/**
 * OLAT - Online Learning and Training<br>
 * http://www.olat.org
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License"); <br>
 * you may not use this file except in compliance with the License.<br>
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing,<br>
 * software distributed under the License is distributed on an "AS IS" BASIS, <br>
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
 * See the License for the specific language governing permissions and <br>
 * limitations under the License.
 * <p>
 * Copyright (c) 1999-2007 at Multimedia- & E-Learning Services (MELS),<br>
 * University of Zurich, Switzerland.
 * <p>
 */

package org.olat.ims.cp;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;

import org.dom4j.tree.DefaultDocument;
import org.dom4j.tree.DefaultElement;
import org.olat.core.id.OLATResourceable;
import org.olat.core.logging.OLATRuntimeException;
import org.olat.core.util.CodeHelper;
import org.olat.core.util.FileUtils;
import org.olat.core.util.ZipUtil;
import org.olat.core.util.vfs.LocalFolderImpl;
import org.olat.core.util.vfs.VFSContainer;
import org.olat.core.util.vfs.VFSItem;
import org.olat.core.util.vfs.VFSLeaf;
import org.olat.core.util.vfs.VFSManager;
import org.olat.core.util.xml.XMLParser;
import org.olat.fileresource.FileResourceManager;
import org.olat.ims.cp.objects.CPOrganization;
import org.olat.ims.cp.objects.CPResource;
import org.olat.ims.cp.ui.CPPage;
import org.olat.repository.RepositoryEntry;
import org.olat.repository.RepositoryManager;

/**
 * The CP manager implementation.
 * <p>
 * In many cases, method calls are delegated to the content package object.
 * 
 * <P>
 * Initial Date: 04.07.2008 <br>
 * 
 * @author Sergio Trentini
 */
public class CPManagerImpl extends CPManager {
	
	/**
	 * [spring]
	 */
	private CPManagerImpl() {
		INSTANCE = this;
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#load(org.olat.core.util.vfs.VFSContainer)
	 */
	public ContentPackage load(VFSContainer directory, OLATResourceable ores) {
		XMLParser parser = new XMLParser();
		ContentPackage cp;

		VFSLeaf file = (VFSLeaf) directory.resolve("imsmanifest.xml");

		if (file != null) {
			try {
				DefaultDocument doc = (DefaultDocument) parser.parse(file.getInputStream(), false);
				cp = new ContentPackage(doc, directory, ores);
				// If a wiki is imported or a new cp created, set a unique orga
				// identifier.
				if (cp.getLastError() == null) {
					if (cp.isOLATContentPackage() && CPCore.OLAT_ORGANIZATION_IDENTIFIER.equals(cp.getFirstOrganizationInManifest().getIdentifier())) {
						setUniqueOrgaIdentifier(cp);
					}
				}

			} catch (OLATRuntimeException e) {
				cp = new ContentPackage(null, directory, ores);
				logError("Reading imsmanifest failed. Dir: " + directory.getName() + ". Ores: " + ores.getResourceableId(), e);
				cp.setLastError("Exception reading XML for IMS CP: invalid xml-file ( " + directory.getName() + ")");
			}

		} else {
			cp = new ContentPackage(null, directory, ores);
			cp.setLastError("Exception reading XML for IMS CP: IMS-Manifest not found in " + directory.getName());
			logError("IMS manifiest xml couldn't be found in dir " + directory.getName() + ". Ores: " + ores.getResourceableId(), null);
			throw new OLATRuntimeException(CPManagerImpl.class, "The imsmanifest.xml file was not found.", new IOException());
		}
		return cp;
	}

	/**
	 * @see org.olat.ims.cp.CPManager#createNewCP(org.olat.core.id.OLATResourceable)
	 */
	public ContentPackage createNewCP(OLATResourceable ores, String initalPageTitle) {
		// copy template cp to new repo-location
		if (copyTemplCP(ores)) {
			File cpRoot = FileResourceManager.getInstance().unzipFileResource(ores);
			logDebug("createNewCP: cpRoot=" + cpRoot);
			logDebug("createNewCP: cpRoot.getAbsolutePath()=" + cpRoot.getAbsolutePath());
			System.out.println("createNewCP: cpRoot.getAbsolutePath()=" + cpRoot.getAbsolutePath());
			LocalFolderImpl vfsWrapper = new LocalFolderImpl(cpRoot);
			ContentPackage cp = load(vfsWrapper, ores);

