/*
  Relay 1
  TURN OFF REF
  TURN ON REF
  Relay 2
  TURN OFF RICE COOKER
  TURN ON RICE COOKER
  Relay 3
  TURN OFF AIRCON
  TURN ON AIRCON
  Relay 4
  TURN OFF MAIN BREAKER
  TURN ON MAIN BREAKER
  ALL
  ON ALL
  OFF ALL
*/
#include <SoftwareSerial.h>

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

#define RELAY1_PIN 4
#define RELAY2_PIN 5
#define RELAY3_PIN 6
#define RELAY4_PIN 7

void setup() {
  Serial.begin(115200);
  // Initialize hardware serial communication for GSM module
  gsmSerial.begin(9600);
  // Set GSM module to text mode
  gsmSerial.println("AT+CMGF=1");
  delay(1000);  // Wait for response

  // Enable receiving SMS notifications
  gsmSerial.println("AT+CNMI=2,2,0,0,0");
  delay(1000);  // Wait for response

  // Initialize relay pins as outputs
  pinMode(RELAY1_PIN, OUTPUT);
  pinMode(RELAY2_PIN, OUTPUT);
  pinMode(RELAY3_PIN, OUTPUT);
  pinMode(RELAY4_PIN, OUTPUT);

  // Turn off all relays initially
  digitalWrite(RELAY1_PIN, HIGH);
  digitalWrite(RELAY2_PIN, HIGH);
  digitalWrite(RELAY3_PIN, HIGH);
  digitalWrite(RELAY4_PIN, HIGH);
  Serial.println("Gsm start");
}

void loop() {
  static String message = "";  // Static variable to store incomplete messages

  // Check if there's data available from the GSM module
  while (gsmSerial.available()) {
    char c = gsmSerial.read();  // Read one character
    message += c;               // Add character to buffer

    // Check if the end of message character is received
    if (c == '\n') {
      // Print the complete message
      Serial.println(message);
      if (message.indexOf("TURN ON REF") != -1) {
        digitalWrite(RELAY1_PIN, LOW);
        Serial.println("Ref ON");
      } else if (message.indexOf("TURN OFF REF") != -1) {
        digitalWrite(RELAY1_PIN, HIGH);
        Serial.println("Ref off");
      } else if (message.indexOf("TURN ON RICE COOKER") != -1) {
        digitalWrite(RELAY2_PIN, LOW);
        Serial.println("Cooker on");
      } else if (message.indexOf("TURN OFF RICE COOKER") != -1) {
        digitalWrite(RELAY2_PIN, HIGH);
        Serial.println("Cooker off");
      } else if (message.indexOf("TURN ON AIRCON") != -1) {
        digitalWrite(RELAY3_PIN, LOW);
        Serial.println("AC on");
      } else if (message.indexOf("TURN OFF AIRCON") != -1) {
        digitalWrite(RELAY3_PIN, HIGH);
        Serial.println("AC off");
      } else if (message.indexOf("TURN ON MAIN BREAKER") != -1) {
        digitalWrite(RELAY4_PIN, LOW);
        Serial.println("Breaker on");
      } else if (message.indexOf("TURN OFF MAIN BREAKER") != -1) {
        digitalWrite(RELAY4_PIN, HIGH);
        Serial.println("Breakeroff");
      } else if (message.indexOf("ON ALL") != -1) {
        digitalWrite(RELAY1_PIN, LOW);
        digitalWrite(RELAY2_PIN, LOW);
        digitalWrite(RELAY3_PIN, LOW);
        digitalWrite(RELAY4_PIN, LOW);
      } else if (message.indexOf("OFF ALL") != -1) {
        digitalWrite(RELAY1_PIN, HIGH);
        digitalWrite(RELAY2_PIN, HIGH);
        digitalWrite(RELAY3_PIN, HIGH);
        digitalWrite(RELAY4_PIN, HIGH);
      }


      message = "";  // Clear the buffer for the next message
    }
  }
}