import { Inject, Injectable } from '@nestjs/common';
import type { NotificationType } from '@lehuo/contracts';
import { AppConfigService } from '../config/app-config.service';
export interface SubscriptionMessage {
  openid: string;
  type: NotificationType;
  title: string;
  body: string;
  resourcePublicId: string | null;
}
export interface SubscriptionSendResult {
  providerMessageId: string | null;
}
export abstract class WechatSubscriptionAdapter {
  abstract get configured(): boolean;
  abstract send(message: SubscriptionMessage): Promise<SubscriptionSendResult>;
}
@Injectable()
export class HttpWechatSubscriptionAdapter extends WechatSubscriptionAdapter {
  constructor(@Inject(AppConfigService) private readonly config: AppConfigService) {
    super();
  }
  get configured() {
    return this.config.wechatNotificationConfigured;
  }
  async send(message: SubscriptionMessage) {
    if (!this.config.wechatAppId || !this.config.wechatAppSecret)
      throw new Error('WECHAT_NOT_CONFIGURED');
    const templateId = this.config.wechatNotificationTemplates[message.type];
    if (!templateId) throw new Error('WECHAT_TEMPLATE_NOT_CONFIGURED');
    const tokenResponse = await fetch(
      `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${encodeURIComponent(this.config.wechatAppId)}&secret=${encodeURIComponent(this.config.wechatAppSecret)}`,
    );
    const token = (await tokenResponse.json()) as { access_token?: string; errcode?: number };
    if (!tokenResponse.ok || !token.access_token)
      throw new Error(`WECHAT_TOKEN_${token.errcode ?? 'FAILED'}`);
    const response = await fetch(
      `https://api.weixin.qq.com/cgi-bin/message/subscribe/send?access_token=${encodeURIComponent(token.access_token)}`,
      {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify({
          touser: message.openid,
          template_id: templateId,
          page: message.resourcePublicId
            ? `pages/index/index?resource=${message.resourcePublicId}`
            : 'pages/index/index',
          data: {
            thing1: { value: message.title.slice(0, 20) },
            thing2: { value: message.body.slice(0, 20) },
          },
        }),
      },
    );
    const result = (await response.json()) as {
      errcode?: number;
      errmsg?: string;
      msgid?: string | number;
    };
    if (!response.ok || result.errcode !== 0)
      throw new Error(`WECHAT_SEND_${result.errcode ?? 'FAILED'}`);
    return { providerMessageId: result.msgid?.toString() ?? null };
  }
}