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


struct Count {
    lines: usize,
    words: usize,
    chars: usize,
}


impl Count {

    fn new() -> Self {
        Count {
            lines: 0,
            words: 0,
            chars: 0,
        }
    }

    fn add(&mut self, c: &Count) {
        self.lines += c.lines;
        self.words += c.words;
        self.chars += c.chars;
    }

    fn incr_lines(&mut self) {
        self.lines += 1;
    }

    fn incr_words(&mut self, n: usize) {
        self.words += n;
    }

    fn incr_chars(&mut self, n: usize) {
        self.chars += n;
    }

}


fn main() -> Result<(), io::Error> {
    for filename in env::args().skip(1) {
        let mut f = File::open(&filename)?;
        let mut reader = io::BufReader::new(f);
        let c = wc(&mut reader)?;
        println!("{:>5} {:>5} {:>5} {}", c.lines, c.words, c.chars, filename);
    }
    Ok(())
}


fn wc(reader: &mut io::BufReader<File>) -> Result<Count, io::Error> {
    let mut count = Count::new();
    for line in reader.lines() {
        let line = line?;
        count.add(&count_line(&line));
    }
    Ok(count)
}


fn count_line(line: &str) -> Count{
    let mut count = Count::new();

    // we have a line!
    count.incr_lines();

    // add +1 for newline, which we ASSUME is there
    count.incr_chars(line.chars().count() + 1);

    // count words
    count.incr_words(count_line_words(line));

    count
}


fn count_line_words(line: &str) -> usize {
    let mut in_word = false;
    let mut num_words = 0;

    for c in line.chars() {
        if c.is_alphabetic() {
            if !in_word {
                in_word = true;
                num_words += 1;
            }
        } else {
            in_word = false;
        }
    }

    num_words
}