package lib

import (
	"context"
	"encoding/json"
	"github.com/wechatpay-apiv3/wechatpay-go/core"
	"github.com/wechatpay-apiv3/wechatpay-go/core/auth/verifiers"
	"github.com/wechatpay-apiv3/wechatpay-go/core/downloader"
	"github.com/wechatpay-apiv3/wechatpay-go/core/notify"
	"github.com/wechatpay-apiv3/wechatpay-go/core/option"
	"github.com/wechatpay-apiv3/wechatpay-go/services/payments/jsapi"
	"github.com/wechatpay-apiv3/wechatpay-go/services/payments/native"
	"github.com/wechatpay-apiv3/wechatpay-go/utils"
	"io/ioutil"
	"log"
	"net/http"
	"time"
)

type WechatPay struct {
	AppId                      string       //公众号AppID
	MchID                      string       //商户号
	MchCertificateSerialNumber string       //商户证书序列号
	MchAPIv3Key                string       //商户API V3密钥
	MchPrivateKey              string       //商户私钥
	NotifyUrl                  string       //回调地址
	timeExpire                 time.Time    //订单过期时间
	Client                     *core.Client //client
	Ctx                        context.Context
}

func NewWechatPay(appId, mchID, mchCertificateSerialNumber, mchAPIv3Key, mchPrivateKey, notifyUrl string) (*WechatPay, error) {
	wp := &WechatPay{
		AppId:                      appId,
		MchID:                      mchID,
		MchCertificateSerialNumber: mchCertificateSerialNumber,
		MchAPIv3Key:                mchAPIv3Key,
		MchPrivateKey:              mchPrivateKey,
		NotifyUrl:                  notifyUrl,
		timeExpire:                 time.Now().Add(2 * time.Hour),
	}
	// 使用 utils 提供的函数从私钥的文本内容中加载商户私钥，商户私钥会用来生成请求的签名
	privateKey, err := utils.LoadPrivateKey(mchPrivateKey)
	if err != nil {
		return nil, err
	}
	ctx := context.Background()
	// 使用商户私钥等初始化 client，并使它具有自动定时获取微信支付平台证书的能力
	opts := []core.ClientOption{
		option.WithWechatPayAutoAuthCipher(mchID, mchCertificateSerialNumber, privateKey, mchAPIv3Key),
	}
	client, err := core.NewClient(ctx, opts...)
	if err != nil {
		return nil, err
	}
	wp.Client = client
	wp.Ctx = ctx
	return wp, nil
}

// native支付下单
func (this *WechatPay) NativePayPreOrder(amount int64, description, orderSn string) (string, error) {
	svc := native.NativeApiService{Client: this.Client}
	resp, result, err := svc.Prepay(this.Ctx,
		native.PrepayRequest{
			Appid:       core.String(this.AppId),
			Mchid:       core.String(this.MchID),
			Description: core.String(description),
			OutTradeNo:  core.String(orderSn),
			TimeExpire:  core.Time(this.timeExpire),
			NotifyUrl:   core.String(this.NotifyUrl),
			Amount: &native.Amount{
				Currency: core.String("CNY"),
				Total:    core.Int64(amount),
			},
		},
	)

	if err != nil {
		return "", err
	}
	// 处理返回结果
	log.Println(resp, result)
	return *resp.CodeUrl, nil
}

// jsapi支付下单
func (this *WechatPay) JsApiPreOrder(openId string, amount int64, description, orderSn string) (string, error) {
	svc := jsapi.JsapiApiService{Client: this.Client}
	resp, result, err := svc.PrepayWithRequestPayment(this.Ctx,
		jsapi.PrepayRequest{
			Appid:       core.String(this.AppId),
			Mchid:       core.String(this.MchID),
			Description: core.String(description),
			OutTradeNo:  core.String(orderSn),
			TimeExpire:  core.Time(this.timeExpire),
			NotifyUrl:   core.String(this.NotifyUrl),
			Amount: &jsapi.Amount{
				Currency: core.String("CNY"),
				Total:    core.Int64(amount),
			},
			Payer: &jsapi.Payer{
				Openid: core.String(openId),
			},
		},
	)

	if err != nil {
		return "", err
	}
	// 处理返回结果
	log.Println(resp, result)
	if err != nil {
		return "", err
	}
	respBody, err := json.Marshal(map[string]interface{}{
		"prepayId":  resp.PrepayId,
		"appId":     resp.Appid,
		"timeStamp": resp.TimeStamp,
		"nonceStr":  resp.NonceStr, //随机串
		"package":   resp.Package,
		"signType":  resp.SignType, //微信签名方式：
		"paySign":   resp.PaySign,  //微信签名
	})
	return string(respBody), nil
}

// native支付查询
func (this *WechatPay) NativePayQueryOrder(orderSn string) (string, string, error) {
	svc := native.NativeApiService{Client: this.Client}
	resp, result, err := svc.QueryOrderByOutTradeNo(this.Ctx,
		native.QueryOrderByOutTradeNoRequest{
			OutTradeNo: core.String(orderSn),
			Mchid:      core.String(this.MchID),
		},
	)
	if err != nil {
		return "", "", err
	}
	body, _ := ioutil.ReadAll(result.Response.Body)
	return string(body), *resp.TradeState, nil
}

// jsapi支付查询
func (this *WechatPay) JsApiQueryOrder(orderSn string) (string, string, error) {
	svc := jsapi.JsapiApiService{Client: this.Client}

	resp, result, err := svc.QueryOrderById(this.Ctx,
		jsapi.QueryOrderByIdRequest{
			TransactionId: core.String(orderSn),
			Mchid:         core.String(this.MchID),
		},
	)

	if err != nil {
		return "", "", err
	}
	body, _ := ioutil.ReadAll(result.Response.Body)
	return string(body), *resp.TradeState, nil
}

// 解密回调
func (this *WechatPay) ParseNotifyRequest(request *http.Request) (map[string]interface{}, error) {
	ctx := context.Background()
	content := make(map[string]interface{})
	// 1. 使用 `RegisterDownloaderWithPrivateKey` 注册下载器
	// 使用 utils 提供的函数从私钥的文本内容中加载商户私钥，商户私钥会用来生成请求的签名
	mchPrivateKey, err := utils.LoadPrivateKey(this.MchPrivateKey)
	if err != nil {
		return content, err
	}
	err = downloader.MgrInstance().RegisterDownloaderWithPrivateKey(ctx, mchPrivateKey, this.MchCertificateSerialNumber, this.MchID, this.MchAPIv3Key)
	if err != nil {
		return content, err
	}
	// 2. 获取商户号对应的微信支付平台证书访问器
	certificateVisitor := downloader.MgrInstance().GetCertificateVisitor(this.MchID)
	// 3. 使用证书访问器初始化 `notify.Handler`
	handler := notify.NewNotifyHandler(this.MchAPIv3Key, verifiers.NewSHA256WithRSAVerifier(certificateVisitor))

	notifyReq, err := handler.ParseNotifyRequest(ctx, request, &content)
	log.Println(notifyReq, content)
	return content, nil
}