// File: menu_with_buttons.ino

#include "U8g2lib.h"

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0);

// 'item_sel_outline', 128x21px
const unsigned char bitmap_item_sel_outline [] PROGMEM = {
  0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
  0xFF, 0xFF, 0xFF, 0x03, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x02, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 
  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x0C, 0xFC, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0xF8, 0xFF, 0xFF, 0xFF, 
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x03, 
  };


// Button pins
#define BUTTON_UP_PIN 12
#define BUTTON_DOWN_PIN 4
#define BUTTON_OK_PIN 8

// Button state variables
unsigned long lastDebounceTimeUp = 0;
unsigned long lastDebounceTimeDown = 0;
unsigned long lastDebounceTimeOk = 0;
unsigned long debounceDelay = 50; // 50 ms debounce delay
unsigned long okPressStartTime = 0; // Track OK button long press
bool okLongPressActive = false;

// Menu variables
const int MENU_ITEM_HEIGHT = 16-1;
const int SCREEN_WIDTH = 128;
const int SCREEN_HEIGHT = 64;

int currentMenu = 0;          // Track the current menu
int totalMenus = 5;          // Track max menus
int previousMenu = -1;        // Track the last menu for return
int selectedItem = 0;         // Currently selected menu item

// Menus
const char* mainMenu[] = {"Calib. pH", "Seteo Temp", "Seteo Rango", "Info"};
const int mainMenuItems = sizeof(mainMenu) / sizeof(mainMenu[0]);

const char* subMenu1[] = {"Calib. 4", "Calib. 7", "Calib. 10", "Borrar Calib.", "Valores Calib."};
const int subMenu1Items = sizeof(subMenu1) / sizeof(subMenu1[0]);

const char* subMenu2[] = {"Resolucion 10b", "Offset +0.0 C", "Temp: 25.0 C"};
const int subMenu2Items = sizeof(subMenu2) / sizeof(subMenu2[0]);

const char* subMenu3[] = {"Minimo 6.5", "Maximo 7.5"};
const int subMenu3Items = sizeof(subMenu3) / sizeof(subMenu3[0]);

const char* subMenu4[] = {"Revision 1.0", "IP 192.168.101.79"};
const int subMenu4Items = sizeof(subMenu4) / sizeof(subMenu4[0]);

/**
 * Function to render a menu dynamically
 */
void renderMenu(const char* menuItems[], int numItems, int selectedItem) {
  int previousItem = (selectedItem - 1 + numItems) % numItems;
  int nextItem = (selectedItem + 1) % numItems;

  u8g2.clearBuffer();

  // Draw the selected item background
  u8g2.setDrawColor(1);
  //u8g2.drawBox(0, MENU_ITEM_HEIGHT, SCREEN_WIDTH, MENU_ITEM_HEIGHT);

	// selected item background
  u8g2.drawXBMP(0, 22, 128, 21, bitmap_item_sel_outline);

  // Draw the previous item
  //u8g2.setDrawColor(1);
  u8g2.setFont(u8g2_font_7x14_tf);
  u8g2.drawStr(25, MENU_ITEM_HEIGHT, menuItems[previousItem]);

  // Draw the selected item
  //u8g2.setDrawColor(0);
  u8g2.drawStr(25, MENU_ITEM_HEIGHT + 22, menuItems[selectedItem]);

  // Draw the next item
  //u8g2.setDrawColor(1);
  u8g2.drawStr(25, MENU_ITEM_HEIGHT + 44, menuItems[nextItem]);

  // Scrollbar
  int scrollbarHeight = SCREEN_HEIGHT / numItems;
  int scrollbarPosition = scrollbarHeight * selectedItem;
  u8g2.drawBox(SCREEN_WIDTH - 5, scrollbarPosition, 3, scrollbarHeight);

  u8g2.sendBuffer();
}

/**
 * Function to handle button presses
 */
void handleButtonPress(const char* menuItems[], int numItems) {
  // Handle UP button
  if (digitalRead(BUTTON_UP_PIN) == LOW && (millis() - lastDebounceTimeUp) > debounceDelay) {
    lastDebounceTimeUp = millis();
    selectedItem = (selectedItem - 1 + numItems) % numItems;
  }

  // Handle DOWN button
  if (digitalRead(BUTTON_DOWN_PIN) == LOW && (millis() - lastDebounceTimeDown) > debounceDelay) {
    lastDebounceTimeDown = millis();
    selectedItem = (selectedItem + 1) % numItems;
  }

  // Handle OK button (short press)
  if (digitalRead(BUTTON_OK_PIN) == LOW && !okLongPressActive) {
    if (okPressStartTime == 0) {
      okPressStartTime = millis();
    } else if (millis() - okPressStartTime > 3000) {
      okLongPressActive = true;
      if (previousMenu != -1) {
        currentMenu = previousMenu; // Return to the previous menu
        selectedItem = 0;          // Reset selection
        okPressStartTime = 0;      // Reset timer
      }
    }
  } else if (digitalRead(BUTTON_OK_PIN) == HIGH) {
    if (!okLongPressActive && okPressStartTime > 0) {
      // Handle short press
      previousMenu = currentMenu;
      if (currentMenu == 0) {
        currentMenu = 1; // Navigate to submenu
        selectedItem = 0;
      } else {
        currentMenu = 0; // Return to main menu
        selectedItem = 0;
      }
    }
    okPressStartTime = 0;
    okLongPressActive = false;
  }
}

void setup() {
  u8g2.begin();

  pinMode(BUTTON_UP_PIN, INPUT_PULLUP);
  pinMode(BUTTON_DOWN_PIN, INPUT_PULLUP);
  pinMode(BUTTON_OK_PIN, INPUT_PULLUP);
}

void loop() {
  // Determine the active menu
  if (currentMenu == 0) {
    handleButtonPress(mainMenu, mainMenuItems);
    renderMenu(mainMenu, mainMenuItems, selectedItem);
  } else if (currentMenu == 1) {
    handleButtonPress(subMenu1, subMenu1Items);
    renderMenu(subMenu1, subMenu1Items, selectedItem);
  } else if (currentMenu == 2) {
		handleButtonPress(subMenu2, subMenu2Items);
    renderMenu(subMenu2, subMenu2Items, selectedItem);
	} else if (currentMenu == 3) {
		handleButtonPress(subMenu3, subMenu3Items);
    renderMenu(subMenu3, subMenu3Items, selectedItem);
	}
}