import { createHash } from 'crypto';
import { Injectable, NotImplementedException } from '@nestjs/common';
import * as QRCode from 'qrcode';
import type {
  IWechatProvider,
  WechatCodeSession,
  WechatOAuthSession,
  WechatWxaCodeUnlimitedInput,
} from './wechat.interface';

/**
 * preV1 Mock 微信 Provider。
 *
 * 目的：让「微信授权登录」按钮在不接真实微信的情况下走通。前端仍按真实 OAuth 流程
 * （跳转 oauth-url → 回调携带 code），Mock 端将授权 URL 直接回跳并返回稳定 openId。
 * 后续填入 WX_APP_ID/WX_APP_SECRET 并置 MOCK_WECHAT=false 即切换到真实实现。
 */
@Injectable()
export class WechatMockProvider implements IWechatProvider {
  isEnabled() {
    return true;
  }

  isMock() {
    return true;
  }

  isPayEnabled() {
    return false;
  }

  getMchId() {
    return '';
  }

  /** 由 code 派生稳定 openId，保证同一 code 多次授权指向同一账号 */
  private openIdFromCode(code: string): string {
    return `mockwx_${createHash('md5').update(code).digest('hex').slice(0, 24)}`;
  }

  async code2Session(code: string): Promise<WechatCodeSession> {
    return { openId: this.openIdFromCode(code), sessionKey: 'mock-session-key' };
  }

  async oauth2AccessToken(code: string): Promise<WechatOAuthSession> {
    return { openId: this.openIdFromCode(code), accessToken: 'mock-access-token' };
  }

  async fetchOAuthUserInfo(accessToken: string, openId: string) {
    return {
      openId,
      nickname: 'Mock微信用户',
      headImgUrl: `https://api.dicebear.com/7.x/avataaars/svg?seed=${encodeURIComponent(openId)}`,
    };
  }

  async createJssdkConfig(url: string) {
    return {
      appId: 'mock-appid',
      timestamp: Math.floor(Date.now() / 1000),
      nonceStr: 'mocknonce',
      signature: 'mocksignature',
      url,
      jsApiList: ['getLocation', 'scanQRCode', 'chooseImage'],
    } as unknown as Awaited<ReturnType<IWechatProvider['createJssdkConfig']>>;
  }

  /** 直接把授权链接回跳到 redirectUri 并附带 mock code，模拟微信授权完成 */
  buildOAuthUrl(redirectUri: string, state: string): string {
    const sep = redirectUri.includes('?') ? '&' : '?';
    const code = `mockcode_${state || 'default'}`;
    return `${redirectUri}${sep}code=${encodeURIComponent(code)}&state=${encodeURIComponent(state)}`;
  }

  async getPhoneNumberByCode(): Promise<string> {
    throw new NotImplementedException('Mock 微信不支持获取手机号，请用短信绑定');
  }

  createJsapiPrepay(): never {
    throw new NotImplementedException('FEATURE_DISABLED');
  }

  createNativePrepay(): never {
    throw new NotImplementedException('FEATURE_DISABLED');
  }

  parsePayNotification(): never {
    throw new NotImplementedException('FEATURE_DISABLED');
  }

  createDomesticRefund(): never {
    throw new NotImplementedException('FEATURE_DISABLED');
  }

  parseRefundNotification(): never {
    throw new NotImplementedException('FEATURE_DISABLED');
  }

  /** Mock：用普通二维码 PNG 占位，内容含 scene，便于本地联调上传 OSS */
  async getWxaCodeUnlimited(input: WechatWxaCodeUnlimitedInput): Promise<Buffer> {
    const scene = (input.scene ?? '').trim() || 'mock';
    return QRCode.toBuffer(`mock-wxa://promo?scene=${encodeURIComponent(scene)}`, {
      width: input.width ?? 430,
      margin: 1,
      type: 'png',
      color: { dark: '#1f1a17', light: '#ffffff' },
    });
  }

  async uploadShippingInfo() {
    return { errcode: 0, errmsg: 'ok' };
  }

  async getOrderShippingInfo() {
    return {
      errcode: 0,
      errmsg: 'ok',
      orderState: 3,
      finishShipping: true,
    };
  }

  async getDeliveryList() {
    return [
      { deliveryId: 'SF', deliveryName: '顺丰速运' },
      { deliveryId: 'STO', deliveryName: '申通快递' },
      { deliveryId: 'YTO', deliveryName: '圆通速递' },
      { deliveryId: 'ZTO', deliveryName: '中通快递' },
      { deliveryId: 'YD', deliveryName: '韵达速递' },
    ];
  }
}