#define BLYNK_TEMPLATE_ID "TMPL3DoTa8aLk"
#define BLYNK_TEMPLATE_NAME "Iot Project"
#define BLYNK_AUTH_TOKEN "7jtEfGGXTRqZMzUuaXZt--IcOc_dacS_"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <LiquidCrystal_I2C.h>

char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// LCD settings
LiquidCrystal_I2C LCD(0x27, 16, 2);

const int sensorPin1 = 34; // Sensor 1 (potentiometer)
const int sensorPin2 = 35; // Sensor 2 (potentiometer)
const int sensorPin3 = 32; // Sensor 3 (potentiometer)
const int sensorPin4 = 33; // Sensor 4 (potentiometer)

// Emergency vehicle pins
const int emePin1 = 26;
const int emePin2 = 27;
const int emePin3 = 14;
const int emePin4 = 12;

// LED pins for each lane
const int r1 = 16;
const int g1 = 17;
const int r2 = 18;
const int g2 = 19;
const int r3 = 21;
const int g3 = 22;
const int r4 = 23;
const int g4 = 25;

// Threshold for traffic detection
const int threshold = 500;

// Timing
const unsigned long greenDuration = 10000; // 10 seconds
const unsigned long switchDelay = 5000;   // 5 seconds delay after detecting equal traffic
unsigned long previousMillis = 0;
unsigned long switchStartMillis = 0;
int currentLane = 1; // Start with lane 1

void setup() {
  Serial.begin(115200);
  Blynk.begin(auth, ssid, pass);
  LCD.init();
  LCD.backlight();

  // Initialize LED pins as output
  pinMode(r1, OUTPUT);
  pinMode(g1, OUTPUT);
  pinMode(r2, OUTPUT);
  pinMode(g2, OUTPUT);
  pinMode(r3, OUTPUT);
  pinMode(g3, OUTPUT);
  pinMode(r4, OUTPUT);
  pinMode(g4, OUTPUT);

  // Initialize emergency switch pins as input with pull-up resistors
  pinMode(emePin1, INPUT_PULLUP);
  pinMode(emePin2, INPUT_PULLUP);
  pinMode(emePin3, INPUT_PULLUP);
  pinMode(emePin4, INPUT_PULLUP);

  LCD.setCursor(0, 0);
  LCD.print("Traffic Control");
  delay(2000);
  LCD.clear();

  setAllRed();
  setLane(currentLane, true); // Set initial lane to green
}

void loop() {
  Blynk.run();
  
  // Read sensor values
  int traffic1 = analogRead(sensorPin1);
  int traffic2 = analogRead(sensorPin2);
  int traffic3 = analogRead(sensorPin3);
  int traffic4 = analogRead(sensorPin4);

  // Check emergency vehicle presence
  bool emergency1 = digitalRead(emePin1) == LOW;
  bool emergency2 = digitalRead(emePin2) == LOW;
  bool emergency3 = digitalRead(emePin3) == LOW;
  bool emergency4 = digitalRead(emePin4) == LOW;

  // Print debug information
  Serial.print("Traffic 1: "); Serial.println(traffic1);
  Serial.print("Traffic 2: "); Serial.println(traffic2);
  Serial.print("Traffic 3: "); Serial.println(traffic3);
  Serial.print("Traffic 4: "); Serial.println(traffic4);
  Serial.print("Emergency 1: "); Serial.println(emergency1);
  Serial.print("Emergency 2: "); Serial.println(emergency2);
  Serial.print("Emergency 3: "); Serial.println(emergency3);
  Serial.print("Emergency 4: "); Serial.println(emergency4);

  unsigned long currentMillis = millis();

  // Emergency vehicle handling
  if (emergency1) {
    handleEmergency(1);
  } else if (emergency2) {
    handleEmergency(2);
  } else if (emergency3) {
    handleEmergency(3);
  } else if (emergency4) {
    handleEmergency(4);
  } else {
    // Normal traffic handling
    int maxTraffic = max(max(traffic1, traffic2), max(traffic3, traffic4));
    if (maxTraffic > threshold) {
      // which lane has the highest traffic
      if (traffic1 == maxTraffic) {
        manageTraffic(1, traffic1);
      } else if (traffic2 == maxTraffic) {
        manageTraffic(2, traffic2);
      } else if (traffic3 == maxTraffic) {
        manageTraffic(3, traffic3);
      } else if (traffic4 == maxTraffic) {
        manageTraffic(4, traffic4);
      }
      switchStartMillis = currentMillis; 
    } else {
      // Round-robin lane control
      if (currentMillis - switchStartMillis >= switchDelay) {
        switchStartMillis = currentMillis; 
        currentLane = (currentLane % 4) + 1; // Cycle through lanes 1 to 4
        setAllRed();
        setLane(currentLane, true);
        Serial.print("Switching to lane: "); Serial.println(currentLane);
      }
    }
  }
}

void manageTraffic(int lane, int traffic) {
  if (currentLane != 0 && currentLane != lane) {
    setLane(currentLane, false);
  }
  
  currentLane = lane;
  unsigned long startMillis = millis();
  setLane(lane, true);
  Serial.print("Managing traffic for lane: "); Serial.println(lane);
  while (millis() - startMillis < greenDuration) {
    delay(1000); 
    switch (lane) {
      case 1:
        traffic = analogRead(sensorPin1);
        break;
      case 2:
        traffic = analogRead(sensorPin2);
        break;
      case 3:
        traffic = analogRead(sensorPin3);
        break;
      case 4:
        traffic = analogRead(sensorPin4);
        break;
    }
    Serial.print("Lane "); Serial.print(lane); Serial.print(" traffic: "); Serial.println(traffic);
    if (traffic <= threshold) {
      break;
    }
  }
}

void handleEmergency(int lane) {
  Serial.println("Handling emergency");
  Serial.print("Emergency lane: "); Serial.println(lane);
  setAllRed();
  
  currentLane = lane;
  setLane(lane, true);
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print("Emergency Lane ");
  LCD.print(lane);

  delay(greenDuration); 

  setAllRed();
  currentLane = 1;
  setLane(currentLane, true);
}

void setLane(int lane, bool isGreen) {
  int redLed, greenLED;

  switch (lane) {
    case 1:
      redLed = r1;
      greenLED = g1;
      break;
    case 2:
      redLed = r2;
      greenLED = g2;
      break;
    case 3:
      redLed = r3;
      greenLED = g3;
      break;
    case 4:
      redLed = r4;
      greenLED = g4;
      break;
    default:
      return;
  }

  if (isGreen) {
    digitalWrite(redLed, LOW);
    digitalWrite(greenLED, HIGH);
    LCD.clear();
    LCD.setCursor(0, 0);
    LCD.print("Lane ");
    LCD.print(lane);
    LCD.print(": Green");
    Serial.print("Lane "); Serial.print(lane); Serial.println(": Green");
  } else {
    digitalWrite(redLed, HIGH);
    digitalWrite(greenLED, LOW);
    Serial.print("Lane "); Serial.print(lane); Serial.println(": Red");
  }
}

void setAllRed() {
  digitalWrite(r1, HIGH);
  digitalWrite(g1, LOW);
  digitalWrite(r2, HIGH);
  digitalWrite(g2, LOW);
  digitalWrite(r3, HIGH);
  digitalWrite(g3, LOW);
  digitalWrite(r4, HIGH);
  digitalWrite(g4, LOW);
  Serial.println("All lanes set to Red");
}