//! Day 4: Camp Cleanup

use std::ops::RangeInclusive;

fn get_ranges(input: Vec<String>) -> Vec<(RangeInclusive<u32>, RangeInclusive<u32>)> {
    // 31-31,32-40
    input
        .into_iter()
        .map(|line| {
            let (r1, r2) = line.split_once(',').unwrap();
            (parse_range(r1), parse_range(r2))
        })
        .collect()
}

fn parse_range(s: &str) -> RangeInclusive<u32> {
    let (a, b) = s.split_once('-').unwrap();
    RangeInclusive::new(a.parse().unwrap(), b.parse().unwrap())
}

pub fn part1(input: Vec<String>) -> String {
    let ranges = get_ranges(input);

    ranges
        .iter()
        .filter(|(a, b)| {
            (b.start() >= a.start() && b.end() <= a.end())
                || (a.start() >= b.start() && a.end() <= b.end())
        })
        .count()
        .to_string()
}

pub fn part2(input: Vec<String>) -> String {
    let ranges = get_ranges(input);

    ranges
        .iter()
        .filter(|(a, b)| {
            a.contains(b.start())
                || a.contains(b.end())
                || b.contains(a.start())
                || b.contains(a.end())
        })
        .count()
        .to_string()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn t_example() {
        let input = vec![
            "2-4,6-8".to_owned(),
            "2-3,4-5".to_owned(),
            "5-7,7-9".to_owned(),
            "2-8,3-7".to_owned(),
            "6-6,4-6".to_owned(),
            "2-6,4-8".to_owned(),
        ];
        assert_eq!(part1(input.clone()), "2");
        assert_eq!(part2(input), "4");
    }

    #[test]
    fn t_part1() {
        assert_eq!(part1(crate::read_input(4)), "556");
    }

    #[test]
    fn t_part2() {
        assert_eq!(part2(crate::read_input(4)), "876");
    }
}