import type { WechatJsapiPrepayParams } from '@dukang/shared-types';
import { getRuntimePlatform } from './env';
import { ensureJssdkReady } from './jssdk';
import type { MiniProgramWx } from './types';

export type WechatPayInvokeConfig = {
  apiBase?: string;
  clientApp?: string;
  getAccessToken?: () => string | null;
  /** 显式指定运行端；Taro weapp 须传 mini */
  platform?: 'mini' | 'wechat-h5' | 'browser';
};

/** wx.chooseWXPay 要求 timestamp 小写；服务端签名与 Bridge 使用 timeStamp */
function toChooseWxPayOptions(prepay: WechatJsapiPrepayParams) {
  return {
    timestamp: prepay.timeStamp,
    nonceStr: prepay.nonceStr,
    package: prepay.package,
    signType: prepay.signType,
    paySign: prepay.paySign,
  };
}

function getMiniProgramWx(): MiniProgramWx | undefined {
  const g = globalThis as typeof globalThis & { wx?: MiniProgramWx };
  if (g.wx?.requestPayment) return g.wx;
  if (typeof window !== 'undefined' && window.wx?.requestPayment) return window.wx;
  return undefined;
}

function invokeBridgePay(params: WechatJsapiPrepayParams): Promise<void> {
  return new Promise((resolve, reject) => {
    const bridge = window.WeixinJSBridge;
    if (!bridge) {
      reject(new Error('WeixinJSBridge 不可用'));
      return;
    }
    bridge.invoke(
      'getBrandWCPayRequest',
      {
        appId: params.appId,
        timeStamp: params.timeStamp,
        nonceStr: params.nonceStr,
        package: params.package,
        signType: params.signType,
        paySign: params.paySign,
      },
      (res) => {
        const msg = res.err_msg ?? '';
        if (msg.includes('ok')) resolve();
        else if (msg.includes('cancel')) reject(new Error('用户取消支付'));
        else reject(new Error(msg || '支付失败'));
      },
    );
  });
}

async function waitForWeixinBridge(): Promise<void> {
  if (window.WeixinJSBridge) return;
  if (typeof document === 'undefined') return;
  await new Promise<void>((resolve) => {
    if (window.WeixinJSBridge) resolve();
    else document.addEventListener('WeixinJSBridgeReady', () => resolve(), { once: true });
  });
}

function invokeMiniProgramPay(prepay: WechatJsapiPrepayParams): Promise<void> {
  const wxApi = getMiniProgramWx();
  if (!wxApi?.requestPayment) {
    return Promise.reject(new Error('当前环境不支持微信支付'));
  }
  return new Promise((resolve, reject) => {
    wxApi.requestPayment!({
      timeStamp: prepay.timeStamp,
      nonceStr: prepay.nonceStr,
      package: prepay.package,
      signType: prepay.signType,
      paySign: prepay.paySign,
      success: () => resolve(),
      fail: (err) => {
        const msg = err.errMsg || '支付失败';
        if (msg.includes('cancel')) reject(new Error('用户取消支付'));
        else reject(new Error(msg));
      },
    });
  });
}

/** 调起微信支付 */
export async function invokeWechatPay(
  prepay: WechatJsapiPrepayParams,
  config?: WechatPayInvokeConfig,
): Promise<void> {
  const platform = config?.platform ?? getRuntimePlatform();

  if (platform === 'mini') {
    return invokeMiniProgramPay(prepay);
  }

  if (platform === 'wechat-h5') {
    if (config?.clientApp) {
      await ensureJssdkReady({
        apiBase: config.apiBase ?? '/api/v1',
        clientApp: config.clientApp,
        getAccessToken: config.getAccessToken,
        url: typeof window !== 'undefined' ? window.location.href.split('#')[0] : undefined,
        jsApiList: ['chooseWXPay'],
      });
    }

    // Bridge 参数与商户签名一致，优先于 chooseWXPay
    await waitForWeixinBridge();
    if (window.WeixinJSBridge) {
      return invokeBridgePay(prepay);
    }

    if (window.wx?.chooseWXPay) {
      return new Promise((resolve, reject) => {
        window.wx!.chooseWXPay!({
          ...toChooseWxPayOptions(prepay),
          success: () => resolve(),
          fail: (err) => reject(new Error(err.errMsg || '支付失败')),
          cancel: () => reject(new Error('用户取消支付')),
        });
      });
    }
  }

  throw new Error('当前环境不支持微信支付');
}