#include <Wire.h>         
#include <Arduino.h>    
#include <WiFi.h>         
#include <HTTPClient.h>  
#include "DHTesp.h"      

#define PPM_PIN 16        
#define PIR_PIN 2         // Pin connected to the PIR sensor for motion detection
#define ULTRASONIC_TRIG_PIN 5   // Pin connected to the trigger of the ultrasonic sensor
#define ULTRASONIC_ECHO_PIN 13  // Pin connected to the echo of the ultrasonic sensor
#define LED_RED 12        // Pin for the red LED (traffic light)
#define LED_YELLOW 4      // Pin for the yellow LED (traffic light)
#define LED_GREEN 27      // Pin for the green LED (traffic light)

const char *ssid = "Wokwi-GUEST";   // Wi-Fi SSID (network name)
const char *password = "";          // Wi-Fi password (empty for guest network)
const char *webhookURL = "https://webhookwizard.com/api/webhook/in?key=sk_384fc8b2-402d-4151-9b6f-a82ddb67b8ef"; // Webhook URL for sending sensor data
const int DHT_PIN = 15;   // Pin connected to the DHT22 sensor for temperature and humidity measurements

long distance;            // Variable to store distance measured by the ultrasonic sensor
DHTesp dhtSensor;         // Create a DHT sensor object

// Function to connect to Wi-Fi
void setup_wifi() {
  WiFi.mode(WIFI_STA);        // Set Wi-Fi mode to station (client)
  WiFi.begin(ssid, password); // Connect to the Wi-Fi network
  Serial.print("Connecting to WiFi ..");
  while (WiFi.status() != WL_CONNECTED) {  // Wait until the Wi-Fi is connected
    Serial.print('.');        // Print dots to indicate connection progress
    delay(1000);
  }
  Serial.println("Connected");  // Print when the connection is successful
}

// Function to send sensor data to a server via a webhook
void sendWebhook(String data) {
  HTTPClient http;            // Create HTTP client object
  http.begin(webhookURL);     // Set the webhook URL
  http.addHeader("Content-Type", "application/json");  // Specify that data is sent in JSON format
  http.POST(data);            // Send POST request with sensor data
  http.end();                 // Close the connection
}

// Function to process the distance data and control the traffic light
void processSensorData(long distance) {
  // Traffic light control based on the distance measured by the ultrasonic sensor
  if (distance < 20) {
   // If distance is between 20 cm and 50 cm, caution (yellow light)
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_RED, LOW);
    Serial.println("Moderate Distance - Use Caution");
  } else if (distance > 20 && distance <= 50) {
    // If distance is between 20 cm and 50 cm, caution (yellow light)
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_RED, LOW);
    Serial.println("Moderate Distance - Use Caution");
  } else if (distance > 50 && distance < 400) {
   // If distance is between 20 cm and 50 cm, caution (yellow light)
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_RED, LOW);
    Serial.println("Moderate Distance - Use Caution");
  }
}

void setup() {
  Wire.begin(23, 22);         // Start I2C communication for some sensors (if used)
  Serial.begin(115200);       // Start serial communication at 115200 baud rate
  pinMode(PIR_PIN, INPUT);    // Set PIR sensor pin as input
  pinMode(ULTRASONIC_TRIG_PIN, OUTPUT); // Set ultrasonic sensor trigger pin as output
  pinMode(ULTRASONIC_ECHO_PIN, INPUT);  // Set ultrasonic sensor echo pin as input
  pinMode(LED_RED, OUTPUT);   // Set red LED pin as output
  pinMode(LED_YELLOW, OUTPUT);// Set yellow LED pin as output
  pinMode(LED_GREEN, OUTPUT); // Set green LED pin as output

  // Initialize DHT sensor for temperature and humidity
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  // Initialize Wi-Fi connection
  setup_wifi();
}

void loop() {
  // Read the PIR sensor to detect motion
  int pirValue = digitalRead(PIR_PIN);
  if (pirValue == HIGH) {
    // If motion is detected, stop traffic (turn on red light)
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_YELLOW, HIGH);
    digitalWrite(LED_GREEN, LOW);
    Serial.println("Motion detected - Stop Traffic");
  } else {
    // Read the ultrasonic sensor to measure the distance of vehicles
    digitalWrite(ULTRASONIC_TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(ULTRASONIC_TRIG_PIN, LOW);
    long duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH);  // Measure the time for the pulse to return
    distance = duration * 0.034 / 2;  // Convert time to distance in cm

    // Process sensor data and control the traffic lights accordingly
    processSensorData(distance);

    // Read PPM value from the MQ135 gas sensor (for pollution monitoring)
    int16_t ppmValue = analogRead(PPM_PIN);
    int mappedppmValue = ppmValue / 4.095;  // Map the raw value to the correct scale for the sensor
    Serial.print("PPM: ");  // Print the PPM (pollution level) value to the serial monitor
    Serial.println(mappedppmValue);

    // Send sensor data (distance and PPM) via webhook to a server
    String sensorData = "{\"event\": \"SensorData\", \"distance\": " + String(distance) + ", \"ppm\": " + String(mappedppmValue) + "}";
    sendWebhook(sensorData);
  }

  delay(1000);  // Delay for 1 second before the next loop iteration

  // Read temperature and humidity from the DHT22 sensor
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float temperature = data.temperature;   // Get temperature in Celsius
  float humidity = data.humidity;         // Get humidity percentage

  // Send sensor data (distance, temperature, and humidity) via webhook to a server
  String sensorData = "{\"event\": \"SensorData\", \"distance\": " + String(distance) + ", \"temperature\": " + String(temperature) + ", \"humidity\": " + String(humidity) + "}";
  sendWebhook(sensorData);

  delay(1000);  // Delay for 1 second before the next loop iteration
}