#include <avr/io.h>
#include <avr/delay.h>

#define MIN(a, b) (a < b) ? a : b
#define MAX(a, b) (a > b) ? a : b
#define BTN(id) (0xFF ^ (1 << id))

#define RGBDOWN(dest, src) {\
	src = MAX(src - 1, 0);\
	dest = levels[src];\
	break;\
}

#define RGBUP(dest, src) {\
	src = MIN(src + 1, 7);\
	dest = levels[src];\
	break;\
}

int16_t levels[] = {
	255 - 0,
	255 - 255 * 0.1429,
	255 - 255 * 0.2857,
	255 - 255 * 0.4286,
	255 - 255 * 0.5714,
	255 - 255 * 0.7142,
	255 - 255 * 0.8571,
	255 - 255
};

int main(void) {
	TCCR0|=(1<<WGM00)|(1<<WGM01)|(1<<COM01)|(0<<CS02)|(0<<CS01)|(1<<CS00);
	TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
	TCCR1B|=(1<<WGM13)|(1<<WGM12)|(0<<CS12)|(0<<CS11)|(1<<CS10);
	ICR1=255;
	DDRB |= (1 << PB3);
	DDRD |= (1 << PD5) | (1 << PD4);
	DDRA = 0x00;
	PORTA = 0xFF;

	int rLvl = 0;
	int gLvl = 0;
	int bLvl = 0;
	OCR0 = levels[rLvl];
	OCR1B = levels[gLvl];
	OCR1A = levels[bLvl];

	uint32_t counter = 0;
	uint32_t lastDebounceTime = 0;
	uint32_t debounceDelay = 10000;
	int buttonState = 0;
	int lastButtonState = 0;

	while(1) {
		counter++;
		int reading = PINA;
		if (reading != lastButtonState) {
			lastDebounceTime = counter;
		}
		if ((counter - lastDebounceTime) > debounceDelay) {
			if (reading != buttonState) {
				buttonState = reading;
				switch (PINA) {
					case BTN(0): RGBDOWN(OCR0, rLvl);
					case BTN(1): RGBUP(OCR0, rLvl);
					case BTN(2): RGBDOWN(OCR1B, gLvl);
					case BTN(3): RGBUP(OCR1B, gLvl);
					case BTN(4): RGBDOWN(OCR1A, bLvl);
					case BTN(5): RGBUP(OCR1A, bLvl);
				}
			}
		}
		lastButtonState = reading;
	}
	return 0;
}