#include "dht11.h"

Dht11::Dht11(volatile unsigned char * const port, volatile unsigned char * const inPort, volatile unsigned char * const port_ctl, const unsigned char pin): _port(port), _inPort(inPort), _port_ctl(port_ctl), _pin(pin)
{}

uint8_t Dht11::read()
{
	// BUFFER TO RECEIVE
	uint8_t bits[5];
	uint8_t cnt = 7;
	uint8_t idx = 0;

	// EMPTY BUFFER
	for (uint8_t i=0; i< 5; i++) bits[i] = 0;

	// REQUEST SAMPLE
	setDirection(_port_ctl, _pin, true);
	writePin(_port, _pin, false);
	_delay_ms(2);
	writePin(_port, _pin, true);
	setDirection(_port_ctl, _pin, false);
	_delay_us(42);
	

	// ACKNOWLEDGE or TIMEOUT
	unsigned int loopCnt = LOOP_TIMEOUT_COUNT;
	while(!readPin(_inPort, _pin))
		if (loopCnt-- == 0) return 1;

	loopCnt = LOOP_TIMEOUT_COUNT;
	while(readPin(_inPort, _pin) )
		if (loopCnt-- == 0) return 2;

	// READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT
	for (uint8_t i=0; i<40; i++)
	{
		loopCnt = LOOP_TIMEOUT_COUNT;
		while(!readPin(_inPort, _pin))
			if (loopCnt-- == 0) return 3;

		loopCnt = 0;
		while(readPin(_inPort, _pin))
		{
			_delay_us(10);
			if (loopCnt++ > LOOP_TIMEOUT_SMALL_COUNT) return 4;
		}

		if( loopCnt > BIT_COUNT )bits[idx] |= (1 << cnt);
		if (cnt == 0)   // next byte?
		{
			cnt = 7;    // restart at MSB
			idx++;      // next byte!
		}
		else cnt--;
	}
	
	uint8_t sum;
	if constexpr(DHT22) sum= bits[0] + bits[1] + bits[2] + bits[3];
	else sum = bits[1] + bits[3];
	
	if(bits[4] == sum && sum != 0)
	{
		if constexpr(DHT22)
		{
			humidity    = (static_cast<uint16_t>(bits[0]) << 8) + bits[1]; 
			temperature = (static_cast<uint16_t>((bits[2] & 0b01111111) << 8) + bits[3]);
			if(bits[2] & 0b10000000) temperature=temperature*-1;
		}
		else
		{
			humidity = bits[1];
			temperature = bits[3]*10;
		}
		return 0;
	}
	else return 5;
}