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

#define PIN_TRIG 2
#define PIN_ECHO 15
#define PIN_LED 5
#define SDA_PIN 12
#define SCL_PIN 13

#define SOUND_SPEED 0.034  // Speed of sound in cm per microsecond

long duration;  // Global variable to store the pulse duration
float distanceCm; // Variable to store the calculated distance in centimeters

// Replace with your network credentials
const char* ssid = "Wokwi_Guest";
const char* password = "your_PASSWORD";

// Telegram Bot credentials
#define BOT_TOKEN "8009275723:AAE7DnKJrG94o0F_F-FItq3ZqYd-OTndS-M"
#define CHAT_ID "1418696775"

LiquidCrystal_I2C lcd(0x27, 16, 2);  // LCD setup with I2C address 0x27, 16 columns, 2 rows

void setup() {
  Serial.begin(115200);  // Start serial communication at 115200 baud rate
  
  pinMode(PIN_TRIG, OUTPUT);  // Set the TRIG pin as an output
  pinMode(PIN_LED, OUTPUT);   // Set the LED pin as an output
  pinMode(PIN_ECHO, INPUT);   // Set the ECHO pin as an input

  // Initialize I2C communication
  Wire.begin(SDA_PIN, SCL_PIN);
  
  // Initialize the LCD
  lcd.init();
  lcd.backlight();  // Turn on the LCD backlight

  // Initialize Wi-Fi
  connectToWiFi();
}

void loop() {
  // Trigger the ultrasonic sensor
  digitalWrite(PIN_TRIG, LOW);  // Make sure TRIG is low initially
  delayMicroseconds(2);          // Wait for 2 microseconds
  digitalWrite(PIN_TRIG, HIGH); // Send a 10 microsecond pulse
  delayMicroseconds(10);        
  digitalWrite(PIN_TRIG, LOW);  // End the pulse

  // Measure the time taken for the pulse to return
  duration = pulseIn(PIN_ECHO, HIGH); // Read the pulse duration on ECHO pin
  
  // Calculate the distance based on the duration of the pulse
  distanceCm = duration * SOUND_SPEED / 2;  // Distance = time * speed of sound / 2 (for round trip)

  // Control the LED based on the distance
  if (distanceCm < 10) {  // If the distance is less than 10 cm
    digitalWrite(PIN_LED, HIGH);  // Turn on LED
    sendTelegramMessage("Warning! Object is closer than 10 cm!");  // Send Telegram message
  } else {
    digitalWrite(PIN_LED, LOW);   // Turn off LED
  }

  // Output the distance to the serial monitor
  Serial.print("Distance in CM: ");
  Serial.println(distanceCm);

  // Update the LCD display
  lcd.clear();  // Clear the previous text on the LCD
  lcd.setCursor(0, 0);  // Set cursor to the first row, first column
  lcd.print("Distance: ");
  lcd.print(distanceCm);  // Print the distance on the LCD

  delay(1000);  // Wait for 1 second before the next reading
}

void connectToWiFi() {
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  
  // Wait for the WiFi connection to be established
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi!");
}

void sendTelegramMessage(String message) {
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + String(BOT_TOKEN) + "/sendMessage?chat_id=" + String(CHAT_ID) + "&text=" + message;

  http.begin(url);  // Start HTTP request
  int httpCode = http.GET();  // Send GET request to Telegram API

  if (httpCode > 0) {  // If the request was successful
    Serial.println("Message sent to Telegram.");
  } else {
    Serial.println("Failed to send message.");
  }

  http.end();  // End HTTP request
}