#include <EEPROM.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

const int slideSwitchPin = 10; // Slide switch pin
const int triggerPin = 8;
const int echoPin = 9;
const int buzzerPin = 13;
const int thresholdPin = A0;
const int potPin = A1; // Slide potentiometer pin

long duration, inches;
int set_val, percentage;
bool pumpState = false;
bool manualMode = false;

void setup() {
  lcd.begin(16, 2);
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1);
  lcd.print("PUMP: OFF  AUTO");

  pinMode(triggerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(thresholdPin, INPUT);
  pinMode(potPin, INPUT); // Slide potentiometer pin
  pinMode(slideSwitchPin, INPUT_PULLUP); // Slide switch pin

  set_val = EEPROM.read(0);
  if (set_val > 150) set_val = 150;
}

void loop() {
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  inches = microsecondsToInches(duration);
  percentage = (set_val - inches) * 100 / set_val;

  lcd.setCursor(12, 0);
  if (percentage < 0) percentage = 0;
  lcd.print(percentage);
  lcd.print("%   ");

  if (percentage < 30 && !manualMode) {
    pumpState = true;
  }
  if (percentage > 99) {
    pumpState = false;
  }
  digitalWrite(buzzerPin, pumpState ? HIGH : LOW); // Activate buzzer if pump is on

  lcd.setCursor(5, 1);
  if (pumpState) lcd.print("ON  ");
  else lcd.print("OFF ");

  lcd.setCursor(11, 1);
  if (manualMode) lcd.print("MANUAL");
  else lcd.print("AUTO  ");

  if (digitalRead(slideSwitchPin) == LOW) { // Slide switch activated (connected to GND)
    manualMode = !manualMode; // Toggle manual/auto mode
    delay(500); // Debounce delay
  }

  if (manualMode && digitalRead(slideSwitchPin) == HIGH) { // Slide switch in auto mode position
    set_val = analogRead(thresholdPin); // Read the analog value from the potentiometer
    set_val = map(set_val, 0, 1023, 0, 150); // Map the analog value to the range 0-150
    EEPROM.write(0, set_val); // Save the threshold value to EEPROM
    delay(500); // Debounce delay
  }

  delay(500);
}

long microsecondsToInches(long microseconds) {
  return microseconds / 74 / 2;
}