package regx

import (
	"encoding/json"
	"errors"
	"fmt"
	"git.sre.ink/go/gtool/date"
	"io/ioutil"
	"regexp"
	"strconv"
)

// Check Perform global verification
func (rr *Regx) IsIdCardCheck(id string) (bool, error) {
	//digit check
	flag, err := rr.IsValidIdCard(id)
	if err != nil {
		return flag, err
	}
	//Check the date
	birth := id[6:14]
	_, err = rr.CheckBirthdayCode(birth)
	if err != nil {
		return false, err
	}
	return true, nil
}

var area = make(map[string]string)

// initConfig locale configuration
func (rr *Regx) initConfig() {
	c := "./area.json"
	raw, err := ioutil.ReadFile(c)
	err = json.Unmarshal(raw, &area)
	if err != nil {
		err = fmt.Errorf("Failed to parse basic configuration file：%s\n", err.Error())
		return
	}
}

// GetProvinceByIdCard get province
func (rr *Regx) GetProvinceByIdCard(address string) string {
	rr.initConfig()
	address = address[:6]
	provincialCode := address[:3] + "000"
	cityCode := address[:4] + "00"
	return area[provincialCode] + area[cityCode] + area[address]
}

// IsValidCard Verify that the ID is legal
func (rr *Regx) IsValidIdCard(id string) (bool, error) {
	if len(id) != 15 && len(id) != 18 {
		return false, errors.New("身份证长度不对")
	}
	return rr.CheckValidNo18(id)
}

// 18-digit ID verification code
func (rr *Regx) CheckValidNo18(id string) (bool, error) {
	//string -> []byte
	id18 := []byte(id)
	nSum := 0
	for i := 0; i < len(id18)-1; i++ {
		n, _ := strconv.Atoi(string(id18[i]))
		nSum += n * weight[i]
	}
	//mod gets 18-bit ID verification code
	mod := nSum % 11
	if validValue[mod] == id18[17] {
		return true, nil
	}

	return false, errors.New("身份证不正确请进行核实")
}

// 校验身份证号格式
func (rr *Regx) IsIdCardFormat(identityCard string) bool {
	switch len(identityCard) {
	case 15:
		// 15位身份证号码：15位全是数字
		result, _ := regexp.MatchString(`^(\d{15})$`, identityCard)
		return result
	case 18:
		// 18位身份证：前17位为数字，第18位为校验位，可能是数字或X
		result, _ := regexp.MatchString(`^(\d{17})([0-9]|X|x)$`, identityCard)
		return result
	default:
		//身份证位数应该为：15位 与 18位
		return false
	}
	return true
}

// GetAgeByIdCard Get age based on ID
func (rr *Regx) GetAgeByIdCard(id string) int {
	d := new(date.DateTime)
	now := d.Now().Time()
	birth, _ := rr.GetBirthByIdCard(id)
	startTime, err := d.Parse(birth)
	if err != nil {
		return 0
	}
	if startTime.Time().Before(now) {
		diff := now.Unix() - startTime.Time().Unix()
		Age := diff / (3600 * 365 * 24)
		return int(Age)
	}
	return 0
}

// GetBirthByIdCard get birthday
func (rr *Regx) GetBirthByIdCard(id string) (string, error) {
	birth := id[6:14]
	_, err := rr.CheckBirthdayCode(birth)
	if err != nil {
		return "", err
	}
	return birth[:4] + "-" + birth[4:6] + "-" + birth[6:], nil
}

// GetYearByIdCard Year based on ID
func (rr *Regx) GetYearByIdCard(id string) string {
	return id[6:14][:4]
}

// GetMonthByIdCard Get the month of your birthday based on your ID
func (rr *Regx) GetMonthByIdCard(id string) string {
	return id[6:14][4:6]
}

// GetDayByIdCard Get birthday based on ID
func (rr *Regx) GetDayByIdCard(id string) string {
	return id[6:14][6:]
}

// GetSex Get gender based on ID
// Description 0 Female 1 Male 3 unknown ID card gender identification error
func (rr *Regx) GetSex(id string) uint {
	var unknown uint = 3
	sexStr := id[16:17]
	if sexStr == "" {
		return unknown
	}
	i, err := strconv.Atoi(sexStr)
	if err != nil {
		return unknown
	}
	if i%2 != 0 {
		return 1
	}
	return 0
}

// Convert15To18 15-digit ID card to 18-digit
// 15位身份证转为18位
var weight = [17]int{7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2}
var validValue = [11]byte{'1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'}

func (rr *Regx) Convert15To18(id string) string {
	nLen := len(id)
	if nLen != 15 {
		return "身份证不是15位！"
	}
	id18 := make([]byte, 0)
	id18 = append(id18, id[:6]...)
	id18 = append(id18, '1', '9')
	id18 = append(id18, id[6:]...)

	sum := 0
	for i, v := range id18 {
		n, _ := strconv.Atoi(string(v))
		sum += n * weight[i]
	}
	mod := sum % 11
	id18 = append(id18, validValue[mod])
	return string(id18)
}