package utils

import (
	"crypto/md5"
	"fmt"
	"regexp"
	"strings"
)

// MD5 字符串MD5加密
func MD5(s string) string {
	data := []byte(s)
	has := md5.Sum(data)
	return fmt.Sprintf("%x", has)
}

// IsEmail 验证邮箱格式
func IsEmail(email string) bool {
	pattern := `^[0-9a-z][_.0-9a-z-]{0,31}@([0-9a-z][0-9a-z-]{0,30}[0-9a-z]\.){1,4}[a-z]{2,4}$`
	reg := regexp.MustCompile(pattern)
	return reg.MatchString(email)
}

// IsMobile 验证手机号格式
func IsMobile(mobile string) bool {
	pattern := `^1[3-9]\d{9}$`
	reg := regexp.MustCompile(pattern)
	return reg.MatchString(mobile)
}

// RemoveSpaces 去除字符串中的空格
func RemoveSpaces(s string) string {
	return strings.ReplaceAll(s, " ", "")
}

// Substr 字符串截取
func Substr(s string, start, length int) string {
	runes := []rune(s)
	total := len(runes)

	if start >= total {
		return ""
	}

	end := start + length
	if end > total {
		end = total
	}

	return string(runes[start:end])
}
func SplitAndFetch(s, sep string, index int) string {
	arr := strings.Split(s, sep)
	if index >= len(arr) {
		return ""
	}
	return arr[index]
}