#include <SoftwareSerial.h>

SoftwareSerial gsm(2,3); //RX, TX

  namespace GSM{
    void SendMessage(char NUM[],char SMS[]="ALERT. GAS LEAK")
{
   Serial.println("Setting the GSM in text mode");
   gsm.print("\n");
   gsm.print("AT+CMGF=1\r");
  //  delay(2000);

   String NUMBER="AT+CMGS=\"NUMBER\"\r";
   NUMBER.replace("NUMBER",NUM);
   gsm.print("\n");
   gsm.print(NUMBER);
   // Replace x with mobile number
  //  delay(2000);
   gsm.print("\n");
   gsm.print(SMS);    // SMS Text
  //  delay(200);
   gsm.print(">");               // ASCII code of CTRL+Z
  //  delay(2000);
}

  };

class COMMS{
   public:

  int on=11;
  int warn=10;
  int relay=12;
  int buzzer=9;
 
  COMMS(){

    

    pinMode(on, OUTPUT);
    pinMode(warn, OUTPUT);
    pinMode(relay, OUTPUT);
    pinMode(buzzer, OUTPUT);


  }


  void ALERT(){

    digitalWrite(relay, HIGH);
    digitalWrite(warn, HIGH);
    digitalWrite(buzzer, HIGH);
    delay(500);
    digitalWrite(buzzer,LOW);
    digitalWrite(warn, LOW);
    delay(500);
    
    // gsm.print("w");
    // Serial.println("WARNING");
    
  }
};
// instantiate your class for external communication
COMMS comm;
int MQ6 =A0;
int DATA;
int threshold =200;
void setup() {
  pinMode(MQ6, INPUT);
  digitalWrite(comm.on, HIGH);
  Serial.begin(9600);
  gsm.begin(9600);
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:
  // read data, from sensor
  DATA=analogRead(MQ6);
  // Serial.println(DATA);
  
    if(DATA>=threshold){
      BEGINNING:
    GSM::SendMessage("+263784370495");
    int start=millis()/1000;
     //repeat until data is below threshold
     while(true){
      int stop=millis()/1000;
      int current_time=stop-start;
      comm.ALERT();
      DATA=analogRead(MQ6);
      // Serial.println(DATA);
      Serial.print("Time elapsed since SMS in seconds:");
      Serial.print(current_time);
      Serial.println("");
      if(current_time>=60){
        goto BEGINNING;
      }
      if(DATA<threshold){
       digitalWrite(comm.relay, LOW);
      //  delay(1000);
      stop=0;
       break;

      }
      else{
        delay(1000);
        continue;
      }
     }

  }


}