package main

import (
	"bytes"
	"fmt"
	"regexp"
	"strings"

	jsoniter "github.com/json-iterator/go"
)

type User struct {
	Name  string `json:"name"`
	Age   int    `json:"age"`
	Email string `json:"email"`
}

func main() {
	// user := User{
	// 	Name: "John Doe",
	// 	Age:  30,

	// 	Email: "john@example.com",
	// }

	// // 调用函数
	// params := StructToMap(user)
	// // 打印结果
	// fmt.Println(params["age"])
	fmt.Println(IsValidIDCard("452224200009060026"))

}

// IsValidIDCard 检查身份证号是否合法
func IsValidIDCard(idCard string) bool {
	if len(idCard) != 18 {
		return false
	}

	// 前 17 位必须为数字
	for i := 0; i < 17; i++ {
		if idCard[i] < '0' || idCard[i] > '9' {
			return false
		}
	}
	// 最后一位可以是数字或 'X' 或 'x'
	lastChar := idCard[17]
	if (lastChar < '0' || lastChar > '9') && lastChar != 'X' && lastChar != 'x' {
		return false
	}

	// 加权因子
	weight := []int{7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2}
	// 校验码对应值
	checkCodes := []rune{'1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'}

	// 计算校验和
	sum := 0
	for i := 0; i < 17; i++ {
		sum += int(idCard[i]-'0') * weight[i]
	}
	// 计算校验码索引
	index := sum % 11
	// 比较校验码
	expectedCheckCode := checkCodes[index]
	if lastChar != byte(expectedCheckCode) && lastChar != byte(expectedCheckCode+32) {
		return false
	}

	return true

}

// UnderlineToCamel 下划线命名转驼峰命名
func UnderlineToCamel(str string) string {
	re := regexp.MustCompile(`_(\w)`)
	return re.ReplaceAllStringFunc(str, func(s string) string {
		return strings.ToUpper(string(s[1]))
	})
}

// CamelToUnderline 驼峰命名转下划线命名
func CamelToUnderline(str string) string {
	re := regexp.MustCompile(`([A-Z])`)
	return strings.ToLower(re.ReplaceAllString(str, "_$1"))[1:]
}

func StructToMap(params any) map[string]any {
	mapParams := map[string]interface{}{}

	jsonParams, err := jsoniter.Marshal(params)
	if err != nil {
		return mapParams
	}
	if err := jsoniter.Unmarshal(jsonParams, &mapParams); err != nil {
		return mapParams
	}
	return mapParams
}

func StrUppercase(str string) string {
	str = strings.Title(str)
	re := regexp.MustCompile(`_(\w)`)
	result := re.ReplaceAllStringFunc(str, func(s string) string {
		return "_" + strings.ToUpper(string(s[1]))
	})
	result = strings.ReplaceAll(result, "_", "")
	return result
}

func CamelCase(s string) string {
	if s == "" {
		return ""
	}
	t := make([]byte, 0, 32)
	i := 0
	if s[0] == '_' {
		t = append(t, 'X')
		i++
	}
	for ; i < len(s); i++ {
		c := s[i]
		if c == '_' && i+1 < len(s) && isASCIIUpper(s[i+1]) {
			continue
		}
		if isASCIIDigit(c) {
			t = append(t, c)
			continue
		}

		if isASCIIUpper(c) {
			c ^= ' '
		}
		t = append(t, c)

		for i+1 < len(s) && isASCIIUpper(s[i+1]) {
			i++
			t = append(t, '_')
			t = append(t, bytes.ToLower([]byte{s[i]})[0])
		}
	}
	return string(t)
}

// 是否是大写字母
func isASCIIUpper(c byte) bool {
	return 'A' <= c && c <= 'Z'
}

// 是否是数字
func isASCIIDigit(c byte) bool {
	return '0' <= c && c <= '9'
}