#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address and dimensions of the LCD

// Define menu states
enum MenuState {
  MAIN_MENU,
  SUBMENU_1,
  SUBMENU_2,
  SUBMENU_3,
  FLOAT_VARIABLES,
  LONG_CONSTANTS,
  ULONG_VARIABLES,
  INT_CONSTANTS
};

// Define button pins
const int LEFT_BUTTON_PIN = 2;
const int RIGHT_BUTTON_PIN = 3;
const int UP_BUTTON_PIN = 4;
const int DOWN_BUTTON_PIN = 5;

// Define variables
float SourceLowV = 10.70;
float SourceOverV = 14.30;
float BatLowV = 10.70;
float BatOverV = 14.30;
long Long1 = 1234567890;
long Long2 = -987654321;
unsigned long ulongVar1 = 4294967295; // Maximum value of unsigned long
unsigned long ulongVar2 = 987654321;
const int constInt1 = 100;
const int constInt2 = -50;

// Define initial menu state
MenuState currentMenu = MAIN_MENU;
// Function prototypes
void displayMenu();
void displaySubmenu1();
void displaySubmenu2();
void displaySubmenu3();
void updateMenu();

void setup() {
  lcd.init();                 // initialize the lcd 
  lcd.backlight();
  Serial.begin(9600);
  pinMode(LEFT_BUTTON_PIN,INPUT_PULLUP);
  pinMode(RIGHT_BUTTON_PIN,INPUT_PULLUP);
  pinMode(UP_BUTTON_PIN,INPUT_PULLUP);
  pinMode(DOWN_BUTTON_PIN,INPUT_PULLUP);
  // Print initial message on LCD
  lcd.print("Charger Control");
  lcd.setCursor(0, 1);
  lcd.print("V.1.0.");
  delay(3000);
}

void loop() {
  // Display current menu
  displayMenu();

  // Handle button press
  int buttonPressed = checkButtons();
  
  // Change menu or adjust variables based on button press
  switch (buttonPressed) {
    case 1:
     navigateMenu(-1); // Button 1 (left or previous)
    break;
    case 2:
      navigateMenu(1); // Button 2 (right or next)
      break;
    case 3:
      adjustVariable(1); // Button 3 (up or increase)
      break;
    case 4:
      adjustVariable(-1); // Button 4 (down or decrease)
      break;
    case 5:
      // Additional functionality for button 5 (select) if needed
      break;
    default:
      break;
  }

}

// Function to navigate through menu based on button press
void navigateMenu(int button) {
  switch (currentMenu) {
    case MAIN_MENU:
      if (button == 1) {
        currentMenu = FLOAT_VARIABLES; // Change to float menu
      Serial.println("Left button pressed");
      } 
      else if (button == 2) {
        currentMenu = LONG_CONSTANTS; // Change to long menu
      Serial.println("RIGHT button pressed");
      } else if (button == 3) {
        currentMenu = ULONG_VARIABLES; // Change to unsigned long menu
      Serial.println("UP button pressed");
      } else if (button == 4) {
        currentMenu = INT_CONSTANTS; // Change to int menu
      Serial.println("DOWN button pressed");
      }
      break;
    case FLOAT_VARIABLES:
    case LONG_CONSTANTS:
    case ULONG_VARIABLES:
    case INT_CONSTANTS:
      if (button == 5) {
        currentMenu = MAIN_MENU; // Return to main menu
      }
      break;
  }
}

// Function to adjust variable values based on button press
void adjustVariable(int button) {
  switch (currentMenu) {
    case FLOAT_VARIABLES:
      if (button == 1) {
        //Serial.println("Left button pressed");
        SourceLowV += 0.1; // Increase float variable by 0.1
      }else if (button == 2) {
        // Serial.println("Right button pressed");
        SourceLowV -= 0.1; // Decrease float variable by 0.1
      }else if (button == 3) {
        // Serial.println("Up button pressed");
        SourceOverV += 0.1; // Increase float variable by 0.1
      }else if (button == 4) {
        // Serial.println("Down button pressed");
        SourceOverV -= 0.1; // Decrease float variable by 0.1
      }
      break;
    case LONG_CONSTANTS:
      if (button == 1) {
        Long1 += 1; // Increase const long variable by 100
      } else if (button == 2) {
        Long1 -= 1; // Decrease const long variable by 100
      } else if (button == 3) {
        Long2 += 1; // Increase const long variable by 100
      } else if (button == 4) {
        Long2 -= 1; // Decrease const long variable by 100
      }
      break;
    // Add cases for ULONG_MENU, INT_MENU similarly
  }
}

// Function to display current menu and variable values on LCD
void displayMenu() {
  //lcd.clear();
  switch (currentMenu) {
    case MAIN_MENU:
      lcd.setCursor(0, 0);
      lcd.print("Main Menu      ");
      // Display options for other menus if needed
      break;
    case FLOAT_VARIABLES:
      lcd.setCursor(0, 0);
      lcd.print("SourceLowV:");
      lcd.setCursor(11, 0);
      lcd.print(SourceLowV);
      lcd.setCursor(0, 1);
      lcd.print("SourceOveV:");
      lcd.setCursor(11, 1);
      lcd.print(SourceOverV);
      break;
      case LONG_CONSTANTS:
      lcd.setCursor(0, 0);
      lcd.print("ConstLong1: ");
      lcd.print(Long1);
      lcd.setCursor(0, 1);
      lcd.print("ConstLong2: ");
      lcd.print(Long2);
      break;
    // Add cases for other menu states similarly
  }
}

void displaySubmenu1() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Submenu 1");
  // Add additional submenu 1 options if needed
}

void displaySubmenu2() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Submenu 2");
  // Add additional submenu 2 options if needed
}

void displaySubmenu3() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Submenu 3");
  // Add additional submenu 3 options if needed
}

void updateMenu(int button) {
  switch (currentMenu) {
    case MAIN_MENU:
      displayMenu();
      // Check for button press to navigate to submenu
      if (button == 1) {
        currentMenu = SUBMENU_1;
      } else if (button == 2) {
        currentMenu = SUBMENU_2;
      } else if (button == 3) {
        currentMenu = SUBMENU_3;
      }
      break;
    case SUBMENU_1:
      displaySubmenu1();
      // Add logic to navigate back to main menu or perform actions
      break;
    case SUBMENU_2:
      displaySubmenu2();
      // Add logic to navigate back to main menu or perform actions
      break;
    case SUBMENU_3:
      displaySubmenu3();
      // Add logic to navigate back to main menu or perform actions
      break;
  }
}

// Function to check which button is pressed
int checkButtons() {
  // Check which button is pressed and return the pin number of the pressed button
  if (digitalRead(LEFT_BUTTON_PIN) == LOW) {
    delay(50); // Debounce
    
    return LEFT_BUTTON_PIN;
  } else if (digitalRead(RIGHT_BUTTON_PIN) == LOW) {
    delay(50); // Debounce
    
    return RIGHT_BUTTON_PIN;
  } else if (digitalRead(UP_BUTTON_PIN) == LOW) {
    delay(50); // Debounce
    
    return UP_BUTTON_PIN;
  } else if (digitalRead(DOWN_BUTTON_PIN) == LOW) {
    delay(50); // Debounce
    
    return DOWN_BUTTON_PIN;
  }
  return 0;
}