use std::error::Error;
use gpio_cdev::{Chip, LineRequestFlags, EventRequestFlags, EventType};

const GPIO_LED: u32 = 23;
const GPIO_SW: u32 = 22;

fn main() -> Result<(), Box<dyn Error>> {
    let mut chip = Chip::new("/dev/gpiochip0")?;
    let led_handle = chip
        .get_line(GPIO_LED)?
        .request(LineRequestFlags::OUTPUT, 0, "led")?;
    let sw = chip.get_line(GPIO_SW)?;
    for event in sw.events(
        LineRequestFlags::INPUT,
        EventRequestFlags::BOTH_EDGES,
        "sw",
    )? {
        let evt = event?;
        match evt.event_type() {
            EventType::RisingEdge => {
                led_handle.set_value(1)?;
            }
            EventType::FallingEdge => {
                led_handle.set_value(0)?;
            }
        }
    }

    Ok(())
}
