/*
 * Copyright (C) 2006-2010 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */

package org.alfresco.filesys.alfresco;

import java.util.Enumeration;

import org.alfresco.filesys.config.ServerConfigurationBean;
import org.alfresco.filesys.repo.ContentContext;
import org.alfresco.jlan.server.SrvSession;
import org.alfresco.jlan.server.auth.InvalidUserException;
import org.alfresco.jlan.server.config.InvalidConfigurationException;
import org.alfresco.jlan.server.config.ServerConfiguration;
import org.alfresco.jlan.server.config.ServerConfigurationAccessor;
import org.alfresco.jlan.server.core.ShareMapper;
import org.alfresco.jlan.server.core.ShareType;
import org.alfresco.jlan.server.core.SharedDevice;
import org.alfresco.jlan.server.core.SharedDeviceList;
import org.alfresco.jlan.server.filesys.DiskInterface;
import org.alfresco.jlan.server.filesys.DiskSharedDevice;
import org.alfresco.jlan.server.filesys.FilesystemsConfigSection;
import org.alfresco.jlan.server.filesys.quota.QuotaManager;
import org.alfresco.model.ContentModel;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.service.cmr.repository.NodeService;
import org.alfresco.service.cmr.security.PersonService;
import org.alfresco.util.PropertyCheck;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.extensions.config.ConfigElement;

/**
 * Home Share Mapper Class
 * 
 * <p>Maps disk share lookup requests to the list of shares defined in the server
 * configuration and provides a dynamic home share mapped to the users home node.
 * 
 * @author GKSpencer
 * @author mrogers
 */
public class HomeShareMapper implements ShareMapper
{
    // Logging
    
    private static final Log logger = LogFactory.getLog("org.alfresco.filesys.alfresco.HomeShareMapper");
    
    //  Home folder share name
    public static final String HOME_FOLDER_SHARE = "HOME";
    
    // Server configuration
    private ServerConfigurationAccessor m_config;
        
    // Home folder share name
    private String homeShareName = HOME_FOLDER_SHARE;
    
    private PersonService personService;
    private NodeService nodeService;
    private DiskInterface repoDiskInterface;
    
    private QuotaManager quotaManager; // optional quota manager
    
    public void init()
    {
        PropertyCheck.mandatory(this, "ServerConfiguration", m_config);
        PropertyCheck.mandatory(this, "Home share name", homeShareName);
        PropertyCheck.mandatory(this, "personService", getPersonService());
        PropertyCheck.mandatory(this, "nodeService", getNodeService());
        PropertyCheck.mandatory(this, "repoDiskInterface", getRepoDiskInterface());
        
    }
    
    public void setServerConfiguration(ServerConfiguration config)
    {
        m_config = config;
    }

    public void setHomeShareName(String shareName)
    {
        homeShareName = shareName;
    }

    /**
     * Default constructor
     */
    public HomeShareMapper()
    {
    }
    
    /**
     * Initialize the share mapper
     * 
     * @param config ServerConfiguration
     * @param params ConfigElement
     * @exception InvalidConfigurationException
     */
    public void initializeMapper(ServerConfiguration config, ConfigElement params) throws InvalidConfigurationException
    {
        // Save the server configuration
        setServerConfiguration(config);
    }

    /**
     * Return the home folder share name
     * 
     * @return String
     */
    public final String getHomeFolderName()
    {
        return homeShareName;
    }
    
    /**
     * Return the list of available shares.
     * 
     * @param host String
     * @param sess SrvSession
     * @param allShares boolean
     * @return SharedDeviceList
     */
    public SharedDeviceList getShareList(String host, SrvSession sess, boolean allShares)
    {
        // Check if the user has a home folder, and the session does not currently have any
        // dynamic shares defined
        
        if ( sess != null && 
                sess.hasClientInformation() && 
                sess.hasDynamicShares() == false &&
        		sess.getClientInformation() instanceof AlfrescoClientInfo)
        {
            AlfrescoClientInfo client = (AlfrescoClientInfo) sess.getClientInformation();
            
            NodeRef personNode = getPersonService().getPerson(client.getUserName());
            
            if(personNode != null)
            {
                NodeRef homeSpaceRef = (NodeRef)getNodeService().getProperty(personNode, ContentModel.PROP_HOMEFOLDER);
            
                if (homeSpaceRef != null)
                {
                    // Create the home folder share                
                    DiskSharedDevice homeShare = createHomeDiskShare(homeSpaceRef, client.getUserName());
                    sess.addDynamicShare(homeShare);
                
                
                    if ( logger.isDebugEnabled())
                    {
                        logger.debug("Added " + getHomeFolderName() + " share to list of shares for " + client.getUserName());
                    }
                }
            }
        }
        
        // Make a copy of the global share list and add the per session dynamic shares
        
        SharedDeviceList shrList = new SharedDeviceList(getFilesystemsConfigSection().getShares());
        
        if ( sess != null && sess.hasDynamicShares()) {
            
            // Add the per session dynamic shares
            
            shrList.addShares(sess.getDynamicShareList());
        }
          
        // Remove unavailable shares from the list and return the list

        if ( allShares == false)
        {
            shrList.removeUnavailableShares();
        }
        return shrList;
    }

    /**
     * Find a share using the name and type for the specified client.
     * 
     * @param tohost String
     * @param name String
     * @param typ int
     * @param sess SrvSession
     * @param create boolean
     * @return SharedDevice
     * @exception InvalidUserException
     */
    public SharedDevice findShare(String tohost, String name, int typ, SrvSession sess, boolean create)
            throws Exception
    {
        
