/*
 * Copyright (C) 2005-2012 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.repo.download;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import org.alfresco.model.ContentModel;
import org.alfresco.model.ForumModel;
import org.alfresco.model.RenditionModel;
import org.alfresco.repo.action.executer.ActionExecuter;
import org.alfresco.repo.action.executer.ActionExecuterAbstractBase;
import org.alfresco.repo.security.authentication.AuthenticationUtil;
import org.alfresco.repo.security.authentication.AuthenticationUtil.RunAsWork;
import org.alfresco.repo.transaction.RetryingTransactionHelper;
import org.alfresco.repo.transaction.RetryingTransactionHelper.RetryingTransactionCallback;
import org.alfresco.service.cmr.action.Action;
import org.alfresco.service.cmr.action.ParameterDefinition;
import org.alfresco.service.cmr.coci.CheckOutCheckInService;
import org.alfresco.service.cmr.download.DownloadRequest;
import org.alfresco.service.cmr.download.DownloadStatus;
import org.alfresco.service.cmr.download.DownloadStatus.Status;
import org.alfresco.service.cmr.repository.ContentData;
import org.alfresco.service.cmr.repository.ContentIOException;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.service.cmr.repository.NodeService;
import org.alfresco.service.cmr.view.ExporterCrawlerParameters;
import org.alfresco.service.cmr.view.ExporterService;
import org.alfresco.service.cmr.view.Location;
import org.alfresco.service.namespace.QName;
import org.alfresco.util.TempFileProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * {@link ActionExecuter} for creating an archive (ie. zip) file containing
 * content from the repository. 
 * 
 * The maximum total size of the content which can be downloaded is controlled
 * by the maximumContentSie property. -1 indicates no limit.
 *
 * @author Alex Miller
 */
public class CreateDownloadArchiveAction extends ActionExecuterAbstractBase
{
    private static final Logger log = LoggerFactory.getLogger(CreateDownloadArchiveAction.class);
    
    
    private static final String CREATION_ERROR = "Unexpected error creating archive file for download";
    private static final String TEMP_FILE_PREFIX = "download";
    private static final String TEMP_FILE_SUFFIX = ".zip"; 
    
    // Dependencies
    private CheckOutCheckInService checkOutCheckInService;
    private ContentServiceHelper  contentServiceHelper;
    private DownloadStorage downloadStorage;
    private ExporterService exporterService;
    private NodeService nodeService;
    private RetryingTransactionHelper transactionHelper;
    private DownloadStatusUpdateService updateService;

    private long maximumContentSize = -1l;
    
    private static class SizeEstimator extends BaseExporter 
    {
        /**
         * @param checkOutCheckInService
         * @param nodeService
         */
        SizeEstimator(CheckOutCheckInService checkOutCheckInService, NodeService nodeService)
        {
            super(checkOutCheckInService, nodeService);
        }

        private long size = 0;
        private long fileCount = 0;


        @Override
        protected void contentImpl(NodeRef nodeRef, QName property, InputStream content, ContentData contentData, int index)
        {
            size = size + contentData.getSize();
            fileCount = fileCount + 1;
        }

        public long getSize()
        {
            return size;
        }

        public long getFileCount()
        {
            return fileCount;
        }

    }
    
    // Dependency setters
    public void setCheckOutCheckInSerivce(CheckOutCheckInService checkOutCheckInService)
    {
        this.checkOutCheckInService = checkOutCheckInService;
    }
    
    
    public void setContentServiceHelper(ContentServiceHelper contentServiceHelper)
    {
        this.contentServiceHelper = contentServiceHelper;
    }
    
    public void setDownloadStorage(DownloadStorage downloadStorage)
    {
        this.downloadStorage = downloadStorage;
    }
    
    public void setExporterService(ExporterService exporterService)
    {
        this.exporterService = exporterService;
    }
    
    /**
     * Set the maximum total size of content that can be added to a single
     * download. -1 indicates no limit. 
     */
    public void setMaximumContentSize(long maximumContentSize)
    {
        this.maximumContentSize = maximumContentSize;
    }
    
    public void setNodeService(NodeService nodeService)
    {
        this.nodeService = nodeService;
    }
    
    public void setTransactionHelper(RetryingTransactionHelper transactionHelper)
    {
        this.transactionHelper = transactionHelper;
    }
    
    public void setUpdateService(DownloadStatusUpdateService updateService)
    {
        this.updateService = updateService;
    }

    /**
     * Create an archive file containing content from the repository.
     * 
     * Uses the {@link ExporterService} with custom exporters to create the
     * archive files.
     * 
     * @param actionedUponNodeRef Download node containing information required
     *   to create the archive file, and which will eventually have its content
     *   updated with the archive file. 
     */
    @Override
    protected void executeImpl(Action action, final NodeRef actionedUponNodeRef)
    {
        // Get the download request data and set up the exporter crawler parameters.
        final DownloadRequest downloadRequest = downloadStorage.getDownloadRequest(actionedUponNodeRef);
        
