// 使用示例：
// import IDCardParser from '@/utils/IDCardParser';

// const handleCheck = (idStr) => {
//   const parser = new IDCardParser(idStr);
//   const result = parser.getInfo();
//   if(result.valid) {
//       // 填充表单
//       console.log(result.age, result.gender);
//   } else {
//       alert(result.message);
//   }
// }

class IDCardParser {
    constructor(idNumber) {
        this.idNumber = idNumber ? idNumber.trim().toUpperCase() : "";
        this.provinceMap = {
            11: "北京市",
            12: "天津市",
            13: "河北省",
            14: "山西省",
            15: "内蒙古自治区",
            21: "辽宁省",
            22: "吉林省",
            23: "黑龙江省",
            31: "上海市",
            32: "江苏省",
            33: "浙江省",
            34: "安徽省",
            35: "福建省",
            36: "江西省",
            37: "山东省",
            41: "河南省",
            42: "湖北省",
            43: "湖南省",
            44: "广东省",
            45: "广西壮族自治区",
            46: "海南省",
            50: "重庆市",
            51: "四川省",
            52: "贵州省",
            53: "云南省",
            54: "西藏自治区",
            61: "陕西省",
            62: "甘肃省",
            63: "青海省",
            64: "宁夏回族自治区",
            65: "新疆维吾尔自治区",
            71: "台湾省",
            81: "香港特别行政区",
            82: "澳门特别行政区"
        };

        // 初始化验证结果
        const validation = this._validate();
        this.isValid = validation.isValid;
        this.errorMsg = validation.msg;

        // 如果合法，预先解析数据
        if (this.isValid) {
            this._parseData();
        }
    }

    /**
     * 核心校验逻辑
     */
    _validate() {
        // 1. 基础正则 (18位，末位数字或X)
        if (!/^\d{17}[\d|X]$/.test(this.idNumber)) {
            return {
                isValid: false,
                msg: "格式错误：必须是18位，末位为数字或X"
            };
        }

        // 2. 省份校验
        const provinceCode = parseInt(this.idNumber.substring(0, 2));
        if (!this.provinceMap[provinceCode]) {
            return {
                isValid: false,
                msg: "省份代码错误"
            };
        }

        // 3. 日期合法性严格校验
        const year = parseInt(this.idNumber.substring(6, 10));
        const month = parseInt(this.idNumber.substring(10, 12));
        const day = parseInt(this.idNumber.substring(12, 14));

        const date = new Date(year, month - 1, day);
        // JS Date会自动纠错(例如2月30会变成3月)，所以必须反向比对
        if (
            date.getFullYear() !== year ||
            date.getMonth() + 1 !== month ||
            date.getDate() !== day
        ) {
            return {
                isValid: false,
                msg: "出生日期无效"
            };
        }

        // 检查年份范围（可选，例如限制在1900年以后）
        if (year < 1900 || date > new Date()) {
            return {
                isValid: false,
                msg: "出生日期不在合理范围内"
            };
        }

        // 4. 校验码计算 (ISO 7064:1983.MOD 11-2)
        if (!this._checkSum()) {
            return {
                isValid: false,
                msg: "校验码错误（身份证可能无效）"
            };
        }

        return {
            isValid: true,
            msg: "验证通过"
        };
    }

    /**
     * 校验码算法
     */
    _checkSum() {
        const factors = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2];
        const checkCodes = ['1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'];

        let sum = 0;
        for (let i = 0; i < 17; i++) {
            sum += parseInt(this.idNumber[i]) * factors[i];
        }

        const mod = sum % 11;
        return checkCodes[mod] === this.idNumber[17];
    }

    /**
     * 解析内部数据
     */
    _parseData() {
        const year = parseInt(this.idNumber.substring(6, 10));
        const month = parseInt(this.idNumber.substring(10, 12));
        const day = parseInt(this.idNumber.substring(12, 14));

        this.birthDate = new Date(year, month - 1, day);
        this.province = this.provinceMap[parseInt(this.idNumber.substring(0, 2))];

        // 性别：第17位，奇数男，偶数女
        const genderCode = parseInt(this.idNumber.substring(16, 17));
        this.gender = genderCode % 2 !== 0 ? "男" : "女";
    }

    /**
     * 获取所有信息
     */
    getInfo() {
        if (!this.isValid) {
            return {
                valid: false,
                message: this.errorMsg
            };
        }

        return {
            valid: true,
            idNumber: this.idNumber,
            province: this.province,
            birthday: this._formatDate(this.birthDate),
            gender: this.gender,
            age: this._calculateAge(),
            zodiac: this._getZodiac(), // 生肖
            constellation: this._getConstellation() // 星座
        };
    }

    _formatDate(date) {
        const y = date.getFullYear();
        const m = String(date.getMonth() + 1).padStart(2, '0');
        const d = String(date.getDate()).padStart(2, '0');
        return `${y}-${m}-${d}`;
    }

    _calculateAge() {
        const today = new Date();
        let age = today.getFullYear() - this.birthDate.getFullYear();
        const m = today.getMonth() - this.birthDate.getMonth();

        // 如果没过生日，年龄减1
        if (m < 0 || (m === 0 && today.getDate() < this.birthDate.getDate())) {
            age--;
        }
        return age;
    }

    _getZodiac() {
        // 猴鸡狗猪鼠牛虎兔龙蛇马羊 (对应余数 0-11)
        const zodiacs = "猴鸡狗猪鼠牛虎兔龙蛇马羊";
        return zodiacs.charAt(this.birthDate.getFullYear() % 12);
    }

    _getConstellation() {
        const month = this.birthDate.getMonth() + 1;
        const day = this.birthDate.getDate();

        // 星座分割日
        const dates = [20, 19, 21, 20, 21, 22, 23, 23, 23, 24, 23, 22];
        const constellations = [
            "摩羯座", "水瓶座", "双鱼座", "白羊座", "金牛座", "双子座",
            "巨蟹座", "狮子座", "处女座", "天秤座", "天蝎座", "射手座", "摩羯座"
        ];

        if (day < dates[month - 1]) {
            return constellations[month - 1];
        } else {
            return constellations[month];
        }
    }
}


export default IDCardParser;