ExceptionHtmlRepresentationRenderer

/*
 * Copyright 2013 smartics, Kronseder & Reiner GmbH
 *
 * Licensed 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.
 */
package de.smartics.properties.admin.resources.representation.html.share;

import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.List;

import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriInfo;

import org.apache.commons.lang3.StringUtils;

import de.smartics.exceptions.i18n.CauseTrailMessages;
import de.smartics.exceptions.i18n.LocalizedException;
import de.smartics.exceptions.i18n.message.MessageType;
import de.smartics.exceptions.i18n.message.Messages;
import de.smartics.html5.jatl.HtmlResourceContext;
import de.smartics.properties.admin.domain.model.CannotInitializeManagedApplicationException;
import de.smartics.properties.admin.domain.model.Paths;
import de.smartics.properties.admin.resources.controller.ApiResource;
import de.smartics.properties.admin.resources.representation.share.BreadcrumbHelper;
import de.smartics.properties.admin.resources.representation.share.LinkDescriptorFactory;
import de.smartics.resteasy.hypermedia.renderer.LinkDescriptor;
import de.smartics.resteasy.hypermedia.renderer.LocalizationProvider;
import de.smartics.resteasy.hypermedia.renderer.ResourceContext;

/**
 * HTML view to render exception information.
 */
public class ExceptionHtmlRepresentationRenderer extends
    AbstractHtmlRepresentationRenderer<Throwable>
{
  // ********************************* Fields *********************************

  // --- constants ------------------------------------------------------------

  // --- members --------------------------------------------------------------

  /**
   * The domain object to render.
   */
  private final Throwable domainObject;

  // ****************************** Initializer *******************************

  // ****************************** Constructors ******************************

  /**
   * Default constructor.
   *
   * @param htmlContext the context information to render the representation.
   * @param domainObject the domain object to render.
   * @param entityStream the stream to write to.
   */
  public ExceptionHtmlRepresentationRenderer(
      final HtmlResourceContext htmlContext, final Throwable domainObject,
      final OutputStream entityStream)
  {
    super(htmlContext, entityStream);
    this.domainObject = domainObject;
  }

  // ****************************** Inner Classes *****************************

  // ********************************* Methods ********************************

  // --- init -----------------------------------------------------------------

  // --- get&set --------------------------------------------------------------

  @Override
  protected String getTitle()
  {
    return "Exception raised";
  }

  // --- business -------------------------------------------------------------

  @Override
  protected void bodyContents()
  {
    if (domainObject instanceof LocalizedException)
    {
      renderSmartException();
    }
    else if (domainObject instanceof CannotInitializeManagedApplicationException)
    {
      renderCannotInitializeManagedApplicationException();
    }
    else
    {
      renderThrowable();
    }
  }

  private void renderSmartException()
  {
    final LocalizedException localizedException =
        (LocalizedException) domainObject;

    final Messages messages = localizedException.createMessages();
    renderPageTitle(messages.getMessage(MessageType.TITLE));
    html.p().text("An exception has been raised!").end();

    html.h2().text("Raised Exception").end();
    renderException(localizedException, messages);

    final CauseTrailMessages causeTrail = localizedException.getCauseTrail();
    for (final Messages causeMessages : causeTrail.getTrail())
    {
      html.h2().text(messages.getMessage(MessageType.SUMMARY)).end();
      renderException(null, causeMessages);
    }
    html.h2().text("Stack Trace").end();
    html.p().text("This is the stack trace to the exception:").end();
    final StringBuilder buffer = new StringBuilder();
    for (final StackTraceElement element : localizedException.getStackTrace())
    {
      buffer.append("  at ").append(element.getClassName()).append(".")
          .append(element.getMethodName()).append(":")
          .append(element.getLineNumber()).append('\n');
    }
    final String text = buffer.toString();
    html.pre().text(text).end();
  }

  private void renderCannotInitializeManagedApplicationException()
  {
    renderPageTitle("!?!");
    html.p().text("An exception has been raised!").end();

    html.div().classAttr("alert alert-info");
    html.button().type("button").classAttr("close")
        .attr("data-dismiss", "alert").raw("&times;").end();
    html.h4().text("Managed Application Problem").end();
    html.text("The application to be managed cannot be initialized."
              + " Maybe you want to provide the required boot properties via JNDI?");
    html.p();
    final LinkDescriptor link =
        linkDescriptorFactory.createDescriptor(ApiResource.JNDI, "getAsHtml");
    html.link(link);
    html.end();

