/**
    * This file Copyright (c) 2003-2015 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.repository;
  
  import info.magnolia.audit.MgnlAuditLoggingContentDecorator;
  import info.magnolia.audit.MgnlAuditLoggingContentDecoratorSessionWrapper;
  import info.magnolia.cms.core.SystemProperty;
  import info.magnolia.cms.core.version.MgnlVersioningSession;
  import info.magnolia.cms.security.AccessDeniedException;
  import info.magnolia.cms.util.ConfigUtil;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.jcr.RuntimeRepositoryException;
  import info.magnolia.jcr.predicate.AbstractPredicate;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.jcr.wrapper.MgnlPropertySettingContentDecorator;
  import info.magnolia.objectfactory.Classes;
  import info.magnolia.objectfactory.Components;
  import info.magnolia.repository.definition.RepositoryDefinition;
  import info.magnolia.repository.definition.RepositoryMappingDefinition;
  import info.magnolia.repository.definition.RepositoryMappingDefinitionReader;
  import info.magnolia.repository.definition.WorkspaceMappingDefinition;
  import info.magnolia.repository.mbean.TrackingSessionWrapper;
  import info.magnolia.stats.JCRStats;
  
  import java.io.InputStream;
  import java.util.Collection;
  
  import javax.inject.Singleton;
  import javax.jcr.Credentials;
  import javax.jcr.NoSuchWorkspaceException;
  import javax.jcr.Node;
  import javax.jcr.Repository;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import org.apache.commons.io.IOUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Manages all used Repositories.
   */
  @Singleton
  public final class DefaultRepositoryManager implements RepositoryManager {
  
      private static final Logger log = LoggerFactory.getLogger(DefaultRepositoryManager.class);
  
      private final WorkspaceMapping workspaceMapping = new WorkspaceMapping();
  
      @Override
      public void init() {
          log.info("Loading JCR");
          workspaceMapping.clearRepositories();
          try {
              loadRepositories();
              log.debug("JCR loaded");
          } catch (Exception e) {
              log.error(e.getMessage(), e);
          }
      }
  
      @Override
      public void shutdown() {
          log.info("Shutting down JCR");
          for (RepositoryDefinition repositoryDefinition : workspaceMapping.getRepositoryDefinitions()) {
              Provider provider = workspaceMapping.getRepositoryProvider(repositoryDefinition.getName());
              provider.shutdownRepository();
         }
         workspaceMapping.clearAll();
     }
 
     @Override
     public boolean checkIfInitialized() throws AccessDeniedException, RepositoryException {
         Collection<String> workspaceNames = workspaceMapping.getLogicalWorkspaceNames();
         for (String workspace : workspaceNames) {
             if (checkIfInitialized(workspace)) {
                 return true;
             }
         }
         return false;
     }
 
     @Override
     public boolean checkIfInitialized(String logicalWorkspace) throws RepositoryException, AccessDeniedException {
         log.debug("Checking [{}] repository.", logicalWorkspace);
         // TODO cant we login without using the system context?
         Session session = MgnlContext.getSystemContext().getJCRSession(logicalWorkspace);
 
         if (session == null) {
             throw new RuntimeException("Repository [" + logicalWorkspace + "] not loaded");
         }
 
         Node startPage = session.getRootNode();
 
         // return any kind of children
         Iterable<Node> children = NodeUtil.getNodes(startPage, new AbstractPredicate<Node>() {
             @Override
             public boolean evaluateTyped(Node content) {
                 String name;
                 try {
                     name = content.getName();
                 } catch (RepositoryException e) {
                     throw new RuntimeRepositoryException(e);
                 }
                 return (!name.startsWith(NodeTypes.JCR_PREFIX) && !name.startsWith(NodeTypes.REP_PREFIX));
             }
         });
 
         if (children.iterator().hasNext()) {
             log.debug("Content found in [{}].", logicalWorkspace);
             return true;
         }
         return false;
     }
 
     @Override
     public void reload() {
 
         // TODO what exactly is this method supposed to do?!
 
         log.info("Reloading JCR");
         init();
     }
 
     private void loadRepositories() throws Exception {
         final String path = SystemProperty.getProperty(SystemProperty.MAGNOLIA_REPOSITORIES_CONFIG);
         if (path == null) {
             throw new RepositoryNotInitializedException("No value found for property " + SystemProperty.MAGNOLIA_REPOSITORIES_CONFIG + ": can not start repository.");
         }
         final String tokenizedConfig = ConfigUtil.getTokenizedConfigFile(path);
         InputStream stream = IOUtils.toInputStream(tokenizedConfig);
 
         RepositoryMappingDefinitionReader reader = new RepositoryMappingDefinitionReader();
         RepositoryMappingDefinition mapping = reader.read(stream);
 
         for (RepositoryDefinition repositoryDefinition : mapping.getRepositories()) {
             if (repositoryDefinition.getWorkspaces().isEmpty()) {
                 repositoryDefinition.addWorkspace("default");
             }
             workspaceMapping.addRepositoryDefinition(repositoryDefinition);
             loadRepository(repositoryDefinition);
         }
 
         for (WorkspaceMappingDefinition workspaceMapping : mapping.getWorkspaceMappings()) {
             this.workspaceMapping.addWorkspaceMappingDefinition(workspaceMapping);
         }
     }
 
     @Override
     public void loadRepository(RepositoryDefinition definition) throws RepositoryNotInitializedException, InstantiationException, IllegalAccessException, ClassNotFoundException {
         log.info("Loading JCR {}", definition.getName());
 
