const dayjs = require("dayjs");
const request = require("../../request");
const crypto = require('crypto');

const baseUrl = process.env.CONFIG_UNION_PAY_BASE_URL;
const appId = process.env.CONFIG_UNION_PAY_APPID;
const appKey = process.env.CONFIG_UNION_PAY_APPKEY;
const mid = process.env.CONFIG_UNION_PAY_MID;
const tid = process.env.CONFIG_UNION_PAY_TID;
const notifyUrl = process.env.CONFIG_UNION_PAY_NOTIFY;

const BillStatus = {
  PAID: 'PAID', // 已支付
  UNPAID: 'UNPAID', // 未支付
  CLOSED: 'CLOSED', // 已关闭
  REFUND: 'REFUND', // 已退款  
  UNKNOWN: 'UNKNOWN' // 未知状态
}

const accessToken = {
  promise: null,
  token: '',
  expireTime: 0,
}

function getNonce() {
  const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  let result = '';
  for (let i = 0; i < 128; i++) {
    result += chars[Math.floor(Math.random() * chars.length)];
  }
  return result;
}

function getSignature(timestamp, nonce) {
  const str = appId + timestamp + nonce + appKey;
  return crypto.createHash('sha256').update(str, 'utf8').digest('hex');
}

exports.main = async (event) => {
  switch (event.type) {
    case 'closeUnpayTrade':
      return await closeUnpayTrade(event);
    case 'getUnionPayQrcode':
      return await getUnionPayQrcode(event);
    case 'getUnionPayBill':
      return await getUnionPayBill(event);
    case 'refundUnionPayBill':
      return await refundUnionPayBill(event);
  }
}

async function closePayQrcode(ctx) {
  const qrCodeId = typeof ctx.qrCodeId === 'string' ? ctx.qrCodeId.trim() : '';
  if (!qrCodeId) {
    return { success: false, message: '参数错误' }
  }
  const data = {
    qrCodeId,
    mid,
    tid,
    instMid: 'QRPAYDEFAULT',
    requestTimestamp: dayjs().format("YYYY-MM-DD HH:mm:ss")
  }
  const res = await unionPayRequest(`${baseUrl}/netpay/bills/close-qrcode`, data);
  if (res.success) {
    return { success: true, data: res.data, message: '银联支付二维码关闭成功' }
  }
  return res
}

async function closeUnpayTrade(ctx) {
  const billNo = typeof ctx.billNo === 'string' ? ctx.billNo.trim() : '';
  const billDate = ctx.billDate && dayjs(ctx.billDate).isValid() ? dayjs(ctx.billDate).format("YYYY-MM-DD") : '';
  const qrCodeId = typeof ctx.qrCodeId === 'string' ? ctx.qrCodeId.trim() : '';
  if (!billNo || !billDate || !qrCodeId) {
    return { success: false, message: '参数错误' }
  }
  const { success, data, message } = await getUnionPayBill({ billNo, billDate });
  if (!success) {
    return { success: false, message };
  }
  if (data.billStatus == BillStatus.UNPAID) {
    const res = await closePayQrcode({ qrCodeId });
    if (!res.success) {
      return res;
    }
    return { success: true, tradeStatus: 'closed', message: '银联支付订单关闭成功' }
  }
  if (data.billStatus == BillStatus.CLOSED) {
    return { success: true, tradeStatus: 'closed', message: '银联支付订单已关闭' }
  }
  if (data.billStatus == BillStatus.PAID) {
    return { success: false, tradeStatus: 'paid', message: '银联支付订单已支付' }
  }
  if (data.billStatus == BillStatus.REFUND) {
    return { success: false, tradeStatus: 'refund', message: '银联支付订单已退款' }
  }
  return { success: false, message: '银联支付订单状态未知' }
}

async function getAccessToken() {
  if (accessToken.token && Date.now() < accessToken.expireTime) {
    return { success: true, data: accessToken.token, message: '获取access token成功' }
  }
  accessToken.promise = accessToken.promise || getUnionPayAccessToken();
  const res = await accessToken.promise;
  if (res.success) {
    accessToken.token = res.data;
    accessToken.expireTime = res.expireTime;
    accessToken.promise = null;
  }
  return res;
}

