#include "funshield.h"
#include "string.h"

// map of letter glyphs
constexpr byte LETTER_GLYPH[] {
  0b10001000,   // A
  0b10000011,   // b
  0b11000110,   // C
  0b10100001,   // d
  0b10000110,   // E
  0b10001110,   // F
  0b10000010,   // G
  0b10001001,   // H
  0b11111001,   // I
  0b11100001,   // J
  0b10000101,   // K
  0b11000111,   // L
  0b11001000,   // M
  0b10101011,   // n
  0b10100011,   // o
  0b10001100,   // P
  0b10011000,   // q
  0b10101111,   // r
  0b10010010,   // S
  0b10000111,   // t
  0b11000001,   // U
  0b11100011,   // v
  0b10000001,   // W
  0b10110110,   // ksi
  0b10010001,   // Y
  0b10100100,   // Z
};
constexpr byte EMPTY_GLYPH = 0b11111111;

constexpr int positionsCount = 4;
constexpr unsigned int scrollingInterval = 300;

void displayChar(char ch, byte pos)
{
  byte glyph;
  if (isAlpha(ch)) {
    glyph = LETTER_GLYPH[ ch - (isUpperCase(ch) ? 'A' : 'a') ];
  }
  else if (isDigit(ch)) {
    glyph = digits[ch - '0'];
  }
  else {
     glyph = EMPTY_GLYPH;
  }
  
  digitalWrite(latch_pin, LOW);
  shiftOut(data_pin, clock_pin, MSBFIRST, glyph);
  shiftOut(data_pin, clock_pin, MSBFIRST, 1 << pos);
  digitalWrite(latch_pin, HIGH);
}

const char* message = "Ahoj";

class Display
{
  public:
    
    void loop()
    {
      int message_len = strlen(message);
      char c = pozicia_ < message_len ? message[pozicia_] : ' ';
      displayChar(c, pozicia_);

      pozicia_++;
      pozicia_ %= 4;
    }
  private:
    int pozicia_ = 0;
};

void setup() {
  pinMode(latch_pin, OUTPUT);
  pinMode(clock_pin, OUTPUT);
  pinMode(data_pin, OUTPUT);

}

Display d;

void loop() {
  d.loop();

}
///////////////////////////////////////////POINTER & ARRAY///////////////////////////////////////
#include <stdio.h>
#include <string.h>

constexpr char* str_ptr = "Ahoj";
//   A   |  h  |   o   |   j   |   '\0'
//   ^   |  ^   
//str_ptr|str_ptr+1

const char str_arr[5] {'A', 'h', 'o', 'j', '\0'};

const size_t size_arr = sizeof(str_arr);  // 5 -> 5 prvkov velkosti 1B
const size_t size_ptr = sizeof(str_ptr);  // 8 -> velkost adresy na ktoru pointer ukazuje


const char c1 = *str_ptr; // 'A'
const char c2 = str_arr[0];  // 'A'
const char c3 = *(str_ptr + 1); // 'h'
const char c4 = str_ptr[1]; // 'h'

int mystrlen(const char* s)
{
  int i = 0;
  while(*s++) ++i;
  return i;
}

const char* str1 = "Ahoj1";
const char* str2 = "Ahoj2123";

int main()
{
  str1 = str2; // str1 ukazuje teraz na rovnake miesto v pamati ako str2, teda na "Ahoj2123"

  const char* str = str1;

  int str_size = strlen(str);
  int mystr_size = mystrlen(str);
  

  printf("String size from strlen is %d\n", str_size);
  printf("String size from mystrlen is %d\n", mystr_size);

}