#include <EEPROM.h>
#include <LiquidCrystal.h>

// Initialize the LCD with the pins you specified
LiquidCrystal lcd_1(33, 25, 26, 27, 14, 12);

// Pin assignments
const int trigPin = 23;
const int echoPin = 22;
const int relayPin = 19;
const int modeButtonPin = 5; // Use this button to toggle between manual/auto modes
const int pumpButtonPin = 17; // Use this button to turn the pump on/off in manual mode
const int buzzerPin = 21; // GPIO 21 for Buzzer

long duration;
int distance;
int setLevel;
bool pumpState = false; // False = OFF, True = ON
bool manualMode = false;
bool pumpButtonPressed = false;
bool modeButtonPressed = false;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50; // Debounce delay to avoid false triggers

void setup()
{
  // Set up the LCD's number of columns and rows:
  lcd_1.begin(16, 2);
  
  // Print initial messages to the LCD.
  lcd_1.print("WATER LEVEL: ");
  lcd_1.setCursor(0, 1);
  lcd_1.print("PUMP: OFF");

  // Initialize pin modes
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(relayPin, OUTPUT);
  pinMode(modeButtonPin, INPUT_PULLUP); // Button for mode toggle (Manual/Auto)
  pinMode(pumpButtonPin, INPUT_PULLUP); // Button for pump control in manual mode
  pinMode(buzzerPin, OUTPUT); // Buzzer output

  // Load the stored set level from EEPROM (maximum distance when tank is empty)
  setLevel = EEPROM.read(0);
  if (setLevel > 400 || setLevel < 15) setLevel = 400; // Ensure valid range (15 cm as empty)
}

void loop()
{
  // Check the mode toggle button with debouncing
  if (digitalRead(modeButtonPin) == LOW && (millis() - lastDebounceTime) > debounceDelay)
  {
    lastDebounceTime = millis(); // Reset the debounce timer
    modeButtonPressed = !modeButtonPressed; // Toggle the button press state
    manualMode = !manualMode; // Toggle the mode between Manual and Auto
  }

  // Read the pump control button in manual mode
  if (digitalRead(pumpButtonPin) == LOW && !pumpButtonPressed)
  {
    pumpButtonPressed = true;
    if (manualMode)
    {
      pumpState = !pumpState; // Toggle the pump state only in manual mode
    }
  }

  if (digitalRead(pumpButtonPin) == HIGH)
  {
    pumpButtonPressed = false; // Reset button press flag when released
  }

  // Measure the current distance
  int currentDistance = measureDistance();

  // Calculate the percentage of water level based on distance
  int percentage = map(currentDistance, setLevel, 2, 0, 100); // Empty tank is at setLevel distance
  if (percentage < 0) percentage = 0;
  if (percentage > 100) percentage = 100;

  // Update the LCD with the current water level percentage
  lcd_1.setCursor(13, 0);
  lcd_1.print(percentage);
  lcd_1.print("%   ");

  // Automatic control based on water level percentage (only in auto mode)
  if (!manualMode)
  {
    if (percentage < 30) pumpState = true;  // Turn pump ON if water is below 30%
    if (percentage >= 95) pumpState = false; // Turn pump OFF if water is above 95%
  }

  // Control the relay (pump) based on the pump state
  // If relay is active-low, reverse the logic
  digitalWrite(relayPin, pumpState ? HIGH : LOW); // LOW turns ON the pump, HIGH turns it OFF

  // Control the buzzer for low water levels (below 30%)
  if (percentage < 30)
  {
    digitalWrite(buzzerPin, HIGH); // Buzzer ON when water level is low
  }
  else
  {
    digitalWrite(buzzerPin, LOW);  // Buzzer OFF
  }

  // Update the LCD with the current pump status
  lcd_1.setCursor(6, 1);
  if (pumpState) lcd_1.print("ON ");
  else lcd_1.print("OFF");

  // Display the current mode (Manual/Auto)
  lcd_1.setCursor(10, 1);
  if (manualMode) lcd_1.print("MANUAL ");
  else lcd_1.print("AUTO   ");

  delay(500); // Small delay for stability
}

// Function to measure distance using the ultrasonic sensor
int measureDistance()
{
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  return duration * 0.034 / 2;
}