// utils/wxpay.js
const API_BASE_URL = 'https://yourdomain.com/api';

class WxPay {
  constructor() {
    this.isWeixin = this.checkWeixin();
    this.openid = uni.getStorageSync('wx_openid') || '';
  }
  
  // 检查是否在微信环境
  checkWeixin() {
    const ua = navigator.userAgent.toLowerCase();
    return ua.indexOf('micromessenger') !== -1;
  }
  
  // 获取 URL 参数
  getQueryParam(name) {
    const reg = new RegExp('(^|&)' + name + '=([^&]*)(&|$)', 'i');
    const r = window.location.search.substr(1).match(reg);
    if (r != null) return decodeURIComponent(r[2]);
    return null;
  }
  
  // 微信授权获取 code
  async wxAuth() {
    if (!this.isWeixin) {
      uni.showToast({ title: '请在微信中打开', icon: 'none' });
      return null;
    }
    
    const code = this.getQueryParam('code');
    
    if (!code) {
      // 跳转微信授权
      const currentUrl = encodeURIComponent(window.location.href.split('#')[0]);
      const authUrl = `https://open.weixin.qq.com/connect/oauth2/authorize?appid=${this.appId}&redirect_uri=${currentUrl}&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect`;
      window.location.href = authUrl;
      return null;
    }
    
    return code;
  }
  
  // 通过 code 获取 openid
  async getOpenId(code) {
    try {
      const response = await uni.request({
        url: `${API_BASE_URL}/wx/auth`,
        method: 'GET',
        data: { code }
      });
      
      if (response[1].data.code === 0) {
        const { openid } = response[1].data.data;
        this.openid = openid;
        uni.setStorageSync('wx_openid', openid);
        return openid;
      }
      return null;
    } catch (error) {
      console.error('获取openid失败:', error);
      return null;
    }
  }
  
  // 初始化微信 JS-SDK
  async initWxJsSDK() {
    if (!this.isWeixin) return false;
    
    try {
      // 获取当前页面 URL（去掉 # 后面的部分）
      const currentUrl = window.location.href.split('#')[0];
      
      const response = await uni.request({
        url: `${API_BASE_URL}/jssdk/config`,
        method: 'GET',
        data: { url: encodeURIComponent(currentUrl) }
      });
      
      if (response[1].data.code === 0) {
        const config = response[1].data.data;
        
        // 引入微信 JS-SDK
        await this.loadWxJsSDK();
        
        // 配置微信 JS-SDK
        wx.config({
          debug: false, // 开启调试模式
          appId: config.appId,
          timestamp: config.timestamp,
          nonceStr: config.nonceStr,
          signature: config.signature,
          jsApiList: [
            'chooseWXPay',
            'onMenuShareTimeline',
            'onMenuShareAppMessage',
            'scanQRCode'
          ]
        });
        
        return new Promise((resolve) => {
          wx.ready(() => {
            console.log('微信 JS-SDK 初始化成功');
            resolve(true);
          });
          
          wx.error((err) => {
            console.error('微信 JS-SDK 初始化失败:', err);
            uni.showToast({ title: '微信初始化失败', icon: 'none' });
            resolve(false);
          });
        });
      }
      return false;
    } catch (error) {
      console.error('初始化JS-SDK失败:', error);
      return false;
    }
  }
  
  // 动态加载微信 JS-SDK
  loadWxJsSDK() {
    return new Promise((resolve, reject) => {
      if (typeof wx !== 'undefined') {
        resolve();
        return;
      }
      
      const script = document.createElement('script');
      script.src = 'https://res.wx.qq.com/open/js/jweixin-1.6.0.js';
      script.onload = resolve;
      script.onerror = reject;
      document.head.appendChild(script);
    });
  }
  
  // 创建支付订单
  async createPayment(orderData) {
    try {
      // 确保有 openid
      if (!this.openid) {
        const code = await this.wxAuth();
        if (code) {
          await this.getOpenId(code);
        }
      }
      
      if (!this.openid) {
        throw new Error('获取用户信息失败');
      }
      
      const response = await uni.request({
        url: `${API_BASE_URL}/wxpay/unifiedorder`,
        method: 'POST',
        header: { 'Content-Type': 'application/json' },
        data: {
          openid: this.openid,
          body: orderData.body || '账户充值',
          total_fee: orderData.amount,
          out_trade_no: orderData.orderNo,
          attach: orderData.attach || ''
        }
      });
      
      if (response[1].data.code === 0) {
        return response[1].data.data;
      } else {
        throw new Error(response[1].data.msg || '创建订单失败');
      }
    } catch (error) {
      console.error('创建支付订单失败:', error);
      throw error;
    }
  }
  
  // 发起微信支付
  async launchPayment(payData) {
    return new Promise((resolve, reject) => {
      wx.chooseWXPay({
        timestamp: payData.timeStamp,
        nonceStr: payData.nonceStr,
        package: payData.package,
        signType: payData.signType,
        paySign: payData.paySign,
        success: (res) => {
          if (res.errMsg === 'chooseWXPay:ok') {
            resolve({ success: true, message: '支付成功' });
          } else {
            reject(new Error('支付失败: ' + res.errMsg));
          }
        },
        fail: (err) => {
          reject(new Error('支付失败: ' + JSON.stringify(err)));
        },
        cancel: () => {
          reject(new Error('用户取消支付'));
        }
      });
    });
  }
  
  // 完整的支付流程
  async pay(amount, orderNo, attach = '') {
    try {
      // 1. 检查环境
      if (!this.isWeixin) {
        uni.showToast({ title: '请在微信中打开', icon: 'none' });
        return { success: false, message: '非微信环境' };
      }
      
      // 2. 初始化 JS-SDK
      const initSuccess = await this.initWxJsSDK();
      if (!initSuccess) {
        return { success: false, message: '微信初始化失败' };
      }
      
      // 3. 创建支付订单
      const payData = await this.createPayment({
        amount: amount,
        orderNo: orderNo,
        attach: attach
      });
      
      // 4. 发起支付
      const result = await this.launchPayment(payData);
      
      // 5. 验证支付结果
      if (result.success) {
        // 支付成功，可以查询订单确认
        await this.verifyPayment(orderNo);
        return { success: true, message: '支付成功' };
      }
      
      return result;
    } catch (error) {
      console.error('支付流程错误:', error);
      return { 
        success: false, 
        message: error.message || '支付失败' 
      };
    }
  }
  
  // 验证支付结果
  async verifyPayment(orderNo) {
    try {
      const response = await uni.request({
        url: `${API_BASE_URL}/wxpay/query`,
        method: 'GET',
        data: { out_trade_no: orderNo }
      });
      
      if (response[1].data.code === 0) {
        const orderData = response[1].data.data;
        if (orderData.trade_state === 'SUCCESS') {
          return true;
        }
      }
      return false;
    } catch (error) {
      console.error('验证支付结果失败:', error);
      return false;
    }
  }
}

export default new WxPay();