#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Define ultrasonic sensor pins
const int trigPin = 9;
const int echoPin = 10;

// Define buzzer pin
const int buzzerPin = 6;

// Define main switch and switch pins
const int mainSwitchPin = 4;  // Digital input pin for the main switch
const int switchPin = 5;     // Digital input pin for the switch
const int ledPin = 7;        // Digital output pin for the switch indicator LED
const int waterLevelLedPin = 8; // Digital output pin for the water level indicator LED

// Define the maximum and minimum distances for the tank
const int maxDistance = 70;  // 48 cm as the maximum depth
const int minDistance = 25;  // 25 cm as the minimum distance

bool buzzerActive = false;
bool introDisplayed = false; // Flag to track if the intro is displayed

void displayIntro() {
  // Display the introductory text
  lcd.init();
  lcd.backlight();
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("ANWIN V ANDREWS");
  delay(2000); // Show for 2 seconds
  lcd.clear();
  introDisplayed = true; // Set the flag to indicate intro displayed
}

void setup() {
  // Set up the main switch pin as an input
  pinMode(mainSwitchPin, INPUT);

  // Set up the ultrasonic sensor and alert pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  // Set up the switch pin as an input
  pinMode(switchPin, INPUT);

  // Set up the LED pins as outputs
  pinMode(ledPin, OUTPUT);
  pinMode(waterLevelLedPin, OUTPUT);

  Serial.begin(9600);
}

void loop() {
  // Read the state of the main switch
  int mainSwitchState = digitalRead(mainSwitchPin);

  if (mainSwitchState == HIGH) {
    // Main switch is off, disconnect everything
    introDisplayed = false; // Reset the intro flag
    lcd.noBacklight(); // Turn off the LCD backlight
    lcd.noDisplay(); // Turn off the LCD display
    digitalWrite(ledPin, LOW);   // LED off when the main switch is off
    digitalWrite(buzzerPin, LOW); // Buzzer off when the main switch is off
    buzzerActive = false;
    digitalWrite(waterLevelLedPin, LOW); // Turn off the water level indicator LED
  } else {
    // Main switch is on, run the system
    if (!introDisplayed) {
      displayIntro(); // Display the intro scene when the main switch is turned on
    }
    lcd.backlight(); // Turn on the LCD backlight
    lcd.display(); // Turn on the LCD display

    // Read the state of the switch
    int switchState = digitalRead(switchPin);

    // Turn off the LED and buzzer when the switch is off
    if (switchState == HIGH) {
      digitalWrite(ledPin, LOW);   // LED off when the switch is off
      digitalWrite(buzzerPin, LOW); // Buzzer off when the switch is off
      buzzerActive = false;
    } else {
      digitalWrite(ledPin, HIGH); // LED on when the switch is on
    }

    // Rest of the code remains the same
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Read the distance from the sensor
    long duration = pulseIn(echoPin, HIGH);
    int distance = duration / 58.2; // Convert the time to distance in cm

    // Ensure the distance is within the specified range
    distance = constrain(distance, minDistance, maxDistance);

    // Calculate the water level percentage
    int waterLevel = map(distance, minDistance, maxDistance, 100, 0);
    waterLevel = constrain(waterLevel, 0, 100);

    // Determine the water level status
    String waterStatus;
    if (waterLevel > 96) {
      waterStatus = "Full";
      digitalWrite(waterLevelLedPin, HIGH); // Turn on the water level indicator LED
      if (switchState == LOW && !buzzerActive) {
        // Turn on the buzzer when the switch is on
        digitalWrite(buzzerPin, HIGH);
        buzzerActive = true;
      }
    } else if (waterLevel < 30) {
      waterStatus = "Low";
      digitalWrite(waterLevelLedPin, LOW); // Turn off the water level indicator LED
      digitalWrite(buzzerPin, LOW); // Turn off the buzzer
      buzzerActive = false;
    } else {
      waterStatus = "Medium";
      digitalWrite(waterLevelLedPin, LOW); // Turn off the water level indicator LED
      digitalWrite(buzzerPin, LOW); // Turn off the buzzer
      buzzerActive = false;
    }

    // Display the water level status as numbers and graphical representation
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(waterLevel);
    lcd.print(" %");

    lcd.setCursor(0, 1);
    for (int i = 0; i < waterLevel / 5; i++) {
      lcd.print("#");
    }
    lcd.setCursor(8, 0);
    lcd.print(waterStatus);

    delay(1000); // Update the display every second
  }
}