"use strict";

import { readFile } from "fs/promises";

if (process.argv.length <= 2) {
	console.error(`Needs more args >:(`).
	process.exit(0);
}

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

/** @type {Array<Array<string>>} */
const wordSearch = [];

for (const line of file.split(`\n`)) {
	wordSearch.push(line.split(``));
};


let total = 0;

// Iterating the puzzle space, which is reduced by one in both axis'
// in order to reducing the number of iterations since we can't match
// along the edges anyway
for (let y = 1, l1 = wordSearch.length - 1; y < l1; y++) {
	for (let x = 1, l2 = wordSearch[y].length - 1; x < l2; x++) {


		// Short-circuit for performance
		const middle = wordSearch[y][x];
		if (`A` !== middle) {
			continue;
		};

		try {
			const ne = wordSearch[y - 1][x + 1];
			const se = wordSearch[y + 1][x + 1];
			const sw = wordSearch[y + 1][x - 1];
			const nw = wordSearch[y - 1][x - 1];

			let valid = ne === nw && se === sw;
			valid ||= ne === se && nw === sw;

			valid &&= (ne === `M` && se === `S`) || (ne === `S` || se === `M`);

			if (valid) total += 1;
		} catch (c){console.error(c)}

	};
};

console.log(`Found ${total} instances of X'd MAS`);