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

#define F_CPU 16000000UL

typedef enum
{
  green_state,
  red_state,
  yellow_state,
  pedstrian_walk,
  pedstrian_dont_walk
}currentstate;

volatile currentstate state = green_state;
volatile uint8_t pedostrian_request = 0;

void updatelights(void)
{
  switch(state)
  {
    case green_state: 
    PORTD = (1 << PD0);
    PORTC = (1 << PC0);
    break;
    case red_state: 
    PORTD = (1 << PD1);
    PORTB = (1 << PB0);
    PORTC &= ~(1 << PC0);
    break;
    case yellow_state: 
    PORTD = (1 << PD2);
    PORTC = (1 << PC0);
    PORTB &= ~(1 << PB0);
    break;
    case pedstrian_walk: 
    PORTB = (1 << PB0);
    PORTD &= ~(1 << PD2);
    PORTC &= ~(1 << PC0);
    break;
    case pedstrian_dont_walk: 
    PORTC = (1 << PC0);
    PORTB &= ~(1 << PB0);
    break;
  }
}

void init(void)
{
  DDRD |= (1 << PD0) | (1 << PD1) | (1 << PD2);
  DDRB |= (1 << PB0);
  DDRC |= (1 << PC0);

  TCCR1A |= (1 << COM1A1);
  TCCR1B |= (1 << WGM12) | (1 << CS12) | (1 << CS10);
  OCR1A = 15624;
  TIMSK1 |= (1 << OCIE1A);

  DDRD &= ~(1 << PD3);
  PORTD |= (1 << PD3);

  EICRA |= (1 << ISC11);
  EIMSK |= (1 << INT1);

  sei();
}

ISR(TIMER1_COMPA_vect)
{
  static uint8_t timeinstate = 0;
  timeinstate++;
  switch(state)
  {
    case green_state: 
    if(timeinstate >= 7 || pedostrian_request)
    {
      state = red_state;
      timeinstate = 0;
      pedostrian_request = 0;
    }
    break;
    case red_state: 
    if(timeinstate >= 5)
    {
      state = yellow_state;
      timeinstate = 0;
    }
    break;
    case yellow_state:
    if(timeinstate >= 3)
    {
      state = pedstrian_walk;
      timeinstate = 0;
    }
    break;
    case pedstrian_walk:
    if(timeinstate >= 5)
    {
      state = pedstrian_dont_walk;
      timeinstate = 0;
    }
    break;
    case pedstrian_dont_walk:
    if(timeinstate >= 4)
    {
      state = green_state;
      timeinstate = 0;
    }
    break;
  }
  updatelights();
}

ISR(INT1_vect)
{
  if(state == green_state)
  {
    pedostrian_request = 1; 
  }
}

int main(void)
{
  init();
  updatelights();
  while(1)
  {

  }
  return 0;
}