         Class<? extends Provider> providerClass = Classes.getClassFactory().forName(definition.getProvider());
         Provider provider = Components.getComponentProvider().newInstance(providerClass);
         provider.init(definition);
         Repository repository = provider.getUnderlyingRepository();
         workspaceMapping.setRepository(definition.getName(), repository);
         workspaceMapping.setRepositoryProvider(definition.getName(), provider);
 
         if (definition.isLoadOnStartup()) {
             for (String workspaceId : definition.getWorkspaces()) {
                 registerNameSpacesAndNodeTypes(workspaceId, definition, provider);
             }
         }
     }
 
     @Override
     public void loadWorkspace(String repositoryId, String physicalWorkspaceName) throws RepositoryException {
         log.info("Loading workspace {}", physicalWorkspaceName);
 
         workspaceMapping.addWorkspaceMapping(new WorkspaceMappingDefinition(physicalWorkspaceName, repositoryId, physicalWorkspaceName));
 
         Provider provider = getRepositoryProvider(repositoryId);
         provider.registerWorkspace(physicalWorkspaceName);
         RepositoryDefinition repositoryDefinition = workspaceMapping.getRepositoryDefinition(repositoryId);
 
         registerNameSpacesAndNodeTypes(physicalWorkspaceName, repositoryDefinition, provider);
     }
 
     private void registerNameSpacesAndNodeTypes(String physicalWorkspaceName, RepositoryDefinition repositoryDefinition, Provider provider) {
         try {
             Session session = provider.getSystemSession(physicalWorkspaceName);
             try {
                 provider.registerNamespace(RepositoryConstants.NAMESPACE_PREFIX, RepositoryConstants.NAMESPACE_URI, session.getWorkspace());
                 provider.registerNodeTypes();
             } finally {
                 session.logout();
             }
         } catch (RepositoryException e) {
             log.error("Failed to initialize workspace " + physicalWorkspaceName + " in repository " + repositoryDefinition.getName(), e);
         }
     }
 
     @Override
     public Session getSession(String logicalWorkspaceName, Credentials credentials) throws RepositoryException {
         WorkspaceMappingDefinition mapping = this.workspaceMapping.getWorkspaceMapping(logicalWorkspaceName);
         if (mapping == null) throw new NoSuchWorkspaceException(logicalWorkspaceName);
         Repository repository = getRepository(mapping.getRepositoryName());
         String physicalWorkspaceName = mapping.getPhysicalWorkspaceName();
 
         Session session = repository.login(credentials, physicalWorkspaceName);
         return wrapSession(session, logicalWorkspaceName);
     }
 
     @Override
     public Session getSystemSession(String logicalWorkspaceName) throws RepositoryException {
         WorkspaceMappingDefinition mapping = this.workspaceMapping.getWorkspaceMapping(logicalWorkspaceName);
         if (mapping == null) throw new NoSuchWorkspaceException(logicalWorkspaceName);
         Provider provider = getRepositoryProvider(mapping.getRepositoryName());
         return wrapSession(provider.getSystemSession(mapping.getPhysicalWorkspaceName()), logicalWorkspaceName);
     }
 
     private Session wrapSession(Session session, String logicalWorkspaceName) {
         session = new TrackingSessionWrapper(session, JCRStats.getInstance());
         if ("imaging".equals(logicalWorkspaceName) || "Expressions".equals(logicalWorkspaceName) || "Store".equals(logicalWorkspaceName) || "mgnlSystem".equals(logicalWorkspaceName)) {
             // don't wrap imaging, expression and store into audit logging session
             // it's only temporary solution. It will be removed when MAGNOLIA-5012 is resolved.
             return new MgnlVersioningSession(session);
         }
         if (!RepositoryConstants.VERSION_STORE.equals(logicalWorkspaceName)) {
             //do not wrap version store in versioning session or we get infinite redirect loop and stack overflow
             session = new MgnlVersioningSession(session);
         }
 
         // VersioningSessionWrapper has to be applied last, as it will end the chain of restore calls (doesn't forward there)
         session = new MgnlPropertySettingContentDecorator().wrapSession(session);
         return new MgnlAuditLoggingContentDecoratorSessionWrapper(session, new MgnlAuditLoggingContentDecorator());
     }
 
     @Override
     public boolean hasRepository(String repositoryId) {
         return workspaceMapping.getRepositoryDefinition(repositoryId) != null;
     }
 
     @Override
     public RepositoryDefinition getRepositoryDefinition(String repositoryId) {
         return workspaceMapping.getRepositoryDefinition(repositoryId);
     }
 
     @Override
     public Provider getRepositoryProvider(String repositoryId) {
         return workspaceMapping.getRepositoryProvider(repositoryId);
     }
 
     @Override
     public Repository getRepository(String repositoryId) {
         return workspaceMapping.getRepository(repositoryId);
     }
 
     @Override
     public void addWorkspaceMapping(WorkspaceMappingDefinition mapping) {
         workspaceMapping.addWorkspaceMapping(mapping);
     }
 
     @Override
     public boolean hasWorkspace(String logicalWorkspaceName) {
         return workspaceMapping.getWorkspaceMapping(logicalWorkspaceName) != null;
     }
 
     @Override
     public Collection<WorkspaceMappingDefinition> getWorkspaceMappings() {
         return workspaceMapping.getWorkspaceMappings();
     }
 
     @Override
     public WorkspaceMappingDefinition getWorkspaceMapping(String logicalWorkspaceName) {
         return workspaceMapping.getWorkspaceMapping(logicalWorkspaceName);
     }
 
     @Override
     public Collection<String> getWorkspaceNames() {
         return workspaceMapping.getLogicalWorkspaceNames();
     }
 }