import { autoUpdater } from 'electron-updater';
import { BrowserWindow, ipcMain, app } from 'electron';
import { IPC_EVENTS } from '@runtime/lib/constants';

export class AppUpdater {
  private mainWindow: BrowserWindow | null = null;
  private static _instance: AppUpdater;
  private _initialized: boolean = false;

  private constructor() {
    autoUpdater.autoDownload = false;
  }

  public init() {
    if (this._initialized) return;
    this._initialized = true;
    this.setupListeners();
    this.registerHandlers();
  }

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

  setMainWindow(window: BrowserWindow) {
    this.mainWindow = window;
  }

  private setupListeners() {
    autoUpdater.on('checking-for-update', () => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'checking' }));
    autoUpdater.on('update-available', (info) => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'available', info }));
    autoUpdater.on('update-not-available', () => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'not-available' }));
    autoUpdater.on('download-progress', (progress) => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'downloading', progress }));
    autoUpdater.on('update-downloaded', (info) => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'downloaded', info }));
    autoUpdater.on('error', (error) => this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'error', error: error.message }));
  }

  private sendToRenderer(channel: string, data: any) {
    BrowserWindow.getAllWindows().forEach(win => {
      if (!win.isDestroyed()) {
        win.webContents.send(channel, data);
      }
    });
  }

  private registerHandlers() {
    ipcMain.handle(IPC_EVENTS.UPDATE_CHECK, () => {
      if (app.isPackaged) {
        return autoUpdater.checkForUpdates();
      } else {
        // 在开发环境下模拟
        this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'checking' });
        setTimeout(() => {
          this.sendToRenderer(IPC_EVENTS.UPDATE_STATUS_CHANGED, { status: 'not-available' });
        }, 1500);
        return null;
      }
    });
    
    ipcMain.handle(IPC_EVENTS.UPDATE_DOWNLOAD, () => {
      if (app.isPackaged) {
        return autoUpdater.downloadUpdate();
      }
      return null;
    });
    
    ipcMain.handle(IPC_EVENTS.UPDATE_INSTALL, () => {
      if (app.isPackaged) {
        return autoUpdater.quitAndInstall();
      }
      return null;
    });

    ipcMain.handle(IPC_EVENTS.UPDATE_VERSION, () => {
      return app.getVersion();
    });
  }
}

export const appUpdater = AppUpdater.getInstance();