EDIT

/**

* Copyright (C) 2009 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.persistence.query;

import java.util.Arrays;

import java.util.List;

import java.util.Map;

import org.apache.log4j.Logger;

import org.apache.lucene.search.SortField;

import org.hibernate.Criteria;

import org.hibernate.criterion.Order;

import org.hibernate.envers.query.AuditEntity;

import org.hibernate.envers.query.AuditQuery;

import eu.etaxonomy.cdm.hibernate.search.NomenclaturalSortOrderBrigde;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.cdm.model.common.IdentifiableEntity;

import eu.etaxonomy.cdm.persistence.dao.common.OperationNotSupportedInPriorViewException;

public class OrderHint {

    public enum SortOrder {

        /**

         * items are sorted in increasing

         * order.

         */

        ASCENDING("asc"),

        /**

         * items are sorted in decreasing

         * order.

         */

        DESCENDING("desc");

        private String hql;

        private SortOrder(String hqlStr){

            hql = hqlStr;

        }

        public String toHql(){

            return hql;

        }

    }

    public static final Logger logger = Logger.getLogger(OrderHint.class);

    private final String propertyName;

    private final SortOrder sortOrder;

    public final String LUCENE_SCORE = "LUCENE_SCORE";

    public static final List<OrderHint> ORDER_BY_ID = Arrays.asList(new OrderHint[]{new OrderHint("id", SortOrder.ASCENDING)});

    public static final List<OrderHint> ORDER_BY_TITLE_CACHE = Arrays.asList(new OrderHint[]{new OrderHint("titleCache", SortOrder.ASCENDING)});

    public static final List<OrderHint> NOMENCLATURAL_SORT_ORDER = Arrays.asList(new OrderHint[]{new OrderHint(NomenclaturalSortOrderBrigde.NAME_SORT_FIELD_NAME, SortOrder.ASCENDING)});

    /**

     * @param clazz

     * @return "by titleCache" for all IdentifiableEntitys otherwise "by id"

     */

    public static List<OrderHint> defaultOrderHintsFor(Class<? extends CdmBase> clazz) {

        if (clazz.isAssignableFrom(IdentifiableEntity.class)) {

            return ORDER_BY_TITLE_CACHE;

        } else {

            return ORDER_BY_ID;

        }

    }

    public OrderHint(String fieldName, SortOrder sortOrder) {

        super();

        this.propertyName = fieldName;

        this.sortOrder = sortOrder;

    }

    /**

     * The property of a bean

     * @return

     */

    public String getPropertyName() {

        return propertyName;

    }

    /**

     * possible sort orders are {@link SortOrder.ASCENDING} or {@link SortOrder.DESCENDING}

     * @return

     */

    public SortOrder getSortOrder() {

        return sortOrder;

    }

    public boolean isAscending(){

        return sortOrder.equals(SortOrder.ASCENDING);

    }

    /**

     * FIXME document this

     *

     * @param criteria

     * @param criteriaMap

     */

    public void add(Criteria criteria, Map<String, Criteria> criteriaMap) {

        if(getPropertyName().indexOf(".") != -1) {

            /**

             * Here we have to work a bit of magic as currently hibernate will

             * throw an error if we attempt to join the same association twice.

             *

             * http://opensource.atlassian.com/projects/hibernate/browse/HHH-879

             */

            Order order;

            String[] assocObjs = getPropertyName().split("\\.");

            String path = "";

            Criteria c = criteria;

            for(int i = 0; i < assocObjs.length - 1; i++) {

                path = path + assocObjs[i];

                if(criteriaMap.get(path) == null) {

                    c = c.createCriteria(assocObjs[i]);

                    criteriaMap.put(path, c);

                } else {

                    c = criteriaMap.get(path);

                }

                path = path + '.';

            }

            String propname = assocObjs[assocObjs.length - 1];

            if(isAscending()){

                c.addOrder(Order.asc(propname));

            } else {

                c.addOrder(Order.desc(propname));

            }

        } else {

            if(isAscending()){

                criteria.addOrder(Order.asc(getPropertyName()));

            } else {

                criteria.addOrder(Order.desc(getPropertyName()));

            }

        }

    }

    /**

     * FIXME document this

     *

     * @param query

     */

    public void add(AuditQuery query) {

        if(getPropertyName().indexOf('.', 0) >= 0){

            throw new OperationNotSupportedInPriorViewException("Sorting by related properties is not supported in the history view");

        } else {

            if(isAscending()){

                query.addOrder(AuditEntity.property(getPropertyName()).asc());

            } else {

                query.addOrder(AuditEntity.property(getPropertyName()).desc());

            }

        }

    }

    /**

     * Returns a hql order by clause element which can directly be used in hql queries.

     *

     * e.g.: "titleCache ASC"

     *

     * @return an hql order by clause element

     */

    public String toHql(){

        if(propertyName.equals(LUCENE_SCORE)){

            logger.error("LUCENE_SCORE not allowed in hql query");

        }

        return propertyName + " " + sortOrder.toHql();

    }

    /**

     * @return a Lucene {@link SortField} for the Lucene field type <code>Sting</code>

     */

    public SortField toSortField() {

        if(propertyName.equals(LUCENE_SCORE)){

            return SortField.FIELD_SCORE;

        }

        return new SortField(propertyName, SortField.Type.STRING, sortOrder.equals(SortOrder.DESCENDING));

    }

    @Override

    public boolean equals(Object obj) {

        if (obj == this){

            return true;

        }

        if (obj == null){

            return false;

        }

        if (!OrderHint.class.isAssignableFrom(obj.getClass())){

            return false;

        }

        OrderHint orderHint= (OrderHint)obj;

        boolean propertyNameEqual = orderHint.getPropertyName().equals(this.getPropertyName());

        boolean sortOrderEqual = orderHint.getSortOrder().equals(this.getSortOrder());

        if (! propertyNameEqual || !sortOrderEqual){

                return false;

        }

        return true;

    }

    @Override

    public int hashCode() {

           int hashCode = 7;

           hashCode = 29 * hashCode + this.getPropertyName().hashCode() * this.getSortOrder().hashCode();

           return hashCode;

    }

}