/**
    * This file Copyright (c) 2011-2013 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.setup.for4_5;
  
  import static java.lang.String.format;
  import static org.apache.commons.lang.ArrayUtils.contains;
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.HierarchyManager;
  import info.magnolia.cms.core.NodeData;
  import info.magnolia.cms.filters.FilterManager;
  import info.magnolia.cms.util.ContentUtil;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.module.InstallContext;
  import info.magnolia.module.delta.AbstractRepositoryTask;
  import info.magnolia.module.delta.TaskExecutionException;
  
  import java.util.Collection;
  import java.util.Set;
  
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang.ArrayUtils;
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.common.base.Function;
  import com.google.common.base.Predicates;
  import com.google.common.collect.Iterables;
  import com.google.common.collect.Sets;
  
  /**
   * Updates the given security filter's client callback configuration to reflect the changes introduced in 4.5.
   */
  public class UpdateSecurityFilterClientCallbacksConfiguration extends AbstractRepositoryTask {
  
      private static final Logger log = LoggerFactory.getLogger(UpdateSecurityFilterClientCallbacksConfiguration.class);
  
      private static final String FORM_CLASS = "info.magnolia.cms.security.auth.callback.FormClientCallback";
      private static final String COMPOSITE_CLASS = "info.magnolia.cms.security.auth.callback.CompositeCallback";
      private static final String BASIC_CLASS = "info.magnolia.cms.security.auth.callback.BasicClientCallback";
      private static final String REDIRECT_CLASS = "info.magnolia.cms.security.auth.callback.RedirectClientCallback";
      private static final String[] SIMPLE_CALLBACK_CLASSES = new String[]{FORM_CLASS, BASIC_CLASS, REDIRECT_CLASS};
      private final String fromFilterName;
      private final String targetFilterName;
      private boolean wereWeAbleToUpdateEverything = true;
  
      public UpdateSecurityFilterClientCallbacksConfiguration(String fromFilterName, String targetFilterName) {
          super("Security filter configuration", "Moves the client callback configuration from the " + fromFilterName + " to the new " + targetFilterName + " filter to enable multiple client callbacks.");
          this.fromFilterName = fromFilterName;
          this.targetFilterName = targetFilterName;
      }
  
      @Override
      protected void doExecute(InstallContext ctx) throws RepositoryException, TaskExecutionException {
          final HierarchyManager hm = ctx.getConfigHierarchyManager();
          final Content fromFilterNode = hm.getContent(FilterManager.SERVER_FILTERS + "/" + fromFilterName);
          final Content targetFilterNode = hm.getContent(FilterManager.SERVER_FILTERS + "/" + targetFilterName);
  
          final Content newCallbacksNode = targetFilterNode.createContent("clientCallbacks", NodeTypes.ContentNode.NAME);
          final Content currentCallbackNode = fromFilterNode.getContent("clientCallback");
          final String currentClass = currentCallbackNode.getNodeData("class").getString();
          if (contains(SIMPLE_CALLBACK_CLASSES, currentClass)) {
              addCallback(ctx, newCallbacksNode, null, currentCallbackNode, null);
          } else if (!currentCallbackNode.hasChildren()) {
              // we can assume it's a simple custom callback which we can simply move
              addCallback(ctx, newCallbacksNode, "custom", currentCallbackNode, null);
          } else if (COMPOSITE_CLASS.equals(currentClass)) {
             final Collection<Content> existingCallbacks = currentCallbackNode.getContent("patterns").getChildren();
             for (Content existingCallback : existingCallbacks) {
                 final String clazz = existingCallback.getNodeData("class").getString();
                 if ("info.magnolia.cms.util.UrlPatternDelegate".equals(clazz)) {
                     final String url = existingCallback.getNodeData("url").getString();
                     addCallback(ctx, newCallbacksNode, existingCallback.getName(), existingCallback.getContent("delegate"), url);
                 } else {
                     ctx.warn("Unknown callback class at " + existingCallback.getHandle() + ":" + clazz);
                     wereWeAbleToUpdateEverything = false;
                 }
             }
         } else {
             ctx.warn("Unknown callback class:" + currentClass);
             wereWeAbleToUpdateEverything = false;
         }
 
