use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;

use clap::Arg;
use clap::Command;

fn main() {
    let matches = Command::new("Day1").arg(Arg::new("filename")).get_matches();
    let filename = matches
        .get_one::<String>("filename")
        .expect("Need a filename");
    println!("Processing {}...", filename);

    let file = File::open(filename).expect("Can't read file");
    let reader = BufReader::new(file);

    let mut max_calories = 0;
    let mut elf_calories = 0;

    for line in reader.lines() {
        let line = line.unwrap();
        let line = line.trim();

        // XXX I want to do this with an iterator!
        if line.is_empty() {
            if elf_calories > max_calories {
                max_calories = elf_calories;
            }
            elf_calories = 0;
        } else {
            println!("Line: {}", line);
            elf_calories += line.parse::<u32>().unwrap();
        }
    }
    println!("Max: {}", max_calories);
}