#include <Arduino.h> 
#include <Wire.h>                      // needed for LCD with PCF8574 port expander
#include <LiquidCrystal_I2C.h>
#include <EEPROM.h> 
#include <Pushbutton.h> 

#define DISP_ITEM_ROWS 3
#define DISP_CHAR_WIDTH 20
#define PACING_MS 25
#define FLASH_RST_CNT 30
#define SETTINGS_CHKVAL 3647

//----------------------------------------
//                DECLARATIONS
//----------------------------------------

// I/O PORT ALLOCATIONS
const int BTN_OK = A0;
const int BTN_BACK = A3;
const int BTN_UP = A2;
const int BTN_DOWN = A1;
const int BTN_PLUS = 2;
const int BTN_MINUS = 3;

// BUTTONS
Pushbutton btnOk(BTN_OK);
Pushbutton btnBack(BTN_BACK);
Pushbutton btnUp(BTN_UP);
Pushbutton btnDown(BTN_DOWN);
Pushbutton btnPlus(BTN_PLUS);
Pushbutton btnMinus(BTN_MINUS);

// MENU STRUCTURE
enum pageType {
    MENU_ROOT,
    MENU_SUB1,
    MENU_SUB1_A,
    MENU_SUB1_B,
    MENU_SUB2,
    MENU_SUB3,
    MENU_SUB4,
    MENU_SETTINGS,
};
enum pageType currPage = MENU_ROOT;
void page_MenuRoot();
void page_MenuSub1();
void page_MenuSub1_A();
void page_MenuSub1_B();
void page_MenuSub2();
void page_MenuSub3();
void page_MenuSub4();
void page_MenuSettings();

// MENU INTERNALS
uint32_t loopStartMs;  
bool updateAllItems;
bool updateItemsValue;
uint8_t ItemsCnt;
uint8_t pntrPos;
uint8_t dispOffset;
uint8_t flashCntr;
bool flashIsOn;
void initMenuPage(String title, uint8_t itemCount);
void captureButtonDownStates();
void adjustBoolean(boolean *v);
void adjustUint8_t(uint8_t *v, uint8_t min, uint8_t max);
void doPointerNavigation();
bool isFlashChanged();
void pacingWait();
bool menuItemPrintable(uint8_t xPos, uint8_t yPos);

// PRINT TOOLS
void printPointer();
void printOffsetArrows();
void printOnOff(bool val);
void printUint32_tAtWidth(uint32_t value, uint8_t width, char c, boolean isRight);

// SETTINGS
struct MySettings{
  boolean Test1_OnOff = false;
  uint8_t Test2_Num = 60;
  uint8_t Test3_Num = 255;
  uint8_t Test4_Num = 0;
  uint8_t Test5__OnOff = true;
  uint8_t Test6_Num = 197;
  uint16_t settingCheckValue = SETTINGS_CHKVAL;  
};
MySettings settings;
void sets_SetDefaults();
void sets_Load();
void sets_Save();

// DISPLAY
LiquidCrystal_I2C lcd(0x27, 20, 4);  
byte chrUp[] = {0b00000,
                0b00100,
                0b00100,
                0b01110,
                0b01110,
                0b11111,
                0b11111,
                0b00000,};
byte chrDn[] = {0b00000,
                0b11111,
                0b11111,
                0b01110,
                0b01110,
                0b00100,
                0b00100,
                0b00000,};
byte chrF1[] = {0b10000,
                0b01000,
                0b10100,
                0b01010,
                0b10100,
                0b01000,
                0b10000,
                0b00000,};
byte chrF2[] = {0b00001,
                0b00010,
                0b00101,
                0b01010,
                0b00101,
                0b00010,
                0b00001,
                0b00000,};
byte chrAr[] = {0b00000,
                0b01100,
                0b11110,
                0b10010,
                0b11110,
                0b01100,
                0b00000,
                0b00000,};                            


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

lcd.init();

 
  lcd.createChar(1, chrUp);
  lcd.createChar(2, chrDn);
  lcd.createChar(3, chrF1);
  lcd.createChar(4, chrF2);
  lcd.createChar(5, chrAr); 

  
  lcd.backlight();                     // turn on backlight

 
  lcd.clear();                          

  
  sets_Load();
}


// =======================================================================================
// ||                                  MAIN LOOP                                        ||
// =======================================================================================
void loop() {

  switch (currPage){
    case MENU_ROOT:     page_MenuRoot(); break;
    case MENU_SUB1:     page_MenuSub1(); break;
    case MENU_SUB1_A:     page_MenuSub1_A(); break;
    case MENU_SUB1_B:     page_MenuSub1_B(); break;
    case MENU_SUB2:     page_MenuSub2(); break;
    case MENU_SUB3:     page_MenuSub3(); break;
    case MENU_SUB4:     page_MenuSub4(); break;
    case MENU_SETTINGS:     page_MenuSettings(); break; 
  }
 }

// =======================================================================================
// ||                               ROOT MENU                                           ||
// =======================================================================================
void page_MenuRoot(){
    
