#include "LiquidCrystal_I2C.h"
LiquidCrystal_I2C lcd(0x27,20,4);

//DEFINE FOR OLED
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);


#define ROOT_MENU_CNT  3
#define SUB_MENU1_CNT  4
#define SUB_MENU2_CNT  5
#define SUB_MENU3_CNT  2

// setup the emum with all the menu pages options
enum pageType {ROOT_MENU, SUB_MENU1, SUB_MENU2, SUB_MENU3};

// holds which page is currently selected
enum pageType currPage = ROOT_MENU;

// selected item pointer for the root menu
uint8_t root_Pos = 1;

// constants holding port addresses
const int BTN_ACCEPT = A0;
const int BTN_UP = A2;
const int BTN_DOWN = A1;
const int BTN_CANCEL = A3;

// =======================================================================================
// ||                                    SETUP                                          ||
// =======================================================================================
void setup() {


  // Inițializarea ecranului OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3D)) {
    display.println(F("Failed to initialize SSD1306 OLED!"));
    for (;;); // Oprire dacă inițializarea nu reușește
  }
  
  // Curățarea ecranului la pornire
  display.clearDisplay();
  display.display();





  lcd.init();
  lcd.backlight();

  // init the display port to be used as a display return
  //display.begin(115200);

  // setup the basic I/O's
  pinMode(BTN_ACCEPT, INPUT_PULLUP);
  pinMode(BTN_UP, INPUT_PULLUP);
  pinMode(BTN_DOWN, INPUT_PULLUP);
  pinMode(BTN_CANCEL, INPUT_PULLUP);
  
}


// =======================================================================================
// ||                                  MAIN LOOP                                        ||
// =======================================================================================
void loop() {
  display.setRotation(1);
  switch (currPage){
    case ROOT_MENU:     page_RootMenu(); break;
    case SUB_MENU1:     page_SubMenu1(); break;
    case SUB_MENU2:     page_SubMenu2(); break;
    case SUB_MENU3:     page_SubMenu3(); break;
  }

}

// =======================================================================================
// ||                               PAGE - ROOT MENU                                    ||
// =======================================================================================
void page_RootMenu(void) {
  
  //flag for updating the display
  boolean updateDisplay = true;
  
  // tracks when entered top of loop
  uint32_t loopStartMs;

  //tracks button states
  boolean btn_Up_WasDown = false;
  boolean btn_Down_WasDown = false;
  boolean btn_Accept_WasDown = false;
  
  display.clearDisplay();  // Curățare ecran
  display.setTextSize(1);  // Dimensiune text
  display.setTextColor(SSD1306_WHITE);  // Culoare text
  display.setCursor(0, 40);  // Poziționare cursor

  //inner loop
  while (true){

    // capture start time
    loopStartMs = millis();

    // print the display
    if (updateDisplay){
      
      // clear the update flag
      updateDisplay = false;

      //clear the display
      clearScreen();

      //menu title
      lcd.println(F("MAIN MENU"));

      //print a divider line
      //printDivider();

      // print the items
      printSelected(1, root_Pos); lcd.println(F("SUB 1"));
      printSelected(2, root_Pos); lcd.println(F("SUB 2"));
      printSelected(3, root_Pos); lcd.println(F("SUB 3"));
      printSelected(1, root_Pos); display.println(F("SUB 1"));
      printSelected(2, root_Pos); display.println(F("SUB 2"));
      printSelected(3, root_Pos); display.println(F("SUB 3"));
      //lcd.println();
      //lcd.println();
      display.display();
      delay(200);
      //print a divider line
      //printDivider();
      
    }

    // capture the button down states
    if (btnIsDown(BTN_UP)) {btn_Up_WasDown = true;}
    if (btnIsDown(BTN_DOWN)) {btn_Down_WasDown = true;}
    if (btnIsDown(BTN_ACCEPT)) {btn_Accept_WasDown = true;}

    //move the pointer down
    if (btn_Down_WasDown && btnIsUp(BTN_DOWN)){
      if (root_Pos == ROOT_MENU_CNT) {root_Pos = 1;} else {root_Pos++;}
      updateDisplay = true;
      btn_Down_WasDown = false;
    }

