package org.apache.lenya.cms.cocoon.transformation;

import java.io.IOException;

import java.util.Arrays;

import java.util.Map;

import org.apache.avalon.framework.parameters.Parameters;

import org.apache.avalon.framework.service.ServiceSelector;

import org.apache.cocoon.ProcessingException;

import org.apache.cocoon.environment.ObjectModelHelper;

import org.apache.cocoon.environment.Request;

import org.apache.cocoon.environment.SourceResolver;

import org.apache.cocoon.transformation.AbstractSAXTransformer;

import org.apache.lenya.ac.AccessControlException;

import org.apache.lenya.ac.AccessController;

import org.apache.lenya.ac.AccessControllerResolver;

import org.apache.lenya.ac.AccreditableManager;

import org.apache.lenya.ac.Policy;

import org.apache.lenya.ac.PolicyManager;

import org.apache.lenya.cms.publication.DocumentBuildException;

import org.apache.lenya.cms.publication.DocumentFactory;

import org.apache.lenya.cms.publication.DocumentUtil;

import org.apache.lenya.cms.publication.Proxy;

import org.apache.lenya.cms.publication.Publication;

import org.apache.lenya.cms.publication.PublicationUtil;

import org.apache.lenya.cms.repository.RepositoryUtil;

import org.apache.lenya.cms.repository.Session;

import org.apache.lenya.util.ServletHelper;

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.AttributesImpl;

public class ProxyTransformer extends AbstractSAXTransformer {

  protected static final String[] elementNames = { "a", "object", "img",

      "link", "form" };

  protected static final String[] attributeNames = { "href", "src", "data",

      "action" };

  private boolean ignoreLinkElement = false;

  private String indent = "";

  private DocumentFactory factory;

  private Publication publication;

  private String url;

  private ServiceSelector serviceSelector;

  private AccessControllerResolver acResolver;

  private AccreditableManager accreditableManager;

  private PolicyManager policyManager;

  protected static final String PARAMETER_FACTORY = "private.factory";

  public void setup(SourceResolver _resolver, Map _objectModel, String _source,

      Parameters _parameters) throws ProcessingException, SAXException,

      IOException {

    super.setup(_resolver, _objectModel, _source, _parameters);

    Request _request = ObjectModelHelper.getRequest(_objectModel);

    try {

      Session session = RepositoryUtil.getSession(this.manager, _request);

      this.factory = DocumentUtil.createDocumentFactory(this.manager, session);

      this.url = ServletHelper.getWebappURI(_request);

      this.publication = PublicationUtil.getPublicationFromUrl(this.manager,

          factory, url);

    } catch (final Exception e) {

      throw new RuntimeException(e);

    }

    this.serviceSelector = null;

    try {

      this.serviceSelector = (ServiceSelector) this.manager

          .lookup(AccessControllerResolver.ROLE + "Selector");

      this.acResolver = (AccessControllerResolver) this.serviceSelector

          .select(AccessControllerResolver.DEFAULT_RESOLVER);

      AccessController accessController = this.acResolver

          .resolveAccessController(url);

      this.accreditableManager = accessController.getAccreditableManager();

      this.policyManager = accessController.getPolicyManager();

    } catch (final Exception e) {

      throw new RuntimeException(e);

    }

  }

  public void startElement(String uri, String name, String qname,

      Attributes attrs) throws SAXException {

    if (getLogger().isDebugEnabled()) {

      getLogger().debug(

          this.indent + "<" + qname + "> (ignoreAElement = "

              + this.ignoreLinkElement + ")");

      this.indent += "  ";

    }

    AttributesImpl newAttrs = null;

    if (lookingAtLinkElement(name)) {

      for (int i = 0; i < attributeNames.length; i++) {

        String linkUrl = attrs.getValue(attributeNames[i]);

        if (linkUrl != null) {

          if (linkUrl.startsWith("/")) {

            try {

              newAttrs = new AttributesImpl(attrs);

              rewriteLink(newAttrs, attributeNames[i], linkUrl);

              if (getLogger().isDebugEnabled()) {

                getLogger().debug(this.indent + "link URL: [" + linkUrl + "]");

              }

            } catch (final Exception e) {

              getLogger().error("startElement failed: ", e);

              throw new SAXException(e);

            }

          }

        }

      }

      if (newAttrs == null)

        super.startElement(uri, name, qname, attrs);

      else

        super.startElement(uri, name, qname, newAttrs);

    } else

      super.startElement(uri, name, qname, attrs);

  }

  public void endElement(String uri, String name, String qname)

      throws SAXException {

    if (getLogger().isDebugEnabled()) {

      this.indent = this.indent.substring(2);

      getLogger().debug(this.indent + "</" + qname + ">");

    }

    if (getLogger().isDebugEnabled()) {

      getLogger().debug(this.indent + "</" + qname + "> sent");

    }

    super.endElement(uri, name, qname);

  }

  private void rewriteLink(AttributesImpl newAttrs, String attributeName,

      String linkUrl) throws AccessControlException, DocumentBuildException {

    String rewrittenURL = "";

    Policy policy;

    policy = this.policyManager.getPolicy(this.accreditableManager, linkUrl);

    String area = "";

    try {

      area = factory.getFromURL(linkUrl).getArea();

    } catch (RuntimeException e) {

      getLogger().warn("global link");

    }

    if (PublicationUtil.isValidArea(area)) {

      Proxy proxy = this.publication.getProxy(area, policy.isSSLProtected());

      if (proxy == null) {

        rewrittenURL = this.request.getContextPath() + linkUrl;

      } else {

        String prefix = "/" + publication.getId() + "/" + area;

        if (linkUrl.startsWith(prefix))

          rewrittenURL = proxy.getUrl() + linkUrl.substring(prefix.length());

        else

          rewrittenURL = proxy.getUrl() + linkUrl;

      }

      if (getLogger().isDebugEnabled()) {

        getLogger().debug(

            this.indent + "SSL protection: [" + policy.isSSLProtected() + "]");

        getLogger().debug(this.indent + "Resolved proxy: [" + proxy + "]");

      }

      if (getLogger().isDebugEnabled()) {

        getLogger().debug(

            this.indent + "Rewriting URL to: [" + rewrittenURL + "]");

      }

    } else {

      rewrittenURL = linkUrl;

      getLogger().warn("URL [" + rewrittenURL + "] could not be rewritten.");

    }

    setAttribute(newAttrs, attributeName, rewrittenURL);

  }

  private boolean lookingAtLinkElement(String name) {

    return Arrays.asList(elementNames).contains(name);

  }

  /**

   * Sets the value of the href attribute.

   * 

   * @param attr

   *          The attributes.

   * @param name

   *          The attribute name.

   * @param value

   *          The value.

   * @throws IllegalArgumentException

   *           if the href attribute is not contained in this attributes.

   */

  protected void setAttribute(AttributesImpl attr, String name, String value) {

    int position = attr.getIndex(name);

    if (position == -1) {

      throw new IllegalArgumentException("The href attribute is not available!");

    }

    attr.setValue(position, value);

  }

}

      <map:transformer name="proxy" logger="lenya.sitemap.transformer.proxy" src="org.apache.lenya.cms.cocoon.transformation.ProxyTransformer"/>

                    <map:transform type="proxy"/>