async function getUnionPayAccessToken() {
  const now = dayjs();
  const params = {
    appId,
    timestamp: dayjs().format("YYYYMMDDHHmmss"),
    nonce: getNonce(),
    signMethod: 'SHA256',
  }
  params.signature = getSignature(params.timestamp, params.nonce);
  const res = await request.main(`${baseUrl}/token/access`, params, "POST");
  if (res && res.errCode === '0000') {
    const expireTime = now.add(res.expiresIn, 'second').valueOf();
    const token = `OPEN-ACCESS-TOKEN AccessToken=${res.accessToken}`;
    return { success: true, data: token, message: '获取access token成功', expireTime }
  }
  return { success: false, message: `获取银联access token失败:${res?.errCode || res?.errInfo || '未知错误'}` }
}

async function getUnionPayBill(ctx) {
  const billNo = typeof ctx.billNo === 'string' ? ctx.billNo.trim() : '';
  const billDate = ctx.billDate && dayjs(ctx.billDate).isValid() ? dayjs(ctx.billDate).format("YYYY-MM-DD") : '';
  if (!billNo || !billDate) {
    return { success: false, message: '参数错误' }
  }
  const data = {
    billNo,
    billDate,
    mid,
    tid,
    instMid: 'QRPAYDEFAULT',
    requestTimestamp: dayjs().format("YYYY-MM-DD HH:mm:ss"),
  }
  const res = await unionPayRequest(`${baseUrl}/netpay/bills/query`, data);
  if (res.success) {
    return { success: true, data: res.data, message: '查询银联支付订单成功' }
  }
  return res
}

async function getUnionPayQrcode(ctx) {
  // 生产环境 银联分配的账单号必须以3JHR开头
  if (typeof ctx.billNo !== 'string' || !ctx.billNo.startsWith('3JHR')) {
    return { success: false, message: '账单号格式错误(以3JHR开头)' }
  }
  const data = {
    mid,
    tid,
    instMid: 'QRPAYDEFAULT',
    requestTimestamp: dayjs().format("YYYY-MM-DD HH:mm:ss"),
    billNo: ctx.billNo,
    billDate: dayjs().format("YYYY-MM-DD"),
    billDesc: ctx.desc || '',
    totalAmount: ctx.totalAmount,
    notifyUrl,
    expireTime: ctx.expireTime
  }
  const res = await unionPayRequest(`${baseUrl}/netpay/bills/get-qrcode`, data);
  if (res.success) {
    return { success: true, notifyUrl, appId, qrCodeId: res.data.qrCodeId, qrcode: res.data.billQRCode, message: '获取银联支付二维码成功' }
  }
  return res
}

async function refundUnionPayBill(ctx) {
  const billNo = typeof ctx.billNo === 'string' ? ctx.billNo.trim() : '';
  const billDate = ctx.billDate && dayjs(ctx.billDate).isValid() ? dayjs(ctx.billDate).format("YYYY-MM-DD") : '';
  const refundAmount = ctx.refundAmount > 0 && Number.isInteger(Number(ctx.refundAmount)) ? Number(ctx.refundAmount) : 0;
  const refundOrderId = typeof ctx.refundOrderId === 'string' ? ctx.refundOrderId.trim() : '';
  if (!billNo || !billDate || !refundAmount) {
    return { success: false, message: '参数错误' }
  }
  const data = {
    billDate: billDate,
    billNo: billNo,
    mid,
    refundAmount,
    tid,
    instMid: 'QRPAYDEFAULT',
    requestTimestamp: dayjs().format("YYYY-MM-DD HH:mm:ss"),
  }
  if (refundOrderId) {
    data.refundOrderId = refundOrderId;
  }
  const res = await unionPayRequest(`${baseUrl}/netpay/bills/refund`, data);
  if (res.success) {
    return { success: true, data: res.data, message: '银联支付订单退款成功' }
  }
  return res
}

async function unionPayRequest(url, data) {
  const res = await getAccessToken();
  if (!res || !res.success) {
    return res
  }
  const headers = { Authorization: res.data };
  const result = await request.main(url, data, "POST", { headers });
  if (result && result.errCode === 'SUCCESS') {
    return { success: true, data: result, message: '银联业务请求成功' }
  }
  return { success: false, message: `银联业务请求失败:${result?.errMsg || result?.errCode || '未知错误'}` }
}