#![forbid(elided_lifetimes_in_paths, unsafe_code)]

use aoc23::read;
use chumsky::{prelude::*, text::int};
use std::collections::HashSet;

struct Card {
	id: usize,
	winning_nums: HashSet<usize>,
	nums: HashSet<usize>
}

impl Card {
	fn parser() -> impl Parser<char, Self, Error = Simple<char>> {
		let nums = just(" ")
			.repeated()
			.ignore_then(int(10))
			.separated_by(just(" "))
			.map(|nums| {
				nums.into_iter()
					.map(|num: String| num.parse().unwrap())
					.collect::<HashSet<usize>>()
			});

		just("Card")
			.ignore_then(just(" ").repeated())
			.ignore_then(int(10))
			.then_ignore(just(": "))
			.then(nums)
			.then_ignore(just(" | "))
			.then(nums)
			.map(|((id, winning_nums), nums): ((String, _), _)| Self {
				id: id.parse().unwrap(),
				winning_nums,
				nums
			})
	}
}

fn parser() -> impl Parser<char, Vec<Card>, Error = Simple<char>> {
	Card::parser()
		.then_ignore(just("\n"))
		.repeated()
		.then_ignore(end())
}

fn main() -> anyhow::Result<()> {
	let cards = read("inputs/day4.txt", parser())?;

	let mut points = 0;
	for card in &cards {
		let matches = card
			.nums
			.iter()
			.filter(|num| card.winning_nums.contains(num))
			.count();
		if matches > 0 {
			points += 1 << (matches - 1);
		}
	}
	println!("{points}");

	Ok(())
}