/*

  * Copyright 2006-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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 org.kuali.rice.krad.service.impl;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.config.property.ConfigurationService;

 import org.kuali.rice.krad.bo.Attachment;

 import org.kuali.rice.krad.bo.Note;

 import org.kuali.rice.krad.bo.PersistableBusinessObject;

 import org.kuali.rice.krad.dao.AttachmentDao;

 import org.kuali.rice.krad.document.Document;

 import org.kuali.rice.krad.service.AttachmentService;

 import org.kuali.rice.krad.util.KRADConstants;

 import org.springframework.transaction.annotation.Transactional;

 import java.io.BufferedInputStream;

 import java.io.BufferedOutputStream;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.UUID;

 /**

  * Attachment service implementation

  */

 @Transactional

 public class AttachmentServiceImpl implements AttachmentService {

         private static final int MAX_DIR_LEVELS = 6;

     private static Logger LOG = Logger.getLogger(AttachmentServiceImpl.class);

     private ConfigurationService kualiConfigurationService;

     private AttachmentDao attachmentDao;

     /**

      * Retrieves an Attachment by note identifier.

      * 

      * @see org.kuali.rice.krad.service.AttachmentService#getAttachmentByNoteId(java.lang.Long)

      */

     public Attachment getAttachmentByNoteId(Long noteId) {

                 return attachmentDao.getAttachmentByNoteId(noteId);

         }

     /**

      * @see org.kuali.rice.krad.service.DocumentAttachmentService#createAttachment(java.lang.String, java.lang.String, int,

      *      java.io.InputStream, Document)

      */

     public Attachment createAttachment(PersistableBusinessObject parent, String uploadedFileName, String mimeType, int fileSize, InputStream fileContents, String attachmentTypeCode) throws IOException {

         if ( LOG.isDebugEnabled() ) {

             LOG.debug("starting to create attachment for document: " + parent.getObjectId());

         }

         if (parent == null) {

             throw new IllegalArgumentException("invalid (null or uninitialized) document");

         }

         if (StringUtils.isBlank(uploadedFileName)) {

             throw new IllegalArgumentException("invalid (blank) fileName");

         }

         if (StringUtils.isBlank(mimeType)) {

             throw new IllegalArgumentException("invalid (blank) mimeType");

         }

         if (fileSize <= 0) {

             throw new IllegalArgumentException("invalid (non-positive) fileSize");

         }

         if (fileContents == null) {

             throw new IllegalArgumentException("invalid (null) inputStream");

         }

         String uniqueFileNameGuid = UUID.randomUUID().toString();

         String fullPathUniqueFileName = getDocumentDirectory(parent.getObjectId()) + File.separator + uniqueFileNameGuid;

         writeInputStreamToFileStorage(fileContents, fullPathUniqueFileName);

         // create DocumentAttachment

         Attachment attachment = new Attachment();

         attachment.setAttachmentIdentifier(uniqueFileNameGuid);

         attachment.setAttachmentFileName(uploadedFileName);

         attachment.setAttachmentFileSize(new Long(fileSize));

         attachment.setAttachmentMimeTypeCode(mimeType);

         attachment.setAttachmentTypeCode(attachmentTypeCode);

         LOG.debug("finished creating attachment for document: " + parent.getObjectId());

         return attachment;

     }

     private void writeInputStreamToFileStorage(InputStream fileContents, String fullPathUniqueFileName) throws IOException {

         File fileOut = new File(fullPathUniqueFileName);

         FileOutputStream streamOut = null;

         BufferedOutputStream bufferedStreamOut = null;

         try {

             streamOut = new FileOutputStream(fileOut);

             bufferedStreamOut = new BufferedOutputStream(streamOut);

             int c;

             while ((c = fileContents.read()) != -1) {

                 bufferedStreamOut.write(c);

             }

         }

         finally {

             bufferedStreamOut.close();

             streamOut.close();

         }

     }

     public void moveAttachmentWherePending(Note note) {

             if (note == null) {

                     throw new IllegalArgumentException("Note must be non-null");

             }

             if (StringUtils.isBlank(note.getObjectId())) {

                     throw new IllegalArgumentException("Note does not have a valid object id, object id was null or empty");

             }

             Attachment attachment = note.getAttachment();

             if(attachment!=null){

                     try {

                             moveAttachmentFromPending(attachment, note.getObjectId());

                     }

                     catch (IOException e) {

                             throw new RuntimeException("Problem moving pending attachment to final directory");    

                     }

             }

     }

     private void moveAttachmentFromPending(Attachment attachment, String objectId) throws IOException {

         //This method would probably be more efficient if attachments had a pending flag

         String fullPendingFileName = getPendingDirectory() + File.separator + attachment.getAttachmentIdentifier();

         File pendingFile = new File(fullPendingFileName);

         if(pendingFile.exists()) {

             BufferedInputStream bufferedStream = null;

             FileInputStream oldFileStream = null;

