#!/usr/bin/env deno

import "https://github.com/emn178/js-sha512/raw/v0.8.0/build/sha512.min.js";

const CHUNKSIZE = 128;

async function main() {

	let files = [];

	if (Deno.args.length > 1) {
		files.push(...await Promise.all(
			Deno.args.slice(1).map(async path => ({
				path,
				file: await Deno.open(path, "r"),
			}))
		));
	} else {
		files.push({
			path: "-",
			file: Deno.stdin,
		});
	}

	const hashes = await Promise.all(
		files.map(async file => {
			const hash = sha384.create();
			const buf = new Uint8Array(CHUNKSIZE);

			let read = 0;
			while (true) {
				read = await file.file.read(buf);
				hash.update(buf.slice(0, read));
				if (read === Deno.EOF) {
					break;
				}
			}

			return {
				...file,
				hash: hash.hex(),
			};
		})
	);

	for (const file of hashes) {
		console.log(`${file.hash}  ${file.path}`);
	}

}

main();