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

LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

const int triggerPin = 8;
const int echoPin = 9;
const int manualSwitchPin = 10;
const int autoSwitchPin = 11;
const int pumpPin = 12;

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

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

  pinMode(triggerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(manualSwitchPin, INPUT_PULLUP);
  pinMode(autoSwitchPin, INPUT_PULLUP);
  pinMode(pumpPin, OUTPUT);

  set_val = min(EEPROM.read(0), 150);
}

void loop() {
  measureWaterLevel();
  updateDisplay();
  checkPumpState();
  handleSwitches();
  delay(500);
}

void measureWaterLevel() {
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  inches = microsecondsToInches(duration);
  percentage = map(constrain(set_val - inches, 0, set_val), 0, set_val, 0, 100);
}

void updateDisplay() {
  lcd.setCursor(12, 0);
  lcd.print(percentage);
  lcd.print("%   ");

  lcd.setCursor(5, 1);
  lcd.print(pumpState ? "ON " : "OFF");

  lcd.setCursor(9, 1);
  lcd.print(manualMode ? "MANUAL" : "AUTO   ");
}

void checkPumpState() {
  pumpState = (percentage < 30 && digitalRead(autoSwitchPin));
  digitalWrite(pumpPin, !pumpState);
}

void handleSwitches() {
  if (!digitalRead(manualSwitchPin) && !manualMode) {
    manualMode = true;
    set_val = inches;
    EEPROM.write(0, set_val);
  }

  if (!digitalRead(manualSwitchPin) && !digitalRead(autoSwitchPin) && !manualMode) {
    manualMode = true;
    pumpState = !pumpState;
  }

  if (digitalRead(manualSwitchPin))
    manualMode = false;
}

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