#include <avr/io.h>
#include <avr/eeprom.h>
#include <util/delay.h>
#include <avr/sleep.h>
#include <avr/interrupt.h>

uint16_t pwmee EEMEM;
volatile uint16_t adcval;

volatile struct
{
  uint8_t pwm_int: 1;
  uint8_t adc_int: 1;
  uint8_t tmr_int: 1;
}
intflags;


unsigned char debug EEMEM = 1;

ISR(ADC_vect)
{
	adcval = ADCW;
	ADCSRA &= ~_BV(ADIE);         /* disable ADC interrupt */
	intflags.adc_int = 1;
}

ISR(TIMER1_OVF_vect)
{
	TIMSK &= ~_BV(TOIE1);
	intflags.pwm_int = 1;
}

ISR(TIMER0_COMPA_vect)
{
	intflags.tmr_int = 1;
}

struct {
	unsigned char intensity :2;
	unsigned char length :6;
} pattern[] = { {1, 2}, {0, 4}, { 1, 2 }, {0, 15}, {0, 0} };
	
static void inline init_pwm()
{
	TCCR1C = _BV(COM1D0) | _BV(COM1D1) | _BV(PWM1D);
	TCCR1A = _BV(COM1A0) | _BV(COM1A1) | _BV(COM1B0) | _BV(COM1B1) | _BV(PWM1A) | _BV(PWM1B);
	TCCR1B = 0x80| _BV(CS13) | _BV(CS11);
	TC1H  = 0x03;
	OCR1C = 0xFF;
	OCR1D = OCR1B = OCR1A = 0x40;
	TCNT1 = 0;
	DDRB |= _BV( PB5 ) | _BV( PB1 ) | _BV( PB3 );
	PORTB &= ~(_BV( PB5 ) | _BV( PB1 ) | _BV( PB3 ));
	TIMSK |= _BV(TOIE1);
}

static void inline init_adc()
{
	ADCSRA = _BV(ADEN) | _BV(ADATE) | _BV(ADPS1) | _BV(ADPS0);
	ADMUX = _BV(REFS1) | _BV(MUX0);
	// ADCSRB = _BV(REFS2); 
	DIDR0 = _BV(ADC1D) | _BV(AREFD);
}

static void inline init_tmr()
{
	TCCR0A = _BV(WGM00);
	TCCR0B = _BV(CS02); // | _BV(CS00);
	OCR0A = 0x80;
	TIMSK |= _BV(OCIE0A);
	DDRA |= _BV( PA0 );
}

int main(void)
{
	char seen = 0;
	char pcount, ppos;

	init_pwm();
	init_adc();
	init_tmr();

	ppos = 0;
	pcount = pattern[ppos].length;
        if (pattern[ppos].intensity) {
		PORTA |=  _BV( PA0 );
	}

	while (1) {
		unsigned char pwmhi, pwmlo;

		if (intflags.adc_int) {
			intflags.adc_int = 0;

			if (adcval > 0x3C0)
				adcval = 0x3C0;
			if (adcval < 1)
				adcval = 1;
			pwmhi = adcval >> 8;
			pwmlo = adcval & 0xFF;

			TC1H = pwmhi;
			OCR1D = pwmlo;

			TC1H = pwmhi;
			OCR1B = pwmlo;

			TC1H = pwmhi;
			OCR1A = pwmlo;

			TIMSK |= _BV(TOIE1);
		}

		if (intflags.pwm_int) {
			intflags.pwm_int = 0;
			ADCSRA |= _BV(ADIE) | _BV(ADSC);
		}

		if (intflags.tmr_int) {
			intflags.tmr_int = 0;
			if (--pcount == 0) {
				ppos++;
				pcount = pattern[ppos].length;
				if (!pcount) {
					ppos = 0;
					pcount = pattern[ppos].length;
				}
				if (pattern[ppos].intensity) {
					PORTA |= _BV(PA0);
				} else {
					PORTA &= ~_BV(PA0);
				}
			}
		}

		sei();
		sleep_mode();
		cli();

#if 0
		if (!seen) {
			seen = 1;
			eeprom_write_byte(&debug, 2);
		}
#endif
	}

    DDRA |= _BV( PA0 );
    while( 1 ) { 
        PORTA |=  _BV( PA0 );
        _delay_ms(2000);
        PORTA &=~ _BV( PA0 );
        _delay_ms(2000);
    }
}