         // only rename if unsuccessful ?
         if (wereWeAbleToUpdateEverything) {
             currentCallbackNode.delete();
         } else {
             ContentUtil.moveInSession(currentCallbackNode, fromFilterNode.getHandle() + "/_clientCallback_backup_config");
             ctx.warn(format(
                             "Client callback configuration for %s was not standard: an untouched copy of %s has been kept at %s. Please check, validate and correct the new configuration at %s.",
                             fromFilterName, fromFilterNode.getHandle() + "/clientCallback", fromFilterNode.getHandle() + "/_clientCallback_backup_config", newCallbacksNode.getHandle()
                     ));
 
         }
     }
 
     private void addCallback(InstallContext ctx, Content target, String givenCallbackName, Content source, String urlPattern) throws RepositoryException {
         final String clazz = source.getNodeData("class").getString();
         final String newName;
         if (givenCallbackName == null && contains(SIMPLE_CALLBACK_CLASSES, clazz)) {
             newName = simplifyClassName(clazz);
         } else if (givenCallbackName != null) {
             newName = givenCallbackName;
         } else {
             log.warn("Can not determine name for callback at " + source.getHandle());
             wereWeAbleToUpdateEverything = false;
             return;
         }
 
         final Content newCallback = target.createContent(newName, NodeTypes.ContentNode.NAME);
         copyStringProperty(source, newCallback, "class");
         if (FORM_CLASS.equals(clazz)) {
             copyStringProperty(source, newCallback, "loginForm");
             logAndIgnore(ctx, source, "realmName");
             checkRemainingProperties(ctx, source, "class", "loginForm", "realmName");
         } else if (REDIRECT_CLASS.equals(clazz)) {
             copyStringProperty(source, newCallback, "location");
             logAndIgnore(ctx, source, "realmName");
             checkRemainingProperties(ctx, source, "class", "location", "realmName");
         } else if (BASIC_CLASS.equals(clazz)) {
             copyStringProperty(source, newCallback, "realmName");
             checkRemainingProperties(ctx, source, "class", "realmName");
         } else {
             log.warn("Unknown callback class: " + clazz + "; copying all properties.");
             wereWeAbleToUpdateEverything = false;
             copyRemainingProperties(ctx, source, newCallback, "class");
         }
 
         if (urlPattern != null) {
             Content urlPatternContent = newCallback.createContent("urlPattern", NodeTypes.ContentNode.NAME);
             urlPatternContent.setNodeData("class", "info.magnolia.cms.util.SimpleUrlPattern");
             urlPatternContent.setNodeData("patternString", urlPattern);
         }
 
     }
 
     private String simplifyClassName(String clazz) {
         return StringUtils.removeEnd(StringUtils.substringAfterLast(clazz, "."), "ClientCallback").toLowerCase();
     }
 
     private void copyStringProperty(Content source, Content target, String propertyName) throws RepositoryException {
         target.setNodeData(propertyName, source.getNodeData(propertyName).getString());
     }
 
     /**
      * Checks if the given node has a given property; logs it and continues if so.
      */
     private void logAndIgnore(InstallContext ctx, Content source, String propertyName) throws RepositoryException {
         if (source.hasNodeData(propertyName)) {
             ctx.warn(source.getHandle() + " has a '" + propertyName + "' property; it is ignored and has been removed.");
         }
     }
 
     /**
      * Checks if the given node has other properties than those specified by the ignoredProperties parameter.
      */
     private void checkRemainingProperties(InstallContext ctx, Content source, String... ignoredProperties) {
         final Set<String> ignoredPropsSet = Sets.newHashSet(ignoredProperties);
         final Collection<NodeData> allProps = source.getNodeDataCollection();
         final Iterable<String> allPropsNames = Iterables.transform(allProps, new Function<NodeData, String>() {
             @Override
             public String apply(NodeData from) {
                 return from.getName();
             }
         });
         final Iterable<String> remaining = Iterables.filter(allPropsNames, Predicates.not(Predicates.in(ignoredPropsSet)));
         if (!Iterables.isEmpty(remaining)) {
             log.warn(source.getHandle() + " has the following unknown properties which were not copied: " + remaining);
             wereWeAbleToUpdateEverything = false;
         }
     }
 
     private void copyRemainingProperties(InstallContext ctx, Content source, Content target, String... ignoredProperties) throws RepositoryException {
         final Collection<NodeData> existingProps = source.getNodeDataCollection();
         for (NodeData prop : existingProps) {
             if (ArrayUtils.contains(ignoredProperties, prop.getName())) {
                 continue;
             }
             copyStringProperty(source, target, prop.getName());
         }
     }
 
 }