#include <Stepper.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

// LCD configuration
#define LCD_ADDRESS 0x27          // I2C address of the LCD
#define LCD_COLUMNS 20            // Number of columns of the LCD
#define LCD_ROWS 4                // Number of rows of the LCD

// Keypad configuration
const byte ROWS = 4;              // Number of rows on the keypad
const byte COLS = 4;              // Number of columns on the keypad

// Characters on the buttons of the keypad
char hexaKeys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

// Pin configuration for keypad rows and columns
byte rowPins[ROWS] = {2, 3, 4, 5};    // Connect to the row pinouts of the keypad
byte colPins[COLS] = {6, 7, 8, 9};    // Connect to the column pinouts of the keypad

// Create the Keypad
Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);

// Stepper motor configuration
const int stepPin = 12;           // Pin for controlling steps
const int dirPin = 13;            // Pin for controlling direction
const int stepsPerMilliliter = 100; // Hypothetical steps required to pump 1 mL

// Global variables
#define LENGTH 3                  // Length of the dose input array
char dose[LENGTH];                // Array to store the dose input
int data_count = 0;               // Counter for dose input
char customKey;                   // Variable to store the key pressed
int num = 0;                      // Variable to store the dose amount
int totalPumped = 0;              // Variable to track total volume pumped
String currentDisplay = "";       // Variable to store the current display content

// Create the LCD
LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);

// Timing variables for non-blocking delays
unsigned long previousMillis = 0;
const long interval = 500;        // Interval for delay

void setup() {
  pinMode(stepPin, OUTPUT);       // Set the step pin as output
  pinMode(dirPin, OUTPUT);        // Set the direction pin as output
  Serial.begin(9600);             // Initialize serial communication
  
  lcd.begin(LCD_COLUMNS, LCD_ROWS);  // Initialize the LCD with the given columns and rows
  lcd.setCursor(0, 1);               // Set cursor position on the LCD
  lcd.print("Group B");              // Display "Group B" on the LCD
  delay(2000);                       // Wait for 2 seconds
  lcd.clear();                       // Clear the LCD
  lcd.print("Starting");             // Display "Starting" on the LCD
  for (int i = 0; i < 8; i++) {      // Loop to display dots
    delay(500);                      // Wait for 500 milliseconds
    lcd.print(".");                  // Display a dot
  }
  lcd.clear();                       // Clear the LCD
  lcd.setCursor(0, 0);               // Set cursor position
  lcd.print("do(ml)");               // Display "do(ml)" on the LCD
  lcd.setCursor(0, 1);               // Set cursor position
}

void loop() {
  customKey = customKeypad.getKey();  // Get the key pressed on the keypad
  if (customKey) {                    // If a key is pressed
    dose[data_count] = customKey;     // Store the key in the dose array
    lcd.print(dose[data_count]);      // Display the key on the LCD
    Serial.println(dose[data_count]); // Print the key to the serial monitor
    Serial.println(data_count);       // Print the current data count to the serial monitor
    data_count++;                     // Increment the data count
  }

  if (data_count == LENGTH - 1) {     // If the expected length of input is reached
    data_count = 0;                   // Reset the data count
    delay(1000);                      // Wait for 1 second
    updateLCD("dose is ");            // Update the LCD with "dose is"
    num = (dose[1] - '0') + ((dose[0] - '0') * 10);  // Convert the dose input to an integer
    updateLCD(String(num) + "mm");    // Update the LCD with the dose amount in mm
    delay(4000);                      // Wait for 4 seconds

    totalPumped += num;               // Add the dose to the total pumped volume
    if (totalPumped > 50) {           // If total pumped volume exceeds 50 mL
      totalPumped = 50;               // Limit the total pumped volume to 50 mL
    }

    // Stepper motor operation using function
    operateStepperMotor(num, LOW);    // Pump the volume

    if (totalPumped == 50) {          // If the total pumped volume reaches 50 mL
      delay(5000);                    // Wait for 5 seconds
      operateStepperMotor(totalPumped, HIGH); // Retract the motor
      totalPumped = 0;                // Reset the total pumped volume
    }

    lcd.clear();                      // Clear the LCD
    lcd.begin(LCD_COLUMNS, LCD_ROWS); // Re-initialize the LCD
    lcd.print("Starting");            // Display "Starting" on the LCD
    for (int i = 0; i < 8; i++) {     // Loop to display dots
      delay(500);                     // Wait for 500 milliseconds
      lcd.print(".");                 // Display a dot
    }
    lcd.clear();                      // Clear the LCD
    lcd.setCursor(0, 0);              // Set cursor position
    lcd.print("do(ml)");              // Display "do(ml)" on the LCD
    lcd.setCursor(0, 1);              // Set cursor position
  }
}

void operateStepperMotor(int steps, int direction) {
  digitalWrite(dirPin, direction);     // Set the direction of the motor
  for (int x = 0; x < steps * stepsPerMilliliter; x++) { // Loop to create the required number of steps
    digitalWrite(stepPin, HIGH);       // Set the step pin high
    delayMicroseconds(2000);           // Wait for 2 milliseconds
    digitalWrite(stepPin, LOW);        // Set the step pin low
    delayMicroseconds(2000);           // Wait for 2 milliseconds
  }
}

void updateLCD(String message) {
  if (message != currentDisplay) {     // If the message is different from the current display
    lcd.clear();                       // Clear the LCD
    lcd.print(message);                // Print the new message
    currentDisplay = message;          // Update the current display variable
  }
}