//DECODE VARIABLES:
volatile uint8_t pulseIndex = 0;
uint32_t storedSignals = 0; //STORED INFO
uint64_t storedData = 0;
volatile uint8_t binaryData;


//TIMER VARIABLES:
volatile int16_t delaTimeInerrupt;
volatile int16_t previousDeltaTime;
volatile int16_t storedTime;

//PROTOCOL DETECTION VARIABLES:
uint8_t protocolType;
short protocolStartBurstLength[4] = {2220, 1110, 840, 590};
//0: NEC, 1:SAMSUNG, 2:JAPAN, 3:SIRCS
bool midwayFlag = false;

void setup(){
  Serial.begin(9600);
  outputSetUp();
  timerSetUp();
}
void loop(){

}


void outputSetUp(){
  DDRD   &= ~(1 << DDD2);    // Imposta il Pin 2 come input (DDRD bit 2 a 0)
  PORTD  |= (1 << PORTD2);   // Abilita la resistenza di pull-up interna sul Pin 2 (PORTD bit 2 a 1)
  PCICR  |= (1 << PCIE2);    // Abilita l'interrupt Pin Change 2 (PCICR bit 2 a 1)
  PCMSK2 |= (1 << PCINT18);  // Abilita l'interrupt per il Pin 2 (PCMSK2 bit 2 a 1)
}

void timerSetUp(){
  TCCR1A  = 0; 
  TCCR1B  = 0;
  TCNT1   = 0; 
  TCCR1B |= (1 << CS11) | (1 << CS10); //PRESCALLAR 64:
  OCR1A   = 16875;                     // (67,500 / 4) (16875) old
  TIMSK1 |= (1 << OCIE1A);             // Enable timerinterrupt
  TCCR1B |= (1 << WGM12);
}

ISR(TIMER1_COMPA_vect) {     //Every 67,500 ms
  PCMSK2 |= (1 << PCINT18);  // Enable interrupt for Pin 2 
  pulseIndex = 0;
  midwayFlag = false; 
  binaryData = 0;
}

ISR(PCINT2_vect) {  //PIN2 interrupt
  if (pulseIndex == 0){timerSetUp();}
  getTime();

  
  if (pulseIndex - 2 <= 0){
    StartOfFrameCheck(delaTimeInerrupt); pulseIndex++; return;
  }
  if ((pulseIndex > 34 && pulseIndex < 51)){
    if (pulseIndex % 2 == 1){previousDeltaTime = delaTimeInerrupt;}
    else {
      if((previousDeltaTime - delaTimeInerrupt > -2)){decode(0);}
      else {decode(1);}
    }
  }

  if(pulseIndex == 67){ 
    storedSignals = 0;
    volatile uint8_t inverse = binaryData;
    inverse = ~inverse;
    storeData(inverse);
    Serial.print("0x");
    Serial.println(storedSignals, HEX);
  }
  pulseIndex++;
}
void getTime(){
  delaTimeInerrupt = TCNT1 - storedTime;
  storedTime = TCNT1;
}
void decode(byte data) {
  binaryData >>= 1;           // Shift everything to the left
  binaryData |= (data << 7);  // Add the new bit
}  

void storeData(uint8_t inverse){
  storedSignals <<= 8;
  storedSignals |= 0xFF;
  storedSignals <<= 8;
  storedSignals |= binaryData;
  storedSignals <<= 8;
  storedSignals |= inverse;
  storedData <<= 32;
  storedData |= storedSignals;
}

void StartOfFrameCheck(uint16_t time){
  if (pulseIndex == 0){return;}
  if (pulseIndex == 1){
    for (byte i = 0; i < 5; i++){
      if(time - protocolStartBurstLength[i] >= 0){
        midwayFlag = true; protocolType = i;
        return;
      }
    }
  }

  if (pulseIndex == 2 && midwayFlag == true){
    switch (protocolType){
      case 0: if(time - protocolStartBurstLength[1] >= 0){return;}
      case 1: if(time - protocolStartBurstLength[1] >= 0){return;}
      case 2: if(time - protocolStartBurstLength[2] / 2 >= 0){return;}
      case 3: if(time - protocolStartBurstLength[3] / 4 >= 0){return;}
    }
  }

  PCMSK2 &= ~(1 << PCINT18);// Disable interrupt for Pin 2
}