        //  Check for the special HOME disk share
        
        SharedDevice share = null;
        
        if (( typ == ShareType.DISK || typ == ShareType.UNKNOWN) && name.equalsIgnoreCase(getHomeFolderName()) &&
                    sess.getClientInformation() != null && sess.getClientInformation() instanceof AlfrescoClientInfo) {

            //  Get the client details
            
            AlfrescoClientInfo client = (AlfrescoClientInfo) sess.getClientInformation();
                        
            //  DEBUG
            
            if ( logger.isDebugEnabled())
                logger.debug("Map share " + name + ", type=" + ShareType.TypeAsString(typ) + ", client=" + client);
                
            //  Check if the user has a home folder node

            if ( client != null ) {
                
                //  Check if the share has already been created for the session

                if ( sess.hasDynamicShares()) {
                    
                    //  Check if the required share exists in the sessions dynamic share list
                    
                    share = sess.getDynamicShareList().findShare(name, typ, false);
                    
                    //  DEBUG
                    
                    if ( logger.isDebugEnabled())
                        logger.debug("  Reusing existing dynamic share for " + name);
                }

                //  Check if we found a share, if not then create a new dynamic share for the home directory
                                
                if ( share == null && create == true) {
                    
                    // Create the home share mapped to the users home folder
                    
                    NodeRef personNode = getPersonService().getPerson(client.getUserName());
                    
                    if(personNode != null)
                    {
                        NodeRef homeSpaceRef = (NodeRef)getNodeService().getProperty(personNode, ContentModel.PROP_HOMEFOLDER);
                    
                        DiskSharedDevice diskShare = createHomeDiskShare(client.getHomeFolder(), client.getUserName());
                    
                        // Add the new share to the sessions dynamic share list

                        sess.addDynamicShare(diskShare);                    
                        share = diskShare;
                    
                        if (logger.isDebugEnabled())
                        {
                            logger.debug("  Mapped share " + name + " to " + client.getHomeFolder());
                        }
                    }
                }
            }
            else
            {
                throw new InvalidUserException("No home directory");
            }
        }
        else 
        {
        
            //  Find the required share by name/type. Use a case sensitive search first, if that fails use a case
            //  insensitive search.
            FilesystemsConfigSection filesystemsConfigSection = getFilesystemsConfigSection();
            share = filesystemsConfigSection.getShares().findShare(name, typ, false);
            
            if ( share == null) {
                
                //  Try a case insensitive search for the required share
                
                share = filesystemsConfigSection.getShares().findShare(name, typ, true);
            }
        }
        
        //  Check if the share is available
        
        if ( share != null && share.getContext() != null && share.getContext().isAvailable() == false)
        {
            share = null;
        }
        
        //  Return the shared device, or null if no matching device was found
        
        return share;
    }

    /**
     * Delete temporary shares for the specified session
     * 
     * @param sess SrvSession
     */
    public void deleteShares(SrvSession sess)
    {

        //  Check if the session has any dynamic shares
        
        if ( sess.hasDynamicShares() == false)
            return;
            
        //  Delete the dynamic shares
        
        SharedDeviceList shares = sess.getDynamicShareList();
        Enumeration<SharedDevice> enm = shares.enumerateShares();
        
        while ( enm.hasMoreElements()) {

            //  Get the current share from the list
            
            SharedDevice shr = (SharedDevice) enm.nextElement();
            
            //  Close the shared device
            
            shr.getContext().CloseContext();
            
            //  DEBUG
            
            if (logger.isDebugEnabled())
                logger.debug("Deleted dynamic share " + shr);
        }
        
        // Clear the dynamic share list
        
        shares.removeAllShares();
    }

    /**
     * Close the share mapper, release any resources.
     */
    public void closeMapper()
    {
    	// Nothing to do
    }

    /**
     * Create a disk share for the home folder
     * 
     * @param homeFolderRef nodeRef
     * @param userName user name
     * @return DiskSharedDevice
     */
    private final DiskSharedDevice createHomeDiskShare(NodeRef homeFolderRef, String userName)
    {
        //  Create the disk driver and context
        logger.debug("create home share for user " + userName);
        
        DiskInterface diskDrv = getRepoDiskInterface();
   
        ContentContext diskCtx = new ContentContext( getHomeFolderName(), "", "", homeFolderRef);
        
        if ( getQuotaManager() != null)
        {
            diskCtx.setQuotaManager( getQuotaManager());
        }
        
        ServerConfigurationBean config = (ServerConfigurationBean)m_config;            
        config.initialiseRuntimeContext("cifs.home." + userName, diskCtx);

        //  Create a temporary shared device for the users home directory
        return new DiskSharedDevice(getHomeFolderName(), diskDrv, diskCtx, SharedDevice.Temporary);
    }
    
    protected FilesystemsConfigSection getFilesystemsConfigSection()
    {
        return (FilesystemsConfigSection)m_config.getConfigSection(FilesystemsConfigSection.SectionName);
    }

    public void setPersonService(PersonService personService)
    {
        this.personService = personService;
    }

    public PersonService getPersonService()
    {
        return personService;
    }

    public void setNodeService(NodeService nodeService)
    {
        this.nodeService = nodeService;
    }

    public NodeService getNodeService()
    {
        return nodeService;
    }

    public void setRepoDiskInterface(DiskInterface repoDiskInterface)
    {
        this.repoDiskInterface = repoDiskInterface;
    }

    public DiskInterface getRepoDiskInterface()
    {
        return repoDiskInterface;
    }

    public void setQuotaManager(QuotaManager quotaManager)
    {
        this.quotaManager = quotaManager;
    }

    public QuotaManager getQuotaManager()
    {
        return quotaManager;
    }
}