/*

  * unbuffered I/O

  * Copyright (c) 2001 Fabrice Bellard

  *

  * 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 "libavutil/avstring.h"

 #include "libavutil/dict.h"

 #include "libavutil/opt.h"

 #include "libavutil/time.h"

 #include "os_support.h"

 #include "avformat.h"

 #if CONFIG_NETWORK
 #include "network.h"
 #endif

 #include "url.h"

 static URLProtocol *first_protocol = NULL;
 
 URLProtocol *ffurl_protocol_next(URLProtocol *prev)
 {
     return prev ? prev->next : first_protocol;
 }
 

 /** @name Logging context. */
 /*@{*/
 static const char *urlcontext_to_name(void *ptr)
 {
     URLContext *h = (URLContext *)ptr;

     if (h->prot)
         return h->prot->name;
     else
         return "NULL";

 }

 
 static void *urlcontext_child_next(void *obj, void *prev)
 {
     URLContext *h = obj;
     if (!prev && h->priv_data && h->prot->priv_data_class)
         return h->priv_data;
     return NULL;
 }
 
 static const AVClass *urlcontext_child_class_next(const AVClass *prev)
 {
     URLProtocol *p = NULL;
 
     /* find the protocol that corresponds to prev */
     while (prev && (p = ffurl_protocol_next(p)))
         if (p->priv_data_class == prev)
             break;
 
     /* find next protocol with priv options */
     while (p = ffurl_protocol_next(p))
         if (p->priv_data_class)
             return p->priv_data_class;
     return NULL;
 }
 

 static const AVOption options[] = { { NULL } };

 const AVClass ffurl_context_class = {

     .class_name       = "URLContext",
     .item_name        = urlcontext_to_name,
     .option           = options,
     .version          = LIBAVUTIL_VERSION_INT,
     .child_next       = urlcontext_child_next,

     .child_class_next = urlcontext_child_class_next,

 };

 /*@}*/

 const char *avio_enum_protocols(void **opaque, int output)
 {

     URLProtocol *p;
     *opaque = ffurl_protocol_next(*opaque);

     if (!(p = *opaque))
         return NULL;

     if ((output && p->url_write) || (!output && p->url_read))
         return p->name;

     return avio_enum_protocols(opaque, output);

 }
 

 int ffurl_register_protocol(URLProtocol *protocol)

 {
     URLProtocol **p;
     p = &first_protocol;

     while (*p != NULL)
         p = &(*p)->next;
     *p             = protocol;

     protocol->next = NULL;
     return 0;
 }
 

 static int url_alloc_for_protocol(URLContext **puc, struct URLProtocol *up,
                                   const char *filename, int flags,
                                   const AVIOInterruptCB *int_cb)

 {
     URLContext *uc;
     int err;
 

 #if CONFIG_NETWORK

     if (up->flags & URL_PROTOCOL_FLAG_NETWORK && !ff_network_init())

         return AVERROR(EIO);
 #endif

     if ((flags & AVIO_FLAG_READ) && !up->url_read) {
         av_log(NULL, AV_LOG_ERROR,
                "Impossible to open the '%s' protocol for reading\n", up->name);
         return AVERROR(EIO);
     }
     if ((flags & AVIO_FLAG_WRITE) && !up->url_write) {
         av_log(NULL, AV_LOG_ERROR,
                "Impossible to open the '%s' protocol for writing\n", up->name);
         return AVERROR(EIO);
     }

     uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);

     if (!uc) {

         err = AVERROR(ENOMEM);

         goto fail;
     }

     uc->av_class = &ffurl_context_class;

     uc->filename = (char *)&uc[1];

     strcpy(uc->filename, filename);

     uc->prot            = up;
     uc->flags           = flags;
     uc->is_streamed     = 0; /* default = not streamed */

     uc->max_packet_size = 0; /* default: stream file */

     if (up->priv_data_size) {
         uc->priv_data = av_mallocz(up->priv_data_size);

         if (!uc->priv_data) {
             err = AVERROR(ENOMEM);
             goto fail;
         }

         if (up->priv_data_class) {

             int proto_len= strlen(up->name);

             char *start = strchr(uc->filename, ',');

