#include <stdint.h>
#include <stddef.h>
#include <stdio.h>
#include <ucore/ucore_string.h>

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

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

    for (i = 0, t = 0; i < len; ++i,t+=2) {

        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, char *delim)
{
    unsigned int i;
    char *outp = out;

    out[0] = 0;

    for (i = 0; i < inlen && outlen > 0; i++) {
        int rc = snprintf(outp, outlen, "%02X%s", in[i], delim);
        if (rc <= 0)
            break;
        outp += rc;
        outlen -= rc;
    }

    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 && in[i] && in[i + 1]; i+=2 , ++t) {
        int hn, ln;
        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;
    }

    return &out[t];
}