part1.ts

import * as fs from 'fs';

const input = fs.readFileSync('input', 'utf8').split('\n');

type Module = { destinations: string[]; type: string; pulseSent: boolean; pulseReceived: boolean };

const modules: Module[] = [];
const result = [0, 0];

for (const line of input) {
	const type = line[0];
	const moduleName = type === 'b' ? 'broadcaster' : line.split(' -> ')[0].slice(1);
	const destinations = line.split(' -> ')[1].split(', ');
	modules[moduleName] = {
		destinations,
		type: type,
		pulseSent: false,
		pulseReceived: false,
	};
	if (type === '%') {
		modules[moduleName].on = false;
	} else if (type === '&') {
		modules[moduleName].inputs = {};
	}
}

for (const module of Object.values(modules)) {
	module.destinations = module.destinations.map((x) => modules[x]);
}

for (const [moduleName, module] of Object.entries(modules)) {
	for (const destination of module.destinations) {
		if (typeof destination != 'undefined' && destination.type === '&') {
			destination.inputs[moduleName] = module;
		}
	}
}

function receivePulse(module: Module) {
	return (destination) => {
		if (typeof destination === 'undefined') {
			result[Number(module.pulseSent)]++;
		} else if (destination.type === '%' && module.pulseSent) {
			result[1]++;
		} else {
			result[Number(module.pulseSent)]++;
			destination.pulseReceived = module.pulseSent;
		}
	};
}

function filterDestinations(module) {
	return (destination) =>
		typeof destination != 'undefined' && !(destination.type === '%' && module.pulseSent);
}

for (let i = 0; i < 1000; i++) {
	const queue = [Object.values(modules).find((x) => x.type === 'b')];
	result[0]++;
	while (queue.length > 0) {
		const module = queue.shift();
		if (typeof module == 'undefined') {
			continue;
		}
		switch (module.type) {
			case '%':
				if (!module.pulseReceived) {
					module.pulseSent = module.on = !module.on;
				}
				break;
			case '&':
				module.pulseSent = !Object.values(module.inputs).every((x) => x.pulseSent);
				break;
		}
		if (module.type === '&' || !module.pulseReceived) {
			module.destinations.forEach(receivePulse(module));
			queue.push(...module.destinations.filter(filterDestinations(module)));
		}
	}
}

console.log(result[0] * result[1]);