/*
  * Copyright (c) 2012 Nicolas George
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <string.h>
 #include "libavutil/avstring.h"
 #include "libavutil/base64.h"
 #include "url.h"
 
 typedef struct {
     const uint8_t *data;
     void *tofree;
     size_t size;
     size_t pos;
 } DataContext;
 
 static av_cold int data_open(URLContext *h, const char *uri, int flags)
 {
     DataContext *dc = h->priv_data;
     const char *data, *opt, *next;
     char *ddata;
     int ret, base64 = 0;
     size_t in_size;
 
     /* data:content/type[;base64],payload */
 
     av_strstart(uri, "data:", &uri);
     data = strchr(uri, ',');
     if (!data) {
         av_log(h, AV_LOG_ERROR, "No ',' delimiter in URI\n");
         return AVERROR(EINVAL);
     }
     opt = uri;
     while (opt < data) {
         next = av_x_if_null(memchr(opt, ';', data - opt), data);
         if (opt == uri) {
             if (!memchr(opt, '/', next - opt)) { /* basic validity check */
                 av_log(h, AV_LOG_ERROR, "Invalid content-type '%.*s'\n",
                        (int)(next - opt), opt);
                 return AVERROR(EINVAL);
             }
             av_log(h, AV_LOG_VERBOSE, "Content-type: %.*s\n",
                    (int)(next - opt), opt);
         } else {
             if (!av_strncasecmp(opt, "base64", next - opt)) {
                 base64 = 1;
             } else {
                 av_log(h, AV_LOG_VERBOSE, "Ignoring option '%.*s'\n",
                        (int)(next - opt), opt);
             }
         }
         opt = next + 1;
     }
 
     data++;
     in_size = strlen(data);
     if (base64) {
         size_t out_size = 3 * (in_size / 4) + 1;
 
         if (out_size > INT_MAX || !(ddata = av_malloc(out_size)))
             return AVERROR(ENOMEM);
         if ((ret = av_base64_decode(ddata, data, out_size)) < 0) {
             av_free(ddata);
             av_log(h, AV_LOG_ERROR, "Invalid base64 in URI\n");
             return ret;
         }
         dc->data = dc->tofree = ddata;
         dc->size = ret;
     } else {
         dc->data = data;
         dc->size = in_size;
     }
     return 0;
 }
 
 static av_cold int data_close(URLContext *h)
 {
     DataContext *dc = h->priv_data;
 
     av_freep(&dc->tofree);
     return 0;
 }
 
 static int data_read(URLContext *h, unsigned char *buf, int size)
 {
     DataContext *dc = h->priv_data;
 
     if (dc->pos >= dc->size)
         return AVERROR_EOF;
     size = FFMIN(size, dc->size - dc->pos);
     memcpy(buf, dc->data + dc->pos, size);
     dc->pos += size;
     return size;
 }
 
 URLProtocol ff_data_protocol = {
     .name           = "data",
     .url_open       = data_open,
     .url_close      = data_close,
     .url_read       = data_read,
     .priv_data_size = sizeof(DataContext),
 };