import { Injectable } from '@nestjs/common';
import { Subscriber } from 'rxjs';
import { In } from 'typeorm';

import { ROOT_ROLE_ID } from '~/constants/system.constant';

import { RoleEntity } from '~/modules/system/role/role.entity';
import { UserEntity } from '~/modules/user/user.entity';

export interface MessageEvent {
  data?: string | object;
  id?: string;
  type?: 'ping' | 'close' | 'updatePermsAndMenus';
  retry?: number;
}

const clientMap: Map<number, Subscriber<MessageEvent>> = new Map();

@Injectable()
export class SseService {
  addClient(uid: number, subscriber: Subscriber<MessageEvent>) {
    clientMap.set(uid, subscriber);
  }

  removeClient(uid: number): void {
    const client = clientMap.get(uid);
    client?.complete();
    clientMap.delete(uid);
  }

  sendToClient(uid: number, data: MessageEvent): void {
    const client = clientMap.get(uid);
    client?.next?.(data);
  }

  sendToAll(data: MessageEvent): void {
    clientMap.forEach(client => {
      client.next(data);
    });
  }

  /**
   * 通知前端重新获取权限菜单
   * @param uid
   * @constructor
   */
  async noticeClientToUpdateMenusByUserIds(uid: number | number[]) {
    const userIds = [].concat(uid) as number[];
    userIds.forEach(uid => {
      this.sendToClient(uid, { type: 'updatePermsAndMenus' });
    });
  }

  /**
   * 通过menuIds通知用户更新权限菜单
   */
  async noticeClientToUpdateMenusByMenuIds(menuIds: number[]): Promise<void> {
    const roleMenus = await RoleEntity.find({
      where: {
        menus: {
          id: In(menuIds)
        }
      }
    });
    const roleIds = roleMenus.map(n => n.id).concat(ROOT_ROLE_ID);
    await this.noticeClientToUpdateMenusByRoleIds(roleIds);
  }

  /**
   * 通过roleIds通知用户更新权限菜单
   */
  async noticeClientToUpdateMenusByRoleIds(roleIds: number[]): Promise<void> {
    const users = await UserEntity.find({
      where: {
        roles: {
          id: In(roleIds)
        }
      }
    });
    if (users) {
      const userIds = users.map(n => n.id);
      await this.noticeClientToUpdateMenusByUserIds(userIds);
    }
  }
}