package utils

import (
	"context"
	"errors"
	"fmt"
	"github.com/redis/go-redis/v9"
	"math/rand"
	"qnc-server/config"
	"qnc-server/db"
	"regexp"
	"time"
)

var ctx = context.Background()

func GenerateVerificationCode() string {
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	code := fmt.Sprintf("%06d", r.Intn(1000000))
	return code
}

// 验证手机号码格式的函数
func IsValidPhoneNumber(phone string) bool {
	re := regexp.MustCompile(`^1[3-9]\d{9}$`)
	return re.MatchString(phone)
}

// StoreVerificationCode 存储验证码到 Redis
func StoreVerificationCode(phoneNumber, code string) error {
	err := db.RedisClient.Set(ctx, phoneNumber, code, config.ConfigData.VerifyCode.Expiration).Err()
	if err != nil {
		return err
	}
	err = SetThrottle(phoneNumber)
	if err != nil {
		return err
	}
	return nil
}

// VerifyCode 验证验证码
func VerifyCode(phoneNumber, code string) (bool, error) {
	//if phoneNumber == "18276151590" {
	//	return true, nil
	//}
	storedCode, err := db.RedisClient.Get(ctx, phoneNumber).Result()
	if errors.Is(err, redis.Nil) {
		return false, fmt.Errorf("验证码不存在或已过期")
	} else if err != nil {
		return false, err
	}
	if storedCode == code {
		return true, nil
	} else {
		return false, nil
	}
}

// CanRequestCode 检查用户是否可以请求新的验证码
func CanRequestCode(phoneNumber string) (bool, error) {
	key := "throttle:" + phoneNumber
	exists, err := db.RedisClient.Exists(ctx, key).Result()
	if err != nil {
		return false, err
	}
	return exists == 1, nil
}

// SetThrottle 设置用户请求的节流
func SetThrottle(phoneNumber string) error {
	key := "throttle:" + phoneNumber
	err := db.RedisClient.Set(ctx, key, "1", config.ConfigData.VerifyCode.ThrottleTime).Err()
	if err != nil {
		return err
	}
	return nil
}