use std::env::args;
use std::fs::File;
use std::io::stdout;
use std::io::Read;
use std::io::Write;
use std::iter::repeat_with;
use std::thread::sleep;
use std::time::Duration;

use rand::thread_rng;
use rand::Rng;

use pixelfoo::color::Color;

type Frame = Vec<Vec<Color>>;

fn send<T: Write>(w: &mut T, f: &Frame) -> std::io::Result<()> {
    for l in f {
        for c in l {
            w.write_all(&c.rgb())?;
        }
    }
    w.flush()
}

fn pick_color<R>(c0: Color, c1: Color, rng: &mut R) -> Color
where
    R: Rng,
{
    if rng.gen::<f64>() < 0.5 {
        c0.interpolate(c1, rng.gen::<f64>().powf(2.0))
    } else {
        Color::black()
    }
}

fn main() -> std::io::Result<()> {
    let args = args().collect::<Vec<_>>();
    eprintln!("executing {}", args[0]);

    let x_size = args[1].parse::<usize>().unwrap();
    let y_size = args[2].parse::<usize>().unwrap();
    eprintln!("screen size {}x{}", x_size, y_size);

    let mut f = File::open("apps/pet-2.bin")?;
    let mut buffer = Vec::new();
    f.read_to_end(&mut buffer)?;

    let t_frame = 0.040; // s
    let delay = Duration::new(0, (1_000_000_000.0 * t_frame) as u32);

    let c0 = Color::new(0, 138, 170);
    let c1 = Color::new(0, 160, 95);

    let mut rng = thread_rng();

    let mut frame = repeat_with(|| {
        repeat_with(|| pick_color(c0, c1, &mut rng))
            .take(x_size)
            .collect::<Vec<_>>()
    })
    .take(y_size)
    .collect::<Vec<_>>();
    loop {
        let x = rng.gen_range(0, x_size / 8);
        let y = rng.gen_range(0, y_size / 8);
        let color = pick_color(c0, c1, &mut rng);
        let start_index = rng.gen_range(0, buffer.len() / 8) * 8;
        for i in start_index..(start_index + 8) {
            let b = buffer[i];
            for j in 0..8 {
                frame[y][x] = {
                    if b & (1 << j) != 0 {
                        color
                    } else {
                        Color::black()
                    }
                };
            }
        }

        let mut buf = Vec::with_capacity(x_size * y_size * 3);
        send(&mut buf, &frame)?;
        stdout().write_all(&buf)?;
        stdout().flush()?;
        sleep(delay);
    }
}