#define BLYNK_TEMPLATE_ID "TMPL3z-YoNg_A"
#define BLYNK_TEMPLATE_NAME "Annal D"
#define BLYNK_AUTH_TOKEN "J21YQhvW64KFD8883UZqu_BRZ4eZzpPe"
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <TinyGPS++.h>
#include <HardwareSerial.h>
#include <DHT.h>
#include <Ultrasonic.h>
#include <BlynkSimpleEsp32.h>

// Blynk Auth Token
char auth[] = "J21YQhvW64KFD8883UZqu_BRZ4eZzpPe";

// WiFi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Create a TinyGPS++ object
TinyGPSPlus gps;
HardwareSerial GPS_Serial(2);  // UART2 for GPS
#define OUT_PIN TX
#define IN_PIN RX
gpsmodule ChargingPoint(OUT_PIN,IN_PIN);

// DHT22
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// Ultrasonic Sensor
#define TRIG_PIN 5
#define ECHO_PIN 15
Ultrasonic ultrasonic(TRIG_PIN, ECHO_PIN);

// LCD
#define SDA_PIN 21
#define SCL_PIN 22
LiquidCrystal_I2C lcd(0x27, 16, 2,SDA_PIN,SCL_PIN);

// Potentiometer
#define POT_PIN 34

// Buzzer
#define BUZZER_PIN 13

// Virtual pins for Blynk
#define VPIN_LATITUDE V1
#define VPIN_LONGITUDE V2
#define VPIN_NEAREST_CHARGING V3
#define VPIN_BATTERY_LEVEL_SPEED V4
#define VPIN_HUMIDITY_TEMPERATURE V5
// Function to calculate distance using the Haversine formula
double calculateDistance(float lat1, float lon1, float lat2, float lon2) {
  const float R = 6371; // Radius of the Earth in km
  float dLat = radians(lat2 - lat1);
  float dLon = radians(lon2 - lon1);
  float a = sin(dLat/2) * sin(dLat/2) +
            cos(radians(lat1)) * cos(radians(lat2)) *
            sin(dLon/2) * sin(dLon/2);
  float c = 2 * atan2(sqrt(a), sqrt(1-a));
  float distance = R * c; // Distance in km
  return distance;
}

// Predefined charging points
struct ChargingPoint {
  float latitude;
  float longitude;
  String name;
};

ChargingPoint chargingPoints[] = {
  {37.7749, -122.4194, "Charging Point 1"},
  {34.0522, -118.2437, "Charging Point 2"},
  {40.7128, -74.0060, "Charging Point 3"}
};

// Find nearest charging point
ChargingPoint findNearestChargingPoint(float currentLat, float currentLon) {
  ChargingPoint nearest = chargingPoints[0];
  double minDistance = calculateDistance(currentLat, currentLon, nearest.latitude, nearest.longitude);
  
  for (int i = 1; i < sizeof(chargingPoints)/sizeof(chargingPoints[0]); i++) {
    double distance = calculateDistance(currentLat, currentLon, chargingPoints[i].latitude, chargingPoints[i].longitude);
    if (distance < minDistance) {
      minDistance = distance;
      nearest = chargingPoints[i];
    }
  }
  return nearest;
}

void setup() {
  Serial.begin(115200);
  GPS_Serial.begin(9600, SERIAL_8N1, 16, 17);  // GPS
  
  dht.begin();
  lcd.begin();
  lcd.backlight();
  
  pinMode(POT_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  
  Blynk.begin(auth, ssid, pass);

  Serial.println("Setup complete");
}

void loop() {
  Blynk.run();

  while (GPS_Serial.available() > 0) {
    gps.encode(GPS_Serial.read());
  }

  if (gps.location.isUpdated()) {
    float latitude = gps.location.lat();
    float longitude = gps.location.lng();
    float speed = gps.speed.kmph();

    Serial.print("Latitude: "); Serial.println(latitude, 6);
    Serial.print("Longitude: "); Serial.println(longitude, 6);
    Serial.print("Speed: "); Serial.println(speed);

    ChargingPoint nearest = findNearestChargingPoint(latitude, longitude);
    Serial.print("Nearest Charging Point: "); 
    Serial.println(nearest.name);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Speed: ");
    lcd.print(speed);
    lcd.print(" km/h");
    
    Blynk.virtualWrite(VPIN_LATITUDE, latitude);
    Blynk.virtualWrite(VPIN_LONGITUDE, longitude);
    Blynk.virtualWrite(VPIN_NEAREST_CHARGING, nearest.name);
  }

  int potValue = analogRead(POT_PIN);
  float batteryLevel = potValue * (3.3 / 4095.0);
  Serial.print("Battery Level: "); Serial.println(batteryLevel);

  float distance = ultrasonic.read();
  Serial.print("Distance: "); Serial.println(distance);

  float h = dht.readHumidity();
  float t = dht.readTemperature();
  Serial.print("Humidity: "); Serial.println(h);
  Serial.print("Temperature: "); Serial.println(t);

  if (t > 30.0) {
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }
  delay(2000);
}