package org.gcube.portlets.widgets.ckandatapublisherwidget.server.utils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

import org.gcube.common.homelibrary.home.HomeLibrary;
import org.gcube.common.homelibrary.home.exceptions.InternalErrorException;
import org.gcube.common.homelibrary.home.workspace.Workspace;
import org.gcube.common.homelibrary.home.workspace.WorkspaceFolder;
import org.gcube.common.homelibrary.home.workspace.WorkspaceItem;
import org.gcube.common.homelibrary.home.workspace.catalogue.WorkspaceCatalogue;
import org.gcube.common.homelibrary.home.workspace.folder.FolderItem;
import org.gcube.datacatalogue.ckanutillibrary.models.ResourceBean;
import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.DatasetMetadataBean;
import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.ResourceElementBean;
import org.slf4j.LoggerFactory;

public class WorkspaceUtils {


	private static final org.slf4j.Logger logger = LoggerFactory.getLogger(WorkspaceUtils.class);
	private static final String RESOURCES_NAME_SEPARATOR = "_";

	/**
	 * Copy into the .catalogue area folder the checked resources
	 * @param folderId
	 * @param userName
	 * @param bean
	 * @return
	 */
	public static List<ResourceBean> copyResourcesToUserCatalogueArea(String folderId, String userName, DatasetMetadataBean bean) throws Exception{

		logger.debug("Request to copy onto catalogue area....");
		List<ResourceBean> resources = new ArrayList<ResourceBean>();
		WorkspaceItem copiedFolder = null;
		WorkspaceCatalogue userCatalogue = null;
		List<ResourceElementBean> resourcesToAdd = bean.getResources();

		// in to the .catalogue area of the user's workspace
		Workspace ws = HomeLibrary
				.getHomeManagerFactory()
				.getHomeManager()
				.getHome()
				.getWorkspace();

		// Retrieve the catalogue of the user
		userCatalogue = ws.getCatalogue();

		// Create the folder in the catalogue
		copiedFolder = userCatalogue.addWorkspaceItem(folderId, userCatalogue.getId()); // add to .catalogue root area

		// change description for the folder
		copiedFolder.setDescription(bean.getDescription());

		// change name of the copied folder to match the title (append the timestamp to avoid ties)
		((WorkspaceFolder)copiedFolder).rename(org.gcube.datacatalogue.ckanutillibrary.utils.UtilMethods.fromProductTitleToName(bean.getTitle()) + "_" + System.currentTimeMillis());

		// copy only the selected ones
		for(ResourceElementBean resource : resourcesToAdd){

			if (resource.isToBeAdded()) {

				// ok it is a file, so copy it into the copiedFolder
				WorkspaceItem copiedFile = userCatalogue.addWorkspaceItem(resource.getOriginalIdInWorkspace(), copiedFolder.getId());

				// name and description could have been edited
				copiedFile.setDescription(resource.getDescription());

				resources.add(new ResourceBean(
						copiedFile.getPublicLink(true), 
						resource.getName(), 
						copiedFile.getDescription(), 
						copiedFile.getId(),
						userName, 
						null, // to be set
						((FolderItem)copiedFile).getMimeType()));

				// postpone rename operation
				copiedFile.rename(resource.getName() + "_" + System.currentTimeMillis());
			}
		}

		// return
		return resources;
	}

	/**
	 * This method receives a folder id within the user's workspace and set the list of resources in the dataset bean to be returned
	 * @param folderId
	 * @param owner
	 * @param bean
	 * @param userName
	 * @throws Exception
	 */
	public static void handleWorkspaceResources(String folderId, String userName,
			DatasetMetadataBean bean) throws Exception {

		// get workspace
		Workspace ws = HomeLibrary
				.getHomeManagerFactory()
				.getHomeManager()
				.getHome().getWorkspace();

		WorkspaceItem originalFolder = ws.getItem(folderId);

		// set some info
		String onlyAlphanumericTitle = originalFolder.getName().replaceAll("[^A-Za-z0-9.-_]", " "); // that is, remove characters different than the ones inside
		// since it will (likely) be the name of the product
		bean.setTitle(onlyAlphanumericTitle);
		bean.setDescription(originalFolder.getDescription());

		// Create the folder in the catalogue
		Map<String, String> folderItems = Utils.getGcubeItemProperties(originalFolder);
		bean.setCustomFields(folderItems);

		// set them into the bean
		bean.setResources(Arrays.asList(WorkspaceUtils.getTreeFromFolder(folderId, ws)));

	}

	/**
	 * Returns a tree object
	 * @param workspaceFolderId
	 * @param ws
	 * @return ResourceElementBean a tree object
	 * @throws Exception 
	 */
	public static ResourceElementBean getTreeFromFolder(String workspaceFolderId, Workspace ws) throws Exception{

		// start tree construction
		ResourceElementBean rootElem = new ResourceElementBean();
		String pathSeparator = ws.getPathSeparator();
		try{
			WorkspaceItem initialItemWS = ws.getItem(workspaceFolderId);
			String fullPathBase = initialItemWS.getPath();
			fullPathBase = fullPathBase.endsWith(ws.getPathSeparator()) ? fullPathBase : fullPathBase + ws.getPathSeparator();
			rootElem.setFolder(initialItemWS.isFolder());
			rootElem.setFullPath(initialItemWS.getPath().replace(fullPathBase, ""));
			rootElem.setParent(null);
			rootElem.setName(initialItemWS.getName());
			rootElem.setOriginalIdInWorkspace(initialItemWS.getId());
			replaceFullPath(rootElem, pathSeparator);
			// start visiting
			visit(rootElem, initialItemWS, fullPathBase, pathSeparator);
		}catch(Exception e){
			logger.error("Failed to build the resource tree", e);
			return null;
		}
		return rootElem;
	}

	/**
	 * Replaces the "/" char with a custom one
	 * @param rootElem
	 * @param pathSeparatorInWs
	 */
	private static void replaceFullPath(ResourceElementBean rootElem, String pathSeparatorInWs) {
		
		if(rootElem == null)
			return;
		
		String elemName = rootElem.getName();
		int lastIndex = rootElem.getFullPath().lastIndexOf(elemName);
		String fullPath = rootElem.getFullPath().substring(0, lastIndex);
		fullPath = fullPath.replaceAll(pathSeparatorInWs, RESOURCES_NAME_SEPARATOR) + elemName;
		rootElem.setFullPath(fullPath);
	}

	/**
	 * Recursive visit of a workspace item
	 * @param rootElem
	 * @param initialItemWS
	 * @throws InternalErrorException
	 */
	private static void visit(ResourceElementBean rootElem, WorkspaceItem initialItemWS, String fullPathBase, String pathSeparator) throws InternalErrorException {
		List<? extends WorkspaceItem> children = initialItemWS.getChildren();
		ArrayList<ResourceElementBean> childrenInTree = new ArrayList<ResourceElementBean>(children.size());
		for (WorkspaceItem workspaceItem : children) {
			ResourceElementBean elem = new ResourceElementBean();
			elem.setFolder(workspaceItem.isFolder());
			elem.setOriginalIdInWorkspace(workspaceItem.getId());
			elem.setFullPath(workspaceItem.getPath().replace(fullPathBase, "")); 
			elem.setParent(rootElem);
			elem.setName(workspaceItem.getName());
			replaceFullPath(elem, pathSeparator);
			childrenInTree.add(elem);
			visit(elem, workspaceItem, fullPathBase, pathSeparator);
		}
		rootElem.setChildren(childrenInTree);
	}

}