pub trait Descriptor {
    fn info(&self) -> String {
        "Descriptor".to_string()
    }
    fn resize(&self, img: image::DynamicImage) -> image::DynamicImage {
        img.grayscale().thumbnail_exact(8, 8)
    }
    fn describe(&self, img: image::DynamicImage) -> u64;
    fn distance(&self, a: u64, b: u64) -> u64 {
        (a^b).count_ones().into()
    }
}

/// Interprets a 64-element array as an 8x8 matrix
/// returns a nicely printable string
fn print_matrix<T: ToString + std::fmt::Display>(array: [T; 64]) -> String {
    let mut output = String::new();
    for x in 0..8 {
        for y in 0..8 {
            let element = format!("{:.2}", &array[x*8+y]);
            let element = format!("{:8}\t", element);
            output.push_str(&element);
        }
        output.push('\n');
    }
    output
}

/// A struct representing a Discrete Cosine Transform descriptor
/// Transforms an image into an 8x8 grayscale version, and transforms it
/// into the frequency domain
pub struct DCT {
    quantization_matrix: [u8; 64]
}
pub mod dct;

// fn median64<T: Ord + Copy>(values: &[T]) -> T {
//     let mut sorted_values = values.to_vec();
//     sorted_values.sort();
//     let len = sorted_values.len();
//     sorted_values[len/2]
// }


// pub struct Median;

// impl Descriptor for Median {
//     fn describe(&self, img: image::DynamicImage) -> u64 {
//         let img = self.resize(img);
//         let mut values: [u8; 64] = [0; 64];
//         let mut i: usize = 0;
//         for (_, _, pix) in img.pixels() {
//             values[i] = pix[0];
//             i = i+1;
//         }
//         let median = median64(&values);
//         let mut mask: u64 = 0;
//         img.save("debug.png").unwrap();
//         for (_, _, pix) in img.pixels() {
//             if pix[0] > median {
//                 mask += 1;
//             }
//             mask = mask << 1;
//         }
//         mask
//     }
// }