use image::ImageReader;
use std::{env, str};
use image::imageops::FilterType;
use tokio::io::AsyncWriteExt;
use tokio_serial::SerialPortBuilderExt;


const DEFAULT_TTY: &str = "/dev/ttyACM1";

#[tokio::main]
async fn main() -> tokio_serial::Result<()> {
    let mut args = env::args();
    let path = args.nth(1).unwrap();
    let mut img = ImageReader::open(&path).unwrap().decode().unwrap();

    let tty_path = args.nth(2).unwrap_or_else(|| DEFAULT_TTY.into());

    const WIDTH: usize = 800;
    const HEIGHT: usize = 480;
    const TOTAL_BYTES: usize = WIDTH * HEIGHT * 3;
    const MAX_WRITE_LEN: usize = 115_200;

    if img.width() < img.height() {
        img = img.rotate90();
    }

    let ratio = WIDTH as f64 / img.width() as f64;
    let height = (ratio * img.height() as f64) as u32;

    let rgb_img = img.resize_exact(WIDTH.try_into().unwrap(), height, FilterType::Nearest).into_rgb8();
    let mut raw_img = rgb_img.into_raw();
    raw_img.resize(TOTAL_BYTES, 0x00);

    let mut port = tokio_serial::new(tty_path, TOTAL_BYTES.try_into().unwrap()).open_native_async()?;

    port.write(&[ 'i' as u8 ] ).await?;
    port.flush().await?;

    let mut total: usize = raw_img.len();
    let mut pos: usize = 0;

    while total > 0 {
        let mut size = MAX_WRITE_LEN;

        if size > total {
            size = total;
        }

        port.write(&raw_img[pos..(pos+size)]).await?;
        port.flush().await?;

        total -= size;
        pos += size;
    }

    Ok(())
}