#include <TinyGPSPlus.h>

//GSM - Serial [1]
//GPS - Serial [2]
#define Gas_Sensor    A1
#define Flame_Sensor  2
#define BuzzerPin     6
#define RedLED        4
#define GreenLED      5
#define YellowLED     3

int Gas_State;
int Flame_State;
int flag1 = 0;
int flag2 = 0;

char   google_maps_link[70];
String google_maps_link_string = "";
String Longitude = "1";
String Latitude = "1";

TinyGPSPlus gps;

void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);// for GSM
  Serial2.begin(9600);// for GPS
  pinMode(Gas_Sensor, INPUT);
  pinMode(Flame_Sensor, INPUT);
  pinMode(BuzzerPin, OUTPUT);
  pinMode(RedLED, OUTPUT);
  pinMode(GreenLED, OUTPUT);
  pinMode(YellowLED, OUTPUT);
  delay(10000);
  sendSMSLoop();
}

void loop() {
  Gas_State   = analogRead(Gas_Sensor);
  Flame_State = digitalRead(Flame_Sensor);
  Serial.println(Gas_State);
  Serial.println(Flame_State);
  read_GPS_receiver();
  if (Flame_State == 0 && flag1 == 0) {
    flag1 = 1;
    SendFlameSMS();
    digitalWrite(YellowLED , HIGH );
    digitalWrite(GreenLED , LOW );
    analogWrite(BuzzerPin, 255);
    delay(500);
    analogWrite(BuzzerPin, 155);
    delay(500);
    analogWrite(BuzzerPin, 255);
    delay(500);
    analogWrite(BuzzerPin, 155);
    delay(500);
    delay(5000);
  }
  else if (Flame_State == 1 && flag1 == 1) {
    flag1 = 0;
    analogWrite(BuzzerPin, 0);
    digitalWrite(YellowLED , LOW  );
    digitalWrite(GreenLED , HIGH );
  }
  if (Gas_State > 250 && flag2 == 0) {
    flag2 = 1;
    SendGasSMS();
    digitalWrite(RedLED , HIGH );
    digitalWrite(GreenLED , LOW );
    analogWrite(BuzzerPin, 255);
    delay(500);
    analogWrite(BuzzerPin, 50);
    delay(500);
    analogWrite(BuzzerPin, 255);
    delay(500);
    analogWrite(BuzzerPin, 50);
    delay(500);
    delay(5000);
  }
  else if (Gas_State < 250 && flag2 == 1) {
    flag2 = 0;
    analogWrite(BuzzerPin, 0);
    digitalWrite(RedLED , LOW  );
    digitalWrite(GreenLED , HIGH );
  }
}

void read_GPS_receiver() {
  while (Serial2.available() > 0) {
    if (gps.encode(Serial2.read())) {
      if (gps.location.isValid()) {
        Latitude  = String(gps.location.lat(), 6);
        Longitude = String(gps.location.lng(), 6);
        Serial.print(Latitude);
        Serial.print(",");
        Serial.print(Longitude);
        Serial.println();
        google_maps_link_string = "http://maps.google.com/maps?&z=15&mrt=yp&t=k&q=" + Latitude + "+" + Longitude;
        google_maps_link_string.toCharArray(google_maps_link, 70);
      }
      else  {
        //Serial.println(F("INVALID"));
        google_maps_link_string = "http://maps.google.com/maps?&z=15&mrt=yp&t=k&q=1.23+1.23";
        google_maps_link_string.toCharArray(google_maps_link, 70);
      }
    }
  }
  if (millis() > 5000 && gps.charsProcessed() < 10) {
    Serial.println(F("No GPS detected: check wiring."));
    while (true);
  }
}

void sendSMSLoop() {
  Serial.println ("Sending Message");
  Serial1.println("AT+CMGF=1");    //Sets the GSM Module in Text Mode
  delay(1000);
  Serial.println ("Set SMS Number");
  //                             *********
  Serial1.println("AT+CMGS=\"+966554418546\"\r"); //Mobile phone number to send message
  delay(1000);
  Serial.println ("Set SMS Content");
  Serial1.println("Ardunio: OK");//"GSM Connected, Project is ON");// Messsage content
  delay(100);
  Serial.println ("Finish");
  Serial1.println((char)26);// ASCII code of CTRL+Z
  delay(1000);
  Serial.println ("Message has been sent");
}

void SendFlameSMS() {
  Serial.println ("Sending Flame Message");
  Serial1.println("AT+CMGF=1");    //Sets the GSM Module in Text Mode
  delay(1000);
  Serial.println ("Set SMS Number");
  //                             *********
  Serial1.println("AT+CMGS=\"+966554418546\"\r"); //Mobile phone number to send message
  delay(1000);
  Serial.println ("Set SMS Content");
  Serial1.println("Flame Detected");
  Serial1.println(google_maps_link);
  delay(100);
  Serial.println ("Finish");
  Serial1.println((char)26);// ASCII code of CTRL+Z
  delay(1000);
  Serial.println ("Message has been sent");
}

void SendGasSMS() {
  Serial.println ("Sending GAS Message");
  Serial1.println("AT+CMGF=1");    //Sets the GSM Module in Text Mode
  delay(1000);
  Serial.println ("Set SMS Number");
  //                             *********
  Serial1.println("AT+CMGS=\"+966554418546\"\r"); //Mobile phone number to send message
  delay(1000);
  Serial.println ("Set SMS Content");
  Serial1.println("Gas Leaking Detected");
  Serial1.println(google_maps_link);
  delay(100);
  Serial.println ("Finish");
  Serial1.println((char)26);// ASCII code of CTRL+Z
  delay(1000);
  Serial.println ("Message has been sent");
}