#include <iostream>
#include "trf.h"

#define ascii_alphanum_base 48

char* trf::string::int2hex(unsigned int outputdigits, long long input)
{
    //sanity checking and warnings
    if (outputdigits == 0 || input == NULL)
    {
        printf("ERROR: bad output length or input: int2hex(outputdigits: %i, input: %lli) \n", outputdigits, input);
        return nullptr;
    }
    if (outputdigits < sizeof(input))
    {
        printf("WARNING: output size smaller than input, result might be incorrect \n \n");
    }

    char *nibbles = new char[outputdigits];
    int shiftoffset;

    //deflate the input into its constituent nibbles and convert them to ASCII letters,
    //taking only the desired amount of nibbles specified in outputdigits
    for (int currentnibble = outputdigits - 1; currentnibble >= 0; currentnibble--)
    {
        shiftoffset = 4 * ((outputdigits-1) - currentnibble);
        nibbles[currentnibble] = (char)((input >> shiftoffset) & 15) + ascii_alphanum_base;
        //ascii numbers and letters arent contiguous so a small fix needs to be done for A-F
        if (nibbles[currentnibble] > ascii_alphanum_base + 9)
        {
            nibbles[currentnibble] += 7;
        }
    }

    return nibbles;
}