#include <LCDI2C_Multilingual_MCD.h>
LCDI2C_Vietnamese lcd(0x27, 20, 4);

char LineText[] = "kachnicka a slepicka9899987";
char CurTime[] = "26-01-05,21:12:35";
uint32_t timestamp;

typedef const __FlashStringHelper *	FStringPtr;
// FStringPtr txtP;

class Disp {
  public:
    void LcdLine2(uint8_t line, FStringPtr txt) {
      char Tline[21] = {};
      lcd.setCursor(0, line);
      lcd.print(F("                    "));
      strncpy_PF(Tline, txt, 20);
      Serial.println("Fstring overload used");
      lcd.setCursor(0, line);
      lcd.print(Tline);
    }

    void LcdLine2(uint8_t line, char *txt) {
      char Tline[21] = {};
      lcd.setCursor(0, line);
      lcd.print(F("                    "));
      strncpy(Tline, txt, 20);
      Serial.println("pointer overload used");
      lcd.setCursor(0, line);
      lcd.print(Tline);
    }
};

Disp DisplayP; 

void setup() {
  // typedef const __FlashStringHelper *	FStringPtr;
  // void LcdLineP(uint8_t line, const __FlashStringHelper *  txt);

  Serial.begin(115200);
  lcd.init();
  lcd.backlight();

  lcd.println("____________________");
  lcd.println("____________________");
  lcd.println("____________________");
  lcd.println("____________________");
  timestamp = micros();
  // LcdLine(0, "káchníčka ä slep");
  // LcdLineU8(0, "káchníčká a slép");
  // LcdLineU8(0, "25°C slépícka kohoutek");
  LcdLineU8(0, "kvók");
  // LcdLineU8(0, "Cao đẳng Việt Nam");
  timestamp =  micros() - timestamp;
  Serial.print("Function LcdLineU8 time: ");
  Serial.println(timestamp);
  // timestamp = micros();
  // LcdLine3(1, "kachnicka a slepicka");
  // timestamp =  micros() - timestamp;
  // Serial.print("Function old time: ");
  // Serial.println(timestamp);
  // Serial.print("Printing affected array: ");
  // Serial.println(LineText);
  // lcd.print("X");
  // LcdLine(1, "Slepicka");
  timestamp = micros();
  // LcdLineP(2, PSTR("kokrhacek a kdakalka kokodak"));
  // LcdLineP(2, PSTR("kokrhacek P kdakalka"));
  // LcdLineP(2, F("kokrhacek a kdakalka"));
  LcdLinePU8(2, PSTR("kokrhacek"));
  timestamp =  micros() - timestamp;
  Serial.print("Function PROGMEM time: ");
  Serial.println(timestamp);
  lcd.print("X");
  // DisplayP.LcdLine2(1, F("kokrhacek Fstr kdakalka kokodak"));
  // DisplayP.LcdLine2(3, "kokrhacek point kdakalka kokodak");
  // strcpy(CurTime, CurTime + 9);
  // Serial.println("Test of copying inplace:");
  // Serial.println(CurTime);
}

void loop() {
  // put your main code here, to run repeatedly:

}

// Print on empty line of LC display memory based char array.
void LcdLine(uint8_t line, char *txt) {
  size_t ArrLen = strlen(txt);
  // size_t ArrLen = strnlen(txt, 20);
  lcd.setCursor(0, line);
  lcd.print(txt);
  for (uint8_t i = ArrLen; i < 20; i++) {
    lcd.write(' ');
  }
  lcd.setCursor(ArrLen, line);
}

