/*
    * Copyright 2013 The Kuali Foundation.
    * 
    * Licensed under the Educational Community License, Version 1.0 (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/ecl1.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.ole;
  
  import org.kuali.rice.core.api.CoreApiServiceLocator;
  import org.kuali.rice.core.api.impex.xml.DirectoryXmlDocCollection;
  import org.kuali.rice.core.api.impex.xml.FileXmlDocCollection;
  import org.kuali.rice.core.api.impex.xml.XmlDocCollection;
  import org.kuali.rice.core.api.impex.xml.ZipXmlDocCollection;
  import org.kuali.rice.kew.batch.XmlPollerService;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.text.Format;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Calendar;
  import java.util.Collection;
  import java.util.Date;
  import java.util.Iterator;
  import java.util.List;
  
  public class OleXmlPollerServiceImpl implements XmlPollerService {
  
  	private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(OleXmlPollerServiceImpl.class);
  	private static final Format DIR_FORMAT = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss-SSS");
  
  	/**
  	 * Specifies the polling interval that should be used with this task.
  	 */
  	private int pollIntervalSecs = 5 * 60; // default to 5 minutes
  	/**
  	 * Specifies the initial delay the poller should wait before starting to poll
  	 */
  	private int initialDelaySecs = 30; // default to 30 seconds
  	/**
  	 * Location in which to find XML files to load.
  	 */
  	private String xmlPendingLocation;
  	/**
  	 * Location in which to place successfully loaded XML files.
  	 */
  	private String xmlCompletedLocation;
  	/**
  	 * Location in which to place XML files which have failed to load.
  	 */
  	private String xmlProblemLocation;
  
  	private String xmlParentDirectory;
  	private static final String PENDING_MOVE_FAILED_ARCHIVE_FILE = "movesfailed";
  	private static final String NEW_LINE = "\n";
  
  	public void run() {
  		// if(!directoriesWritable()){
  		// LOG.error("Error writing to xml data directories. Stopping xmlLoader ...");
  		// this.cancel();
  		// }
  		LOG.debug("checking for xml data files...");
  		File[] files = getXmlPendingDir().listFiles();
  		Arrays.sort(files);
  		if (files == null || files.length == 0) {
  			return;
  		}
  		LOG.info("Found " + files.length + " files to ingest.");
  		for (int i = 0; i < files.length; i++) {
  			LOG.info(files[i].getAbsolutePath());
  		}
  		List<XmlDocCollection> collections = new ArrayList<XmlDocCollection>();
  		for (File file : files) {
  			if (file.isDirectory()) {
  				collections.add(new DirectoryXmlDocCollection(file));
  			} else if (file.getName().equals(PENDING_MOVE_FAILED_ARCHIVE_FILE)) {
  				// the movesfailed file...ignore this
  				continue;
  			} else if (file.getName().toLowerCase().endsWith(".zip")) {
  				try {
  					collections.add(new ZipXmlDocCollection(file));
  				} catch (IOException ioe) {
  					LOG.error("Unable to load file: " + file);
  				}
  			} else if (file.getName().endsWith(".xml")) {
  				collections.add(new FileXmlDocCollection(file));
 			} else {
 				LOG.warn("Ignoring extraneous file in xml pending directory: " + file);
 			}
 		}
 
 		// Cull any resources which were already processed and whose moves failed
 		Iterator collectionsIt = collections.iterator();
 		Collection<XmlDocCollection> culled = new ArrayList<XmlDocCollection>();
 		while (collectionsIt.hasNext()) {
 			XmlDocCollection container = (XmlDocCollection) collectionsIt.next();
 			// if a move has already failed for this archive, ignore it
 			if (inPendingMoveFailedArchive(container.getFile())) {
 				LOG.info("Ignoring previously processed resource: " + container);
 				culled.add(container);
 			}
 		}
 		collections.removeAll(culled);
 
 		if (collections.size() == 0) {
 			LOG.debug("No valid new resources found to ingest");
 			return;
 		}
 
 		Date LOAD_TIME = Calendar.getInstance().getTime();
 		// synchronization around date format should not be an issue as this code is single-threaded
 		File completeDir = new File(getXmlCompleteDir(), DIR_FORMAT.format(LOAD_TIME));
 		File failedDir = new File(getXmlProblemDir(), DIR_FORMAT.format(LOAD_TIME));
 
 		// now ingest the containers
 		Collection failed = null;
 		try {
 			failed = CoreApiServiceLocator.getXmlIngesterService().ingest(collections);
 		} catch (Exception e) {
 			LOG.error("Error ingesting data", e);
 			// throw new RuntimeException(e);
 		}
 
 		// now iterate through all containers again, and move containers to approprate dir
 		LOG.info("Moving files...");
 		collectionsIt = collections.iterator();
 		while (collectionsIt.hasNext()) {
 			XmlDocCollection container = (XmlDocCollection) collectionsIt.next();
 			LOG.debug("container: " + container);
 			try {
 				// "close" the container
 				// this only matters for ZipFiles for now
 				container.close();
 			} catch (IOException ioe) {
 				LOG.warn("Error closing " + container, ioe);
 			}
 			if (failed.contains(container)) {
 				// some docs must have failed, move the whole
 				// container to the failed dir
 				if (container.getFile() != null) {
 					LOG.error("Moving " + container.getFile() + " to problem dir.");
 					if ((!failedDir.isDirectory() && !failedDir.mkdirs()) || !moveFile(failedDir, container.getFile())) {
 						LOG.error("Could not move: " + container.getFile());
 						recordUnmovablePendingFile(container.getFile(), LOAD_TIME);
 					}
 				}
 			} else {
 				if (container.getFile() != null) {
 					LOG.info("Moving " + container.getFile() + " to loaded dir.");
 					if ((!completeDir.isDirectory() && !completeDir.mkdirs()) || !moveFile(completeDir, container.getFile())) {
 						LOG.error("Could not move: " + container.getFile());
 						recordUnmovablePendingFile(container.getFile(), LOAD_TIME);
 					}
 				}
 			}
 		}
 	}
 
