，默认7天
  private LOG_RETENTION_DAYS = 7;

  // 清理间隔，默认24小时（毫秒）
  private readonly CLEANUP_INTERVAL_MS = 24 * 60 * 60 * 1000;

  private constructor() {
    this.logDirPath = path.join(getUserDataDir(), 'logs');
    const logPath = this.logDirPath;
    // c:users/{username}/AppData/Roaming/{appName}/logs

    // 创建日志目录
    try {
      if (!fs.existsSync(logPath)) {
        fs.mkdirSync(logPath, { recursive: true });
      }
    } catch (err) {
      this.error('Failed to create log directory:', err);
    }

    // 配置electron-log
    log.transports.file.resolvePathFn = () => {
      // 使用当前日期作为日志文件名，格式为 YYYY-MM-DD.log
      const today = new Date();
      const formattedDate = `${today.getFullYear()}-${String(today.getMonth() + 1).padStart(2, '0')}-${String(today.getDate()).padStart(2, '0')}`;
      return path.join(logPath, `${formattedDate}.log`);
    };

    // 配置日志格式
    log.transports.file.format = '[{y}-{m}-{d} {h}:{i}:{s}.{ms}] [{level}] {text}';

    // 配置日志文件大小限制，默认10MB
    log.transports.file.maxSize = 10 * 1024 * 1024; // 10MB

    // 配置控制台日志级别，开发环境可以设置为debug，生产环境可以设置为info
    log.transports.console.level = process.env.NODE_ENV === 'development' ? 'debug' : 'info';

    // 配置文件日志级别
    log.transports.file.level = 'debug';

    // 设置IPC事件
    this._setupIpcEvents();
    // 重写console方法
    this._rewriteConsole();


    this.info('LogService initialized successfully.');
    this._cleanupOldLogs();
    // 定时清理旧日志
    setInterval(() => this._cleanupOldLogs(), this.CLEANUP_INTERVAL_MS);
  }

  private _setupIpcEvents() {
    ipcMain.on(IPC_EVENTS.LOG_DEBUG, (_e, message: string, ...meta: any[]) => this.debug(message, ...meta));
    ipcMain.on(IPC_EVENTS.LOG_INFO, (_e, message: string, ...meta: any[]) => this.info(message, ...meta));
    ipcMain.on(IPC_EVENTS.LOG_WARN, (_e, message: string, ...meta: any[]) => this.warn(message, ...meta));
    ipcMain.on(IPC_EVENTS.LOG_ERROR, (_e, message: string, ...meta: any[]) => this.error(message, ...meta));
  }

  private _rewriteConsole() {
    console.debug = log.debug;
    console.log = log.info;
    console.info = log.info;
    console.warn = log.warn;
    console.error = log.error;
  }

  private async _cleanupOldLogs() {
    try {
      const logPath = path.join(getUserDataDir(), 'logs');

      if (!fs.existsSync(logPath)) return;

      const now = new Date();
      const expirationDate = new Date(now.getTime() - this.LOG_RETENTION_DAYS * 24 * 60 * 60 * 1000);

      const files = await readdirAsync(logPath);

      let deletedCount = 0;

      for (const file of files) {
        if (!file.endsWith('.log')) continue;
        const filePath = path.join(logPath, file);
        try {
          const stats = await statAsync(filePath);
          if (stats.isFile() && (stats.birthtime < expirationDate)) {
            await unlinkAsync(filePath);
            deletedCount++;
          }
        } catch (error) {
          this.error(`Failed to delete old log file ${filePath}:`, error);
        }
      }
      if (deletedCount > 0) {
        this.info(`Successfully cleaned up ${deletedCount} old log files.`);
      }

    } catch (err) {
      this.error('Failed to cleanup old logs:', err);
    }
  }

  public static getInstance(): LogService {
    if (!this._instance) {
      this._instance = new LogService();
    }
    return this._instance;
  }

  /**
   * 记录调试信息
   * @param {string} message - 日志消息
   * @param {any[]} meta - 附加的元数据
   */
  public debug(message: string, ...meta: any[]): void {
    log.debug(message, ...meta);
  }

  /**
   * 记录一般信息
   * @param {string} message - 日志消息
   * @param {any[]} meta - 附加的元数据
   */
  public info(message: string, ...meta: any[]): void {
    log.info(message, ...meta);
  }

  /**
   * 记录警告信息
   * @param {string} message - 日志消息
   * @param {any[]} meta - 附加的元数据
   */
  public warn(message: string, ...meta: any[]): void {
    log.warn(message, ...meta);
  }

  /**
   * 记录错误信息
   * @param {string} message - 日志消息
   * @param {any[]} meta - 附加的元数据，通常是错误对象
   */
  public error(message: string, ...meta: any[]): void {
    log.error(message, ...meta);
  }


  public logApiRequest(endpoint: string, data: any = {}, method: string = 'POST'): void {
    this.info(`API Request: ${endpoint}, Method: ${method}, Request: ${JSON.stringify(data)}`);
  }

  public logApiResponse(endpoint: string, response: any = {}, statusCode: number = 200, responseTime: number = 0): void {
    if (statusCode >= 400) {
      this.error(`API Error Response: ${endpoint}, Status: ${statusCode}, Response Time: ${responseTime}ms, Response: ${JSON.stringify(response)}`);
    } else {
      this.debug(`API Response: ${endpoint}, Status: ${statusCode}, Response Time: ${responseTime}ms, Response: ${JSON.stringify(response)}`);
    }
  }

  public logUserOperation(operation: string, userId: string = 'unknown', details: any = {}): void {
    this.info(`User Operation: ${operation} by ${userId}, Details: ${JSON.stringify(details)}`);
  }

  public async readRecentLogText(tailLines: number = 200): Promise<string> {
    const safeTailLines = Number.isFinite(tailLines) ? Math.max(1, Math.floor(tailLines)) : 200;
    const filePath = this._getCurrentLogFilePath();

    if (!fs.existsSync(filePath)) {
      return '';
    }

    const file = await fs.promises.open(filePath, 'r');

    try {
      const fileStat = await file.stat();
      if (fileStat.size === 0) {
        return '';
      }

      const chunkSize = 64 * 1024;
      let position = fileStat.size;
      let content = '';
      let lineCount = 0;

      while (position > 0 && lineCount <= safeTailLines) {
        const bytesToRead = Math.min(chunkSize, position);
        position -= bytesToRead;

        const buffer = Buffer.allocUnsafe(bytesToRead);
        await file.read(buffer, 0, bytesToRead, position);
        content = `${buffer.toString('utf-8')}${content}`;
        lineCount = content.split('\n').length - 1;
      }

      const lines = content.split('\n');
      if (lines.length <= safeTailLines) {
        return content;
      }

      return lines.slice(-safeTailLines).join('\n');
    } finally {
      await file.close();
    }
  }

  private _getCurrentLogFilePath(): string {
    const today = new Date();
    const formattedDate = `${today.getFullYear()}-${String(today.getMonth() + 1).padStart(2, '0')}-${String(today.getDate()).padStart(2, '0')}`;
    return path.join(this.logDirPath, `${formattedDate}.log`);
  }

}

export const logManager = LogService.getInstance();
export default logManager;