/*
 * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  Crate licenses
 * this file to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.  You may
 * obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial agreement.
 */

package io.crate.sql.tree;

import com.google.common.base.MoreObjects;

public class SortItem
    extends Node {
    public enum Ordering {
        ASCENDING, DESCENDING
    }

    public enum NullOrdering {
        FIRST, LAST, UNDEFINED
    }

    private final Expression sortKey;
    private final Ordering ordering;
    private final NullOrdering nullOrdering;

    public SortItem(Expression sortKey, Ordering ordering, NullOrdering nullOrdering) {
        this.ordering = ordering;
        this.sortKey = sortKey;
        this.nullOrdering = nullOrdering;
    }

    public Expression getSortKey() {
        return sortKey;
    }

    public Ordering getOrdering() {
        return ordering;
    }

    public NullOrdering getNullOrdering() {
        return nullOrdering;
    }

    @Override
    public <R, C> R accept(AstVisitor<R, C> visitor, C context) {
        return visitor.visitSortItem(this, context);
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
            .add("sortKey", sortKey)
            .add("ordering", ordering)
            .add("nullOrdering", nullOrdering)
            .toString();
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        SortItem sortItem = (SortItem) o;

        if (nullOrdering != sortItem.nullOrdering) {
            return false;
        }
        if (ordering != sortItem.ordering) {
            return false;
        }
        if (!sortKey.equals(sortItem.sortKey)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        int result = sortKey.hashCode();
        result = 31 * result + (ordering != null ? ordering.hashCode() : 0);
        result = 31 * result + (nullOrdering != null ? nullOrdering.hashCode() : 0);
        return result;
    }

}