#define BLYNK_TEMPLATE_ID "TMPL3M0TZv3M7"
#define BLYNK_TEMPLATE_NAME "Traffic Intensity Detection"
#define BLYNK_AUTH_TOKEN "EZ3-4DOs0LIfhcMm7KoC9jpU0fKRu6YD"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>

// Pin Definitions
const int triggerPins[4] = {23, 22, 21, 19};
const int echoPins[4] = {2, 4, 16, 17};
const int redLEDs[4] = {14, 27, 26, 25};
const int yellowLEDs[4] = {32, 33, 4, 5};
const int greenLEDs[4] = {18, 19, 21, 22};
const int ledPin = 13;

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

BlynkTimer timer;

void setup() {
  Serial.begin(115200);
  Serial.println("Initializing System...");

  for (int i = 0; i < 4; i++) {
    pinMode(triggerPins[i], OUTPUT);
    pinMode(echoPins[i], INPUT);
    pinMode(redLEDs[i], OUTPUT);
    pinMode(yellowLEDs[i], OUTPUT);
    pinMode(greenLEDs[i], OUTPUT);
  }

  pinMode(ledPin, OUTPUT);

  Serial.println("Connecting to Blynk...");
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi Connection Failed! Check Credentials.");
    while (true);
  }

  Serial.println("Blynk Connected!");
  timer.setInterval(1000L, controlTraffic);
  Serial.println("Setup Complete. Starting...");
}

void controlTraffic() {
  int trafficDensities[4] = {0};
  int totalDensity = 0;

  // Measure traffic density for each lane
  for (int i = 0; i < 4; i++) {
    trafficDensities[i] = detectTraffic(triggerPins[i], echoPins[i]);
    totalDensity += trafficDensities[i];
    Serial.print("Lane ");
    Serial.print(i + 1);
    Serial.print(" Traffic Density: ");
    Serial.println(trafficDensities[i]);
  }

  // Skip empty lanes and allocate proportional green light time
  for (int i = 0; i < 4; i++) {
    if (trafficDensities[i] > 0) {
      int greenTime = (trafficDensities[i] * 10) / (totalDensity + 1); // Proportional time
      Serial.print("Allocating Green Light for Lane ");
      Serial.print(i + 1);
      Serial.print(" for ");
      Serial.print(greenTime);
      Serial.println(" seconds.");
      activateGreenLight(i, greenTime);
    } else {
      Serial.print("Lane ");
      Serial.print(i + 1);
      Serial.println(": Skipped (No Traffic)");
      activateRedLight(i);
    }
  }

  // Blinking additional LED for debugging
  digitalWrite(ledPin, HIGH);
  delay(500);
  digitalWrite(ledPin, LOW);
}

int detectTraffic(int triggerPin, int echoPin) {
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);

  long duration = pulseIn(echoPin, HIGH);
  int distance = duration * 0.034 / 2;

  if (duration == 0 || distance > 400) {
    Serial.println("No valid echo detected or object out of range.");
    return 0; // Default to no traffic
  }

  Serial.print("Measured Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance > 200) {
    return 100; // High traffic density
  } else if (distance > 150 && distance <= 200) {
    return 75; // Moderate traffic density
  } else if (distance > 100 && distance <= 150) {
    return 50; // Medium traffic density
  } else if (distance > 40 && distance <= 100) {
    return 25; // Low traffic density
  } else {
    return 10; // Very low traffic density
  }
}

void activateRedLight(int lane) {
  digitalWrite(redLEDs[lane], HIGH);
  digitalWrite(yellowLEDs[lane], LOW);
  digitalWrite(greenLEDs[lane], LOW);
  Blynk.virtualWrite(V1 + lane, "Red Light ON");
  Serial.print("Lane ");
  Serial.print(lane + 1);
  Serial.println(": Red Light ON");
}

void activateGreenLight(int lane, int greenTime) {
  digitalWrite(redLEDs[lane], LOW);
  digitalWrite(yellowLEDs[lane], LOW);
  digitalWrite(greenLEDs[lane], HIGH);
  Blynk.virtualWrite(V1 + lane, "Green Light ON");
  Serial.print("Lane ");
  Serial.print(lane + 1);
  Serial.println(": Green Light ON");
  delay(greenTime * 1000);

  digitalWrite(greenLEDs[lane], LOW);
  digitalWrite(yellowLEDs[lane], HIGH);
  Blynk.virtualWrite(V1 + lane, "Yellow Light ON");
  Serial.print("Lane ");
  Serial.print(lane + 1);
  Serial.println(": Yellow Light ON");
  delay(2000);

  digitalWrite(yellowLEDs[lane], LOW);
  digitalWrite(redLEDs[lane], HIGH);
}

void loop() {
  Blynk.run();
  timer.run();
}