// From rust by example

use std::fs::File;
use std::io::{self, BufRead};
use std::path::Path;

fn aoc_day1(path : &str, n : i64) -> i64 {
    let mut max_calories : [i64; 3] = [0, 0, 0];
    let mut calories : i64 = 0;
    if let Ok(lines) = read_lines(path) {
        for line in lines {
            if let Ok(scalories) = line {
                println!("{}", scalories);
                println!("[{}, {}, {}]", max_calories[0], max_calories[1], max_calories[2]);
                if scalories.len() == 0 {
                    if calories > max_calories[0] {
                        max_calories[0] = calories;
                        max_calories.sort();
                    }
                    calories = 0;
                } else {
                    let snack_calories = scalories.parse::<i64>().unwrap();
                    calories += snack_calories;
                }
            }
        }
        // eof
        if calories > max_calories[0] {
            max_calories[0] = calories;
            max_calories.sort();
        }
    }
    if n == 1 {
        return max_calories[2];
    } else {
        return max_calories.iter().sum();
    }
}

// The output is wrapped in a Result to allow matching on errors
// Returns an Iterator to the Reader of the lines of the file.
fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
where P: AsRef<Path>, {
    let file = File::open(filename)?;
    Ok(io::BufReader::new(file).lines())
}

fn main() {
    aoc_day1("input.txt", 1);
}

#[test]
fn day1input() {
    assert_eq!(aoc_day1("input.txt", 1), 69206);
    assert_eq!(aoc_day1("input.txt", 3), 197400);
}

#[test]
fn example() {
    assert_eq!(aoc_day1("example.txt", 1), 24000);
    assert_eq!(aoc_day1("example.txt", 3), 45000);
}