mod utils;
#[macro_use]
mod log;

use wasm_bindgen::prelude::*;
use image::{ImageBuffer, Rgb, png::PngDecoder, ImageFormat, RgbImage};
use std::io::{Cursor, Seek, SeekFrom, Read};
use wasm_bindgen::__rt::IntoJsResult;

// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
// allocator.
#[cfg(feature = "wee_alloc")]
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;

#[wasm_bindgen]
extern {
    fn alert(s: &str);
}

#[wasm_bindgen]
pub fn greet() {
    alert("Hello, rust-wasm-dev-helper!");
}

#[wasm_bindgen]
pub fn create_img(width: u32, height: u32, r: u8, g: u8, b: u8) -> Vec<u8> {

    // reset width and height
    let width = match width {
        0 => 100,
        _ => width,
    };
    let height = match height {
        0 => 100,
        _ => height,
    };
    let img_path = format!("gen-png/gen-{}_{}-{}_{}_{}.png", width, height, r, g, b);

    std::fs::read(img_path.clone()).unwrap_or_else(|_| {
        let mut img: RgbImage = RgbImage::new(width, height);
        for mut px in img.enumerate_pixels_mut().enumerate() {
            (((px.1).2).0)[0] = r;
            (((px.1).2).0)[1] = g;
            (((px.1).2).0)[2] = b;
        }
        std::fs::create_dir("gen-png").unwrap_or_default();
        img.save(img_path.clone()).unwrap();
        std::fs::read(img_path).unwrap_or_default()
    })
}

#[cfg(test)]
mod tests {
    use crate::create_img;

    #[test]
    pub fn test() {
        println!("{:?}", create_img(375, 250, 0, 0, 0))
    }
}