use clap::arg;
use image::{GenericImageView, DynamicImage};
use colored::{ColoredString, Colorize};
use crate::args::{
    args::Arguments,
    enums::Mode
};

pub fn generate_ascii(image: DynamicImage, args: &Arguments) -> Result<Vec<ColoredString>, error::ASCIIProcessingError> {
    let characters = args.characters.chars().collect::<Vec<char>>();
    trace!("Characters: {:?}, length: {}", characters, characters.len());
    let mut output = Vec::new();
    let (width, height) = image.dimensions();

    for y in 0..height {
        for x in 0..width {
            if y % (args.scale * 2) == 0 && x % args.scale == 0 {
                output.push(get_character(image.get_pixel(x, y), &characters, args.mode));
            }
        }
        // Add a new line at the end of each row
        if y % (args.scale * 2) == 0 {
            output.push("\n".into());
        }
    }

    Ok(output)
}

fn get_character(pixel: image::Rgba<u8>, characters: &Vec<char>, mode: Mode) -> ColoredString {
    let intent = if pixel[3] == 0 { 0 } else { pixel[0] / 3 + pixel[1] / 3 + pixel[2] / 3 };

    let ch = characters[(intent / (32 + 7 - (7 + (characters.len() - 7)) as u8)) as usize];

    let ch = String::from(ch);

    match mode {
        Mode::NormalAscii => ColoredString::from(&*ch),
        Mode::COLORED => {
            ch.to_string()
                .truecolor(pixel[0], pixel[1], pixel[2])
        }
    }
}

mod error {
    use std::error::Error;
    use std::fmt::{Debug, Display, Formatter};

    #[derive(Debug)]
    pub struct ASCIIProcessingError {
        message: String,
    }

    impl ASCIIProcessingError {
        pub fn new(message: String) -> Self {
            ASCIIProcessingError {
                message
            }
        }
    }

    impl Display for ASCIIProcessingError {
        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
            write!(f, "{}", self.message)
        }
    }

    impl Error for ASCIIProcessingError {
        fn description(&self) -> &str {
            &self.message
        }
    }
}