achievement-watcher/celes

import {SSEAchievement} from '../../../types';
import {UnexpectedFileContentError} from '../../utils/errors';

export function parse(buffer: Buffer): SSEAchievement[] {
    const header = buffer.slice(0, 4);
    const entryCount = parseInt(header.slice(0, 1).reverse().toString('hex'), 16);

    const data = bufferSplit(buffer.slice(header.length, buffer.length), 24);
    if (data.length !== entryCount) {
        throw new UnexpectedFileContentError();
    }

    const achievements: SSEAchievement[] = [];

    for (const entry of data) {
        const achieved: number = parseInt(entry.slice(20, 21).toString('hex'), 16);

        achievements.push({
            crc: entry.slice(0, 4).reverse().toString('hex'),
            Achieved: achieved,
            UnlockTime: parseInt(entry.slice(8, 12).reverse().toString('hex'), 16)
        });
    }

    return achievements;
}

function bufferSplit(buffer: Buffer, n: number) {
    const result: Buffer[] = [];
    for (let i = 0, j = 1; i < buffer.length; i += n, j++) {
        result.push(buffer.slice(i, n * j));
    }
    return result;
}