#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

// constants ---------------------------------------------------
const int LED_PIN_1 = 9;  // 500 mL  LED
const int LED_PIN_2 = 8;  // 750 mL  LED
const int LED_PIN_3 = 7;  // 1000 mL LED
const int LED_PIN_4 = 6;  // Alarm   LED

const int Button_PIN_1 = 5;   // 500 mL  Button
const int Button_PIN_2 = 4;   // 750 mL  Button
const int Button_PIN_3 = 3;   // 1000 mL Button
const int Button_PIN_4 = 2;   // Alarm   Button
const int Button_PIN_5 = 11;  // ON/OFF  Button

const int Buzzer_PIN = A2;  // Buzzer  Button

const int Sensor_PIN = 10;  // Sensor  Button


// variables ---------------------------------------------------
int Sensor_State = LOW;  // inital No motion state
int Level = 0;           // Pin Status

int ledState_1 = LOW;  // current state of LEDs
int ledState_2 = LOW;
int ledState_3 = LOW;
int ledState_4 = HIGH;

int lastButtonState_1;  // previous state of buttons
int lastButtonState_2;
int lastButtonState_3;
int lastButtonState_4;
int lastButtonState_5;

int currentButtonState_1;  // current state of buttons
int currentButtonState_2;
int currentButtonState_3;
int currentButtonState_4;
int currentButtonState_5;


// SETUP --------------------------------------------------------
void setup() {
  Serial.begin(9600);

  pinMode(LED_PIN_1, OUTPUT);  // set arduino pin to output mode
  pinMode(LED_PIN_2, OUTPUT);
  pinMode(LED_PIN_3, OUTPUT);
  pinMode(LED_PIN_4, OUTPUT);

  pinMode(Button_PIN_1, INPUT_PULLUP);  // set arduino pin to input pull-up mode
  pinMode(Button_PIN_2, INPUT_PULLUP);
  pinMode(Button_PIN_3, INPUT_PULLUP);
  pinMode(Button_PIN_4, INPUT_PULLUP);
  pinMode(Button_PIN_5, INPUT_PULLUP);

  pinMode(Sensor_PIN, INPUT);

  pinMode(Buzzer_PIN, OUTPUT);

 lcd.init();
 lcd.backlight();
 lcd.clear();
 lcd.setCursor(1, 0);
 lcd.print("Device ON");
 lcd.setCursor(0, 1);
 lcd.print("Select Bag Size");
  
}


// MAIN ---------------------------------------------------------
void loop() {

  lastButtonState_1 = currentButtonState_1;  // save the last state
  lastButtonState_2 = currentButtonState_2;
  lastButtonState_3 = currentButtonState_3;
  lastButtonState_4 = currentButtonState_4;
  lastButtonState_5 = currentButtonState_5;

  currentButtonState_1 = digitalRead(Button_PIN_1);  // read new state
  currentButtonState_2 = digitalRead(Button_PIN_2);
  currentButtonState_3 = digitalRead(Button_PIN_3);
  currentButtonState_4 = digitalRead(Button_PIN_4);
  currentButtonState_5 = digitalRead(Button_PIN_5);

  Level = digitalRead(Sensor_PIN);  // read Sensor input


  //-----------------------------------------------------------------Alarm Button Code


  if (Level == HIGH) {

    if (Sensor_State == LOW) {  // Sensor activated
      digitalWrite(LED_PIN_4, HIGH);  // turn LED ON
      tone(Buzzer_PIN, 600);
      Sensor_State = HIGH;

      Serial.println("DRIP LEVEL LOW... ALARM!");
      lcd.setCursor(1, 0);
      lcd.print("---LEVEL LOW");
    }

    if (lastButtonState_4 == HIGH && currentButtonState_4 == LOW) {
      ledState_4 = !ledState_4;
      digitalWrite(LED_PIN_4, ledState_4);
      noTone(Buzzer_PIN);
      ledState_4 = !ledState_4;

      Serial.println("ALARM deactivated");
      lcd.setCursor(1, 0);
      lcd.print("---Alarm OFF");
    }

  }


  else {

    digitalWrite(LED_PIN_4, LOW);  // turn LED OFF

    if (Sensor_State == HIGH) {  // Sensor deactivated
      Serial.println("LEVEL Corrected");
      noTone(Buzzer_PIN);
      Sensor_State = LOW;
    }
  }


  //------------------------------------------------------------------Bag Size Code


  if (lastButtonState_1 == HIGH && currentButtonState_1 == LOW) {
    ledState_1 = !ledState_1;
    digitalWrite(LED_PIN_2, LOW);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_1, ledState_1);
    ledState_1 = !ledState_1;
    
    Serial.println("500 mL");
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("Bag: 500 mL");
    lcd.setCursor(0, 1);
    lcd.print("Empty in: 8 mins");
  }

  else if (lastButtonState_2 == HIGH && currentButtonState_2 == LOW) {
    ledState_2 = !ledState_2;
    digitalWrite(LED_PIN_1, LOW);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_2, ledState_2);
    ledState_2 = !ledState_2;
   
    Serial.println("750 mL");
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("Bag: 750 mL");
    lcd.setCursor(0, 1);
    lcd.print("Empty in: 10 mins");
  }

  else if (lastButtonState_3 == HIGH && currentButtonState_3 == LOW) {
    ledState_3 = !ledState_3;
    digitalWrite(LED_PIN_1, LOW);
    digitalWrite(LED_PIN_2, LOW);
    digitalWrite(LED_PIN_3, ledState_3);
    ledState_3 = !ledState_3;

    Serial.println("1000 mL");
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("Bag: 1000 mL");
    lcd.setCursor(0, 1);
    lcd.print("Empty in: 12 mins");
  }


  //--------------------------------------------------------------------ON/OFF Code


  if (lastButtonState_5 == HIGH && currentButtonState_5 == LOW) {  // OFF State
    digitalWrite(LED_PIN_1, LOW);
    digitalWrite(LED_PIN_2, LOW);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_4, LOW);
    noTone(Buzzer_PIN);
    
    Serial.println("Systems OFF");
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("Device: OFF");
    lcd.setCursor(0, 1);
    lcd.print("----------------");
  }
}