#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <TinyGPSPlus.h>

// LCD setup (address may vary: use 0x27 or 0x3F)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// GPS using HardwareSerial 2
HardwareSerial GPS(2);
TinyGPSPlus gps;

// Pin definitions
#define BUZZER_PIN 27
#define LED_PIN 26
#define BUTTON_PIN 25

// Location strings
String latitudeStr = "";
String longitudeStr = "";

void setup() {
  // Serial Monitor
  Serial.begin(115200);
  
  // Start GPS Serial
  GPS.begin(9600, SERIAL_8N1, 16, 17); // RX=16, TX=17
  
  // Pin Modes
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  // LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Smart SOS System");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Read GPS data
  while (GPS.available() > 0) {
    gps.encode(GPS.read());
  }

  // When button is pressed (LOW due to INPUT_PULLUP)
  if (digitalRead(BUTTON_PIN) == LOW) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("SOS Activated!");

    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    
    // Get GPS data
    if (gps.location.isValid()) {
      latitudeStr = String(gps.location.lat(), 6);
      longitudeStr = String(gps.location.lng(), 6);

      Serial.println("Sending SOS with Location:");
      Serial.print("Latitude: ");
      Serial.println(latitudeStr);
      Serial.print("Longitude: ");
      Serial.println(longitudeStr);

      lcd.setCursor(0, 1);
      lcd.print("Lat:");
      lcd.print(latitudeStr.substring(0, 5));  // Show 5 digits
      delay(2000);
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Long:");
      lcd.print(longitudeStr.substring(0, 5));
    } else {
      Serial.println("GPS Location Invalid");
      lcd.setCursor(0, 1);
      lcd.print("No GPS Signal");
    }

    delay(5000); // Alert duration
    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
    lcd.clear();
  }
}