/*
 * This file was stolen from ffmpeg and modified for usability here.
 *  The original is
 * 
 * copyright (c) 2009 Michael Niedermayer
 *
 * This version is a derivative work of that version.  It is not free
 *  software; it is licensed under the GNU Lesser General Public
 *  License version 2.1, which places nontrivial restrictions on what
 *  may be done with it.  (I'm not terribly happy about that, but for
 *  my purposes accepting LGPL-infected code is a lower price than
 *  reimplementing it all myself.)
 *
 * The LGPL v2.1 as distributed with ffmpeg is in the accompanying file
 *  `LGPL-v2.1'.
 */

#include <ctype.h>
#include <errno.h>
#include <strings.h>

#include "avutil-mem.h"
#include "avutil-dict.h"
#include "avutil-error.h"
#include "avutil-avstring.h"
#include "avutil-internal.h"

#define Ctoupper(x) toupper((unsigned char)(x))

AVDictionaryEntry *
av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
{
    unsigned int i, j;

    if(!m)
        return 0;

    if(prev) i= prev - m->elems + 1;
    else     i= 0;

    for(; i<m->count; i++){
        const char *s= m->elems[i].key;
        if(flags & AV_DICT_MATCH_CASE) for(j=0;         s[j]  ==         key[j]  && key[j]; j++);
        else                               for(j=0; Ctoupper(s[j]) == Ctoupper(key[j]) && key[j]; j++);
        if(key[j])
            continue;
        if(s[j] && !(flags & AV_DICT_IGNORE_SUFFIX))
            continue;
        return &m->elems[i];
    }
    return 0;
}

int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
{
    AVDictionary      *m = *pm;
    AVDictionaryEntry *tag = av_dict_get(m, key, 0, flags);
    char *oldval = 0;

    if(!m)
        m = *pm = av_mallocz(sizeof(*m));

    if(tag) {
        if (flags & AV_DICT_DONT_OVERWRITE)
            return 0;
        if (flags & AV_DICT_APPEND)
            oldval = tag->value;
        else
            av_free(tag->value);
        av_free(tag->key);
        *tag = m->elems[--m->count];
    } else {
        AVDictionaryEntry *tmp = av_realloc(m->elems, (m->count+1) * sizeof(*m->elems));
        if(tmp) {
            m->elems = tmp;
        } else
            return AVERROR(ENOMEM);
    }
    if (value) {
        if (flags & AV_DICT_DONT_STRDUP_KEY) {
            m->elems[m->count].key   = (char*)(intptr_t)key;
        } else
        m->elems[m->count].key  = av_strdup(key  );
        if (flags & AV_DICT_DONT_STRDUP_VAL) {
            m->elems[m->count].value = (char*)(intptr_t)value;
        } else if (oldval && flags & AV_DICT_APPEND) {
            int len = strlen(oldval) + strlen(value) + 1;
            if (!(oldval = av_realloc(oldval, len)))
                return AVERROR(ENOMEM);
            av_strlcat(oldval, value, len);
            m->elems[m->count].value = oldval;
        } else
            m->elems[m->count].value = av_strdup(value);
        m->count++;
    }
    if (!m->count) {
        av_free(m->elems);
        av_freep(pm);
    }

    return 0;
}

void av_dict_free(AVDictionary **pm)
{
    AVDictionary *m = *pm;

    if (m) {
        while(m->count--) {
            av_free(m->elems[m->count].key);
            av_free(m->elems[m->count].value);
        }
        av_free(m->elems);
    }
    av_freep(pm);
}

void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags)
{
    AVDictionaryEntry *t = 0;

    while ((t = av_dict_get(src, "", t, AV_DICT_IGNORE_SUFFIX)))
        av_dict_set(dst, t->key, t->value, flags);
}