use std::path::PathBuf;

use clap::Parser;
use image::{ imageops::{self, FilterType}, ImageReader };

#[derive(Parser)]
struct Cli {
    path: PathBuf,
    #[arg(short = 'H', long, default_value_t = 30)]
    height: u32,
    #[arg(short, long, default_value_t = 0.4)]
    ratio: f32,
    #[arg(short, long, default_value_t, value_enum)]
    filter: Filter,
}

#[derive(clap::ValueEnum, Clone, Default)]
enum Filter {
    Nearest,
    Triangle,
    Gaussian,
    CatmullRom,
    #[default]
    Lanczos3,
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args = Cli::parse();
    let filter = match args.filter {
        Filter::Nearest    => { FilterType::Nearest },
        Filter::Triangle   => { FilterType::Triangle },
        Filter::CatmullRom => { FilterType::CatmullRom },
        Filter::Gaussian   => { FilterType::Gaussian },
        Filter::Lanczos3   => { FilterType::Lanczos3 },
    };
    let img = ImageReader::open(args.path)?.decode()?;
    let original_ratio = img.width() as f32 / img.height() as f32;
    let width = ( args.height as f32 / args.ratio ) * original_ratio;
    let out = imageops::resize(&img, width as u32, args.height * 2, filter);
    let mut iter = out.enumerate_rows();
    while let Some((_, top)) = iter.next() {
        let (_, bottom) = iter.next().unwrap();
        top.zip(bottom)
            .for_each(|((_, _, t), (_, _, b))| {
                print!("\x1B[38;2;{};{};{};48;2;{};{};{}m\u{2584}", b[0], b[1], b[2], t[0], t[1], t[2])
            });
        println!("\x1B[0m");
    }
    Ok(())
}