/**

  * GMyth Library

  *

  * @file gmyth/gmyth_http.c

  * 

  * @brief <p> GMythHttp class provides a wrapper to access

  * data from the database using http+xml

  *

  * Copyright (C) 2006 INdT - Instituto Nokia de Tecnologia.

  * @author Artur Duque de Souza <@indt.org.br>

  *

  */

 /*

  * 

  * This program 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 of the License, or

  * (at your option) any later version.

  *

  * This program 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 General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public License

  * along with this program; if not, write to the Free Software

  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  */

 #ifdef HAVE_CONFIG_H

 #include "config.h"

 #endif

 #include <assert.h>

 #include <libxml/parser.h>

 #include <libxml/tree.h>

 #include "gmyth_http.h"

 #include "gmyth_debug.h"

 #include "gmyth_socket.h"

 struct MemoryStruct 

 {

   char *memory;

   size_t size;

 };

 /* Aux functions got from libcurl */

 void *myrealloc(void *ptr, size_t size)

 {

     /* There might be a realloc() out there that doesn't like reallocing

         NULL pointers, so we take care of it here */

     if(ptr)

         return realloc(ptr, size);

     else

         return malloc(size);

 }

 size_t

 WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)

 {

   size_t realsize = size * nmemb;

   struct MemoryStruct *mem = (struct MemoryStruct *)data;

   mem->memory = (char *)myrealloc(mem->memory, mem->size + realsize + 1);

   if (mem->memory) {

     memcpy(&(mem->memory[mem->size]), ptr, realsize);

     mem->size += realsize;

     mem->memory[mem->size] = 0;

   }

   return realsize;

 }

 /** Create a String containing the URL with the command

  *

  * @param command A string with the command

  * @param variables Vars to use with their values \

  *                    MUST FINISH WITH NULL!!!

  * @return The response

  */

 GString* gmyth_http_create_command(GString *command, ...)

 {

     va_list args;

     va_start(args, command);

     char* s = NULL;

     g_string_append(command, "?");

     /* Sintax: var, value */

     while ( (s = va_arg(args, char *)) != NULL ) 

     {

         g_string_append(command, s);

         g_string_append(command, "=");

         s = va_arg(args, char *);

         g_string_append(command, s);

         g_string_append(command, "&");

     }

     free(s);

     va_end(args);

     return command;

 }

 /** Send HTTP Command and receives the result of it

  *

  * @return A string with the response from the server

  *          NULL if there is no response.

  */

 GString 

 *gmyth_http_request (GMythBackendInfo *backend_info, GString *command)

 {

     LIBXML_TEST_VERSION

     size_t size = strlen(backend_info->hostname) + strlen(command->str) + 13;

     char *URL = malloc(sizeof(char)*size);

     snprintf(URL, size+1, "http://%s:6544/%s", backend_info->hostname, command->str);     

     CURL *curl_handle;

     struct MemoryStruct chunk;

     chunk.memory=NULL; /* we expect realloc(NULL, size) to work */

     chunk.size = 0;    /* no data at this point */

     curl_global_init(CURL_GLOBAL_ALL);

     /* init the curl session */

     curl_handle = curl_easy_init();

     /* specify URL to get */

     curl_easy_setopt(curl_handle, CURLOPT_URL, URL);

     /* send all data to this function  */

     curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);

     /* we pass our 'chunk' struct to the callback function */

     curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);

     /* some servers don't like requests that are made without a user-agent

         field, so we provide one */

     curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");

     /* get it! */

     curl_easy_perform(curl_handle);

     /* cleanup curl stuff */

     curl_easy_cleanup(curl_handle);

     GString *response = NULL;

     if(chunk.memory)

     {

         response = g_string_new(chunk.memory);

         free(chunk.memory);

     }

     return response;

 }