#![no_main]
#![no_std]

extern crate panic_halt;

use cortex_m_rt::entry;
use hal::{pac, prelude::*, rcc::Config};

#[entry]
fn main() -> ! {
    let dp = pac::Peripherals::take().unwrap();
    let cp = cortex_m::Peripherals::take().unwrap();

    // Configure the clock.
    let mut rcc = dp.RCC.freeze(Config::hsi16());

    let gpioa = dp.GPIOA.split(&mut rcc);
    let gpioc = dp.GPIOC.split(&mut rcc);

    // Configure PA5 as output.
    let mut led = gpioa.pa5.into_push_pull_output();
    let button = gpioc.pc13.into_pull_down_input();

    // Get the delay provider.
    let mut _delay = cp.SYST.delay(rcc.clocks);

    let mut is_on: bool;
    let mut was_on: bool = false;
    #[allow(unused_variables)] // it is used later??
    let mut enable_led: bool = false;

    loop {
        is_on = button.is_low().unwrap();
        if is_on != was_on {
            enable_led ^= true;
        }
        if is_on {
            led.set_high().unwrap();
        } else {
            led.set_low().unwrap();
        }

        was_on = is_on;
    }
}