use bliss_rs::bliss_lib::Song;
use std::env;

/**
 * Simple utility to print distance between two songs according to bliss.
 *
 * Takes two file paths, and analyze the corresponding songs, printing
 * the distance between the two files according to bliss.
 */
fn main() -> Result<(), String> {
    let mut paths = env::args().skip(1).take(2);

    let first_path = paths.next().ok_or("Help: ./distance <song1> <song2>")?;
    let second_path = paths.next().ok_or("Help: ./distance <song1> <song2>")?;

    let song1 = Song::from_path(&first_path).map_err(|x| x.to_string())?;
    let song2 = Song::from_path(&second_path).map_err(|x| x.to_string())?;

    let mut distance_squared: f64 = 0.0;
    let analysis1 = song1.analysis.as_bytes();
    let analysis2 = song2.analysis.as_bytes();
    for (i, feature1) in analysis1.iter().enumerate() {
        distance_squared += (feature1 - analysis2[i]).pow(2) as f64;
    }

    println!(
        "d({:?}, {:?}) = {}",
        &first_path,
        &second_path,
        distance_squared.sqrt(),
    );
    Ok(())
}