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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Address 0x27 for a 16x2 LCD

const int trigPin = 7;    // Ultrasonic sensor trigger pin
const int echoPin = 6;    // Ultrasonic sensor echo pin
const int switchPin = 2;  // Slide switch pin
const int potPin = A1;    // Slide potentiometer pin
const int relayPin = 12;  // Relay control pin
const int buzzerPin = 11; // Buzzer pin

const int numReadings = 10; // Number of readings for moving average filter
const int lowWaterLevel = 10;    // Threshold for low water level
const int priorityThreshold = 30; // Threshold for priority level (percentage)

int waterLevel = 0;         // Current water level (percentage)
int priorityLevel = 0;      // Priority level based on water level
bool isManualMode = false;  // Flag for manual mode

int readings[numReadings];      // Array to store ultrasonic sensor readings
int readIndex = 0;              // Index for reading array
int total = 0;                  // Total of readings

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(switchPin, INPUT_PULLUP);
  pinMode(relayPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1);
  lcd.print("PUMP:OFF MANUAL");

  // Initialize LCD backlight
  lcd.setBacklight(HIGH);

  // Initialize array to 0
  for (int i = 0; i < numReadings; ++i) {
    readings[i] = 0;
  }
}

void loop() {
  // Read water level using moving average filter
  total -= readings[readIndex];                  // Subtract the oldest reading
  readings[readIndex] = measureDistance();       // Read from the sensor
  total += readings[readIndex];                  // Add the new reading
  readIndex = (readIndex + 1) % numReadings;     // Advance to the next position

  // Calculate the average distance
  int distance = total / numReadings;

  // Calculate water level percentage
  int tankCapacity = calculateTankCapacity(distance); // Calculate tank capacity based on distance
  waterLevel = map(distance, 0, tankCapacity, 0, 100); // Map distance to a percentage value based on tank capacity

  // Ensure water level is within 0 to 100 range
  waterLevel = constrain(waterLevel, 0, 100);

  // Read switch state
  isManualMode = digitalRead(switchPin) == LOW;

  // Calculate priority level based on water level
  priorityLevel = calculatePriorityLevel(waterLevel);

  // Update LCD with water level
  lcd.setCursor(12, 0);
  lcd.print(waterLevel);
  lcd.print("%   ");

  lcd.setCursor(5, 1);
  if (digitalRead(relayPin) == HIGH) {
    lcd.print("ON ");
  } else {
    lcd.print("OFF");
  }

  lcd.setCursor(9, 1);
  if (isManualMode) {
    lcd.print("MANUAL");
  } else {
    lcd.print("AUTO  ");
  }

  // Control pump based on priority and manual mode
  if (!isManualMode) {
    if (priorityLevel >= priorityThreshold && digitalRead(relayPin) == LOW) {
      activatePump();
    } else if (priorityLevel < priorityThreshold && digitalRead(relayPin) == HIGH) {
      deactivatePump();
    }
  }

  // Check for low water level
  if (waterLevel <= lowWaterLevel) {
    activateBuzzer();
  } else {
    deactivateBuzzer();
  }

  delay(500);
}

int measureDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH);
  int distance = duration * 0.034 / 2;
  return distance;
}

int calculateTankCapacity(int distance) {
  // Define the formula to calculate tank capacity based on distance
  // For example, you can use a linear formula or any other appropriate method
  // This is just an example, adjust it according to your specific setup
  return map(distance, 0, 150, 50, 150); // Adjust this mapping to match your tank capacity
}

int calculatePriorityLevel(int waterLevel) {
  // Implement area priority logic here
  // For example, prioritize bathroom > kitchen > bedroom
  if (waterLevel >= 90) {
    return 100; // High priority
  } else if (waterLevel >= 60) {
    return 75;  // Medium priority
  } else {
    return 50;  // Low priority
  }
}

void activatePump() {
  digitalWrite(relayPin, HIGH);
}

void deactivatePump() {
  digitalWrite(relayPin, LOW);
}

void activateBuzzer() {
  tone(buzzerPin, 1000); // Activate buzzer at 1kHz frequency
}

void deactivateBuzzer() {
  noTone(buzzerPin); // Turn off buzzer
}