import { readFile } from "fs/promises";

function legalValues(a, b, gap) {
	const delta = Math.abs(a - b);
	console.log(`legaValues(${a}, ${b}, ${gap}){delta=${delta}} = ${delta <= gap}`);
	return delta <= gap;
};

if (process.argv.length <= 2) {
	console.error(`Needs more args >:(`).
	process.exit(1);
}

const fileToRead = process.argv[2];
const file = await readFile(fileToRead, `utf-8`);

let validLines = 0;
for (const line of file.split(`\n`)) {
	// console.log(line)
	const ints = line.split(` `)
		.map(v => Number.parseInt(v));

	const isSafe = ints
		.slice(0, -1)
		.map((v, i) => v - ints[i + 1])
		.every((v, _, a) => Math.sign(v) === Math.sign(a[0]) && Math.abs(v) <= 3);

	// console.log(isSafe)

	if(isSafe) {
		validLines++;
	};
	// break
};

console.log(`Number of valid reports:`, validLines)