/*
 * LinShare is an open source filesharing software, part of the LinPKI software
 * suite, developed by Linagora.
 * 
 * Copyright (C) 2015 LINAGORA
 * 
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version, provided you comply with the Additional Terms applicable for
 * LinShare software by Linagora pursuant to Section 7 of the GNU Affero General
 * Public License, subsections (b), (c), and (e), pursuant to which you must
 * notably (i) retain the display of the “LinShare™” trademark/logo at the top
 * of the interface window, the display of the “You are using the Open Source
 * and free version of LinShare™, powered by Linagora © 2009–2015. Contribute to
 * Linshare R&D by subscribing to an Enterprise offer!” infobox and in the
 * e-mails sent with the Program, (ii) retain all hypertext links between
 * LinShare and linshare.org, between linagora.com and Linagora, and (iii)
 * refrain from infringing Linagora intellectual property rights over its
 * trademarks and commercial brands. Other Additional Terms apply, see
 * <http://www.linagora.com/licenses/> for more details.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Affero General Public License and
 * its applicable Additional Terms for LinShare along with this program. If not,
 * see <http://www.gnu.org/licenses/> for the GNU Affero General Public License
 * version 3 and <http://www.linagora.com/licenses/> for the Additional Terms
 * applicable to LinShare software.
 */
package org.linagora.linshare.core.facade.impl;

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

import org.linagora.linshare.core.domain.constants.AccountType;
import org.linagora.linshare.core.domain.entities.User;
import org.linagora.linshare.core.domain.vo.UserVo;
import org.linagora.linshare.core.exception.BusinessException;
import org.linagora.linshare.core.facade.UserAutoCompleteFacade;
import org.linagora.linshare.core.service.UserService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserAutoCompleteFacadeImpl implements UserAutoCompleteFacade {

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

	final private static int AUTO_COMPLETE_LIMIT = 20;

	private UserService userService;

	public UserAutoCompleteFacadeImpl(UserService userService) {
		super();
		this.userService = userService;
	}

	@Override
	public List<UserVo> autoCompleteUser(UserVo currentUserVo, String pattern) throws BusinessException {
		List<User> users = userService.autoCompleteUser(currentUserVo.getLogin(), pattern);
		logger.debug("nb result for completion : " + users.size());
		// TODO : FMA : Use database configuration for auto complete limit
		return getUserVoList(users, AUTO_COMPLETE_LIMIT, true);
	}

	@Override
	public List<UserVo> autoCompleteUserSortedByFavorites(UserVo currentUserVo, String pattern) throws BusinessException {
		List<User> users = userService.autoCompleteUser(currentUserVo.getLogin(), pattern);
		logger.debug("nb result for completion : " + users.size());

		// TODO : FIXME : FMA : add favorite sort.
		// userSet.addAll(recipientFavouriteFacade.findRecipientFavorite(input,
		// userVo));
		// return recipientFavouriteFacade.recipientsOrderedByWeightDesc(new
		// ArrayList<UserVo>(userSet), userVo);

		// TODO : FMA : Use database configuration for auto complete limit
		return getUserVoList(users, AUTO_COMPLETE_LIMIT, true);
	}

	@Override
	public List<String> autoCompleteMail(UserVo currentUserVo, String pattern) throws BusinessException {
		List<User> users = userService.autoCompleteUser(currentUserVo.getLogin(), pattern);
		logger.debug("nb result for completion : " + users.size());
		// TODO : FMA : Use database configuration for auto complete limit
		return getMailList(users, AUTO_COMPLETE_LIMIT);
	}

	/***********************/
	/** Utility functions **/
	/***********************/

	class EmptyUserVo extends UserVo {
		private static final long serialVersionUID = 1188489032838386296L;

		public EmptyUserVo() {
			super(null, null, null, "...", AccountType.INTERNAL);
		}
	}

	/**
	 * Convert a list of Users to a list of UserVo.
	 * 
	 * @param users
	 *            a list of users.
	 * @param limit
	 * 			set the max element to be return
	 * @param addEmptyUser
	 *            TODO
	 * @return a list of UserVo.
	 */
	private List<UserVo> getUserVoList(List<User> users, int limit, boolean addEmptyUser) {
		List<UserVo> userVos = new ArrayList<UserVo>();
		int count = 0;
		for (User user : users) {
			userVos.add(new UserVo(user));
			count++;
			if (count == limit) {
				if (addEmptyUser)
					userVos.add(new EmptyUserVo());
				break;
			}
		}
		return userVos;
	}
	
	private List<String> getMailList(List<User> users, int limit) {
		int count = 0;
		List<String> res = new ArrayList<String>();
		for (User user : users) {
			res.add(user.getMail());
			count++;
			if (count == limit) {
				res.add("...");
				break;
			}
		}
		return res;
	}
}
