//! This example shows how a embedded program can be written that is testable on the host with
//! libtest.
//!
//! The tests can be run with:
//! ```bash
//! cargo test --example=test-on-host --target=x86_64-unknown-linux-gnu
//! ```

#![cfg_attr(not(test), no_main)]
#![no_std]

#[cfg(not(test))]
extern crate panic_halt;

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

#[cfg_attr(not(test), cortex_m_rt::entry)] // this is the entrypoint unless testing
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());

    // Acquire the GPIOA peripheral. This also enables the clock for GPIOA in
    // the RCC register.
    let gpioa = dp.GPIOA.split(&mut rcc);

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

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

    loop {
        led.set_high().unwrap();
        delay.delay_ms(500_u16);

        let important_number = some_function(19);
        delay.delay_ms(important_number as u16);

        led.set_low().unwrap();
        delay.delay_ms(500_u16);
    }
}

fn some_function(num: i32) -> i32 {
    num * 2
}

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

    #[test]
    fn test_it_works() {
        assert_eq!(some_function(9), 18)
    }
}