/*
     This file is part of libmicrohttpd
     (C) 2007 Daniel Pittman

     libmicrohttpd is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 2, or (at your
     option) any later version.

     libmicrohttpd 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 General Public License
     along with libmicrohttpd; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file response.c
 * @brief  Methods for managing response objects
 * @author Daniel Pittman
 * @author Christian Grothoff
 * @version 0.1.0
 */

#include "internal.h"
#include "response.h"

/**
 * Add a header line to the response.
 *
 * @return MHD_NO on error (i.e. invalid header or content format).
 */
int
MHD_add_response_header(struct MHD_Response * response,
			const char * header,
			const char * content) {
  struct MHD_HTTP_Header * hdr;
  
  if ( (response == NULL) || 
       (header == NULL) || 
       (content == NULL) ||
       (strlen(header) == 0) || 
       (strlen(content) == 0) ||
       (NULL != strstr(header, "\t")) ||
       (NULL != strstr(header, "\r")) ||
       (NULL != strstr(header, "\n")) ||
       (NULL != strstr(content, "\t")) ||
       (NULL != strstr(content, "\r")) ||
       (NULL != strstr(content, "\n")) )
    return MHD_NO;
  hdr = malloc(sizeof(struct MHD_HTTP_Header));
  hdr->header = strdup(header);
  hdr->value = strdup(content);
  hdr->kind = MHD_HEADER_KIND;
  hdr->next = response->first_header;
  response->first_header = hdr;
  return MHD_YES;
}

/**
 * Delete a header line from the response.
 *
 * @return MHD_NO on error (no such header known)
 */
int
MHD_del_response_header(struct MHD_Response * response,
			const char * header,
			const char * content) {
  struct MHD_HTTP_Header * pos;
  struct MHD_HTTP_Header * prev;

  if ( (header == NULL) || 
       (content == NULL) ) 
    return MHD_NO;       
  prev = NULL;
  pos = response->first_header;
  while (pos != NULL) {
    if ( (0 == strcmp(header, pos->header)) &&	  
	 (0 == strcmp(content, pos->value)) ) {      
      free(pos->header);
      free(pos->value);
      if (prev == NULL)
	response->first_header = pos->next;
      else
	prev->next = pos->next;
      free(pos);
      return MHD_YES;
    }
    prev = pos;
    pos = pos->next;
  }
  return MHD_NO;
}

/**
 * Get all of the headers added to a response.
 *
 * @param iterator callback to call on each header;
 *        maybe NULL (then just count headers)
 * @param iterator_cls extra argument to iterator
 * @return number of entries iterated over
 */ 
int
MHD_get_response_headers(struct MHD_Response * response,
			 MHD_KeyValueIterator iterator,
			 void * iterator_cls) {
  struct MHD_HTTP_Header * pos;
  int numHeaders = 0;
  pos = response->first_header;
  while (pos != NULL) {
    numHeaders++;
    if ( (iterator != NULL) &&
	 (MHD_YES != iterator(iterator_cls,
			      pos->kind,
			      pos->header,
			      pos->value)) )
      break;
    pos = pos->next;
  }
  return numHeaders;
}


/**
 * Create a response object.  The response object can be extended with
 * header information and then be used any number of times.
 *
 * @param size size of the data portion of the response, -1 for unknown
 * @param crc callback to use to obtain response data
 * @param crc_cls extra argument to crc
 * @param crfc callback to call to free crc_cls resources
 * @return NULL on error (i.e. invalid arguments, out of memory)
 */
struct MHD_Response *
MHD_create_response_from_callback(size_t size,
				  MHD_ContentReaderCallback crc,
				  void * crc_cls,
				  MHD_ContentReaderFreeCallback crfc) {
  struct MHD_Response * retVal;

  if (crc == NULL) 
    return NULL;
  retVal = malloc(sizeof(struct MHD_Response));
  memset(retVal,
	 0,
	 sizeof(struct MHD_Response));
  if (pthread_mutex_init(&retVal->mutex, NULL) != 0) {
    free(retVal);
    return NULL;
  }
  retVal->crc = crc;
  retVal->crfc = crfc;
  retVal->crc_cls = crc_cls;
  retVal->reference_count = 1;
  retVal->total_size = size;
  return retVal;
}

/**
 * Create a response object.  The response object can be extended with
 * header information and then be used any number of times.
 *
 * @param size size of the data portion of the response
 * @param data the data itself
 * @param must_free libmicrohttpd should free data when done
 * @param must_copy libmicrohttpd must make a copy of data 
 *        right away, the data maybe released anytime after
 *        this call returns
 * @return NULL on error (i.e. invalid arguments, out of memory)
 */
struct MHD_Response *
MHD_create_response_from_data(size_t size,
			      void * data,
			      int must_free,
			      int must_copy) {
  struct MHD_Response * retVal;
  void * tmp;
  
  if ( (data == NULL) &&
       (size > 0) )
    return NULL;
  retVal = malloc(sizeof(struct MHD_Response));
  memset(retVal,
	 0,
	 sizeof(struct MHD_Response));
  if (pthread_mutex_init(&retVal->mutex, NULL) != 0) {
    free(retVal);
    return NULL;
  }
  if ( (must_copy) &&
       (size > 0) ) {
    tmp = malloc(size);
    memcpy(tmp,
	   data, 
	   size);
    must_free = 1;
    data = tmp;
  } 
  retVal->crc = NULL;
  retVal->crfc = must_free ? &free : NULL;
  retVal->crc_cls = must_free ? data : NULL;
  retVal->reference_count = 1;
  retVal->total_size = size;
  retVal->data = data;
  retVal->data_size = size;
  return retVal;
}

/**
 * Destroy a response object and associated resources.  Note that
 * libmicrohttpd may keep some of the resources around if the response
 * is still in the queue for some clients, so the memory may not
 * necessarily be freed immediatley.
 */
void
MHD_destroy_response(struct MHD_Response * response) {
  struct MHD_HTTP_Header * pos;

  if (response == NULL) 
    return;	
  pthread_mutex_lock(&response->mutex);
  if (0 != --response->reference_count) { 
    pthread_mutex_unlock(&response->mutex);
    return;
  }
  pthread_mutex_unlock(&response->mutex);
  pthread_mutex_destroy(&response->mutex);
  while (response->first_header != NULL) {
    pos = response->first_header;    
    response->first_header = pos->next;
    free(pos->header);
    free(pos->value);
    free(pos);
  }
  free(response);
}


void
MHD_increment_response_rc(struct MHD_Response * response) {
  pthread_mutex_lock(&response->mutex);
  response->reference_count++;
  pthread_mutex_unlock(&response->mutex);
}


/* end of response.c */