'use strict';

import { getMainWindow } from 'ee-core/electron';
import { downloadService } from '../service/download/downloadService';
import { logger } from 'ee-core/log';

/** 进度推送通道：界面订阅它刷新"下载中"的进度与状态 */
export const DOWNLOAD_PROGRESS_CHANNEL = 'downloadCtl:progress';

/** 把 in-flight 状态推给渲染进程（窗口还没建好时忽略） */
function broadcast(item) {
  try {
    const win = getMainWindow();
    if (win && !win.isDestroyed?.()) win.webContents.send(DOWNLOAD_PROGRESS_CHANNEL, item);
  } catch {
    // 窗口已关闭：忽略
  }
}

/**
 * 下载管理器 IPC：通道名 controller/downloadCtl/<方法>（ee-core 按文件名自动注册）。
 *
 * 统一返回项目约定 {success, data|message}：失败（路径非法/记录不存在/文件被移走）不抛到 Electron 层，
 * 前端看 message 即可提示。
 */
class DownloadCtl {
  /** 保存一次下载：params { fileName, mime?, data(ArrayBuffer|base64), source? } */
  async saveDownload(params) {
    try {
      return { success: true, data: downloadService.save(params) };
    } catch (e) {
      return { success: false, message: this.message(e, '下载失败') };
    }
  }

  /**
   * 后台下载：主进程流式拉取 URL 落盘并推送进度。
   * params { url, fileName?, headers?, source?, mime? }
   */
  async startDownload(params) {
    try {
      downloadService.setNotifier(broadcast);
      return { success: true, data: downloadService.start(params) };
    } catch (e) {
      return { success: false, message: this.message(e, '下载失败') };
    }
  }

  /** 下载清单 + 当前生效目录 */
  async listDownloads() {
    try {
      return { success: true, data: { dir: downloadService.getDownloadDir(), items: downloadService.list() } };
    } catch (e) {
      return { success: false, message: this.message(e, '读取下载列表失败') };
    }
  }

  async getDownloadDir() {
    try {
      return { success: true, data: { dir: downloadService.getDownloadDir() } };
    } catch (e) {
      return { success: false, message: this.message(e, '读取下载目录失败') };
    }
  }

  /** 设置下载目录；params { dir } 传空恢复系统默认 */
  async setDownloadDir(params) {
    try {
      return { success: true, data: { dir: downloadService.setDownloadDir(params?.dir) } };
    } catch (e) {
      return { success: false, message: this.message(e, '设置下载目录失败') };
    }
  }

  /** 用系统默认程序打开已下载的文件 */
  async openDownloadFile(params) {
    try {
      return { success: true, data: await downloadService.openFile(params?.id) };
    } catch (e) {
      return { success: false, message: this.message(e, '打开文件失败') };
    }
  }

  /** 在文件管理器里定位已下载的文件 */
  async revealDownload(params) {
    try {
      return { success: true, data: downloadService.revealFile(params?.id) };
    } catch (e) {
      return { success: false, message: this.message(e, '定位文件失败') };
    }
  }

  /** 打开下载目录 */
  async openDownloadDir() {
    try {
      return { success: true, data: await downloadService.openDir() };
    } catch (e) {
      return { success: false, message: this.message(e, '打开下载目录失败') };
    }
  }

  /** 只从清单移除记录，不删磁盘上的文件 */
  async removeDownload(params) {
    try {
      return { success: true, data: downloadService.remove(params?.id) };
    } catch (e) {
      return { success: false, message: this.message(e, '移除记录失败') };
    }
  }

  async clearDownloads() {
    try {
      return { success: true, data: downloadService.clear() };
    } catch (e) {
      return { success: false, message: this.message(e, '清空记录失败') };
    }
  }

  message(error, fallback) {
    const msg = error instanceof Error ? error.message : String(error);
    logger.warn('[downloadCtl]', fallback, msg);
    return msg || fallback;
  }
}

export default DownloadCtl;