#pragma once
#include <util/delay.h>

template <int BITS> class ShiftReg
{
private:
	static constexpr int BYTES = (BITS % 8 == 0) ? (BITS/8) : (BITS/8+1);

	static constexpr bool invert = true;

	volatile unsigned char *_port;
	const unsigned char _pinSer;
	const unsigned char _pinSerClk;
	const unsigned char _pinRClk;

	unsigned char _lastData[BYTES] = {};

public:

	ShiftReg(volatile unsigned char* const port, const unsigned char pinSer, const unsigned char pinSerClk,
	         const unsigned char pinRClk):
		_port(port),  _pinSer(pinSer), _pinSerClk(pinSerClk), _pinRClk(pinRClk)
	{
		clear();
	}
	void setBit(unsigned char bit, bool value)
	{
		if(BITS <= bit)
			return;
		bit = BITS - bit - 1;
		if(value)
			_lastData[bit/8] |= (1<<(bit%8));
		else
			_lastData[bit/8] &= ~(1<<(bit%8));
		write(_lastData);
	}
	bool getBit(unsigned char bit)
	{
		if(BITS <= bit)
			return false;
		bit = BITS - bit - 1;
		return _lastData[bit/8] & (1<<(bit%8));
	}
	void write(const unsigned char * const in)
	{
		for(unsigned char i = 0 ; i < BYTES; ++i)
			_lastData[i] = in[i];

		if constexpr(invert)
		{
			*_port |= ((1<<_pinSer) | (1<<_pinSerClk));
			*_port |= (1<<_pinRClk);

			for(unsigned char i = 0; i < BITS; ++i)
			{
				*_port |= (1 << _pinSerClk);
				in[i/8] & (1<<(i%8)) ? (*_port &= ~(1 << _pinSer)) : (*_port |= (1 << _pinSer));
				*_port &= ~(1 << _pinSerClk);
			}
			*_port &= ~(1<<_pinRClk);
		}
		else
		{
			*_port &= ~((1<<_pinSer) | (1<<_pinSerClk));
			*_port &= ~(1<<_pinRClk);
			for(unsigned char i = 0; i < BITS; ++i)
			{
				*_port &= ~(1 << _pinSerClk);
				in[i/8] & (1<<(i%8)) ? (*_port |= (1 << _pinSer)) : (*_port &= ~(1 << _pinSer));
				*_port |= (1 << _pinSerClk);
			}
			*_port |= 1<<_pinRClk;
		}
	}
	void clear(bool value = false)
	{
		for(unsigned char i = 0 ; i < BYTES; ++i)
			_lastData[i] = value ? 0xff : 0x00;
		write(_lastData);
	}
};