package utils

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"os"
	"qnc-server/model/model"
	"regexp"
	"strconv"
	"time"
)

func loadRegions(filename string) (map[string]model.Region, error) {
	file, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	byteValue, _ := ioutil.ReadAll(file)

	var regions map[string]model.Region
	json.Unmarshal(byteValue, &regions)

	return regions, nil
}

func ParseIDCard(id string) (model.IDInfo, error) {

	if len(id) != 18 {
		return model.IDInfo{}, fmt.Errorf("Invalid ID length")
	}

	// Validate the ID card number
	validID, _ := regexp.MatchString(`^\d{17}[\dX]$`, id)
	if !validID {
		return model.IDInfo{}, fmt.Errorf("Invalid ID format")
	}

	regionCode := id[:6]
	birthDate := id[6:14]
	genderCode := id[16:17]

	regions, err := loadRegions("processed.json")
	if err != nil {
		return model.IDInfo{}, fmt.Errorf("loadRegions error: %v", err)
	}

	region, exists := regions[regionCode]
	if !exists {
		return model.IDInfo{}, fmt.Errorf("Region code not found")
	}

	birth, err := time.Parse("20060102", birthDate)
	if err != nil {
		return model.IDInfo{}, fmt.Errorf("Invalid birth date")
	}

	gender, err := strconv.Atoi(genderCode)
	if err != nil {
		return model.IDInfo{}, fmt.Errorf("Invalid gender code")
	}

	genderStr := "男"
	if gender%2 == 0 {
		genderStr = "女"
	}

	return model.IDInfo{
		Location:  region.FullRegion,
		BirthDate: birth.Format("2006年01月02日"),
		Gender:    genderStr,
	}, nil
}