#include <WiFi.h>
#include <ThingESP.h>

// --- ThingESP Setup ---
ThingESP32 thing("mohamedajas", "LEDControl", "ICT323");

// Ultrasonic sensor pins
#define TRIG  25
#define ECHO  26

// Traffic LEDs
#define RED_LED     19
#define YELLOW_LED  17
#define GREEN_LED   16

long duration;
int distance;

unsigned long previousMillis = 0;
const long INTERVAL = 6000; // Prevent sending messages too often

// --- Forward Declarations ---
void measureDistance();
void sendWhatsAppAlert();

// --- ThingESP handler function ---
String customResponse(String msg) {
  if (msg == "alert") {
    return "🚨 Vehicle crossed RED signal! (Simulated in Wokwi)";
  }
  return "Unknown command: " + msg;
}

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

  // --- ThingESP WiFi & Init for Wokwi ---
  thing.SetWiFi("Wokwi-GUEST", "");
  thing.initDevice();

  // --- Pin Modes ---
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
}

void loop() {
  // Handle ThingESP communications
  thing.Handle();

  // --- Traffic Light Sequence ---
  digitalWrite(GREEN_LED, HIGH);
  digitalWrite(YELLOW_LED, LOW);
  digitalWrite(RED_LED, LOW);
  delay(5000); // Green for 5s

  digitalWrite(GREEN_LED, LOW);
  digitalWrite(YELLOW_LED, HIGH);
  delay(2000); // Yellow for 2s

  digitalWrite(YELLOW_LED, LOW);
  digitalWrite(RED_LED, HIGH); // Red ON
  delay(500); // small delay before detection

  // --- Monitor for vehicle crossing during RED ---
  measureDistance();
  if (distance > 0 && distance < 15) { // Threshold 15cm
    sendWhatsAppAlert();
    delay(2000); // Avoid multiple messages
  }

  delay(5000); // Red duration
  digitalWrite(RED_LED, LOW); // Turn off red
}

// --- Function Definitions ---
void measureDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  duration = pulseIn(ECHO, HIGH);
  distance = duration * 0.034 / 2; // cm
  Serial.print("Distance: ");
  Serial.println(distance);
}

void sendWhatsAppAlert() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= INTERVAL) { // Throttle messages
    previousMillis = currentMillis;

    // Simulate sending WhatsApp by calling customResponse
    String response = customResponse("alert");
    Serial.println("Message sent: " + response);
  }
}