package util

import (
	"fmt"
	"math"
	"net/url"
	"regexp"
	"strconv"
	"strings"
	"sync"
)

const (
	NULL = ""
)

var (
	bfPool = sync.Pool{
		New: func() any {
			return &strings.Builder{}
		},
	}
)

// JoinInts format int64 slice like [1,2,3,4,5] to string like 1,2,3,4,5.
func JoinInts(is []int64) string {
	if len(is) == 0 {
		return NULL
	}
	if len(is) == 1 {
		return strconv.FormatInt(is[0], 10)
	}
	buf, ok := bfPool.Get().(*strings.Builder)
	if ok && buf != nil {
		for _, i := range is {
			buf.WriteString(strconv.FormatInt(i, 10))
			buf.WriteByte(',')
		}
		s := buf.String()
		if len(s) > 0 {
			s = s[:len(s)-1]
		}
		buf.Reset()
		bfPool.Put(buf)
		return s
	}
	return NULL
}

// SplitInts split string like 1,2,3,4,5 into int64 slice like [1,2,3,4,5].
func SplitInts(s string) ([]int64, error) {
	if s == NULL {
		return nil, nil
	}
	sArr := strings.Split(s, ",")
	res := make([]int64, 0, len(sArr))
	for _, sc := range sArr {
		i, err := strconv.ParseInt(sc, 10, 64)
		if err != nil {
			return nil, err
		}
		res = append(res, i)
	}
	return res, nil
}

func FormatURLParam(body map[string]any) (urlParam string) {
	v := url.Values{}
	for key, value := range body {
		v.Add(key, value.(string))
	}
	return v.Encode()
}

// VerifyIDCard 计算规则参考“中国国家标准化管理委员会”官方文档：http://www.gb688.cn/bzgk/gb/newGbInfo?hcno=080D6FBF2BB468F9007657F26D60013E
// 身份证号码校验
func VerifyIDCard(idCard string) bool {
	if len([]rune(idCard)) != 18 {
		return false
	}
	// a1与对应的校验码对照表，其中key表示a1，value表示校验码，value中的10表示校验码X
	var a1Map = map[int]int{
		0:  1,
		1:  0,
		2:  10,
		3:  9,
		4:  8,
		5:  7,
		6:  6,
		7:  5,
		8:  4,
		9:  3,
		10: 2,
	}

	var idStr = strings.ToUpper(idCard)
	var reg, err = regexp.Compile(`^[0-9]{17}[0-9X]$`)
	if err != nil {
		return false
	}
	if !reg.Match([]byte(idStr)) {
		return false
	}
	var sum int
	var signChar = ""
	for index, c := range idStr {
		var i = 18 - index
		if i != 1 {
			v, err := strconv.Atoi(string(c))
			if err != nil {
				return false
			}
			// 计算加权因子
			var weight = int(math.Pow(2, float64(i-1))) % 11
			sum += v * weight
		} else {
			signChar = string(c)
		}
	}
	var a1 = a1Map[sum%11]
	var a1Str = fmt.Sprintf("%d", a1)
	if a1 == 10 {
		a1Str = "X"
	}
	return a1Str == signChar
}

// VerifyPhoneNumber 手机号码校验
func VerifyPhoneNumber(phone string) bool {
	if len([]rune(phone)) != 11 {
		return false
	}
	reg, err := regexp.Compile(`^1([38][0-9]|4[5679]|5[^4]|6[2567]|7[0-8]|9[0-35-9])\d{8}$`)
	if err != nil {
		return false
	}
	return reg.Match([]byte(phone))
}