#include <LiquidCrystal_I2C.h>

#define LCD_ADDRESS 0x27
#define LCD_COLUMNS 16
#define LCD_ROWS 2

#define TRIG_PIN 2
#define ECHO_PIN 3
#define RELAY_PIN 13
#define AUTO_MANUAL_SWITCH_PIN 11
#define MANUAL_SWITCH_PIN 10

#define START_PUMP_RANGE 35
#define STOP_PUMP_RANGE 88
#define DELAY_TIME 2000

LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(AUTO_MANUAL_SWITCH_PIN, INPUT_PULLUP);
  pinMode(MANUAL_SWITCH_PIN, INPUT_PULLUP);

  digitalWrite(RELAY_PIN, LOW);
  
  lcd.begin(LCD_COLUMNS, LCD_ROWS);
  lcd.print("GOD IS MY LIGHT");
  delay(2000);
  lcd.clear();
}

void loop() {
  int distance = getDistance();
  int waterLevel = map(distance, START_PUMP_RANGE, STOP_PUMP_RANGE, 0, 100);

  if (digitalRead(AUTO_MANUAL_SWITCH_PIN) == HIGH) {
    lcd.setCursor(0, 0);
    lcd.print("Auto   ");
    
    if (distance < START_PUMP_RANGE) {
      lcd.setCursor(0, 1);
      lcd.print("Pump ON  ");
      digitalWrite(RELAY_PIN, HIGH);
      delay(DELAY_TIME);
    } else if (distance > STOP_PUMP_RANGE) {
      lcd.setCursor(0, 1);
      lcd.print("Pump OFF ");
      digitalWrite(RELAY_PIN, LOW);
      delay(DELAY_TIME);
    }
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Manual ");
    
    if (digitalRead(MANUAL_SWITCH_PIN) == HIGH) {
      lcd.setCursor(0, 1);
      lcd.print("Pump ON  ");
      digitalWrite(RELAY_PIN, HIGH);
    } else {
      lcd.setCursor(0, 1);
      lcd.print("Pump OFF ");
      digitalWrite(RELAY_PIN, LOW);
    }
  }

  lcd.setCursor(8, 0);
  lcd.print("Lvl: " + String(waterLevel) + "%");
}

int getDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  long duration = pulseIn(ECHO_PIN, HIGH);
  int distance = (duration * 0.0343) / 2;
  
  return distance;
}