#include <LiquidCrystal_I2C.h> // Library for LCD I2C
#include <RotaryEncoder.h>   // Library for rotary encoder
// LCD configuration (address: 0x27, columns: 16, rows: 4)
LiquidCrystal_I2C lcd(0x27, 16, 4);
// Rotary encoder pin configuration
#define CLK_PIN 2
#define DT_PIN 3
#define SW_PIN 4
// Initialize rotary encoder
RotaryEncoder encoder(CLK_PIN, DT_PIN);
// Menu variables
int menuLevel = 0; // Current menu level
int menuIndex = 0; // Selected menu item
int lastPosition = -1; // Previous encoder position
int studentCount = 220; // Default student count
bool editingStudents = false; // Editing student count mode
// Main menu
const char *mainMenu[] = {"Univ Batna 1", "Univ Batna 2"};
const int mainMenuSize = 2;
// Faculties for each university
const char *univBatna1Faculties[] = {"Lettres & Philo", "Economie"};
const int univBatna1FacultiesSize = 2;
const char *univBatna2Faculties[] = {"Biologie", "Sciences & Technology", "Informatique"};
const int univBatna2FacultiesSize = 3;
// Departments for each university
const char *univBatna1Departments[] = {"Dept: Lettres", "Dept: Economie"};
const int univBatna1DepartmentsSize = 2;
const char *univBatna2Departments[] = {"Dept: Biologie", "Dept: Informatique", "Dept: elt", "Dept: Eln"};
const int univBatna2DepartmentsSize = 4;
// Specialties for departments
const char *univBatna1LettresSpecialties[] = {"Spec: Lettres", "Spec: Linguistique", "Spec: Philosophie"};
const char *univBatna1EconomieSpecialties[] = {"Spec: Economie", "Spec: Gestion"};
const char *univBatna2BiologieSpecialties[] = {"Spec: Biotech", "Spec: Environnement", "Spec: Biochimie"};
const char *univBatna2InformatiqueSpecialties[] = {"Spec: Réseaux", "Spec: IA", "Spec: Développement"};
const char *univBatna2ElectroniqueSpecialties[] = {"Spec: Microeln", "Spec: Systèmes Emb", "Spec: Automatique"};
const char *univBatna2MecaSpecialties[] = {"Spec: Mécanique", "Spec: Mécatronique", "Spec: Aéronautique"};
// Current menu tracking
int currentMenuSize = mainMenuSize;
const char **currentMenu = mainMenu;
void setup() {
  // Pin configuration
  pinMode(SW_PIN, INPUT_PULLUP);
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();  // Initialize menu variables
  menuIndex = 0;
  currentMenu = mainMenu;
  currentMenuSize = mainMenuSize;
  // Display initial menu
  updateScreen();
}
void loop() {
  encoder.tick();
  int newPosition = encoder.getPosition();
  if (editingStudents) {
    // Adjust the student count while in editing mode
    if (newPosition != lastPosition) {
      if (newPosition > lastPosition) {
        studentCount++;
      } else {
        studentCount--;
      }
      studentCount = max(studentCount, 0); // Ensure student count doesn't go below 0
      lastPosition = newPosition;
      updateScreen();
    }
  } else {
    // Detect rotary encoder movement in menu mode
    if (newPosition != lastPosition) {
      if (newPosition > lastPosition) {
        menuIndex++;
      } else {
        menuIndex--;
      }
      lastPosition = newPosition;
      menuIndex = constrain(menuIndex, 0, currentMenuSize - 1);
      updateScreen();
    }
  }
  // Detect button press
  if (digitalRead(SW_PIN) == LOW) {
    handleButtonPress();
    delay(300); // Debounce delay
  }
}
// Update LCD screen based on the current menu
void updateScreen() {
  lcd.clear();
  lcd.setCursor(0, 0);
  if (editingStudents) {
    // Display student count editing screen
    lcd.print("Editer Nb:");
    lcd.setCursor(0, 1);
    lcd.print(studentCount);
  } else {
    // Display menu items
    for (int i = 0; i < currentMenuSize && i < 4; i++) {
      lcd.setCursor(0, i);
      if (i == menuIndex) {
        lcd.print("> ");
      } else {
        lcd.print("  ");
      }
      lcd.print(currentMenu[i]);
    }
  }
}
// Handle button press on the rotary encoder
void handleButtonPress() {
  if (editingStudents) {
    // Save the changes and exit editing mode
    editingStudents = false;
    menuLevel = 0; // Reset menu level to the main menu
    currentMenu = mainMenu; // Reset to main menu
    currentMenuSize = mainMenuSize;
    menuIndex = 0; // Reset menu index
  } else {
    switch (menuLevel) {
      case 0: // Main menu
        if (menuIndex == 0) {
          currentMenu = univBatna1Faculties;
          currentMenuSize = univBatna1FacultiesSize;
        } else if (menuIndex == 1) {
          currentMenu = univBatna2Faculties;
          currentMenuSize = univBatna2FacultiesSize;
        }
        menuLevel++;
        menuIndex = 0;
        break;
      case 1: // Faculties
        if (currentMenu == univBatna1Faculties) {
          currentMenu = univBatna1Departments;
          currentMenuSize = univBatna1DepartmentsSize;
        } else if (currentMenu == univBatna2Faculties) {
          currentMenu = univBatna2Departments;
          currentMenuSize = univBatna2DepartmentsSize;
        }
        menuLevel++;
        menuIndex = 0;
        break;
      case 2: // Departments
        if (currentMenu == univBatna1Departments) {
          if (menuIndex == 0) {
            currentMenu = univBatna1LettresSpecialties;
            currentMenuSize = 3;
          } else if (menuIndex == 1) {
            currentMenu = univBatna1EconomieSpecialties;
            currentMenuSize = 2;
          }
        } else if (currentMenu == univBatna2Departments) {
          if (menuIndex == 0) {
            currentMenu = univBatna2BiologieSpecialties;
            currentMenuSize = 3;
          } else if (menuIndex == 1) {
            currentMenu = univBatna2InformatiqueSpecialties;
            currentMenuSize = 3;
          } else if (menuIndex == 2) {
            currentMenu = univBatna2MecaSpecialties;
            currentMenuSize = 3;
          } else if (menuIndex == 3) {
            currentMenu = univBatna2ElectroniqueSpecialties;
            currentMenuSize = 3;
          }
        }
        menuLevel++;
        menuIndex = 0;
        break;
      case 3: // Specialties
        editingStudents = true; // Enter student count editing mode
        break;
    }
  }
  updateScreen();
}