             *(const AVClass **)uc->priv_data = up->priv_data_class;

             av_opt_set_defaults(uc->priv_data);

             if(!strncmp(up->name, uc->filename, proto_len) && uc->filename + proto_len == start){

                 int ret= 0;
                 char *p= start;
                 char sep= *++p;
                 char *key, *val;
                 p++;
                 while(ret >= 0 && (key= strchr(p, sep)) && p<key && (val = strchr(key+1, sep))){
                     *val= *key= 0;
                     ret= av_opt_set(uc->priv_data, p, key+1, 0);
                     if (ret == AVERROR_OPTION_NOT_FOUND)
                         av_log(uc, AV_LOG_ERROR, "Key '%s' not found.\n", p);
                     *val= *key= sep;
                     p= val+1;
                 }
                 if(ret<0 || p!=key){
                     av_log(uc, AV_LOG_ERROR, "Error parsing options string %s\n", start);
                     av_freep(&uc->priv_data);
                     av_freep(&uc);

                     err = AVERROR(EINVAL);

                     goto fail;
                 }
                 memmove(start, key+1, strlen(key));
             }

         }
     }

     if (int_cb)
         uc->interrupt_callback = *int_cb;

     *puc = uc;
     return 0;

 fail:

     *puc = NULL;

     if (uc)
         av_freep(&uc->priv_data);
     av_freep(&uc);

 #if CONFIG_NETWORK

     if (up->flags & URL_PROTOCOL_FLAG_NETWORK)
         ff_network_close();

 #endif

     return err;

 }
 

 int ffurl_connect(URLContext *uc, AVDictionary **options)

 {

     int err =

         uc->prot->url_open2 ? uc->prot->url_open2(uc,
                                                   uc->filename,
                                                   uc->flags,
                                                   options) :

         uc->prot->url_open(uc, uc->filename, uc->flags);

     if (err)
         return err;
     uc->is_connected = 1;

     /* We must be careful here as ffurl_seek() could be slow,
      * for example for http */
     if ((uc->flags & AVIO_FLAG_WRITE) || !strcmp(uc->prot->name, "file"))
         if (!uc->is_streamed && ffurl_seek(uc, 0, SEEK_SET) < 0)
             uc->is_streamed = 1;

     return 0;
 }
 

 #define URL_SCHEME_CHARS                        \
     "abcdefghijklmnopqrstuvwxyz"                \
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                \
     "0123456789+-."
 

 static struct URLProtocol *url_find_protocol(const char *filename)

 {

     URLProtocol *up = NULL;

     char proto_str[128], proto_nested[128], *ptr;

     size_t proto_len = strspn(filename, URL_SCHEME_CHARS);

     if (filename[proto_len] != ':' &&
         (filename[proto_len] != ',' || !strchr(filename + proto_len + 1, ':')) ||
         is_dos_path(filename))

         strcpy(proto_str, "file");

     else

         av_strlcpy(proto_str, filename,
                    FFMIN(proto_len + 1, sizeof(proto_str)));

     if ((ptr = strchr(proto_str, ',')))
         *ptr = '\0';

     av_strlcpy(proto_nested, proto_str, sizeof(proto_nested));
     if ((ptr = strchr(proto_nested, '+')))
         *ptr = '\0';
 

     while (up = ffurl_protocol_next(up)) {

         if (!strcmp(proto_str, up->name))

             break;

         if (up->flags & URL_PROTOCOL_FLAG_NESTED_SCHEME &&
             !strcmp(proto_nested, up->name))

             break;

     }

 
     return up;
 }
 
 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
                 const AVIOInterruptCB *int_cb)
 {
     URLProtocol *p = NULL;
 
     if (!first_protocol) {
         av_log(NULL, AV_LOG_WARNING, "No URL Protocols are registered. "
                                      "Missing call to av_register_all()?\n");
     }
 
     p = url_find_protocol(filename);
     if (p)
        return url_alloc_for_protocol(puc, p, filename, flags, int_cb);
 

     *puc = NULL;

     if (av_strstart("https:", filename, NULL))

         av_log(NULL, AV_LOG_WARNING, "https protocol not found, recompile with openssl or gnutls enabled.\n");

     return AVERROR_PROTOCOL_NOT_FOUND;

 }
 

 int ffurl_open(URLContext **puc, const char *filename, int flags,

                const AVIOInterruptCB *int_cb, AVDictionary **options)

 {

     int ret = ffurl_alloc(puc, filename, flags, int_cb);

     if (ret)
         return ret;

     if (options && (*puc)->prot->priv_data_class &&
         (ret = av_opt_set_dict((*puc)->priv_data, options)) < 0)
         goto fail;
     ret = ffurl_connect(*puc, options);

     if (!ret)
         return 0;

 fail:

     ffurl_close(*puc);

     *puc = NULL;
     return ret;
 }
 

 static inline int retry_transfer_wrapper(URLContext *h, uint8_t *buf,
                                          int size, int size_min,
                                          int (*transfer_func)(URLContext *h,
                                                               uint8_t *buf,
                                                               int size))

