#![no_std]
#![no_main]

use esp_backtrace as _;
use esp_println::println;
use core::cell::RefCell;
use critical_section::Mutex;
use hal::{
  clock::ClockControl, 
  peripherals::{self, Peripherals}, 
  prelude::*, 
  gpio,
  interrupt,
  IO,
  riscv
};

static BUTTON: Mutex<RefCell<Option<gpio::Gpio9<gpio::Input<gpio::PullDown>>>>> = Mutex::new(RefCell::new(None));

#[entry]
fn main() -> ! {
  let peripherals = Peripherals::take();
  let mut system = peripherals.SYSTEM.split();
  let clocks = ClockControl::boot_defaults(system.clock_control).freeze();
  
  let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
  let mut led = io.pins.gpio7.into_push_pull_output();
  
  let mut button = io.pins.gpio9.into_pull_down_input();
  button.listen(gpio::Event::FallingEdge);
  critical_section::with(|cs| BUTTON.borrow_ref_mut(cs).replace(button));
  interrupt::enable(peripherals::Interrupt::GPIO, interrupt::Priority::Priority3).unwrap();
    
  unsafe {
    riscv::interrupt::enable()
  }

  loop {}
}

#[interrupt]
fn GPIO() {
  critical_section::with(|cs| {
    println!("GPIO interrupt");
    BUTTON.borrow_ref_mut(cs).as_mut().unwrap().clear_interrupt();
  });
}