/*
 *         Copyright (c) 2004-6, WebThing Ltd
 *         Author: Nick Kew <nick@webthing.com>
 *
 * This program 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 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 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.
 *
 */
#include <apr_strings.h>
#include <httpd.h>
#include <http_config.h>
#include <http_protocol.h>

typedef struct link {
  const char* val ;
  struct link* next ;
} link ;
static link* badrobots ;

static int robot_check(request_rec* r) {
  link* l ;
  const char* ua = apr_table_get(r->headers_in, "User-Agent") ;
  if ( ua ) {
    for ( l = badrobots ; l ; l = l->next ) {
      if ( !strncmp(l->val, ua, strlen(l->val) ) ) {
        r->unparsed_uri = r->uri = r->parsed_uri.path
		= apr_pstrdup(r->pool, "/robots.txt") ;
        apr_table_unset(r->headers_in, "Host") ;
        return OK ;
      }
    }
  }
  return DECLINED ;
}
static int robot_init(apr_pool_t* p0, apr_pool_t* p1, apr_pool_t* p2) {
  badrobots = NULL ;
  return OK;
}
static void robots_hooks(apr_pool_t* pool) {
  ap_hook_post_read_request(robot_check, NULL, NULL, APR_HOOK_FIRST) ;
  ap_hook_pre_config(robot_init, NULL, NULL, APR_HOOK_MIDDLE) ;
}
static const char* robot_deny(cmd_parms* cmd, void* cfg, const char* arg) {
  link* newlink ;
  for ( newlink = badrobots ; newlink ; newlink = newlink->next ) {
    if ( !strcmp(arg, newlink->val) ) {
      return NULL ;
    }
  }
  newlink = apr_palloc(cmd->pool, sizeof(link)) ;
  newlink->val = arg ;
  newlink->next = badrobots ;
  badrobots = newlink ;
  return NULL ;
}
static const command_rec robots_cmds[] = {
  AP_INIT_TAKE1("RobotDeny", robot_deny, NULL, RSRC_CONF, NULL) ,
  { NULL }
} ;
module AP_MODULE_DECLARE_DATA robots_module = {
	STANDARD20_MODULE_STUFF,
	NULL,
	NULL,
	NULL,
	NULL,
	robots_cmds,
	robots_hooks
} ;