#include <DHT.h>
#include <Keypad.h>
// Keypad configuration
const byte ROWS = 4; 
const byte COLS = 4; 
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'} // Using '#' as Enter key and '*' as Backspace key
};

// Pin assignments
byte rowPins[ROWS] = {14, 27, 26, 25}; // Adjust these pins as per your ESP32 model
byte colPins[COLS] = {33, 32, 18, 19}; // Adjust these pins as per your ESP32 model

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
// Security code
const char* password = "1234"; // Your defined security code
char enteredPassword[5]; // Array to store the entered password
int buzzerPin = 17; // Pin for the buzzer
int redLedPin = 5; // Pin for the red LED
#define trigPin 12      // Trig pin of the ultrasonic sensor connected to Arduino pin 12
#define echoPin 13      // Echo pin of the ultrasonic sensor connected to Arduino pin 13
#define LDR_PIN 34    // LDR connected to GPIO34 (Analog)
#define PIR_PIN 23    // PIR connected to GPIO23 (Digital)
#define LED_PIN 22    // LED 1 connected to GPIO22 (Digital)
#define TEMP_LED_PIN 21  // LED 2 connected to GPIO21 (Digital)
#define COLD_LED_PIN 15   // LED 3 connected to GPIO19 (Digital)
#define DHT_PIN 4      // DHT22 sensor connected to GPIO4
#define LED4 16         // LED 4 connected to Arduino pin 11
#define DHTTYPE DHT22
DHT dht(DHT_PIN, DHTTYPE);

void setup() {
    Serial.begin(115200);
    pinMode(trigPin, OUTPUT);   // Set trigPin as an output
    pinMode(echoPin, INPUT);    // Set echoPin as an input
    pinMode(PIR_PIN, INPUT);    // Set PIR pin as input
    pinMode(LED_PIN, OUTPUT);    // Set LED 1 pin as output
    pinMode(TEMP_LED_PIN, OUTPUT);  // Set LED 2 pin as output
    pinMode(COLD_LED_PIN, OUTPUT);    // Set LED 3 pin as output
    pinMode(LED4, OUTPUT);
    pinMode(buzzerPin, OUTPUT);
    pinMode(redLedPin, OUTPUT);
    digitalWrite(redLedPin, LOW); // Ensure LED is off at the start
    dht.begin();                 // Initialize DHT sensor
    digitalWrite(LED_PIN, LOW);  // Turn OFF LED 1
    digitalWrite(TEMP_LED_PIN, LOW); // Turn OFF LED 2
    digitalWrite(COLD_LED_PIN, LOW);  // Turn OFF LED 3
    digitalWrite(LED4, LOW);
}

void loop() {
    long duration, distance;

    digitalWrite(trigPin, LOW); // Clear the trigger
    delayMicroseconds(2);         // Wait for 2 microseconds
    digitalWrite(trigPin, HIGH); // Set the trigger high
    delayMicroseconds(10);        // Keep it high for 10 microseconds
    digitalWrite(trigPin, LOW);  // Set the trigger low

    // Read the echo pin
    duration = pulseIn(echoPin, HIGH); // Read the incoming pulse
    distance = (duration / 2) * 0.0343; // Calculate the distance in cm, speed of sound = 
    int ldrValue = analogRead(LDR_PIN);   // Read LDR value
    int pirValue = digitalRead(PIR_PIN);   // Read PIR value
    float temperature = dht.readTemperature(); // Read temperature from DHT22

    Serial.print("LDR Value: ");
    Serial.print(ldrValue);
    Serial.print(" | PIR Value: ");
    Serial.print(pirValue);
    Serial.print(" | Temperature: ");
    Serial.println(temperature);
    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");

    // Check the conditions for LED 1
    if (pirValue == HIGH && ldrValue < 999) {
        digitalWrite(LED_PIN, HIGH);  // Turn ON LED 1
    } else {
        digitalWrite(LED_PIN, LOW);   // Turn OFF LED 1
    }

    // Check the temperature condition for LED 2
    if (pirValue == HIGH && temperature >= 30.0) {
        digitalWrite(TEMP_LED_PIN, HIGH); // Turn ON LED 2
    } else {
        digitalWrite(TEMP_LED_PIN, LOW);  // Turn OFF LED 2
    }

    // Check conditions for LED 3
    if (pirValue == HIGH && temperature < 20.0) {
        digitalWrite(COLD_LED_PIN, HIGH); // Turn ON LED 3
    } else {
        digitalWrite(COLD_LED_PIN, LOW);   // Turn OFF LED 3
    }

    // Control LEDs based on distance
    if (distance < 200) {
        digitalWrite(LED4, HIGH); // Turn on the 4th LED if distance is less than 200 cm
    } else {
        digitalWrite(LED4, LOW);  // Turn off the 4th LED if distance is 200 cm or more
    }

    delay(100);   // Delay for stability and to prevent excessive readings
  char key = keypad.getKey(); // Get the key pressed

  if (key) {
    Serial.println(key); // Display the pressed key for debugging
    
    // If the enter key '#' is pressed
    if (key == '#') {
      enteredPassword[4] = '\0'; // Null-terminate the string
      if (strcmp(enteredPassword, password) == 0) {
        // If the password is correct
        digitalWrite(redLedPin, LOW); // Turn off the LED
        noTone(buzzerPin); // Turn off the buzzer
        Serial.println("Correct Password!"); // Successful message
        delay(2000); // Optional delay before reset
      } else {
        // If the password is incorrect
        triggerAlarm(); // Call the alarm function
        Serial.println("Incorrect Password!"); // Failure message
      }
      // Reset the password entry
      memset(enteredPassword, 0, sizeof(enteredPassword)); // Clear the entered password
      return; // Exit the loop
    } 
    // If the backspace key '*' is pressed
    else if (key == '*') {
      for (int i = 3; i >= 0; i--) {
        if (enteredPassword[i] != 0) { // Find the last entered character
          enteredPassword[i] = 0; // Clear the last character
          break; // Exit the loop after removing one character
        }
      }
    } else {
      // Add the entered key to the enteredPassword array
      for (int i = 0; i < 4; i++) {
        if (enteredPassword[i] == 0) { // Find the first empty spot
          enteredPassword[i] = key; // Add the key to the enteredPassword
          break;
        }
      }
    }
  }
}
// Function to handle incorrect password entry
void triggerAlarm() {
  while (true) {
    digitalWrite(redLedPin, HIGH); // Turn on the red LED
    tone(buzzerPin, 1000); // Start buzzer sound (1000 Hz)
    delay(300); // Duration buzzer and LED ON
    digitalWrite(redLedPin, LOW); // Turn off the red LED
    noTone(buzzerPin); // Stop buzzer sound
    delay(300); // Duration buzzer and LED OFF
    Serial.println("Incorrect Password!");
    // Check for keypad input to reset alarm
    char key = keypad.getKey();
    if (key == '*') { // Press '*' to reset the alarm
      digitalWrite(redLedPin, LOW); // Turn off the LED
      noTone(buzzerPin); // Turn off the buzzer
      break; // Exit the alarm routine
    }
  }
}