psn-js/src/encoders/packet-header-chunk.ts

import chunk from './chunk.js';

const packetHeader = new DataView(new ArrayBuffer(12));
export default (
	timestamp: bigint,
	versionHigh: number,
	versionLow: number,
	frameId: number,
	framePacketCount: number
): Uint8Array => {
	if (!Number.isInteger(versionHigh)) {
		throw new Error('version high must be an integer');
	}
	if (!Number.isInteger(versionLow)) {
		throw new Error('version low must be an integer');
	}
	if (!Number.isInteger(frameId)) {
		throw new Error('frame id must be an integer');
	}
	if (!Number.isInteger(framePacketCount)) {
		throw new Error('frame packet count must be an integer');
	}

	if (versionHigh > 255 || versionHigh < 0) {
		throw new Error('version high must be >= 0 and <= 255');
	}
	if (versionLow > 255 || versionLow < 0) {
		throw new Error('version low must be >= 0 and <= 255');
	}
	if (frameId > 255 || frameId < 0) {
		throw new Error('frame id must be >= 0 and <= 255');
	}
	if (framePacketCount > 255 || framePacketCount < 0) {
		throw new Error('frame packet count must be >= 0 and <= 255');
	}

	packetHeader.setBigUint64(0, BigInt(timestamp), true);
	packetHeader.setUint8(8, versionHigh);
	packetHeader.setUint8(9, versionLow);
	packetHeader.setUint8(10, frameId);
	packetHeader.setUint8(11, framePacketCount);

	return chunk(0x0000, new Uint8Array(packetHeader.buffer), false);
};