			// Modify the copy of the template to get a unique identifier
			CPOrganization orga = setUniqueOrgaIdentifier(cp);
			setOrgaTitleToRepoEntryTitle(ores, orga);
			// Also set the translated title of the inital page.
			orga.getItems().get(0).setTitle(initalPageTitle);

			writeToFile(cp);
			return cp;

		} else {
			logError("CP couldn't be created. Error when copying template. Ores: " + ores.getResourceableId(), null);
			throw new OLATRuntimeException("ERROR while creating new empty cp. an error occured while trying to copy template CP", null);
		}
	}

	/**
	 * Sets the organization title to the title of the repository entry.
	 * 
	 * @param ores
	 * @param orga
	 */
	private void setOrgaTitleToRepoEntryTitle(OLATResourceable ores, CPOrganization orga) {
		// Set the title of the organization to the title of the resource.
		RepositoryManager resMgr = RepositoryManager.getInstance();
		RepositoryEntry cpEntry = resMgr.lookupRepositoryEntry(ores, false);
		if (cpEntry != null) {
			String title = cpEntry.getDisplayname();
			orga.setTitle(title);
		}
	}

	/**
	 * Assigns the organization a unique identifier in order to prevent any
	 * caching issues in the extjs menu tree later.
	 * 
	 * @param cp
	 * @return The first organization of the content package.
	 */
	private CPOrganization setUniqueOrgaIdentifier(ContentPackage cp) {
		CPOrganization orga = cp.getFirstOrganizationInManifest();
		String newOrgaIdentifier = "olatcp-" + CodeHelper.getForeverUniqueID();
		orga.setIdentifier(newOrgaIdentifier);
		return orga;
	}

	public boolean isSingleUsedResource(CPResource res, ContentPackage cp) {
		return cp.isSingleUsedResource(res);
	}

	@Override
	public String addBlankPage(ContentPackage cp, String title) {
		return cp.addBlankPage(title);
	}

	@Override
	public String addBlankPage(ContentPackage cp, String title, String parentNodeID) {
		return cp.addBlankPage(parentNodeID, title);
	}

	@Override
	public void updatePage(ContentPackage cp, CPPage page) {
		cp.updatePage(page);
	}

	/**
	 * @see org.olat.ims.cp.CPManager#addElement(org.olat.ims.cp.ContentPackage,
	 *      org.dom4j.tree.DefaultElement)
	 */
	public boolean addElement(ContentPackage cp, DefaultElement newElement) {
		return cp.addElement(newElement);

	}

	/**
	 * @see org.olat.ims.cp.CPManager#addElement(org.olat.ims.cp.ContentPackage,
	 *      org.dom4j.tree.DefaultElement, java.lang.String)
	 */
	public boolean addElement(ContentPackage cp, DefaultElement newElement, String parentIdentifier, int position) {
		return cp.addElement(newElement, parentIdentifier, position);
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#addElementAfter(org.olat.ims.cp.ContentPackage,
	 *      org.dom4j.tree.DefaultElement, java.lang.String)
	 */
	public boolean addElementAfter(ContentPackage cp, DefaultElement newElement, String identifier) {
		return cp.addElementAfter(newElement, identifier);
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#removeElement(org.olat.ims.cp.ContentPackage,
	 *      java.lang.String)
	 */
	public void removeElement(ContentPackage cp, String identifier, boolean deleteResource) {
		cp.removeElement(identifier, deleteResource);
	}

	/**
	 * @see org.olat.ims.cp.CPManager#moveElement(org.olat.ims.cp.ContentPackage,
	 *      java.lang.String, java.lang.String, int)
	 */
	public void moveElement(ContentPackage cp, String nodeID, String newParentID, int position) {
		cp.moveElement(nodeID, newParentID, position);
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#copyElement(org.olat.ims.cp.ContentPackage,
	 *      java.lang.String)
	 */
	public String copyElement(ContentPackage cp, String sourceID) {
		return cp.copyElement(sourceID, sourceID);
	}

