'use strict';

/**
 *
 *
 * @author Mai
 * @date
 * @version
 */

const CryptoJS = require('crypto-js');
const LzString = require('lz-string');
const { decode } = require('js-base64');

const _interopDefaultLegacy = function(e) { return e && typeof e === 'object' && 'default' in e ? e : { default: e }; };
const CryptoJS__default = /* #__PURE__*/_interopDefaultLegacy(CryptoJS);
const key = CryptoJS__default.default.enc.Utf8.parse('7563850888ABCDEF'); // 十六位十六进制数作为密钥
const iv = CryptoJS__default.default.enc.Utf8.parse('ABCDEF7563850888'); // 十六位十六进制数作为密钥偏移量

const fs = require('fs');
const ybpSpr = '|----|', rationSpr = '|====|';

const Decrypt = function(str) {
    const encryptedHexStr = CryptoJS__default.default.enc.Hex.parse(str);
    const src = CryptoJS__default.default.enc.Base64.stringify(encryptedHexStr);
    const decrypt = CryptoJS__default.default.AES.decrypt(src, key, {
        iv,
        mode: CryptoJS__default.default.mode.CBC,
        padding: CryptoJS__default.default.pad.Pkcs7,
    });
    const decryptedStr = decrypt.toString(CryptoJS__default.default.enc.Utf8);
    return decryptedStr.toString();
};

class ybp {
    parseSubject(str) {
        if (str.indexOf(rationSpr) >= 0) {
            const arr = str.split(rationSpr);
            const subject = JSON.parse(LzString.decompressFromBase64(arr[0]));
            for (let i = 1; i < arr.length; i++) {
                const ration = JSON.parse(LzString.decompressFromBase64(arr[i]));
                subject.rations.push(...ration);
            }
            return subject;
        } else {
            return JSON.parse(LzString.decompressFromBase64(str));
        }
    }
    decryptBuffer(buffer) {
        const arr = buffer.split(ybpSpr);
        const result = { header: '', subjects: [] };
        arr.forEach((s, i) => {
            if (i === 0) {
                result.header = JSON.parse(Decrypt(s));
            } else {
                switch (result.header.version) {
                    case '3.0':
                        result.subjects.push(this.parseSubject(s));
                        break;
                    default:
                        result.subjects.push(JSON.parse(Decrypt(s)));
                        break;
                }
            }
        });
        return result;
    }
    async decrypt(file) {
        const str = await fs.readFileSync(file, 'utf-8');
        return this.decryptBuffer(str);
    }
}

module.exports = ybp;