 	private boolean inPendingMoveFailedArchive(File xmlDataFile) {
 		if (xmlDataFile == null)
 			return false;
 		BufferedReader inFile = null;
 		File movesFailedFile = new File(getXmlPendingDir(), PENDING_MOVE_FAILED_ARCHIVE_FILE);
 		if (!movesFailedFile.isFile())
 			return false;
 		try {
 			inFile = new BufferedReader(new FileReader(movesFailedFile));
 			String line;
 
 			while ((line = inFile.readLine()) != null) {
 				String trimmedLine = line.trim();
 				if (trimmedLine.equals(xmlDataFile.getName()) || trimmedLine.startsWith(xmlDataFile.getName() + "=")) {
 					return true;
 				}
 			}
 		} catch (IOException e) {
 			LOG.warn("Error reading file " + movesFailedFile);
 			// TODO try reading the pending file or stop?
 		} finally {
 			if (inFile != null)
 				try {
 					inFile.close();
 				} catch (Exception e) {
 					LOG.warn("Error closing buffered reader for " + movesFailedFile);
 				}
 		}
 
 		return false;
 	}
 
 	private boolean recordUnmovablePendingFile(File unMovablePendingFile, Date dateLoaded) {
 		boolean recorded = false;
 		FileWriter archiveFile = null;
 		try {
 			archiveFile = new FileWriter(new File(getXmlPendingDir(), PENDING_MOVE_FAILED_ARCHIVE_FILE), true);
 			archiveFile.write(unMovablePendingFile.getName() + "=" + dateLoaded.getTime() + NEW_LINE);
 			recorded = true;
 		} catch (IOException e) {
 			LOG.error("Unable to record unmovable pending file " + unMovablePendingFile.getName() + "in the archive file " + PENDING_MOVE_FAILED_ARCHIVE_FILE);
 		} finally {
 			if (archiveFile != null) {
 				try {
 					archiveFile.close();
 				} catch (IOException ioe) {
 					LOG.error("Error closing unmovable pending file", ioe);
 				}
 			}
 		}
 		return recorded;
 	}
 
 	private boolean moveFile(File toDirectory, File fileToMove) {
 		boolean moved = true;
 		if (!fileToMove.renameTo(new File(toDirectory.getPath(), fileToMove.getName()))) {
 			LOG.error("Unable to move file " + fileToMove.getName() + " to directory " + toDirectory.getPath());
 			moved = false;
 		}
 		return moved;
 	}
 
 	private File getXmlPendingDir() {
 		return new File(getXmlPendingLocation());
 	}
 
 	private File getXmlCompleteDir() {
 		return new File(getXmlCompletedLocation());
 	}
 
 	private File getXmlProblemDir() {
 		return new File(getXmlProblemLocation());
 	}
 
 	public String getXmlCompletedLocation() {
 		return xmlCompletedLocation;
 	}
 
 	public void setXmlCompletedLocation(String xmlCompletedLocation) {
 		this.xmlCompletedLocation = xmlCompletedLocation;
 	}
 
 	public String getXmlPendingLocation() {
 		return xmlPendingLocation;
 	}
 
 	/*
 	 * public boolean validate(File uploadedFile) { XmlDataLoaderFileFilter filter = new XmlDataLoaderFileFilter(); return
 	 * filter.accept(uploadedFile); }
 	 */
 
 	public void setXmlPendingLocation(String xmlPendingLocation) {
 		this.xmlPendingLocation = xmlPendingLocation;
 	}
 
 	public String getXmlProblemLocation() {
 		return xmlProblemLocation;
 	}
 
 	public void setXmlProblemLocation(String xmlProblemLocation) {
 		this.xmlProblemLocation = xmlProblemLocation;
 	}
 
 	public String getXmlParentDirectory() {
 		return xmlParentDirectory;
 	}
 
 	public void setXmlParentDirectory(String xmlDataParentDirectory) {
 		this.xmlParentDirectory = xmlDataParentDirectory;
 	}
 
 	/**
 	 * Sets the polling interval time in seconds
 	 * 
 	 * @param seconds
 	 *            the polling interval time in seconds
 	 */
 	public void setPollIntervalSecs(int seconds) {
 		this.pollIntervalSecs = seconds;
 	}
 
 	/**
 	 * Gets the polling interval time in seconds
 	 * 
 	 * @return the polling interval time in seconds
 	 */
 	public int getPollIntervalSecs() {
 		return this.pollIntervalSecs;
 	}
 
 	/**
 	 * Sets the initial delay time in seconds
 	 * 
 	 * @param seconds
 	 *            the initial delay time in seconds
 	 */
 	public void setInitialDelaySecs(int seconds) {
 		this.initialDelaySecs = seconds;
 	}
 
 	/**
 	 * Gets the initial delay time in seconds
 	 * 
 	 * @return the initial delay time in seconds
 	 */
 	public int getInitialDelaySecs() {
 		return this.initialDelaySecs;
 	}
 }