 {
     int ret, len;

     int fast_retries = 5;

     int64_t wait_since = 0;

 
     len = 0;

     while (len < size_min) {

         if (ff_check_interrupt(&h->interrupt_callback))
             return AVERROR_EXIT;

         ret = transfer_func(h, buf + len, size - len);

         if (ret == AVERROR(EINTR))
             continue;

         if (h->flags & AVIO_FLAG_NONBLOCK)

             return ret;

         if (ret == AVERROR(EAGAIN)) {
             ret = 0;

             if (fast_retries) {

                 fast_retries--;

             } else {
                 if (h->rw_timeout) {
                     if (!wait_since)
                         wait_since = av_gettime();
                     else if (av_gettime() > wait_since + h->rw_timeout)

                         return AVERROR(EIO);

                 }

                 av_usleep(1000);

             }

         } else if (ret < 1)

             return (ret < 0 && ret != AVERROR_EOF) ? ret : len;

         if (ret)

             fast_retries = FFMAX(fast_retries, 2);

         len += ret;
     }
     return len;
 }
 

 int ffurl_read(URLContext *h, unsigned char *buf, int size)

 {

     if (!(h->flags & AVIO_FLAG_READ))

         return AVERROR(EIO);
     return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
 }
 

 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)

 {

     if (!(h->flags & AVIO_FLAG_READ))

         return AVERROR(EIO);
     return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);

 }
 

 int ffurl_write(URLContext *h, const unsigned char *buf, int size)

 {

     if (!(h->flags & AVIO_FLAG_WRITE))

         return AVERROR(EIO);

     /* avoid sending too big packets */
     if (h->max_packet_size && size > h->max_packet_size)

         return AVERROR(EIO);

     return retry_transfer_wrapper(h, (unsigned char *)buf, size, size, (void*)h->prot->url_write);

 }
 

 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)

 {

     int64_t ret;

 
     if (!h->prot->url_seek)

         return AVERROR(ENOSYS);

     ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);

     return ret;
 }
 

 int ffurl_closep(URLContext **hh)

 {

     URLContext *h= *hh;

     int ret = 0;

     if (!h)
         return 0;     /* can happen when ffurl_open fails */

     if (h->is_connected && h->prot->url_close)

         ret = h->prot->url_close(h);

 #if CONFIG_NETWORK

     if (h->prot->flags & URL_PROTOCOL_FLAG_NETWORK)
         ff_network_close();

 #endif

     if (h->prot->priv_data_size) {
         if (h->prot->priv_data_class)
             av_opt_free(h->priv_data);

         av_freep(&h->priv_data);

     }

     av_freep(hh);

     return ret;
 }
 

 int ffurl_close(URLContext *h)
 {
     return ffurl_closep(&h);
 }
 
 

 const char *avio_find_protocol_name(const char *url)
 {
     URLProtocol *p = url_find_protocol(url);
 
     return p ? p->name : NULL;
 }
 

 int avio_check(const char *url, int flags)
 {
     URLContext *h;

     int ret = ffurl_alloc(&h, url, flags, NULL);

     if (ret)
         return ret;
 
     if (h->prot->url_check) {
         ret = h->prot->url_check(h, flags);
     } else {

         ret = ffurl_connect(h, NULL);

         if (ret >= 0)
             ret = flags;
     }
 
     ffurl_close(h);
     return ret;
 }

 int64_t ffurl_size(URLContext *h)

 {

     int64_t pos, size;

     size = ffurl_seek(h, 0, AVSEEK_SIZE);
     if (size < 0) {

         pos = ffurl_seek(h, 0, SEEK_CUR);
         if ((size = ffurl_seek(h, -1, SEEK_END)) < 0)

             return size;
         size++;

         ffurl_seek(h, pos, SEEK_SET);

     }

     return size;
 }

 int ffurl_get_file_handle(URLContext *h)

 {
     if (!h->prot->url_get_file_handle)
         return -1;
     return h->prot->url_get_file_handle(h);
 }
 

 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
 {
     if (!h->prot->url_get_multi_file_handle) {
         if (!h->prot->url_get_file_handle)
             return AVERROR(ENOSYS);

         *handles = av_malloc(sizeof(**handles));

         if (!*handles)
             return AVERROR(ENOMEM);
         *numhandles = 1;
         *handles[0] = h->prot->url_get_file_handle(h);
         return 0;
     }
     return h->prot->url_get_multi_file_handle(h, handles, numhandles);
 }
 

 int ffurl_shutdown(URLContext *h, int flags)
 {
     if (!h->prot->url_shutdown)
         return AVERROR(EINVAL);
     return h->prot->url_shutdown(h, flags);
 }
 

 int ff_check_interrupt(AVIOInterruptCB *cb)
 {
     int ret;
     if (cb && cb->callback && (ret = cb->callback(cb->opaque)))
         return ret;

     return 0;

 }