/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <httpfilt.h>
    
#include <axis2_const.h>
#include <axis2_defines.h>
#include <axutil_env.h>
#include <axutil_stream.h>

#include "..\\axis2_iis_constants.h"

#define REGISTRY_LOC			 "Software\\Apache Axis2c\\IIS ISAPI Redirector"
#define AXIS2_IIS_AXIS2_LOC		 "axis2_location" 
static char *axis2_loc = "/axis2";

static axis2_char_t redirect_word[INTERNET_MAX_URL_LENGTH] = "/axis2/mod_axis2_IIS.dll\?";
/*
 * Search a given uri to find weather it matches a uri for the axis2
 * The uri format for axis2 is of the form
 * scheme://server:port/axis2/other_parts
 * This function search  a give uri for the /axis2/. If a match
 * is found it will replace the /axis2 part of the url with /axis2/mod_iis.dll?
 */
axis2_bool_t AXIS2_CALL
get_extension_url(
    char url[],
    char ret_url[]);

/*
 * This function is called by the IIS server at the server 
 * initialization. So this is the ideal plcae for initializing 
 * axis2c.
 */
BOOL WINAPI
GetFilterVersion(
    PHTTP_FILTER_VERSION pVer)
{
    DWORD type = 0, size = 0;
    LONG lrc = 0;
    char tmpbuf[INTERNET_MAX_URL_LENGTH];
    HKEY hkey;
    ULONG http_filter_revision = HTTP_FILTER_REVISION;
    pVer->dwFilterVersion = pVer->dwServerFilterVersion;
    if(pVer->dwFilterVersion > http_filter_revision)
    {
        pVer->dwFilterVersion = http_filter_revision;
    }

    /*
     Receive notifictions when
     1. Server preprocessed the headers.
     2. Log
     3. All the request coming in secure and none secure ports.
     */
    pVer->dwFlags = (SF_NOTIFY_ORDER_HIGH | SF_NOTIFY_PREPROC_HEADERS | SF_NOTIFY_SECURE_PORT
        | SF_NOTIFY_NONSECURE_PORT | SF_NOTIFY_AUTH_COMPLETE);

    /* Give a short discription about the module.*/
    strcpy(pVer->lpszFilterDesc, "axis2c filter");
    /* Get the axis2 location from the registry configuration */
    lrc = RegOpenKeyEx(HKEY_LOCAL_MACHINE, REGISTRY_LOC, (DWORD)0, KEY_READ, &hkey);
    if(ERROR_SUCCESS != lrc)
    {
        return FALSE;
    }
    size = INTERNET_MAX_URL_LENGTH;
    lrc = RegQueryValueEx(hkey, AXIS2_IIS_AXIS2_LOC, (LPDWORD)0, &type, (LPBYTE)tmpbuf, &size);
    if((ERROR_SUCCESS == lrc) && (type == REG_SZ))
    {
        tmpbuf[size] = '\0';
        axis2_loc = _strdup(tmpbuf);
    }
    RegCloseKey(hkey);
    return TRUE;
}

/*
 When a notification happens this function is called by the IIS.
 */
DWORD WINAPI
HttpFilterProc(
    PHTTP_FILTER_CONTEXT pfc,
    DWORD notificationType,
    LPVOID pvNotification)
{
    DWORD bufferLength = INTERNET_MAX_URL_LENGTH;
    char url[INTERNET_MAX_URL_LENGTH];
    char modified_url[INTERNET_MAX_URL_LENGTH];

    if(notificationType == SF_NOTIFY_PREPROC_HEADERS)
    {
        pfc->GetServerVariable(pfc, "HTTP_URL", url, &bufferLength);
        if(get_extension_url(url, modified_url))
        {
            ((PHTTP_FILTER_PREPROC_HEADERS)pvNotification)->SetHeader(pfc, "url", modified_url);
            return SF_STATUS_REQ_HANDLED_NOTIFICATION;
        }
    }
    return SF_STATUS_REQ_NEXT_NOTIFICATION;
}

axis2_bool_t AXIS2_CALL
get_extension_url(
    char url[],
    char ret_url[])
{
    axis2_bool_t is_for_us = AXIS2_FALSE;
    int i = 0;
    /* Should contain "/axis2/"*/
    ret_url[0] = '\0';
    if(strlen(url) >= strlen(axis2_loc))
    {
        is_for_us = AXIS2_TRUE;
        while(axis2_loc[i] != '\0')
        {
            if(axis2_loc[i] != (url)[i])
            {
                is_for_us = AXIS2_FALSE;
                break;
            }
            i++;
        }
        if(url[i] != '/' && url[i] != '\0')
        {
            is_for_us = AXIS2_FALSE;
        }
    }
    if(is_for_us)
    {
        strcpy(ret_url, redirect_word);
        strcat(ret_url, &url[i]);
    }
    return is_for_us;
}