package middleware

import (
	"crypto/md5"
	"errors"
	"eta_gn/eta_bridge/controller/resp"
	"eta_gn/eta_bridge/global"
	"eta_gn/eta_bridge/models/crm"
	"eta_gn/eta_bridge/utils"
	"fmt"
	"github.com/gin-gonic/gin"
	"math"
	"sort"
	"strconv"
	"strings"
	"time"
)

func BaseAuthCheck() gin.HandlerFunc {
	return func(c *gin.Context) {
		method := c.Request.Method
		if method != "POST" {
			resp.TokenError(nil, "请求异常", "不支持非POST请求", c)
			c.Abort()
			return
		}
		pass, e := signCheck(c)
		if e != nil {
			resp.TokenError(nil, "签名错误", "签名校验失败, Err: "+e.Error(), c)
			c.Abort()
			return
		}
		if !pass {
			resp.TokenError(nil, "签名错误", "签名错误", c)
			c.Abort()
			return
		}
	}
}

func signCheck(c *gin.Context) (ok bool, err error) {
	params := make(map[string][]string)
	err = c.ShouldBind(params)
	if err != nil {
		return
	}
	signData := convertParam(params)

	ip := c.ClientIP()
	err = checkSignData(signData, ip)
	if err != nil {
		return
	}
	ok = true
	return
}

func convertParam(params map[string][]string) (signData map[string]string) {
	signData = make(map[string]string)
	for key := range params {
		signData[key] = params[key][0]
	}
	return signData
}

func checkSignData(postData map[string]string, ip string) (err error) {
	isSandbox := postData["is_sandbox"]
	if global.CONFIG.Serve.RunMode == "debug" && isSandbox != "" {
		return
	}

	appid := postData["appid"]
	if appid == "" {
		err = errors.New("参数异常，缺少appid")
		return
	}

	openApiOB := new(crm.OpenApiUser)
	apiUser, e := openApiOB.GetItemByAppid(appid)
	if e != nil {
		if e != utils.ErrNoRow {
			err = errors.New("系统异常，请联系管理员")
			return
		}
		err = errors.New("appid异常，请联系管理员")
		return
	}
	if apiUser == nil {
		err = errors.New("系统异常，请联系管理员")
		return
	}

	if apiUser.Ip != "" {
		if !strings.Contains(apiUser.Ip, ip) {
			err = errors.New(fmt.Sprintf("无权限访问该接口,ip:%v，请联系管理员", ip))
			return
		}
	}

	ownSign := postData["sign"]
	if ownSign == "" {
		err = errors.New("参数异常，缺少签名字符串")
		return
	}
	if postData["nonce_str"] == "" {
		err = errors.New("参数异常，缺少随机字符串")
		return
	}
	if postData["timestamp"] == "" {
		err = errors.New("参数异常，缺少时间戳")
		return
	} else {
		timeUnix := time.Now().Unix() // 当前格林威治时间，int64类型
		timestamp, timeErr := strconv.ParseInt(postData["timestamp"], 10, 64)
		if timeErr != nil {
			err = errors.New("参数异常，时间戳格式异常")
			return
		}
		if math.Abs(float64(timeUnix-timestamp)) > 300 {
			err = errors.New("当前时间异常，请调整设备时间与北京时间一致")
			return
		}
	}

	var keys []string
	for k := range postData {
		if k != "sign" {
			keys = append(keys, k)
		}
	}

	sort.Strings(keys)

	var signStr string
	for _, v := range keys {
		signStr += v + "=" + postData[v] + "&"
	}

	sign := strings.ToUpper(fmt.Sprintf("%x", md5.Sum([]byte(signStr+"secret="+apiUser.Secret))))
	if sign != ownSign {
		global.LOG.Info(fmt.Sprintf("签名校验异常，签名字符串：%v；服务端签名值：%v", signStr, sign))
		return errors.New("签名校验异常，请核实签名")
	}
	return nil
}