/**
* 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) since 2004 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <hr>
* <a href="http://www.openolat.org">
* OpenOLAT - Online Learning and Training</a><br>
* This file has been modified by the OpenOLAT community. Changes are licensed
* under the Apache 2.0 license as the original file.  
* <p>
*/ 

package org.olat.core.commons.modules.bc.commands;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.olat.core.commons.modules.bc.FileSelection;
import org.olat.core.commons.modules.bc.components.FolderComponent;
import org.olat.core.commons.services.notifications.NotificationsManager;
import org.olat.core.commons.services.notifications.SubscriptionContext;
import org.olat.core.commons.services.vfs.VFSMetadata;
import org.olat.core.commons.services.vfs.VFSRepositoryService;
import org.olat.core.commons.services.vfs.model.VFSMetadataImpl;
import org.olat.core.gui.UserRequest;
import org.olat.core.gui.components.Component;
import org.olat.core.gui.control.Controller;
import org.olat.core.gui.control.Event;
import org.olat.core.gui.control.WindowControl;
import org.olat.core.gui.control.controller.BasicController;
import org.olat.core.gui.control.generic.modal.DialogBoxController;
import org.olat.core.gui.translator.Translator;
import org.olat.core.id.Identity;
import org.olat.core.logging.AssertException;
import org.olat.core.util.StringHelper;
import org.olat.core.util.ZipUtil;
import org.olat.core.util.vfs.Quota;
import org.olat.core.util.vfs.VFSConstants;
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.vfs.callbacks.VFSSecurityCallback;
import org.springframework.beans.factory.annotation.Autowired;

public class CmdUnzip extends BasicController implements FolderCommand {

	private int status = FolderCommandStatus.STATUS_SUCCESS;
	
	private Translator translator;
	private DialogBoxController lockedFiledCtr;
	
	@Autowired
	private VFSRepositoryService vfsRepositoryService;
	@Autowired
	private NotificationsManager notificationsManager;
	
	public CmdUnzip(UserRequest ureq, WindowControl wControl) {
		super(ureq, wControl);
	}
	
	@Override
	public Controller execute(FolderComponent folderComponent, UserRequest ureq, WindowControl wContr, Translator trans) {
		this.translator = trans;
		// BUG: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
		// FileSelection selection = new FileSelection(ureq, folderComponent.getCurrentContainerPath());
		// FIXED: 
		FileSelection selection = new FileSelection(ureq, folderComponent.getCurrentContainer(), folderComponent.getCurrentContainerPath());
		VFSContainer currentContainer = folderComponent.getCurrentContainer();
		if (currentContainer.canWrite() != VFSConstants.YES)
			throw new AssertException("Cannot unzip to folder. Writing denied.");
			
	  //check if command is executed on a file containing invalid filenames or paths - checks if the resulting folder has a valid name
		if(selection.getInvalidFileNames().size()>0) {				
			status = FolderCommandStatus.STATUS_INVALID_NAME;
			return null;
		}		
		
		List<String> lockedFiles = new ArrayList<>();
		for (String sItem:selection.getFiles()) {
			VFSItem vfsItem = currentContainer.resolve(sItem);
			if (vfsItem instanceof VFSLeaf) {
				try {
					lockedFiles.addAll(checkLockedFiles((VFSLeaf)vfsItem, currentContainer, ureq.getIdentity()));
				} catch (Exception e) {
					String name = vfsItem == null ? "NULL" : vfsItem.getName();
					getWindowControl().setError(translator.translate("FileUnzipFailed", new String[]{name}));
				}
			}
		}
		
		if(!lockedFiles.isEmpty()) {
			String msg = FolderCommandHelper.renderLockedMessageAsHtml(trans, lockedFiles);
			List<String> buttonLabels = Collections.singletonList(trans.translate("ok"));
			lockedFiledCtr = activateGenericDialog(ureq, trans.translate("lock.title"), msg, buttonLabels, lockedFiledCtr);
			return null;
		}
		
		VFSItem currentVfsItem = null;
		try {
			boolean fileNotExist = false;
			for (String sItem:selection.getFiles()) {
				currentVfsItem = currentContainer.resolve(sItem);
				if (currentVfsItem instanceof VFSLeaf) {
					if (!doUnzip((VFSLeaf)currentVfsItem, currentContainer, ureq, wContr)) {
						status = FolderCommandStatus.STATUS_FAILED;
						break;
					}
				} else {
					fileNotExist = true;
					break;
				}
			}
			
			if (fileNotExist) {
				status = FolderCommandStatus.STATUS_FAILED;
				getWindowControl().setError(translator.translate("FileDoesNotExist"));
			}
			
