RocketChat/Rocket.Chat

import type http from 'http';

import type { IUpload } from '@rocket.chat/core-typings';

function getByteRange(header?: string) {
    if (!header) {
        return;
    }
    const matches = header.match(/(\d+)-(\d+)/);
    if (!matches) {
        return;
    }
    return {
        start: parseInt(matches[1], 10),
        stop: parseInt(matches[2], 10),
    };
}

export function getFileRange(file: IUpload, req: http.IncomingMessage) {
    const range = getByteRange(req.headers.range);
    if (!range) {
        return;
    }
    const size = file.size || 0;
    if (range.start > size || range.stop <= range.start || range.stop > size) {
        return { outOfRange: true, start: range.start, stop: range.stop };
    }

    return { outOfRange: false, start: range.start, stop: range.stop };
}

// code from: https://github.com/jalik/jalik-ufs/blob/master/ufs-server.js#L310
export const setRangeHeaders = function (
    range: { start: number; stop: number; outOfRange?: boolean } | undefined,
    file: IUpload,
    res: http.ServerResponse,
) {
    if (!range) {
        return;
    }

    if (range.outOfRange) {
        // out of range request, return 416
        res.removeHeader('Content-Length');
        res.removeHeader('Content-Type');
        res.removeHeader('Content-Disposition');
        res.removeHeader('Last-Modified');
        res.setHeader('Content-Range', `bytes */${file.size}`);
        res.writeHead(416);
        res.end();
        return;
    }

    res.setHeader('Content-Range', `bytes ${range.start}-${range.stop}/${file.size}`);
    res.removeHeader('Content-Length');
    res.setHeader('Content-Length', range.stop - range.start + 1);
    res.statusCode = 206;
};