//sensor pin variables
int speakerPin = D0;
int coSensorPin = A0;
int ledPin = D1;
//time calculating variables
int warningnumber = 0;
long instancetime;
bool counterRunnning = false;
long delaybetweenwarnings = 30*1000;
//sensor readings and output variables
int coValue = 0;
int buzzertone[] = {2551,2273,2551,2273};

void setup()
{

  Serial.begin( 9600 );
  pinMode( coSensorPin, INPUT );
  pinMode( speakerPin, OUTPUT );
  pinMode( ledPin, OUTPUT );
  Particle.variable("CO level", &coValue, INT );
  Particle.variable("Warning number", &coValue, INT );
  Particle.function("Reset Particle", resetParticle);
  Particle.function("Stop Notifying", stopNotifying);
}

void loop()
{
  readFromSensor();
  if (coValue > 4 && warningnumber == 0)
  {
    startCounter();
    activatewarning();
    warningnumber = 1;
  }
  else if (coValue > 11 & warningnumber == 1)
  {
      if (counterRunnning == false)
      {
        startCounter();
        activatewarning();
        warningnumber = 2;
        //Particle.publish("COdetected","second");
      }
  }
  else if (coValue > 11 & warningnumber == 2 )
  {
    if (counterRunnning == false)
    {
      startCounter();
      activatewarning();
      activatewarning();
      warningnumber++;
      //Particle.publish("COdetected","third");
    }
  }
  else if (coValue > 11 & warningnumber > 3)
  {
    if (counterRunnning == false)
    {
      startCounter();
      activatewarning();
      activatewarning();
      warningnumber = 3;
      //Particle.publish("COdetected","fourth");
    }
  }
  if( checkIfCounterIsFinished() )
    {
      digitalWrite(ledPin, LOW);
      counterRunnning = false;
    }
    //checking if warningnumber needs to be reset to 1
  if( instancetime + 5*60*1000 < millis() )
    {
      warningnumber =1;
    }
  delay( 100 );
}

void readFromSensor()
{
  coValue = analogRead(coSensorPin);
  Serial.println( coValue );
}

void activatewarning()
{
  digitalWrite(ledPin, HIGH);
  for(int i=0; i<4; i++)
  {
    tone(speakerPin, buzzertone[i]);
    delay(1000);
  }
  noTone(speakerPin);
}

void startCounter()
{
  counterRunnning = true;
  instancetime = millis() ;
}

bool checkIfCounterIsFinished()
{
  if( counterRunnning == false )
  {
    return false;
  }
  if( instancetime + delaybetweenwarnings < millis() )
  {
    return true;
  }
  return false;
}

int resetParticle(String command)
{
 if(command == "YES")
 {
   warningnumber = 1;
   instancetime = 0;
   counterRunnning = false;
   coValue = 0;
   for(int i=0; i<3;i++)
   {
     digitalWrite(ledPin, HIGH);
     delay (500);
     digitalWrite(ledPin, LOW);
     delay (500);
   }
   return 1;
 }
 return 0;
}

int stopNotifying(String command)
{
 if(command == "YES")
 {
   warningnumber = -1;
   instancetime = 0;
   counterRunnning = false;
   coValue = 0;
   for(int i=0; i<3;i++)
   {
     digitalWrite(ledPin, HIGH);
     delay (500);
     digitalWrite(ledPin, LOW);
     delay (500);
   }
   tone(speakerPin, buzzertone[1],8);
   return 1;
 }
 return 0;
}