import { readFile } from "fs/promises";

if (process.argv.length <= 3) {
	console.error(`Needs more args >:(`);
	process.exit(1);
}

const fileToRead = process.argv[2];
const gap = parseInt(process.argv[3])
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))
		// .reverse()

	let isValid = true;
	let errorCorrected = false;
	let firstSign = null;
	let firstIter = true;
	for (var i = 0; i < ints.length - 1; i++) {
		const a = ints[i];
		const b = ints[i + 1];

		const sign = Math.sign( a - b );
		const delta = Math.abs( a - b );

		firstSign ??= sign;

		const rightDirection = sign === firstSign;
		const deltaWithinRange = delta <= gap;

		if (!rightDirection || !deltaWithinRange) {
			isValid &&= !errorCorrected;
			if (!isValid) {
				break;
			}
			errorCorrected = true;
			ints.splice(i , 1);
			i--;
			continue;
		}
		firstIter = false;
	};
	console.log({ firstSign, isValid, errorCorrected, ints })
	if (isValid) validLines++;
};

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