#include <SoftwareSerial.h>

#define SIM800_RX_PIN 16
#define SIM800_TX_PIN 17

SoftwareSerial sim800(SIM800_RX_PIN, SIM800_TX_PIN);

void setup() {
  Serial.begin(115200);
  sim800.begin(9600);

  Serial.println("Initializing SIM800L...");
  delay(1000);

  sendATCommand("AT");
  sendATCommand("AT+CGMI");
  sendATCommand("AT+CGMM");
  sendATCommand("AT+CGMR");
  sendATCommand("AT+CSQ");

  // Check PIN status
  sendATCommand("AT+CPIN?");

  // Check and set IP status
  checkAndSetIPStatus();

  // Set APN
  sendATCommand("AT+CSTT=\"internet.telekom\"");

  // Try automatic network registration
  sendATCommand("AT+COPS=0");
  delay(10000); // Wait for registration

  sendATCommand("AT+CREG?");
  sendATCommand("AT+COPS?");

  // If automatic fails, try manual registration
  sendATCommand("AT+COPS=1,2,\"21601\"");
  delay(10000);

  sendATCommand("AT+CREG?");
  sendATCommand("AT+COPS?");

  // If still not registered, try alternative codes
  sendATCommand("AT+COPS=1,2,\"01\"");
  delay(10000);

  sendATCommand("AT+CREG?");
  sendATCommand("AT+COPS?");

  sendATCommand("AT+COPS=1,2,\"216F01\"");
  delay(10000);

  sendATCommand("AT+CREG?");
  sendATCommand("AT+COPS?");

  // Try USSD code for balance check
  sendATCommand("AT+CUSD=1,\"*102#\",15");
}

void loop() {
  // Your main code here
}

void sendATCommand(String command) {
  Serial.println("Sending command: " + command);
  sim800.println(command);
  delay(500);

  while(sim800.available()) {
    String response = sim800.readString();
    Serial.println(response);
  }

  Serial.println(); // Add a blank line for readability
}

void checkAndSetIPStatus() {
  Serial.println("SIM800L státusz lekérdezése...");
  sim800.println("AT+CIPSTATUS");
  delay(2000);

  String statusResponse = "";
  while (sim800.available() > 0) {
    char c = sim800.read();
    statusResponse += c;
  }

  Serial.println("SIM800L státusz:");
  Serial.println(statusResponse);

  if (statusResponse.indexOf("STATE: IP START") != -1) {
    Serial.println("Státusz: IP START. Visszaállítás IP INITIAL állapotra...");
    sim800.println("AT+CIPSHUT");
    delay(2000);

    while (sim800.available() > 0) {
      char c = sim800.read();
      Serial.print(c);
    }
  }

  if (statusResponse.indexOf("STATE: IP INITIAL") != -1) {
    Serial.println("Státusz: IP INITIAL. AT+CSTT parancs végrehajtható.");
    sim800.println("AT+CSTT=\"internet\"");
    delay(2000);

    while (sim800.available() > 0) {
      char c = sim800.read();
      Serial.print(c);
    }
  }
}