             String fullPathNewFile = getDocumentDirectory(objectId) + File.separator + attachment.getAttachmentIdentifier();

             try {

                 oldFileStream = new FileInputStream(pendingFile);

                 bufferedStream = new BufferedInputStream(oldFileStream);

                 writeInputStreamToFileStorage(bufferedStream,fullPathNewFile);

             }

             finally {

                 bufferedStream.close();

                 oldFileStream.close();

                 //this has to come after the close

                 pendingFile.delete();

             }

         }

     }

     public void deleteAttachmentContents(Attachment attachment) {

             if (attachment.getNote() == null) throw new RuntimeException("Attachment.note must be set in order to delete the attachment");

         String fullPathUniqueFileName = getDocumentDirectory(attachment.getNote().getRemoteObjectIdentifier()) + File.separator + attachment.getAttachmentIdentifier();

         File attachmentFile = new File(fullPathUniqueFileName);

         attachmentFile.delete();

     }

     private String getPendingDirectory() {

         return this.getDocumentDirectory("");

     }

     private String getDocumentDirectory(String objectId) {

         // Create a directory; all ancestor directories must exist

         File documentDirectory = new File(getDocumentFileStorageLocation(objectId));

         if (!documentDirectory.exists()) {

             boolean success = documentDirectory.mkdirs();

             if (!success) {

                 throw new RuntimeException("Could not generate directory for File at: " + documentDirectory.getAbsolutePath());

             }

         }

         return documentDirectory.getAbsolutePath();

     }

     /**

      * /* (non-Javadoc)

      *

      * @see org.kuali.rice.krad.service.DocumentAttachmentService#retrieveAttachmentContents(org.kuali.rice.krad.document.DocumentAttachment)

      */

     public InputStream retrieveAttachmentContents(Attachment attachment) throws IOException {

         //refresh to get Note object in case it's not there

         if(attachment.getNoteIdentifier()!=null) {

             attachment.refreshNonUpdateableReferences();

         }

         String parentDirectory = "";

         if(attachment.getNote()!=null) {

             parentDirectory = attachment.getNote().getRemoteObjectIdentifier(); 

         }

         return new BufferedInputStream(new FileInputStream(getDocumentDirectory(parentDirectory) + File.separator + attachment.getAttachmentIdentifier()));

     }

     private String getDocumentFileStorageLocation(String objectId) {

         String location = null;

         if(StringUtils.isEmpty(objectId)) {

             location = kualiConfigurationService.getPropertyString(KRADConstants.ATTACHMENTS_PENDING_DIRECTORY_KEY);

         } else {    

                 /* 

                  * We need to create a hierarchical directory structure to store

                  * attachment directories, as most file systems max out at 16k

                  * or 32k entries.  If we use 6 levels of hierarchy, it allows

                  * hundreds of billions of attachment directories.

                  */

             char[] chars = objectId.toUpperCase().replace(" ", "").toCharArray();            

             int count = chars.length < MAX_DIR_LEVELS ? chars.length : MAX_DIR_LEVELS;

             StringBuffer prefix = new StringBuffer();            

             for ( int i = 0; i < count; i++ )

                 prefix.append(File.separator + chars[i]);

             location = kualiConfigurationService.getPropertyString(KRADConstants.ATTACHMENTS_DIRECTORY_KEY) + prefix + File.separator + objectId;

         }

         return  location;

     }

     /**

      * @see org.kuali.rice.krad.service.AttachmentService#deletePendingAttachmentsModifiedBefore(long)

      */

     public void deletePendingAttachmentsModifiedBefore(long modificationTime) {

         String pendingAttachmentDirName = getPendingDirectory();

         if (StringUtils.isBlank(pendingAttachmentDirName)) {

             throw new RuntimeException("Blank pending attachment directory name");

         }

         File pendingAttachmentDir = new File(pendingAttachmentDirName);

         if (!pendingAttachmentDir.exists()) {

             throw new RuntimeException("Pending attachment directory does not exist");

         }

         if (!pendingAttachmentDir.isDirectory()) {

             throw new RuntimeException("Pending attachment directory is not a directory! " + pendingAttachmentDir.getAbsolutePath());

         }

         File[] files = pendingAttachmentDir.listFiles();

         for (File file : files) {

             if (!file.getName().equals("placeholder.txt")) {

                 if (file.lastModified() < modificationTime) {

                     file.delete();

                 }

             }

         }

     }

     // needed for Spring injection

     /**

      * Sets the data access object

      * 

      * @param d

      */

     public void setAttachmentDao(AttachmentDao d) {

         this.attachmentDao = d;

     }

     /**

      * Retrieves a data access object

      */

     public AttachmentDao getAttachmentDao() {

         return attachmentDao;

     }

     /**

      * Gets the configService attribute. 

      * @return Returns the configService.

      */

     public ConfigurationService getKualiConfigurationService() {

         return kualiConfigurationService;

     }

     /**

      * Sets the configService attribute value.

      * @param configService The configService to set.

      */

     public void setKualiConfigurationService(ConfigurationService configService) {

         this.kualiConfigurationService = configService;

     }

 }