/**
 * Constants
 */
const str screen_namespace = "/dev/screen/0"
const str mouse_namespace = "/dev/mouse/0"
const str terminal_namespace = "/dev/term/0"
const str new_line = "\n"
const byte WHITE = 255

/**
 * Devices
 */
plex Terminal {
  nat handle;
}

plex Screen {
  nat handle;
  nat width;
  nat height;
  byte[] buffer;

  draw() {
    write(this, this.buffer, this.buffer_size);
  }
}

plex Mouse {
  nat handle;
  nat x;
  nat y;
  bool left;
  bool right;
  bool middle;
  bool btn4;
  nat size;
}

/**
 * Main function
 */
function main() {
    Screen screen = open(screen_namespace, 0);
    pln(screen.handle as str);
    pln(screen.width as str);
    pln(screen.size as str);
    unsafe {
      pln(screen.screen_buffer.ptr as str);
    }

    Mouse mouse = open(mouse_namespace, 0);
    screen.draw();

    loop {
        if (mouse.left) {
            unsafe {
              screen.buffer[mouse.y * width + mouse.x +
                                  screen.buffer.ptr + 4] = WHITE;
              screen.draw();
            }
        }
    }
}

/**
 * Print with a newline
 */
function pln(str message) {
    Terminal term = open(terminal_namespace, 0);
    write(term, message, message.length);
    write(term, nl, nl.length);
}