// Print UTF-8 text on a single line.
void LcdLineU8(uint8_t line, char *txt) {
  char ExchangeMem = 0;
  uint8_t CntChar = 0;
  uint8_t CntCharU8 = 0;
  while (true) {
    if ((txt[CntChar]) == '\0') {
      break;
    }
    if ((txt[CntChar] & 0xc0) != 0x80) {
      CntCharU8++;
    }
    if (CntCharU8 > 20) {
      ExchangeMem = txt[CntChar];
      txt[CntChar] = '\0';
      break;
    }
    CntChar++;
  }
  lcd.setCursor(0, line);
  lcd.print(txt);
  for (uint8_t i = CntCharU8; i < 20; i++) {
    lcd.write(' ');
  }
  Serial.print("CntChar value: ");
  Serial.println(CntChar);
  lcd.setCursor(CntCharU8, line);
  txt[CntChar] = ExchangeMem;
  // Serial.print("index value: ");
  // Serial.println(index);
  // Serial.print("ExchangeMem: ");
  // Serial.print(ExchangeMem);
  // Serial.println("<");
  Serial.print("txt variable at end: ");
  Serial.print(txt);
  Serial.println("<");
}


/* // Print on empty line of LC display Progmem based char array.
  void LcdLineP(uint8_t line, const __FlashStringHelper *txt) {
  char buffer[21];
  strncpy_PF(buffer, (const char*)txt, 20);
  size_t ArrLen = strlen(buffer);
  lcd.setCursor(0, line);
  buffer[ArrLen] = '\0';
  // if (ArrLen > 20) {
  //   lcd.print(txt);
  //   return;
  // }
  lcd.print(buffer);
  for (uint8_t i = ArrLen; i < 20; i++) {
    lcd.write(' ');
  }
  lcd.setCursor(ArrLen, line);
  } */

void LcdLineP(uint8_t line, char txt[]) {
  char buf[21] = {};
  strncpy_P(buf, txt, 20);
  size_t ArrLen = strlen(buf);
  Serial.print("Buffer size: ");
  Serial.println(ArrLen);
  lcd.setCursor(0, line);
  txt[ArrLen] = '\0';
  lcd.print(buf);
  for (uint8_t i = ArrLen; i < 20; i++) {
    lcd.write(' ');
  }
  lcd.setCursor(ArrLen, line);
}

void LcdLinePU8(uint8_t line, char txt[]) {
  char buff[81];
  uint8_t CntChar = 0;
  uint8_t CntCharU8 = 0;
  while (true) {
    if (pgm_read_byte(&txt[CntChar]) == '\0') {
      buff[CntChar] = '\0';
      break;
    }
    if ((txt[CntChar] & 0xc0) != 0x80) {
      CntCharU8++;
    }
    if (CntCharU8 > 20) {
      buff[CntChar] = '\0';
      break;
    }
    buff[CntChar] = pgm_read_byte(&txt[CntChar]);
    CntChar++;
  }
  lcd.setCursor(0, line);
  lcd.print(buff);
  for (uint8_t i = CntCharU8; i < 20; i++) {
    lcd.write(' ');
  }
  lcd.setCursor(CntCharU8, line);
  // Serial.print("CntChar value: ");
  // Serial.println(CntChar);
  // Serial.print("index value: ");
  // Serial.println(index);
  // Serial.print("ExchangeMem: ");
  // Serial.print(ExchangeMem);
  // Serial.println("<");
  Serial.print("Progmem txt variable at end: ");
  Serial.print(buff);
  Serial.println("<");
}


// pgm_read_byte(&key[i % keylen])

/*
  void LcdLineP(uint8_t line, char *txt) {
  size_t ArrLen = strlen(txt);
  lcd.setCursor(0, line);
  strncpy(txt, txt, 20);
  if (ArrLen > 20) {
    // DEBUG_PRINTLN("Shorting the P array");
    txt[20] = '\0';
    lcd.print(txt);
    return;
  }
  // Serial.println(txt);
  txt[ArrLen] = '\0';
  lcd.print(txt);
  for (uint8_t i = ArrLen; i < 20; i++) {
    lcd.write(' ');
  }
  lcd.setCursor(ArrLen, line);
  } */

// strcpy(text, CurTime + 9);