use ccvl::filter;
use ccvl::image::*;

fn main() -> std::process::ExitCode {
    let args = std::env::args().collect::<Vec<String>>();
    if args.len() != 3 {
        println!("Usage: {} IN OUT", args[0].as_str());
        return std::process::ExitCode::FAILURE;
    }

    let input_path = args[1].as_str();
    let output_path = args[2].as_str();

    match Image::load::<Farbfeld>(input_path) {
        Err(Error::Invalid) => {
            println!("{} is not a valid image", input_path);
            std::process::ExitCode::FAILURE
        }
        Err(Error::Io(err)) => {
            println!("I/O error loading image {}: {}", input_path, err);
            std::process::ExitCode::FAILURE
        }
        Ok(img) => {
            let result = filter::canny(img.map(|p| Luminance::from(p)))
                .map(|p| p.into());
            match result.save::<Farbfeld>(output_path) {
                Err(err) => {
                    println!(
                        "I/O error saving image {}: {}",
                        output_path, err
                    );
                    std::process::ExitCode::FAILURE
                }
                Ok(()) => std::process::ExitCode::SUCCESS,
            }
        }
    }
}