    // initializes the menu page
    initMenuPage(F("MAIN MENU"), 5);

    //inner loop
    while(true){

      // print the display items when requested
    if (updateAllItems){

      // print the visible items
      if (menuItemPrintable(1, 1)){lcd.print(F("Sub Menu #1"));}
      if (menuItemPrintable(1, 2)){lcd.print(F("Sub Menu #2"));}
      if (menuItemPrintable(1, 3)){lcd.print(F("Sub Menu #3"));}
      if (menuItemPrintable(1, 4)){lcd.print(F("Sub Menu #4"));}
      if (menuItemPrintable(1, 5)){lcd.print(F("Settings   "));}

    }
    
    // update any flashing items
    if (isFlashChanged()){printPointer();}
    
    // always clear update flags by this point
    updateAllItems = false;

    // capture the button down states
    captureButtonDownStates(); 
    
    // check for the OK button
    if (btnOk.PressReleased()){
        switch (pntrPos){
          case 1: currPage = MENU_SUB1; return;
          case 2: currPage = MENU_SUB2; return;
          case 3: currPage = MENU_SUB3; return;
          case 4: currPage = MENU_SUB4; return;
          case 5: currPage = MENU_SETTINGS; return;
        }
    }

    // otherwise check for pointer up or down buttons
    doPointerNavigation();

    // keep a specific pace
    pacingWait();
    }
}


// =======================================================================================
// ||                                MENU SUB#1                                         ||
// =======================================================================================
void page_MenuSub1(){
    while(true){}
}


// =======================================================================================
// ||                                MENU SUB#1_A                                       ||
// =======================================================================================
void page_MenuSub1_A(){
    while(true){}
}


// =======================================================================================
// ||                                MENU SUB#1_B                                       ||
// =======================================================================================
void page_MenuSub1_B(){
    while(true){}
}


// =======================================================================================
// ||                                MENU SUB#2                                         ||
// =======================================================================================
void page_MenuSub2(){
    while(true){}
}


// =======================================================================================
// ||                                MENU SUB#3                                         ||
// =======================================================================================
void page_MenuSub3(){
    while(true){}
}


// =======================================================================================
// ||                                MENU SUB#4                                         ||
// =======================================================================================
void page_MenuSub4(){
    while(true){}
}

// =======================================================================================
// ||                                MENU SETTINGS                                  ||
// =======================================================================================
void page_MenuSettings(){
    while(true){}
}

// =======================================================================================
// ||                               TOOLS - MENU INTERNALS                              ||
// =======================================================================================
void initMenuPage(String title, uint8_t itemCount){

  // clear the screen
  lcd.clear();

  // set the cursor position  
  lcd.setCursor(0,0);

  // print the title with fill characters
  uint8_t fillCnt = (DISP_CHAR_WIDTH - title.length()) / 2;
  if (fillCnt > 0){for(uint8_t i = 0; i < fillCnt; i++){lcd.print(F("\03"));}}  // 01234567890123456789
  lcd.print(title);
  if ((title.length() % 2) == 1){fillCnt++;}
  if (fillCnt > 0){for(uint8_t i = 0; i < fillCnt; i++){lcd.print(F("\04"));}} //>>>>>>MAIN MENU<<<<<<

  // clear all button down states
  btnUp.ClearWasDown();
  btnDown.ClearWasDown();
  btnOk.ClearWasDown();
  btnBack.ClearWasDown();
  btnPlus.ClearWasDown();
  btnMinus.ClearWasDown();  

  // set the menu item count
  itemCnt = itemCount;

  // current pointer position
  pntrPos = 1;

  //display offset
  dispOffset = 0;

  // flash counter > force immediate draw at startup
  flashCntr = 0;

  //flash state > will switch to being on at startup
  flashIsOn = false;

  // force a full update
  updateAllItem = true;

  // capture start time
  loopStartMs = millis();
}
                                    //void initMenuPage(String title, uint8_t itemCount){}
void captureButtonDownStates(){
  btnUp.CaptureDownState();
  btnDown.CaptureDownState();
  btnOk.CaptureDownState();
  btnBack.CaptureDownState();
  btnMinus.CaptureDownState(); 
  btnPlus.CaptureDownState();  
}

void adjustBoolean(boolean *v){}
void adjustUint8_t(uint8_t *v, uint8_t min, uint8_t max){}

void doPointerNavigation(){

    // move pointer up
    if (btnUp.PressReleased() && pntrPos > 1){

      // erase the current pointer & reset the flash state to get imediate redraw
      flashIsOn = false; flashCntr = 0; printPointer();

      // if the cursor is already at the top of the display then resquest a list update too
      if (pntrPos - dispOffset == 1){updateAllItems = true; dispOffset--;}
      
      // move the pointer
      pntrPos--;
    }

    // move pointer down
    else if (btnDown.PressReleased() && pntrPos < itemCnt){

          // erase the current pointer & reset the flash state to get imediate redraw
      flashIsOn = false; flashCntr = 0; printPointer();