    html.end();

    renderMessageAndStackTrace();
  }

  private void renderThrowable()
  {
    renderPageTitle("!?!");
    html.p().text("An exception has been raised!").end();

    renderMessageAndStackTrace();
  }

  private void renderMessageAndStackTrace()
  {
    final String message = domainObject.getLocalizedMessage();
    html.pre().text(message).end();

    html.h2().text("Stack Trace").end();
    html.p().text("This is the stack trace to the exception:").end();
    final StringWriter writer = new StringWriter();
    final PrintWriter print = new PrintWriter(writer);
    domainObject.printStackTrace(print);
    final String stacktrace = writer.toString();
    html.pre().text(stacktrace).end();
  }

  private void renderException(final LocalizedException e,
      final Messages messages)
  {
    if (e != null)
    {
      html.h3().text("Metadata").end();
      html.table().classAttr("table table-striped");
      renderMetadataRow("Code", e.getCode());
      renderMetadataRow("ID", e.getId());
      renderMetadataRow("Timestamp", e.getTime());
      html.end();
    }

    renderSection(messages, "Summary", MessageType.SUMMARY);
    renderSection(messages, "Details", MessageType.DETAILS);
    renderSection(messages, "Implications",
        MessageType.IMPLICATIONS_ON_CURRENT_TASK);
    renderSection(messages, "Todo", MessageType.WHAT_TO_DO_NOW);
    renderSection(messages, "URL", MessageType.URL);
  }

  private void renderMetadataRow(final String label, final Object value)
  {
    html.tr().th().text(label).end().td().text(String.valueOf(value)).end()
        .end();
  }

  private void renderSection(final Messages messages, final String label,
      final MessageType type)
  {
    final String message = messages.getMessage(type);
    if (StringUtils.isNotBlank(message))
    {
      html.h3().text(label).end();
      html.p().text(message).end();
    }
  }

  @Override
  protected List<LinkDescriptor> breadcrumbLinks()
  {
    final ResourceContext context = this.htmlContext.getContext();
    final LocalizationProvider provider = context.getL7nProvider();
    final UriInfo uriInfo = context.getUriInfo();
    final LinkDescriptorFactory factory =
        new LinkDescriptorFactory(uriInfo, provider);
    final BreadcrumbHelper breadcrumb =
        new BreadcrumbHelper(factory, "getAsHtml");

    final String path = uriInfo.getPath();
    if (path.startsWith(Paths.PATH_SECURITY))
    {
      return breadcrumb.security();
    }
    if (path.startsWith(Paths.PATH_JNDI))
    {
      return breadcrumb.jndi();
    }
    else if (path.startsWith(Paths.PATH_PROPERTY_DESCRIPTORS))
    {
      return breadcrumbDescriptors(uriInfo, breadcrumb);
    }
    else if (path.startsWith(Paths.PATH_CONFIGURATIONS))
    {
      return breadcrumbConfigurations(uriInfo, breadcrumb);
    }
    else
    {
      return breadcrumb.home();
    }
  }

  private List<LinkDescriptor> breadcrumbDescriptors(final UriInfo uriInfo,
      final BreadcrumbHelper breadcrumb)
  {
    final MultivaluedMap<String, String> params = uriInfo.getPathParameters();
    final String propertyKey = params.getFirst(Paths.PARAM_PROPERTY_KEY);

    final List<LinkDescriptor> descriptors;
    if (StringUtils.isBlank(propertyKey))
    {
      descriptors = breadcrumb.descriptors();
    }
    else
    {
      descriptors = breadcrumb.descriptor(propertyKey);
    }
    return descriptors;
  }

  private List<LinkDescriptor> breadcrumbConfigurations(final UriInfo uriInfo,
      final BreadcrumbHelper breadcrumb)
  {
    final MultivaluedMap<String, String> params = uriInfo.getPathParameters();
    final String configurationKey =
        params.getFirst(Paths.PARAM_CONFIGURATION_KEY);
    final String propertyKey = params.getFirst(Paths.PARAM_PROPERTY_KEY);

    final List<LinkDescriptor> descriptors;
    if (StringUtils.isBlank(configurationKey))
    {
      descriptors = breadcrumb.configurations();
    }
    else if (StringUtils.isBlank(propertyKey))
    {
      descriptors = breadcrumb.configuration(configurationKey);
    }
    else
    {
      descriptors = breadcrumb.property(configurationKey, propertyKey);
    }
    return descriptors;
  }

  // --- object basics --------------------------------------------------------

}