#include <LiquidCrystal.h>

// Pin assignments
const int PIR_PIN = 7;
const int LDR_PIN = A0;
const int LASER_PIN = 13;
const int ULTRASONIC_TRIG_PIN = 8;
const int ULTRASONIC_ECHO_PIN = 10;
const int BUZZER_PIN = 9;
const int LCD_RS_PIN = 11;
const int LCD_EN_PIN = 12;
const int LCD_D4_PIN = 5;
const int LCD_D5_PIN = 4;
const int LCD_D6_PIN = 3;
const int LCD_D7_PIN = 2;
const int SWITCH_PIN = 6;

// System state
boolean alarmTriggered = false;
boolean alarmStopped = false;

// Sensor readings
int PIR_reading = 0;
int LDR_reading = 0;
long ultrasonic_distance = 0;
int Laser_reading = 0;

// LCD display
LiquidCrystal lcd(LCD_RS_PIN, LCD_EN_PIN, LCD_D4_PIN, LCD_D5_PIN, LCD_D6_PIN, LCD_D7_PIN);

// Function to turn on the alarm
void triggerAlarm() {
  alarmTriggered = true;
  digitalWrite(BUZZER_PIN, HIGH);
}

void laserPinCheckFirst() {
  alarmTriggered = true;
  // Laser_reading = digitalRead(LASER_PIN);
  // if(Laser_reading == HIGH){
  digitalWrite(BUZZER_PIN, HIGH);
  // }
  // else {
  //   digitalWrite(BUZZER_PIN, LOW);
  // }
}

// Function to turn off the alarm
void stopAlarm() {
  alarmTriggered = false;
  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LASER_PIN, LOW);
}

// Function to measure the distance to an object using the ultrasonic sensor
long measureDistance() {
  digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);

  long pulseDuration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH);
  long distance = pulseDuration / 58.2;

  return distance;
}

void setup() {
  // Set up the PIR sensor
  pinMode(PIR_PIN, INPUT);

  // Set up the LDR sensor
  pinMode(LDR_PIN, INPUT);

  // Set up the laser module
  pinMode(LASER_PIN, OUTPUT);

  // Set up the ultrasonic sensor
  pinMode(ULTRASONIC_TRIG_PIN, OUTPUT);
  pinMode(ULTRASONIC_ECHO_PIN, INPUT);

  // Set up the buzzer
  pinMode(BUZZER_PIN, OUTPUT);

  // Set up the LCD display
  lcd.begin(16, 2);


  // Turn off the alarm
 // stopAlarm();
}

void loop() {
  // Read the PIR sensor
  PIR_reading = digitalRead(PIR_PIN);

  // Read the LDR sensor
  LDR_reading = analogRead(LDR_PIN);

  // Read the ultrasonic sensor
  ultrasonic_distance = measureDistance();

  lcd.print("Security Theft Defender");

  // Check if any sensor detects an object or motion
  if (ultrasonic_distance < 200 || PIR_reading == HIGH) {
    // Trigger the alarm
    triggerAlarm();
  }

  if (LDR_reading < 500) {
    // Turn on the laser module
    laserPinCheckFirst();
  }
 
  // Check if the alarm is triggered
  if (alarmTriggered) {
    // Display alarm message on LCD
    lcd.clear();
    lcd.print("Alarm Triggered!");

    // Show the sensor name that triggered the alarm on LCD
    if (ultrasonic_distance < 200) {
      lcd.print("\nUltrasonic Sensor");
    } else if (PIR_reading == HIGH) {
      lcd.print("\nPIR Sensor");
    }

    // Show warning message that someone enters on LCD
    lcd.print("\nSomeone Enters!");
  }

  // Check if the alarm is stopped
  else {
    // Display message that the alarm is stopped
    lcd.clear();
    lcd.print("System Armed");
  }

  // Check if the switch is pressed
  boolean switchState = digitalRead(SWITCH_PIN);
  if (switchState == LOW) {
    // Stop the alarm
    stopAlarm();
  }
}