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extern crate clap;

use std::fs;
use std::error::Error;
use clap::ArgMatches;

pub fn wc_line(s: &String) -> usize {
    let split = s.lines();

    let len = split.count();

    println!("Count by lines: {}", len);
    len
}

pub fn wc_word(s: &String) -> usize {
    let split = s.split_whitespace();

    let len = split.count();

    println!("Count by words: {}", len);
    len
}

pub fn wc_char(s: &String) -> usize {
    let len = s.chars().count();

    println!("Count by chars: {}", len);
    len
}

pub fn wc_byte(s: &String) -> usize {
    let len = s.len();

    println!("Count by bytes: {}", len);
    len
}

pub fn run(matches: ArgMatches) -> Result<(), Box<dyn Error>> {
    let file = matches.value_of("input").unwrap();
    println!("Input is: {}", file);
    let contents = fs::read_to_string(file)?;

    println!("file contains: {}", contents);

    if matches.is_present("chars") {
        println!("by char");
        wc_char(&contents);
    } else if matches.is_present("lines") {
        println!("by line");
        wc_line(&contents);
    } else if matches.is_present("bytes") {
        println!("by bytes");
        wc_byte(&contents);
    } else {
        println!("by word");
        wc_word(&contents);
    }

    Ok(())
}

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

    #[test]
    fn test_wc_word() {
        let hi = String::from("hi there");
        assert_eq!(wc_word(&hi), 2);
    }

    #[test]
    fn test_wc_char() {
        let hi = String::from("hi");
        assert_eq!(wc_char(&hi), 2);
    }

    #[test]
    fn test_wc_byte() {
        let hi = String::from("hi");
        assert_eq!(wc_byte(&hi), 2);
    }

    #[test]
    fn test_wc_line() {
        let hi = String::from("hi");
        assert_eq!(wc_line(&hi), 1);
    }
}