#![no_std]
#![feature(asm_experimental_arch)]

extern crate core;

mod macros;
mod types;

use types::*;

use core::arch::asm;

use arduino_hal::{
    delay_us,
    hal::port::{PD0, PD1, PD2, PD3, PD4, PD5, PD6, PD7},
    pac::PORTD,
    port::{mode::Output, Pin, PinOps},
};
use avr_device::interrupt::free;
use neopixel_macros::impl_static_pin;

use smart_leds::{SmartLedsWrite, RGB8};

const LAST_BIT: u8 = 0x80;

#[repr(transparent)]
pub struct Neopixel<P> {
    _pin: Pin<Output, P>,
}

impl<P> Neopixel<P>
where
    P: PinOps + StaticPin,
{
    #[inline]
    pub const fn new(_pin: Pin<Output, P>) -> Self {
        Self { _pin }
    }
}

impl<P> SmartLedsWrite for Neopixel<P>
where
    P: PinOps + StaticPin,
{
    type Error = ();
    type Color = smart_leds::RGB<u8>;
    fn write<T, I>(&mut self, iterator: T) -> Result<(), Self::Error>
    where
        T: IntoIterator<Item = I>,
        I: Into<Self::Color>,
    {
        free(|_cs| {
            for i in iterator {
                let RGB8 { r, g, b } = i.into();
                for value in [g, r, b] {
                    self.priv_write(value);
                }
            }
        });
        Ok(())
    }
}

impl<P> Neopixel<P>
where
    P: PinOps + StaticPin,
{
    fn priv_write(&self, data: u8) {
        let (mut count, mut data, port_data, pin_data) = (8, data, P::read(), 1 << P::PIN_NUM);
        unsafe {
            while count > 0 {
                P::write(port_data | pin_data);
                asm!("rjmp +0");
                if data & LAST_BIT == 0 {
                    P::write(port_data & !pin_data);
                }
                asm!(
                    "
                    rjmp +0
                    rjmp +0
                    "
                );
                P::write(port_data & !pin_data);
                asm!(
                    "
                    rjmp +0
                    rjmp +0
                    rjmp +0
                    "
                );
                data <<= 1;
                count -= 1;
            }
        }
    }
}