	/**
	 * @see org.olat.ims.cp.CPManager#getDocument(org.olat.ims.cp.ContentPackage)
	 */
	public DefaultDocument getDocument(ContentPackage cp) {
		return cp.getDocument();
	}

	public String getItemTitle(ContentPackage cp, String itemID) {
		return cp.getItemTitle(itemID);
	}

	/**
	 * @see org.olat.ims.cp.CPManager#getElementByIdentifier(org.olat.ims.cp.ContentPackage,
	 *      java.lang.String)
	 */
	public DefaultElement getElementByIdentifier(ContentPackage cp, String identifier) {
		return cp.getElementByIdentifier(identifier);
	}

	@Override
	public CPTreeDataModel getTreeDataModel(ContentPackage cp) {
		return cp.buildTreeDataModel();
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#getFirstOrganizationInManifest(org.olat.ims.cp.ContentPackage)
	 */
	@Override
	public CPOrganization getFirstOrganizationInManifest(ContentPackage cp) {
		return cp.getFirstOrganizationInManifest();
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#getFirstPageToDisplay(org.olat.ims.cp.ContentPackage)
	 */
	@Override
	public CPPage getFirstPageToDisplay(ContentPackage cp) {
		return cp.getFirstPageToDisplay();
	}

	/**
	 * @see org.olat.ims.cp.CPManager#WriteToFile(org.olat.ims.cp.ContentPackage)
	 */
	public void writeToFile(ContentPackage cp) {
		cp.writeToFile();
	}

	/**
	 * @see org.olat.ims.cp.CPManager#writeToZip(org.olat.ims.cp.ContentPackage)
	 */
	public VFSLeaf writeToZip(ContentPackage cp) {
		OLATResourceable ores = cp.getResourcable();
		VFSContainer cpRoot = cp.getRootDir();
		VFSContainer oresRoot = FileResourceManager.getInstance().getFileResourceRootImpl(ores);
		RepositoryEntry repoEntry = RepositoryManager.getInstance().lookupRepositoryEntry(ores, false);
		String zipFileName = "imscp.zip";
		if (repoEntry != null) {
			String zipName = repoEntry.getResourcename();
			if (zipName != null && zipName.endsWith(".zip")) {
				zipFileName = zipName;
			}
		}
		// delete old archive and create new one
		VFSItem oldArchive = oresRoot.resolve(zipFileName);
		if (oldArchive != null) {
			oldArchive.delete();
		}
		ZipUtil.zip(cpRoot.getItems(), oresRoot.createChildLeaf(zipFileName));
		VFSLeaf zip = (VFSLeaf) oresRoot.resolve(zipFileName);
		return zip;
	}

	/**
	 * 
	 * @see org.olat.ims.cp.CPManager#getPageByItemId(org.olat.ims.cp.ContentPackage,
	 *      java.lang.String)
	 */
	@Override
	public String getPageByItemId(ContentPackage cp, String itemIdentifier) {
		return cp.getPageByItemId(itemIdentifier);
	}

	/**
	 * copies the default,empty, cp template to the new ores-directory
	 * 
	 * @param ores
	 * @return
	 */
	private boolean copyTemplCP(OLATResourceable ores) {
		File root = FileResourceManager.getInstance().getFileResourceRoot(ores);

		String packageName = ContentPackage.class.getCanonicalName();
		String path = packageName.replace('.', '/');
		path = path.replace("/ContentPackage", "/_resources/imscp.zip");

		path = VFSManager.sanitizePath(path);
		URL url = this.getClass().getResource(path);
		try {
			File f = new File(url.toURI());
			if (f.exists() && root.exists()) {
				FileUtils.copyFileToDir(f, root);
			} else {
				logError("cp template was not copied. Source:  " + url + " Target: " + root.getAbsolutePath(), null);
			}
		} catch (URISyntaxException e) {
			logError("Bad url syntax when copying cp template. url: " + url + " Ores:" + ores.getResourceableId(), null);
			return false;
		}

		return true;
	}

}