mod cpu;

use cpu::Cpu;
use minifb::{Key, Scale, Window, WindowOptions};
use std::{env, fs};

const WIDTH: usize = 64;
const HEIGHT: usize = 32;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args: Vec<String> = env::args().collect();
    if args.len() < 2 {
        eprintln!("Usage: {} <rom.ch8>", args[0]);
        std::process::exit(1);
    }
    let rom = fs::read(&args[1])?;
    let mut chip8 = Cpu::new(&rom);

    let mut window = Window::new(
        "Buttery Chip8",
        WIDTH,
        HEIGHT,
        WindowOptions {
            scale: Scale::X8,
            ..WindowOptions::default()
        },
    )
    .unwrap();

    let mut buffer: Vec<u32> = vec![0; WIDTH * HEIGHT];

    while window.is_open() {
        let keys = [
            window.is_key_down(Key::X),    // 0
            window.is_key_down(Key::Key1), // 1
            window.is_key_down(Key::Key2), // 2
            window.is_key_down(Key::Key3), // 3
            window.is_key_down(Key::Q),    // 4
            window.is_key_down(Key::W),    // 5
            window.is_key_down(Key::E),    // 6
            window.is_key_down(Key::A),    // 7
            window.is_key_down(Key::S),    // 8
            window.is_key_down(Key::D),    // 9
            window.is_key_down(Key::Z),    // A
            window.is_key_down(Key::C),    // B
            window.is_key_down(Key::Key4), // C
            window.is_key_down(Key::R),    // D
            window.is_key_down(Key::F),    // E
            window.is_key_down(Key::V),    // F
        ];
        chip8.prev_keys = chip8.keys;
        chip8.keys = keys;
        for _ in 0..10 {
            // 10 ticks * 60fps = ~600 cycles/sec
            chip8.tick();
        }
        for (i, pixel) in chip8.display.iter().enumerate() {
            buffer[i] = if *pixel { 0xFFFFFFFF } else { 0x00000000 };
        }
        window.update_with_buffer(&buffer, WIDTH, HEIGHT).unwrap();
    }

    Ok(())
}