      // if the cursor is already at the top of the display then resquest a list update too
      if (pntrPos - dispOffset == DISP_ITEM_ROWS){updateAllItems = true; dispOffset++;}
      
      // move the pointer
      pntrPos++;
    }

}

bool isFlashChanged(){

  // check if counter expired
  if (flashCntr == 0){

    // flip the pointer stade
    flashIsOn = !flashIsOn;

    // reset the pointer counter
    flashCntr = FLASH_RST_CNT;

    // indicate it is time to flash
    return true;
  }

  // decrase the flash counter and send a negative response
  else {flashCntr--; return false}
}

void pacingWait(){
      // do the pacing wait
      while (millis() - loopStartMs < PACING_MS) {delay(1);}

      // capture start time
      loopStartMs = millis();
}

bool menuItemPrintable(uint8_t xPos, uint8_t yPos){

  // basic check to see if the basic condition to allow showing this item
  if (!(updateAllItems || (updateItemValue && pntrPos == yPos))){return false;}

  // make a value use later to check if ther is enough offset to make the value visible
  uint8_t yMaxOffset = 0;

  // this case means the value is typically beyond the offset display, so we remove the visible row count
  if (yPos > DISP_ITEM_ROWS) {yMaxOffset = yPos - DISP_ITEM_ROWS;}

  // talking into account any offset, check if the item position is currently visible -> position cursor and return true if so
  if (dispOffset <= (yPos-1) && dispOffset >= yMaxOffset) {lcd.setCursor(xPos, yPos - dispOffset); return true;}

  // otherwise just return false
  return false; 
}


// =======================================================================================
// ||                                  TOOLS - DISPLAY                                  ||
// =======================================================================================
void printPointer(){

    //dont allow printing pointer if less than 2 items
    if (itemCnt < 2){return;}

    // move the cusor
    lcd.setCursor(0, pntrPos - dispOffset);

    // show the pointer if set
    if (flashIsOn){lcd.print(F("\05"));}

    // otherwise hide the pointer
    else {lcd.print(F(" "));}
}

void printOffsetArrows(){}
void printOnOff(bool val){}
void printUint32_tAtWidth(uint32_t value, uint8_t width, char c, boolean isRight){}


// =======================================================================================
// ||                             TOOLS - SETTINGS                                      ||
// =======================================================================================


void sets_SetDefaults(){
    MySettings tempSets;
    memcpy(&settings, &tempSets, sizeof settings);
}


void sets_Load(){


    EEPROM.get(0, settings);


    if (settings.settingCheckValue != SETTINGS_CHKVAL){sets_SetDefaults();}
}


void sets_Save(){
    EEPROM.put(0, settings);
}


/*

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

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

void printDivider(void){
  for (uint8_t i = 0; i < 40; i++) {Serial.print("-");}
  Serial.println();
}







}




  boolean updateDisplay = true;
  boolean btn_Up_WasDown = false;
  boolean btn_Down_WasDown = false;
  boolean btn_Accept_WasDown = false;


constexpr byte cols = 20;              // columns/characters per row
constexpr byte rows = 4;               // how many rows
constexpr byte addr = 0x27;            // set the LCD address to 0x3F or 0x27
LiquidCrystal_I2C lcd(addr, cols, rows);               // create lcd object - with support of special characters

// HERE IS PART#1

#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






// =======================================================================================
// ||                               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;
  
  //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
      Serial.println(F("[ MAIN MENU ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, root_Pos); Serial.println(F("Sub Menu One"));
      printSelected(2, root_Pos); Serial.println(F("Sub Menu Two"));
      printSelected(3, root_Pos); Serial.println(F("Sub Menu Three"));
      Serial.println();
      Serial.println();
      
      //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
      Serial.println(F("[ SUB MENU #1 ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, sub_Pos); Serial.println(F("The First Item"));
      printSelected(2, sub_Pos); Serial.println(F("The Second Item"));
      printSelected(3, sub_Pos); Serial.println(F("The Third Item"));
      printSelected(4, sub_Pos); Serial.println(F("The Forth Item"));
      Serial.println();
      
      //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
      Serial.println(F("[ SUB MENU #2 ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, sub_Pos); Serial.println(F("The First Item"));
      printSelected(2, sub_Pos); Serial.println(F("The Second Item"));
      printSelected(3, sub_Pos); Serial.println(F("The Third Item"));
      printSelected(4, sub_Pos); Serial.println(F("The Forth Item"));
      printSelected(5, sub_Pos); Serial.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);}
    
  }
  
}

//HERE IS PART#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
      Serial.println(F("[ SUB MENU #3 ]"));

      //print a divider line
      printDivider();

      // print the items
      printSelected(1, sub_Pos); Serial.println(F("The First Item"));
      printSelected(2, sub_Pos); Serial.println(F("The Second Item"));
      Serial.println();
      Serial.println();
      Serial.println();
      
      //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 - BUTTON PRESSING                               ||
// =======================================================================================

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

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

*/