#include <Keypad.h>
#include <LiquidCrystal.h>

// Keypad configuration
const byte ROWS = 4; // four rows
const byte COLS = 4; // four columns

char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {9, 8, 7, 6}; // connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // connect to the column pinouts of the keypad

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

// LCD configuration
LiquidCrystal lcd(A2, A1,13, 12, 11, 10);

char msg1[] = "    WELCOME  ";                            //msg1
char msg2[] = "Select Wavelength(nm) A-254,B-302,C-365";  //msg2
char msg3[] = "Exposure Duration(Sec.):";               //msg3
char msg4[] = "Thank you";                               //msg4

String input = "";  // to store the decimal number
String input1 = ""; // to store the input from the keypad

void showLetters(const char *message, int startPos) {
  lcd.setCursor(0, 0);
  for (int i = startPos; i < startPos + 16 && message[i] != '\0'; i++) {
    lcd.print(message[i]);
  }
  delay(250);
}

char getRelaySelection() {
  char input = '\0'; // to store the input from the keypad
 // lcd.clear();
 lcd.setCursor(0, 1); // move the cursor to the second row
 lcd.print("Select Wav.:");
 lcd.setCursor( 13,1); // move the cursor to the second row
  
  while (true) {
    char key = keypad.getKey();
    if (key) {
      if (key == 'D') {
        // Enter key pressed
       // lcd.clear();
        lcd.setCursor(0,1);
        lcd.print("Selected Wav:");
       // lcd.setCursor(0, 1);
        //lcd.print("Wav. ");
       lcd.setCursor(13,1);
        lcd.print(input);
        delay(2000); // wait for 2 seconds to show the selected relay
        return input; // return the selected relay value
      } 
      else if (key == '#') {
        // Backspace key pressed
        if (input != '\0') {
          input = '\0'; // clear the input
         // lcd.clear();
         //deleteCharAt(13,1);
         lcd.setCursor(13,1);
        // Print a space to "delete" the character
         lcd.print(" ");
          lcd.setCursor(0,1); // move the cursor to the second row
          lcd.print("Select Wav.:");
         lcd.setCursor(13,1); // move the cursor to the second row
        }
      } 
      else if (key == 'A' || key == 'B' || key == 'C') {
        // Option key pressed
        input = key;
        lcd.setCursor(13,1);
        lcd.print(input);
      }
    }
  }
}

String getInputFromKeypad() {
  input = ""; // Reset the input string
  while (true) {
    char key = keypad.getKey();
    if (key) {
      if ((key >= '0' && key <= '9') || key == '*') { // If the key is a number or decimal point
        input += (key == '*' ? '.' : key); // Replace '*' with '.' for decimal point
        lcd.setCursor(0, 1); // Move the cursor to the second row
        lcd.print(input); // Display the input
      } else if (key == '#') { // If the key is backspace
        if (input.length() > 0) {
          input.remove(input.length() - 1); // Remove the last character
          lcd.setCursor(0, 1);
          lcd.print("                "); // Clear the second row
          lcd.setCursor(0, 1);
          lcd.print(input); // Display the updated input
        }
      } else if (key == 'D') { // If the key is enter
        return input; // Return the input string
      }
    }
  }
}

void controlRelay(char selection) {
  // Turn off all relays initially
  digitalWrite(A3, LOW);
  digitalWrite(A4, LOW);
  digitalWrite(A5, LOW);

  // Turn on the selected relay
  switch (selection) {
    case 'A':
      digitalWrite(A3, HIGH);
      //delay(2000); // keep the relay on for 2 seconds
     // digitalWrite(A1, LOW);
      break;
    case 'B':
      digitalWrite(A4, HIGH);
     // delay(2000); // keep the relay on for 2 seconds
     // digitalWrite(A2, LOW);
      break;
    case 'C':
      digitalWrite(A5, HIGH);
     // delay(2000); // keep the relay on for 2 seconds
     // digitalWrite(A3, LOW);
      break;
    default:
      // Do nothing if the selection is invalid
      break;
  }
}

void setup() {
  
  // Initialize serial communication
  Serial.begin(9600);
  // Initialize the LCD
  lcd.begin(16, 2);
  
  pinMode(A3, OUTPUT);
  pinMode(A4, OUTPUT);   // Initialize relay pins
  pinMode(A5, OUTPUT);

}

void loop() {

Serial.println("WELCOME");
  lcd.clear();
  lcd.setCursor(0, 0);  // PRINT WELCOME 
  lcd.print(msg1);
  delay(500);

  char key_enter = keypad.getKey(); // Get the key pressed from the keypad
  if (key_enter == 'D') {
    lcd.clear();  // Clear the LCD screen
   lcd.print("Hello, User");  // Print message to the LCD
    delay(2000);

  Serial.println("Select Wavelength(nm) A-254,B-302,C-365 ");
  lcd.clear();
  lcd.setCursor(0, 0);

  for (int i = 0; i <= strlen(msg2) - 16; i++) {
   showLetters(msg2, i);   // Display for selecting the relay
  }

 char selectedRelay = getRelaySelection(); // Get the relay selection from the keypad
  Serial.print("Selected Wav.:");
  Serial.println(selectedRelay);
  lcd.clear();
  lcd.setCursor(0, 0);
  for (int i = 0; i <= strlen(msg3) - 16; i++) {
   showLetters(msg3, i);   // Display for selecting the relay
  }
  delay(500);
  
  Serial.println("Exposure Duration(Sec.):");

  String number = getInputFromKeypad(); // Get the input from the keypad
  delay(500);
  lcd.setCursor(0, 1);
  lcd.print(number); // Display the final number
  lcd.print(" Seconds.");
  Serial.print(number);
  Serial.println(" Seconds.");
  delay(1000); // Wait for 2 seconds
 
  float delay_dur = number.toFloat();

  
controlRelay(selectedRelay); // Control the relay based on the selected value

   lcd.clear();
   lcd.setCursor(0,0);
   lcd.print(" Wavelength ");
   lcd.print(selectedRelay);
   lcd.setCursor(0,1);
   lcd.print("Exp.for ");
   lcd.print(number);
   lcd.print("Sec.");
  delay(delay_dur * 1000);
  digitalWrite(A5, LOW);  
  digitalWrite(A4, LOW);     // Turn off all relays initially
  digitalWrite(A3, LOW);

  Serial.println(msg4);
  lcd.clear();
  lcd.setCursor(2, 0);
  lcd.print(msg4);
  delay(1500);
}
}