package user

import (
	"context"
	"encoding/json"
	"fmt"
	"html/template"
	"io"
	"log"
	"net/http"
	"net/smtp"
	"strings"
	"time"

	"math/rand"

	"github.com/go-redis/redis/v8"
)

type Userregveri struct {
	Email string `json:"email"`
}

func randomCode() string {
	source := rand.NewSource(time.Now().UnixNano())
	r := rand.New(source)
	letters := []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
	b := make([]rune, 6)
	for i := range b {
		b[i] = letters[r.Intn(len(letters))]
	}
	return string(b)
}

func Registerverify(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Access-Control-Allow-Origin", "http://localhost:5173")
	w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
	w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
	w.Header().Set("Access-Control-Allow-Credentials", "true")

	if r.Method == "OPTIONS" {
		w.WriteHeader(http.StatusOK)
		return
	}
	bodyrec, error := io.ReadAll(r.Body)
	if error != nil {
		fmt.Println("接受数据错误")
		return
	}
	var bodyjx Userregveri
	error = json.Unmarshal(bodyrec, &bodyjx)
	if error != nil {
		fmt.Println("数据解析失败")
		return
	}

	var useremail = bodyjx.Email
	log.Println("邮箱是", useremail)

	redisdb := redis.NewClient(&redis.Options{
		Addr:     "localhost:6379",
		Password: "",
		DB:       0,
	})
	var redisverifyhash = "userverify"

	_, error = redisdb.Ping(context.Background()).Result()
	if error != nil {
		log.Println("redis连接失败")
		return
	}

	result, _ := redisdb.Exists(context.Background(), redisverifyhash, useremail).Result()
	if result == 1 {
		log.Println("用户验证码已经存在")
		redisdb.HDel(context.Background(), redisverifyhash, useremail)
	}
	log.Println(result)
	codesend := randomCode()

	error = redisdb.HSet(context.Background(), redisverifyhash, map[string]string{
		"useremail": useremail,
		"userver":   codesend,
	}).Err()
	if error != nil {
		log.Println("redis键值设置失败")
		return
	}

	_, error = redisdb.Expire(context.Background(), redisverifyhash, 3*time.Minute).Result()
	if error != nil {
		log.Println("有效时长设置失败")
		return
	}

	from := "mayiming_person@163.com"
	password := "VChadvNigu6TdzYH"
	to := []string{useremail}
	subject := "MS用户验证码 --MS助手"

	htmlContent := `以下为您的验证码，3分钟内有效，请勿分享给别人.  验证码：` + string(codesend) + ``
	t, err := template.New("emailBody").Parse(htmlContent)
	if err != nil {
		log.Fatal(err)
	}
	var bodyBuilder strings.Builder
	err = t.Execute(&bodyBuilder, nil)
	if err != nil {
		log.Fatal(err)
	}
	body := bodyBuilder.String()

	msg := "From: " + from + "\r\n" +
		"To: " + to[0] + "\r\n" +
		"Subject: " + subject + "\r\n" +
		"\r\n" +
		body

	smtpServer := "smtp.163.com:25"
	auth := smtp.PlainAuth("", from, password, "smtp.163.com")
	err = smtp.SendMail(smtpServer, auth, from, to, []byte(msg))
	if err != nil {
		log.Fatal(err)
	}
	log.Println("邮箱发送成功!")

}