			VFSContainer inheritingCont = VFSManager.findInheritingSecurityCallbackContainer(folderComponent.getRootContainer());
			if(inheritingCont != null) {
				VFSSecurityCallback secCallback = inheritingCont.getLocalSecurityCallback();
				if(secCallback != null) {
					SubscriptionContext subsContext = secCallback.getSubscriptionContext();
					if (subsContext != null) {
						notificationsManager.markPublisherNews(subsContext, ureq.getIdentity(), true);
					}
				}
			}
		} catch (IllegalArgumentException e) {
			logError("Corrupted ZIP", e);
			String name = currentVfsItem == null ? "NULL" : currentVfsItem.getName();
			getWindowControl().setError(translator.translate("FileUnzipFailed", new String[]{name}));
		}
		
		return null;
	}
	
	private List<String> checkLockedFiles(VFSLeaf vfsItem, VFSContainer currentContainer, Identity identity) {
		String name = vfsItem.getName();
		if (!name.toLowerCase().endsWith(".zip")) {
			return Collections.emptyList();
		}
	
		if(currentContainer.canVersion() != VFSConstants.YES) {
			//this command don't overwrite existing folders
			return Collections.emptyList();
		}
		
		String sZipContainer = name.substring(0, name.length() - 4);
		VFSItem zipContainer = currentContainer.resolve(sZipContainer);
		if(zipContainer == null) {
			return Collections.emptyList();
		} else if (zipContainer instanceof VFSContainer) {
			return ZipUtil.checkLockedFileBeforeUnzipNonStrict(vfsItem, (VFSContainer)zipContainer, identity);
		} else {
			//replace a file with a folder ???
			return Collections.emptyList();
		}
	}

	private boolean doUnzip(VFSLeaf vfsItem, VFSContainer currentContainer, UserRequest ureq, WindowControl wControl) {
		String name = vfsItem.getName();
		if (!name.toLowerCase().endsWith(".zip")) {
			wControl.setError(translator.translate("FileUnzipFailed", new String[] {vfsItem.getName()}));
			return false;
		} 
		
		// we make a new folder with the same name as the zip file
		String sZipContainer = name.substring(0, name.length() - 4);
		
		boolean versioning = currentContainer.canVersion() == VFSConstants.YES;
		
		VFSContainer zipContainer = currentContainer.createChildContainer(sZipContainer);
		if (zipContainer == null) {
			if(versioning) {
				VFSItem resolvedItem = currentContainer.resolve(sZipContainer);
				if(resolvedItem instanceof VFSContainer) {
					zipContainer = (VFSContainer)resolvedItem;
				} else {
					String numberedFilename = findContainerName(currentContainer, sZipContainer);
					if(StringHelper.containsNonWhitespace(numberedFilename)) {
						zipContainer = currentContainer.createChildContainer(numberedFilename);
					}
					if(zipContainer == null) {// we try our best
						wControl.setError(translator.translate("unzip.alreadyexists", new String[] {sZipContainer}));
						return false;
					}
				}
			} else {
				// folder already exists... issue warning
				wControl.setError(translator.translate("unzip.alreadyexists", new String[] {sZipContainer}));
				return false;
			}
		} else if (zipContainer.canMeta() == VFSConstants.YES) {
			VFSMetadata info = zipContainer.getMetaInfo();
			if(info instanceof VFSMetadataImpl) {
				((VFSMetadataImpl)info).setFileInitializedBy(ureq.getIdentity());
				vfsRepositoryService.updateMetadata(info);
			}
		}
		
		if (!ZipUtil.unzipNonStrict(vfsItem, zipContainer, ureq.getIdentity(), versioning)) {
			// operation failed - rollback
			zipContainer.delete();
			wControl.setError(translator.translate("failed"));
			return false;
		} else {
			// check quota
			long quotaLeftKB = VFSManager.getQuotaLeftKB(currentContainer);
			if (quotaLeftKB != Quota.UNLIMITED && quotaLeftKB < 0) {
				// quota exceeded - rollback
				zipContainer.delete();
				wControl.setError(translator.translate("QuotaExceeded"));
				return false;
			}
		}
		return true;
	}
	
	private String findContainerName(VFSContainer container, String filename) {
		String newName = filename;
		VFSItem newFile = container.resolve(newName);
		for(int count=1; newFile != null && count < 999 ; count++) {
			newName = filename + "_" + count;
		    newFile = container.resolve(newName);
		}
		if(newFile == null) {
			return newName;
		}
		return null;
	}

	@Override
	public int getStatus() {
		return status;
	}

	@Override
	public boolean runsModal() {
		return false;
	}
	
	@Override
	public String getModalTitle() {
		return null;
	}


	@Override
	protected void doDispose() {
		//autodisposed by BasicController
	}

	@Override
	protected void event(UserRequest ureq, Component source, Event event) {
		// no events to catch
	}
	
	@Override
	public void event(UserRequest ureq, Controller source, Event event) {
		// no events to catch
	}
	
	

}