    //move the pointer Up
    if (btn_Up_WasDown && btnIsUp(BTN_UP)){
      if (root_Pos == 1) {root_Pos = ROOT_MENU_CNT;} else {root_Pos--;}
      updateDisplay = true;
      btn_Up_WasDown = false;
    }

    //move to the selected page
    if (btn_Accept_WasDown && btnIsUp(BTN_ACCEPT)){
      switch (root_Pos) {
        case 1: currPage = SUB_MENU1; return;
        case 2: currPage = SUB_MENU2; return;
        case 3: currPage = SUB_MENU3; return;
      }
    }
 
    // keep a specific pace
    while (millis() - loopStartMs < 25) {delay(2);}
    
  }
  
}


// =======================================================================================
// ||                               PAGE - SUB MENU1                                    ||
// =======================================================================================
void page_SubMenu1(void) {
  
  //flag for updating the display
  boolean updateDisplay = true;
  
  // tracks when entered top of loop
  uint32_t loopStartMs;

  //tracks button states
  boolean btn_Up_WasDown = false;
  boolean btn_Down_WasDown = false;
  boolean btn_Cancel_WasDown = false;
  
  // selected item pointer
  uint8_t sub_Pos = 1;

  //inner loop
  while (true){

    // capture start time
    loopStartMs = millis();

    // print the display
    if (updateDisplay){
      
      // clear the update flag
      updateDisplay = false;

      //clear the display
      clearScreen();

      //menu title
      display.print(F("SUB MENU 1\n"));

      //print a divider line
      //printDivider();

      // print the items
      printSelected(1, sub_Pos); display.print(F("1Item\n"));
      printSelected(2, sub_Pos); display.print(F("2Item\n"));
      
      //print a divider line
      //printDivider();
      
    }

    // capture the button down states
    if (btnIsDown(BTN_UP)) {btn_Up_WasDown = true;}
    if (btnIsDown(BTN_DOWN)) {btn_Down_WasDown = true;}
    if (btnIsDown(BTN_CANCEL)) {btn_Cancel_WasDown = true;}

    //move the pointer down
    if (btn_Down_WasDown && btnIsUp(BTN_DOWN)){
      if (sub_Pos == SUB_MENU1_CNT) {sub_Pos = 1;} else {sub_Pos++;}
      updateDisplay = true;
      btn_Down_WasDown = false;
    }

    //move the pointer Up
    if (btn_Up_WasDown && btnIsUp(BTN_UP)){
      if (sub_Pos == 1) {sub_Pos = SUB_MENU1_CNT;} else {sub_Pos--;}
      updateDisplay = true;
      btn_Up_WasDown = false;
    }

    //move to the go to the root menu
    if (btn_Cancel_WasDown && btnIsUp(BTN_CANCEL)){currPage = ROOT_MENU; return;}

    // keep a specific pace
    while (millis() - loopStartMs < 25) {delay(2);}
    
  }
  
}


// =======================================================================================
// ||                               PAGE - SUB MENU2                                    ||
// =======================================================================================
void page_SubMenu2(void) {
  
  //flag for updating the display
  boolean updateDisplay = true;
  
  // tracks when entered top of loop
  uint32_t loopStartMs;

  //tracks button states
  boolean btn_Up_WasDown = false;
  boolean btn_Down_WasDown = false;
  boolean btn_Cancel_WasDown = false;
  
  // selected item pointer
  uint8_t sub_Pos = 1;

  //inner loop
  while (true){

    // capture start time
    loopStartMs = millis();

    // print the display
    if (updateDisplay){
      
      // clear the update flag
      updateDisplay = false;

      //clear the display
      clearScreen();

      //menu title
      display.println(F("[ SUB MENU #2 ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, sub_Pos); display.println(F("The First Item"));
      printSelected(2, sub_Pos); display.println(F("The Second Item"));
      printSelected(3, sub_Pos); display.println(F("The Third Item"));
      printSelected(4, sub_Pos); display.println(F("The Forth Item"));
      printSelected(5, sub_Pos); display.println(F("The Fifth Item"));
      
      //print a divider line
      printDivider();
      
