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

mod counts;
use counts::*;

fn main() -> io::Result<()> {
    for filename in env::args().skip(1) {
        let mut f = File::open(&filename)?;
        let mut reader = io::BufReader::new(f);
        let counts = count_words(&mut reader)?;
        print(&counts, 10)
    }
    Ok(())
}


fn count_words(reader: &mut io::BufReader<File>) -> io::Result<WordCounts> {
    let mut counts = WordCounts::new();
    for line in reader.lines() {
        let line = line?;
        add_counts(&mut counts, &count_words_in_line(&line));
    }
    Ok(counts)
}


fn count_words_in_line(line: &str) -> WordCounts {
    let mut counts = WordCounts::new();
    let mut word = String::new();
    for c in line.chars() {
        if c.is_alphabetic() {
            word.push(c);
        } else {
            if !word.is_empty() {
                count(&mut counts, word.clone());
                word.clear();
            }
        }
    }
    if !word.is_empty() {
        count(&mut counts, word.clone());
    }
    counts
}