/**
 * A stand-in for a daemon released before `hello.features`: it answers `hello` without `features` and refuses every
 * other operation as an unknown one, as such a daemon refuses `listFiles`. Started as `node old-daemon.ts serve --token
 * <hex>`.
 */
const token = process.argv[process.argv.indexOf("--token") + 1];
process.stdout.write(`PI-ENV ${token}\n`);

function send(type: number, id: number, json: Record<string, unknown>): void {
	const body = Buffer.from(JSON.stringify(json), "utf8");
	const header = Buffer.alloc(13);
	header.writeUInt32BE(9 + body.length, 0);
	header.writeUInt8(type, 4);
	header.writeUInt32BE(id, 5);
	header.writeUInt32BE(body.length, 9);
	process.stdout.write(Buffer.concat([header, body]));
}

let buffered = Buffer.alloc(0);
process.stdin.on("data", (chunk: Buffer) => {
	buffered = Buffer.concat([buffered, chunk]);
	while (buffered.length >= 4 && buffered.length >= 4 + buffered.readUInt32BE(0)) {
		const length = buffered.readUInt32BE(0);
		const type = buffered.readUInt8(4);
		const id = buffered.readUInt32BE(5);
		const jsonLength = buffered.readUInt32BE(9);
		const json = JSON.parse(buffered.subarray(13, 13 + jsonLength).toString("utf8")) as { op?: string };
		buffered = buffered.subarray(4 + length);
		if (type !== 1) continue;
		if (json.op === "hello") {
			send(2, id, {
				protocol: 1,
				version: "1.1.0",
				os: "linux",
				arch: "x86_64",
				home: "/",
				separator: "/",
				tmpdir: "/tmp",
				cwd: "/",
				driveCwds: {},
				pid: process.pid,
			});
		} else {
			send(3, id, { code: "EINVAL", message: `unknown operation ${json.op}` });
		}
	}
});
process.stdin.on("end", () => process.exit(0));