    }

    // capture the button down states
    if (btnIsDown(BTN_UP)) {btn_Up_WasDown = true;}
    if (btnIsDown(BTN_DOWN)) {btn_Down_WasDown = true;}
    if (btnIsDown(BTN_CANCEL)) {btn_Cancel_WasDown = true;}

    //move the pointer down
    if (btn_Down_WasDown && btnIsUp(BTN_DOWN)){
      if (sub_Pos == SUB_MENU2_CNT) {sub_Pos = 1;} else {sub_Pos++;}
      updateDisplay = true;
      btn_Down_WasDown = false;
    }

    //move the pointer Up
    if (btn_Up_WasDown && btnIsUp(BTN_UP)){
      if (sub_Pos == 1) {sub_Pos = SUB_MENU2_CNT;} else {sub_Pos--;}
      updateDisplay = true;
      btn_Up_WasDown = false;
    }

    //move to the go to the root menu
    if (btn_Cancel_WasDown && btnIsUp(BTN_CANCEL)){currPage = ROOT_MENU; return;}

    // keep a specific pace
    while (millis() - loopStartMs < 25) {delay(2);}
    
  }
  
}
// =======================================================================================
// ||                               PAGE - SUB MENU3                                    ||
// =======================================================================================
void page_SubMenu3(void) {
  
  //flag for updating the display
  boolean updateDisplay = true;
  
  // tracks when entered top of loop
  uint32_t loopStartMs;

  //tracks button states
  boolean btn_Up_WasDown = false;
  boolean btn_Down_WasDown = false;
  boolean btn_Cancel_WasDown = false;
  
  // selected item pointer
  uint8_t sub_Pos = 1;

  //inner loop
  while (true){

    // capture start time
    loopStartMs = millis();

    // print the display
    if (updateDisplay){
      
      // clear the update flag
      updateDisplay = false;

      //clear the display
      clearScreen();

      //menu title
      display.println(F("[ SUB MENU #3 ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, sub_Pos); display.println(F("The First Item"));
      printSelected(2, sub_Pos); display.println(F("The Second Item"));
      
      //print a divider line
      printDivider();
      
    }

    // capture the button down states
    if (btnIsDown(BTN_UP)) {btn_Up_WasDown = true;}
    if (btnIsDown(BTN_DOWN)) {btn_Down_WasDown = true;}
    if (btnIsDown(BTN_CANCEL)) {btn_Cancel_WasDown = true;}

    //move the pointer down
    if (btn_Down_WasDown && btnIsUp(BTN_DOWN)){
      if (sub_Pos == SUB_MENU3_CNT) {sub_Pos = 1;} else {sub_Pos++;}
      updateDisplay = true;
      btn_Down_WasDown = false;
    }

    //move the pointer Up
    if (btn_Up_WasDown && btnIsUp(BTN_UP)){
      if (sub_Pos == 1) {sub_Pos = SUB_MENU3_CNT;} else {sub_Pos--;}
      updateDisplay = true;
      btn_Up_WasDown = false;
    }

    //move to the go to the root menu
    if (btn_Cancel_WasDown && btnIsUp(BTN_CANCEL)){currPage = ROOT_MENU; return;}

    // keep a specific pace
    while (millis() - loopStartMs < 25) {delay(2);}
    
  }
  
}

// =======================================================================================
// ||                                  TOOLS - DISPLAY                                  ||
// =======================================================================================

void printSelected(uint8_t p1, uint8_t p2){
  if(p1 == p2){
    display.print(F("-->"));
  }
  else {
    display.print(F(" "));
  }
}

void clearScreen(void){
  for (uint8_t i = 0; i < 100; i++) {display.println();}
}

void printDivider(void){
  for (uint8_t i = 0; i < 19; i++) {display.print("-");}
 // lcd.println();
}
      

// =======================================================================================
// ||                             TOOLS - BUTTON PRESSING                               ||
// =======================================================================================

boolean btnIsDown(int btn){
  return digitalRead(btn) == LOW && digitalRead(btn) == LOW;
}

boolean btnIsUp(int btn){
  return digitalRead(btn) == HIGH && digitalRead(btn) == HIGH;
}