#include <LiquidCrystal.h>

// Define LCD pins
const int rs = 27;
const int en = 26;
const int d4 = 25;
const int d5 = 33;
const int d6 = 32;
const int d7 = 14;

// Define ultrasonic sensor pins
const int trigPin = 4;
const int echoPin = 5;

// Define LED pin
const int ledPin = 16;

// Define buzzer pin
const int buzzerPin = 17;

// Define slide switches pins
const int manualSwitchPin = 18;
const int autoSwitchPin = 19;

// Define environmental factors
float temperature = 25.0; // Temperature in Celsius
float pH = 7.0;           // pH level

// Maximum distance (in cm) the ultrasonic sensor can measure
const int maxDistance = 400;

// Threshold for triggering the buzzer (water level below which alarm triggers)
const int buzzerThreshold = 30;

// Threshold for determining switch state
const int switchThreshold = 500; // Adjust this value as needed

// Variables to store the switch states
bool autoSwitchState = LOW;
bool manualSwitchState = LOW;

// Previous state of the manual switch
bool prevManualSwitchState = LOW;

// Initialize LCD
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize LCD
  lcd.begin(16, 2);

  // Set up ultrasonic sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Set up LED and buzzer pins
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  // Set up slide switch pins
  pinMode(manualSwitchPin, INPUT);
  pinMode(autoSwitchPin, INPUT);

  // Initialize previous manual switch state
  prevManualSwitchState = digitalRead(manualSwitchPin);
}

void loop() {
  // Variables to store the distance and water level
  float distance;
  int waterLevel;

  // Read the switch states
  autoSwitchState = digitalRead(autoSwitchPin);
  manualSwitchState = digitalRead(manualSwitchPin);

  // Check if manual switch state has changed
  if (manualSwitchState != prevManualSwitchState) {
    if (manualSwitchState == HIGH) {
      Serial.println("Manual mode: Manual switch is ON");
    } else {
      Serial.println("Manual mode: Manual switch is OFF");
    }
    // Update previous manual switch state
    prevManualSwitchState = manualSwitchState;
  }

  // Trigger ultrasonic sensor to send pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the pulse travel time to calculate distance (in cm)
  distance = pulseIn(echoPin, HIGH) / 58.0; // Divide by conversion factor

  // Map distance to water level percentage
  waterLevel = map(distance, 0, maxDistance, 0, 100);

  // Ensure water level stays within 0-100 range
  waterLevel = constrain(waterLevel, 0, 100);

  // Print water level to serial monitor
  Serial.print("Water Level: ");
  Serial.print(waterLevel);
  Serial.println("%");

  // Check if water level is below the buzzer threshold
  if (waterLevel <= buzzerThreshold) {
    // Activate LED and buzzer for alarm
    digitalWrite(ledPin, HIGH);
    tone(buzzerPin, 1000); // Buzzer sound

    // Open the valve if in manual mode and water level is low
    if (manualSwitchState == HIGH) {
      Serial.println("Manual mode: Valve is OPEN");
    } else if (autoSwitchState == HIGH) {
      Serial.println("Automatic mode: Valve is OPEN");
    } else {
      Serial.println("Automatic mode: Valve is CLOSED");
    }
  } else {
    // Turn off LED and buzzer
    digitalWrite(ledPin, LOW);
    noTone(buzzerPin);

    // Close the valve if in automatic mode
    if (autoSwitchState == HIGH || (manualSwitchState == HIGH && waterLevel > switchThreshold)) {
      Serial.println("Automatic mode: Valve is CLOSED");
    } else if (manualSwitchState == HIGH) {
      Serial.println("Manual mode: Valve is CLOSED");
    }
  }

  // Display water level and manual switch status on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Water Level:");
  lcd.setCursor(0, 1);
  lcd.print("Level: ");
  lcd.print(waterLevel);
  lcd.print("%");
  lcd.setCursor(10, 1);
  if (manualSwitchState == HIGH) {
    lcd.print("Manual ON ");
  } else {
    lcd.print("Manual OFF");
  }

  // Delay before next reading
  delay(1000);
}