package org.gcube.dataharvest.harvester.sobigdata;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.SortedSet;

import org.apache.commons.lang.Validate;
import org.gcube.common.homelibrary.home.Home;
import org.gcube.common.homelibrary.home.HomeLibrary;
import org.gcube.common.homelibrary.home.HomeManager;
import org.gcube.common.homelibrary.home.exceptions.InternalErrorException;
import org.gcube.common.homelibrary.home.workspace.WorkspaceItem;
import org.gcube.common.homelibrary.home.workspace.accounting.AccountingEntry;
import org.gcube.common.homelibrary.jcr.repository.JCRRepository;
import org.gcube.common.homelibrary.jcr.workspace.JCRWorkspace;
import org.gcube.common.homelibrary.jcr.workspace.JCRWorkspaceItem;
import org.gcube.dataharvest.datamodel.HarvestedData;
import org.gcube.dataharvest.datamodel.HarvestedDataKey;
import org.gcube.dataharvest.utils.DateUtils;
import org.gcube.dataharvest.utils.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Eric Perrone (ISTI - CNR)
 * @author Luca Frosini (ISTI - CNR)
 */
public class DataMethodDownloadHarvester extends SoBigDataHarvester {

	private static Logger logger = LoggerFactory.getLogger(DataMethodDownloadHarvester.class);

	private int count = 0;

	public DataMethodDownloadHarvester(Date start, Date end, String catalogueContext, SortedSet<String> contexts) throws ParseException {
		super(start, end, catalogueContext, contexts);
	}

	@Override
	public List<HarvestedData> getData() throws Exception {
		String defaultContext = Utils.getCurrentContext();
		logger.debug("The context is: "+defaultContext);

		try {

			String vreName = getVRENameToHL(defaultContext);
			logger.debug("Getting VRE Name to HL from context/scope returns: "+vreName);

			String user = vreName + "-Manager";
			logger.debug("Using user '"+user+"' to getHome from HL");

			//ISTANCING HL AND GETTING HOME FOR VRE MANAGER
			HomeManager manager = HomeLibrary.getHomeManagerFactory().getHomeManager();
			@SuppressWarnings("deprecation")
			Home home = manager.getHome(user);
			JCRWorkspace ws = (JCRWorkspace) home.getWorkspace();
//
			String path = "/Workspace/MySpecialFolders/" + vreName;
			logger.debug("Getting item by Path: "+path);
			JCRWorkspaceItem item = (JCRWorkspaceItem) ws.getItemByPath(path);
//
			logger.info("Analyzing " + defaultContext + " in the period [" + startDate.toString() + " to " + endDate.toString() +"] starting from root: "+item.getName());

			HarvestedData defaultHarvesteData = new HarvestedData(HarvestedDataKey.DATA_METHOD_DOWNLOAD, defaultContext, count);

			List<HarvestedData> data = new ArrayList<HarvestedData>();
			for (WorkspaceItem children: item.getChildren()) {
				count = 0; //resettings the counter
				HarvestedData harvestedData;
				//Getting statistics for folder
				if(children.isFolder()){
					logger.info("Getting statistics for folder: "+children.getName());
					getStats(children, startDate, endDate);

					String normalizedName = children.getName().replaceAll("[^A-Za-z0-9]","");
					String scope = mapWsFolderNameToVRE.get(normalizedName);
					//Checking if it is a VRE name to right accouning...
					if(scope!=null && !scope.isEmpty()){
						logger.info("Found scope '" + scope + "' matching with normalized VRE name: "+normalizedName);
						harvestedData = new HarvestedData(HarvestedDataKey.DATA_METHOD_DOWNLOAD, scope, count);
						data.add(harvestedData);
						logger.info("Added data: "+harvestedData);
					}else{
						logger.info("No scope found matching the folder name: "+normalizedName +", accounting its stats in the default context: "+defaultContext);
						//INCREASING THE DEFAULT CONTEXT COUNTER...
						defaultHarvesteData.setMeasure(defaultHarvesteData.getMeasure()+count);
						logger.info("Increased default context stats: "+defaultHarvesteData);
					}

				}
			}

			//ADDING DEFAULT ACCOUNTING
			data.add(defaultHarvesteData);

			logger.info("In the period [from "+startDate+" to "+endDate+ "] returning workspace accouting data:");
			for (HarvestedData harvestedData : data) {
				logger.info(harvestedData.toString());
			}

			return data;

		} catch(Exception e) {
			throw e;
		}

	}


	/**
	 * Gets the stats.
	 *
	 * @param baseItem the base item
	 * @param start the start
	 * @param end the end
	 * @return the stats
	 * @throws InternalErrorException the internal error exception
	 */
	private void getStats(WorkspaceItem baseItem, Date start, Date end) throws InternalErrorException {
		List<? extends WorkspaceItem> children;
		if(baseItem.isFolder()) {
			children = baseItem.getChildren();
			for(WorkspaceItem child : children)
				getStats(child, start, end);
		} else {
			try {

				List<AccountingEntry> accounting = baseItem.getAccounting();
				for(AccountingEntry entry : accounting) {

					switch(entry.getEntryType()) {
						case CREATE:
						case UPDATE:
						case READ:
							Calendar calendar = entry.getDate();
							if(calendar.after(DateUtils.dateToCalendar(start)) && calendar.before(DateUtils.dateToCalendar(end))) {
								count++;
							}

							break;

						default:
							break;
					}

				}
			} catch(Exception e) {
				logger.error("DataMethodDownloadHarvester: " + e.getLocalizedMessage());
				throw new InternalErrorException(e.getLocalizedMessage());
			}
		}
	}


	/**
	 * Gets the VRE name to HL.
	 *
	 * @param vre the vre
	 * @return the VRE name to HL
	 */
	private static String getVRENameToHL(String vre) {
		Validate.notNull(vre, "scope must be not null");

		String newName;
		if(vre.startsWith(JCRRepository.PATH_SEPARATOR))
			newName = vre.replace(JCRRepository.PATH_SEPARATOR, "-").substring(1);
		else
			newName = vre.replace(JCRRepository.PATH_SEPARATOR, "-");
		return newName;
	}

}