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

#define ACTIVE_TIME 1          // minutes
#define ANIMATION_INTERVALL 3  // counter increments (0.016 sec)

uint8_t EEMEM on_off_state;
volatile uint32_t leds = 0x00;
uint8_t anim_nr = 0;

void random(void);
void links_rechts(void);
void (*animation[])(void) = {
    links_rechts,
    random
};

unsigned long NextVal(void)
{
    static unsigned long Seed;
    Seed=Seed*1632125L+1013904223L;
    return Seed;
}

void random(){
    int temp;
    do{
        temp=NextVal();
        temp=1 << (temp%18);
    }while(temp==leds);
    leds=temp; 
}

void links_rechts(){
    static uint8_t dir = 0;
    if(dir)
        leds = leds << 1;
    else
        leds = leds >> 1;

    if(!(leds & 0x1FFFF)){
        leds = 0x08;
        dir^=1;
    }
}

void write_leds(void){
    PORTD = leds & 0xFF;
    PORTC = (leds>>8) & 0x3F;
    PORTB = (leds>>14) & 0x07;
}

int main(void)
{
    // reset switch as on/off switch
    if(eeprom_read_byte(&on_off_state)){
        eeprom_write_byte(&on_off_state, 0);
    }
    else{
        eeprom_write_byte(&on_off_state, 1);
        set_sleep_mode(SLEEP_MODE_PWR_SAVE);
        sleep_mode();
        // power consumption is below 1uA
    }

    DDRC = 0xFF;
    DDRD = 0xFF;
    DDRB = 0x07;

    TCCR0B |= (1<<CS01)|(1<<CS00); 
    TIMSK0 |= 1 << TOIE0;

    ADCSRA |= (1<<ADEN) | (1<<ADPS1) | (1<<ADPS0);
	ADMUX  = 1<<REFS0;
	ADMUX  |= 6;

    sei();

    while(1)
    {
        write_leds();

        //check buttons on ADC6 and ADC7
        ADCSRA |= 1<<ADSC;
        while(ADCSRA & (1<<ADSC));
        if(ADC < 512){
            if(ADMUX & 0x01)
                anim_nr = 0;
            else
                anim_nr = 1;
            anim_nr%=sizeof(animation);
        }
        ADMUX ^= 0x01;
    }
}

ISR(TIMER0_OVF_vect){
    static uint32_t active_count = 0;
    static uint16_t count = 0;

    active_count++;
    if(count>=ANIMATION_INTERVALL){
        count=0;
        (*animation[anim_nr])();
    }
    else
    {
        count++;
    }
    if(active_count >= ACTIVE_TIME * 3662){
        leds=0;
        write_leds();
        eeprom_write_byte(&on_off_state, 1);
        set_sleep_mode(SLEEP_MODE_PWR_SAVE);
        sleep_mode();
    }
}