#include <stdint.h>
#include <ctype.h>
#include <stddef.h>
#include <string.h>
#include "ucore/string.h"
#include "ucore/utils.h"

static const char hx_chars[] = "0123456789ABCDEF" ;

char*
uc_hex_encode(const uint8_t *in, size_t len, char *out)
{
    unsigned int i, t;

    for (i = 0, t = 0; i < len; ++i,t+=2) {
        unsigned int hn, ln;

        hn = (in[i] & 0xF0) >> 4 ;
        ln =  in[i] & 0x0F ;

        out[t]   = hx_chars[hn];
        out[t+1] = hx_chars[ln];
    }

    out[t] = 0;

    return out;
}

char*
uc_hex_encode_delim(const uint8_t *in, size_t inlen, char *out, int outlen, const char *delim)
{
    size_t i;
    char *outp = out;

    for (i = 0; i < inlen; i++) {
        unsigned int hn, ln;
        const char *delimp = delim;

        /** Truncate at a full byte */
        if (outlen <= 2) {
            break;
        }

        hn = (in[i] & 0xF0) >> 4 ;
        ln =  in[i] & 0x0F ;

        outp[0]   = hx_chars[hn];
        outp[1] = hx_chars[ln];
        outlen -= 2;
        outp += 2;

        while (outlen > 1 && *delimp) {
            *outp++ = *delimp++;
            outlen--;
        }
    }

    *outp = 0;

    return outp;
}

/* ASCII only */
static inline int char_to_bin(char c) 
{
    if (c >='0' && c <='9')
        return c - '0';
    else if (c >= 'A' && c <= 'F')
        return c - 'A' + 10;
    else if (c >= 'a' && c <= 'f')
        return c - 'a' + 10;

    return -1;

}

uint8_t*
uc_hex_decode(const char *in, size_t maxlen,uint8_t *out)
{
    size_t i, t;

    for (t = 0,i = 0; i + 1 < maxlen ;) {
        int hn, ln;
        if (!(in[i] && in[i + 1])) {
            break;
        }

        if (in[i] == ' '  ||
            in[i] == '\t' ||
            in[i] == '\r' ||
            in[i] == '\n') {

            i++;
            continue;
        }

        hn = char_to_bin(in[i]);
        ln = char_to_bin(in[i + 1]);
        if (hn == -1 || ln == -1)
            return NULL;

        out[t] = (hn << 4 ) | ln;
        i += 2;
        t++;
    }

    return &out[t];
}