        AuthenticationUtil.runAs(new RunAsWork<Object>()
        {

            @Override
            public Object doWork() throws Exception
            {
        
                ExporterCrawlerParameters crawlerParameters = new ExporterCrawlerParameters();
                
                Location exportFrom = new Location(downloadRequest.getRequetedNodeRefs());
                crawlerParameters.setExportFrom(exportFrom);
                
                crawlerParameters.setCrawlSelf(true);
                crawlerParameters.setExcludeChildAssocs(new QName[] {RenditionModel.ASSOC_RENDITION, ForumModel.ASSOC_DISCUSSION});
                crawlerParameters.setExcludeAspects(new QName[] {ContentModel.ASPECT_WORKING_COPY});
        
                // Get an estimate of the size for statuses
                SizeEstimator estimator = new SizeEstimator(checkOutCheckInService, nodeService);
                exporterService.exportView(estimator, crawlerParameters, null);
                
                if (maximumContentSize > 0 && estimator.getSize() > maximumContentSize) 
                {
                    maximumContentSizeExceeded(actionedUponNodeRef, estimator.getSize(), estimator.getFileCount());
                }
                else
                {
                    createDownload(actionedUponNodeRef, crawlerParameters, estimator);
                }
                return null;
            }

        }, downloadRequest.getOwner());

    }

    @Override
    protected void addParameterDefinitions(List<ParameterDefinition> paramList)
    {
    }


    private void maximumContentSizeExceeded(final NodeRef actionedUponNodeRef, final long size, final long fileCount)
    {
        log.debug("Maximum contentent size ({}), exceeded ({})", maximumContentSize, size);
        
        //Update the content and set the status to done. 
        transactionHelper.doInTransaction(new RetryingTransactionCallback<Object>()
        {
         
            @Override
            public Object execute() throws Throwable
            {
                DownloadStatus status = new DownloadStatus(Status.MAX_CONTENT_SIZE_EXCEEDED, maximumContentSize, size, 0, fileCount);
                updateService.update(actionedUponNodeRef, status, 1);
                return null;
            }
        }, false, true);
    }

    private void createDownload(final NodeRef actionedUponNodeRef, ExporterCrawlerParameters crawlerParameters, SizeEstimator estimator)
    {
        // perform the actual export
        final File tempFile = TempFileProvider.createTempFile(TEMP_FILE_PREFIX, TEMP_FILE_SUFFIX);
        final ZipDownloadExporter handler = new ZipDownloadExporter(tempFile, checkOutCheckInService, nodeService, transactionHelper, updateService, downloadStorage, actionedUponNodeRef, estimator.getSize(), estimator.getFileCount());
        
        try {
            exporterService.exportView(handler, crawlerParameters, null);
            archiveCreationComplete(actionedUponNodeRef, tempFile, handler);
        }
        catch (DownloadCancelledException ex) 
        {
            downloadCancelled(actionedUponNodeRef, handler);
        }
        finally
        {
            tempFile.delete();
        }
    }


    private void archiveCreationComplete(final NodeRef actionedUponNodeRef, final File tempFile,
                final ZipDownloadExporter handler)
    {
        //Update the content and set the status to done. 
        transactionHelper.doInTransaction(new RetryingTransactionCallback<Object>()
        {
         
            @Override
            public Object execute() throws Throwable
            {
                try
                {
                    contentServiceHelper.updateContent(actionedUponNodeRef, tempFile);
                    DownloadStatus status = new DownloadStatus(Status.DONE, handler.getDone(), handler.getTotal(), handler.getFilesAdded(), handler.getTotalFiles());
                    updateService.update(actionedUponNodeRef, status, handler.getNextSequenceNumber());
                    
                    return null;
                }
                catch (ContentIOException ex)
                {
                    throw new DownloadServiceException(CREATION_ERROR, ex);
                }
                catch (FileNotFoundException ex)
                {
                    throw new DownloadServiceException(CREATION_ERROR, ex);
                }
                catch (IOException ex)
                {
                    throw new DownloadServiceException(CREATION_ERROR, ex);
                }
         
            }
        }, false, true);
    }


    private void downloadCancelled(final NodeRef actionedUponNodeRef, final ZipDownloadExporter handler)
    {
        //Update the content and set the status to done. 
        transactionHelper.doInTransaction(new RetryingTransactionCallback<Object>()
        {
            @Override
            public Object execute() throws Throwable
            {
                DownloadStatus status = new DownloadStatus(Status.CANCELLED, handler.getDone(), handler.getTotal(), handler.getFilesAdded(), handler.getTotalFiles());
                updateService.update(actionedUponNodeRef, status, handler.getNextSequenceNumber());
                
                return null;
            }
        }, false, true);

    }

}