/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */
package at.knowcenter.wag.egov.egiz.sig.connectors.bku;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
import org.apache.commons.httpclient.methods.multipart.PartSource;
import org.apache.commons.httpclient.methods.multipart.StringPart;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.gv.egiz.pdfas.api.commons.Constants;
import at.knowcenter.wag.egov.egiz.sig.SignatureData;

/**
 * Helper class with methods that use the Apache Https Client to send HTTP
 * requests.
 * 
 * @author wprinz
 */
public final class BKUPostConnection
{
  /**
   * The response Properties key that identifies the response string.
   */
  public static final String RESPONSE_STRING_KEY = "response_string"; //$NON-NLS-1$

  /**
   * The response Properties key that identifies the BKU Server header.
   */
  public static final String BKU_SERVER_HEADER_KEY = "BKU-Server-Header"; //$NON-NLS-1$
  
  /**
   * The response property that declares the signature layout being applied.
   */
  public static final String BKU_SIGNATURE_LAYOUT_HEADER_KEY = "BKU-Signature-Layout"; //$NON-NLS-1$

  /**
   * The response Properties key that identifies the BKU User-Agent header.
   */
  public static final String BKU_USER_AGENT_HEADER_KEY = "BKU-User-Agent-Header"; //$NON-NLS-1$

  /**
   * The log.
   */
  private static Log log = LogFactory.getLog(BKUPostConnection.class);

  /**
   * Sends a multipart/form-data HTTP Post request to the given URL.
   * 
   * @param url The url the request is directed to.
   * @param request The request XML, which will be the UTF-8 text/xml first part of the message.
   * @param data The binary second part of the message.
   * @return Returns the response properties which, among others, contain the response String.
   * @throws HttpException
   * @throws IOException
   */
  public static Properties doPostRequestMultipart(String url, String request,
      final SignatureData data) throws HttpException, IOException
  {
    log.debug("doPostRequestMultipart:"); //$NON-NLS-1$

    StringPart xmlpart = new StringPart("XMLRequest", request, "UTF-8");  //$NON-NLS-1$//$NON-NLS-2$

    // TODO this is a BUG in BKU that doesn't allow the Content-Type header
    xmlpart.setContentType(null);
    xmlpart.setTransferEncoding(null);
    // BKU 2.7.4 can't handle the Content-Type Header for the XML
    // xmlpart.setContentType("text/xml");
    // xmlpart.setTransferEncoding(null);

    final String filename = data.getMimeType().equals("application/pdf") ? "myfile.pdf" : "myfile.txt"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
    PartSource ps = new PartSource() {
      public InputStream createInputStream() throws IOException
      {
         return data.getDataSource().createInputStream();
      }

      public String getFileName()
      {
        return filename;
      }

      public long getLength()
      {
        return data.getDataSource().getLength();
      }
    };
    //ByteArrayPartSource baps = new ByteArrayPartSource(filename, data.getData());
    FilePart filepart = new FilePart("fileupload", ps); //$NON-NLS-1$
    filepart.setContentType(data.getMimeType());

    // not really needed since external referenced data has to be taken "as-is" (binary stream) for
    // digest calculation, so neither content type nor charset is relevant
    filepart.setCharSet(data.getCharacterEncoding());

    Part[] parts = { xmlpart, filepart };

    HttpMethodParams method_params = new HttpMethodParams();
    method_params.setContentCharset("UTF-8"); //$NON-NLS-1$

    PostMethod post_method = new PostMethod(url);
    post_method.setParams(method_params);

    MultipartRequestEntity mprqe = new MultipartRequestEntity(parts, post_method.getParams());
    post_method.setRequestEntity(mprqe);

    HttpClient http_client = new HttpClient();
 
    int method_response = http_client.executeMethod(post_method);
    log.debug("method_response = " + method_response); //$NON-NLS-1$

    Properties response_properties = new Properties();

    if (log.isDebugEnabled())
    {
      Header[] response_headers = post_method.getResponseHeaders();
      for (int i = 0; i < response_headers.length; i++)
      {
        log.debug("  response_header[" + i + "]: name = " + response_headers[i].getName() + ", value = " + response_headers[i].getValue()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
      }
    }
    Header server_header = post_method.getResponseHeader("Server"); //$NON-NLS-1$
    if (server_header != null) {
       response_properties.setProperty(BKU_SERVER_HEADER_KEY, server_header.getValue());
    } else {
       log.warn("BKU response header \"Server\" is empty.");
    }

    Header signatureLayoutHeader = post_method.getResponseHeader(Constants.BKU_HEADER_SIGNATURE_LAYOUT); //$NON-NLS-1$
    if (signatureLayoutHeader != null) {
       response_properties.setProperty(BKU_SIGNATURE_LAYOUT_HEADER_KEY, signatureLayoutHeader.getValue());
    }
    
    String responseCharSet = post_method.getResponseCharSet();
    if (!"UTF8".equalsIgnoreCase(responseCharSet) && !"UTF-8".equalsIgnoreCase(responseCharSet)) {
       log.warn("BKU response charset is not UTF-8!"); //$NON-NLS-1$
    }
    String response_string = post_method.getResponseBodyAsString();

    response_properties.setProperty(RESPONSE_STRING_KEY, response_string);

    log.debug("doPostRequestMultipart finished."); //$NON-NLS-1$
    
    return response_properties;
  }

}