#include <Servo.h> // Servo library
#include <HX711_ADC.h> // HX711 library
#include <LiquidCrystal_I2C.h> // LCD library
#include <Keypad.h> // Keypad library

// Define pin numbers
const int confirmButtonPin = 13; // Pin number for the confirmation button
const int taree = 12; // Pin number for the tare button
const int buzzerPin = 24; // Pin number for the buzzer
const int buttonA3 = 37; // Pin number for button A3
const int buttonA4 = 39; // Pin number for button A4
const int buttonA5 = 41; // Pin number for button A5
int valuer = 0; // Variable to track the number of decimal places for weight input

HX711_ADC LoadCell(4, 5); // Load cell initialization
LiquidCrystal_I2C lcd(0x27, 20, 4); // LCD initialization
Servo myservo1;
Servo myservo2;

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {37, 39, 41, 43}; // R1, R2, R3, R4
byte colPins[COLS] = {45, 47, 49, 51}; // C1, C2, C3, C4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

unsigned long selectContainerTimer = 0; // Timer for SELECT CONTAINER message

float count = 0; // Variable to store the weight count
bool containerSelected = false;

void selectContainer(int container);
void printWeight(float value, int row);
void beepBuzzer(int numBeeps);

void setup() {
  pinMode(confirmButtonPin, INPUT_PULLUP);
  pinMode(taree, INPUT_PULLUP);
  pinMode(buzzerPin, OUTPUT);
  pinMode(buttonA3, INPUT_PULLUP);
  pinMode(buttonA4, INPUT_PULLUP);
  pinMode(buttonA5, INPUT_PULLUP);

  myservo1.attach(9); // Attaches the servo on pin 9 to the servo object
  myservo2.attach(10); // Attaches the servo on pin 10 to the servo object

  LoadCell.begin(); // Start connection to HX711
  LoadCell.start(9000); // Load cells get 1000ms of time to stabilize
  LoadCell.setCalFactor(412); // Calibrate your load cell with a 100g weight, and change the value according to readings

  lcd.begin(20, 4); // Begins connection to the LCD module
  lcd.backlight(); // Turns on the backlight
  lcd.setCursor(18, 0); // Set cursor to first row and position it at 18th column
  lcd.print("g"); // Print "g" at the top right corner of the LCD
  lcd.setCursor(0, 2); // Set cursor to second row
  lcd.print("Enter Grams: "); 
  lcd.setCursor(18, 2);
  lcd.print(" g"); 
  lcd.setCursor(0, 3); // Set cursor to third row
  lcd.print("Confirm: "); // Print out confirmation label
  lcd.setCursor(14, 3); // Set cursor position for confirmation value
  lcd.print("0.00 g"); // Print the initial confirmation value with two decimal places and leading zero
  lcd.setCursor(0, 1); // Set cursor to the fourth row
  lcd.print("Select: "); // Print out the selection label
}

void loop() {
  char key = keypad.getKey(); // Read the keypad

  if (key != NO_KEY) {
    if (key == 'A') { // Container 1 selected
      selectContainer(1);
      lcd.print("Container 1");
    } else if (key == 'B') { // Container 2 selected
      selectContainer(2);
      lcd.print("Container 2");
    } else if (key == 'C') { // Container 3 selected
      selectContainer(3);
      lcd.print("Container 3");
    } else if (key == '#') {
      // Erase number from 1 column
      if (valuer > 0) {
        lcd.setCursor(12 + valuer - 0, 2); // Set cursor to the position of the last entered digit
        lcd.print(" "); // Clear the previous digit
        valuer--;
        count /= 10; // Remove the last digit from the count
      }
    } else if (key == '*') {
      // Insert decimal point if not already present
      if (valuer < 5 && count == (int)count) { // Check if decimal point is not already present and there are less than 6 digits
        lcd.setCursor(13 + valuer, 2); // Set cursor to the position where the decimal point will be inserted
        lcd.print("."); // Print the decimal point
        valuer++; // Increment the number of digits
      }
    } else {
      // Handle numeric input
      if (valuer < 6 && key >= '0' && key <= '9') {
        count = count * 10 + (key - '0'); // Update the count with the new digit
        valuer++;
        lcd.setCursor(12 + valuer, 2); // Set cursor to the position of the last entered digit
        lcd.print(key); // Print the entered digit
      }
    }
  }

  // Confirm button pressed
  if (digitalRead(confirmButtonPin) == LOW) {
    if (containerSelected) {
      printWeight(count, 3); // Print the count value on the screen with 2 decimal places
    } else {
      lcd.setCursor(0, 1); // Set cursor position to second row
      lcd.print("SELECT CONTAINER"); // Print out the message to select container
      selectContainerTimer = millis(); // Start the timer for SELECT CONTAINER message
      beepBuzzer(3); // Beep the buzzer 3 times
    }
  }

  // If SELECT CONTAINER message is displayed for 5 seconds, clear the message and reset containerSelected
  if (millis() - selectContainerTimer >= 5000 && !containerSelected) {
    lcd.setCursor(0, 1);
    lcd.print("Select: "); // Clear the SELECT CONTAINER message
    containerSelected = false; // Reset containerSelected flag
    lcd.setCursor(0, 3);
    lcd.print(""); // Clear the confirmation message
  }

  // Update current weight display
  lcd.setCursor(0, 0); // Set cursor to first row
  lcd.print("Current: "); // Print out to LCD with a space after colon
  LoadCell.update(); // Retrieve data from the load cell
  float currentWeight = LoadCell.getData(); // Get current weight value from the load cell
  printWeight(currentWeight, 0); // Print out the current weight with two decimal places

  // Servo control based on weight comparison
  if (currentWeight > count) {
    // Adjust servo position accordingly
    myservo1.write(90); // Example: move servo to 90 degrees
  } else {
    // Adjust servo position accordingly
    myservo1.write(0); // Example: move servo to 0 degrees
  }

  // Tare functionality
  if (currentWeight < 0) {
    lcd.setCursor(0, 3); // Set cursor to the fourth row
    lcd.print("click Taring..."); // Print out taring message
  }

  // Tare button pressed
  if (digitalRead(taree) == LOW) {
    lcd.setCursor(0, 3); // Set cursor to the fourth row
    lcd.print("Taring..."); // Print out taring message
    delay(1000); // Wait for stability
    LoadCell.start(10); // Perform tare operation
    lcd.setCursor(0, 3);
    lcd.print("Confirm "); // Clear the taring message after 1 second
  }
}

void selectContainer(int container) {
  lcd.setCursor(8, 1); // Set cursor position for container selection
  lcd.print("Container "); // Print out the
  lcd.print(container); // Print out the container number
  containerSelected = true;
  lcd.setCursor(0, 1); // Set cursor to the fourth row
  lcd.print("Select: "); // Print out the selection label
  delay(200); // Delay to prevent multiple presses on the button
}

void printWeight(float value, int row) {
  lcd.setCursor(14, row); // Set cursor position for weight value
  lcd.print(value, 2); // Print out the weight value with two decimal places
  lcd.print(" g"); // Print the unit
}

void beepBuzzer(int numBeeps) {
  for (int i = 0; i < numBeeps; i++) {
    tone(buzzerPin, 1000); // Generate a tone of 1000 Hz
    delay(100); // Wait
    noTone(buzzerPin); // Turn off the tone
    delay(100); // Wait
  }
}