/*
* Copyright 2014, Stratio.
*
* Licensed 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.
*/
package com.stratio.cassandra.index.query;
import com.google.common.base.Objects;
import com.stratio.cassandra.index.schema.Column;
import com.stratio.cassandra.index.schema.mapping.ColumnMapper;
import com.stratio.cassandra.index.schema.Columns;
import com.stratio.cassandra.index.schema.Schema;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.codehaus.jackson.annotate.JsonCreator;
import org.codehaus.jackson.annotate.JsonProperty;
import java.nio.ByteBuffer;
import java.util.Comparator;
/**
* A sorting for a field of a search.
*
* @author Andres de la Pena <adelapena@stratio.com>
*/
public class SortField {
/** The default reverse option. */
public static final boolean DEFAULT_REVERSE = false;
/** The name of field to sortFields by. */
@JsonProperty("field")
private final String field;
/** {@code true} if natural order should be reversed. */
@JsonProperty("reverse")
private final boolean reverse;
/**
* Returns a new {@link SortField}.
*
* @param field The name of field to sortFields by.
* @param reverse {@code true} if natural order should be reversed.
*/
@JsonCreator
public SortField(@JsonProperty("field") String field, @JsonProperty("reverse") Boolean reverse) {
this.field = field;
this.reverse = reverse == null ? DEFAULT_REVERSE : reverse;
}
/**
* Returns the Lucene {@link org.apache.lucene.search.SortField} representing this {@link SortField}.
*
* @param schema The {@link Schema} to be used.
* @return the Lucene {@link org.apache.lucene.search.SortField} representing this {@link SortField}.
*/
public org.apache.lucene.search.SortField sortField(Schema schema) {
if (field == null || field.trim().isEmpty()) {
throw new IllegalArgumentException("Field name required");
}
ColumnMapper columnMapper = schema.getMapper(field);
if (columnMapper == null) {
throw new IllegalArgumentException("No mapper found for sortFields field " + field);
} else {
return columnMapper.sortField(field, reverse);
}
}
/**
* Returns a Java {@link Comparator} for {@link Columns} with the same logic as this {@link SortField}.
*
* @return A Java {@link Comparator} for {@link Columns} with the same logic as this {@link SortField}.
*/
public Comparator<Columns> comparator() {
return new Comparator<Columns>() {
public int compare(Columns o1, Columns o2) {
if (o1 == null) {
return o2 == null ? 0 : 1;
}
if (o2 == null) {
return -1;
}
Column column1 = o1.getColumn(field);
Column column2 = o2.getColumn(field);
if (column1 == null) {
return column2 == null ? 0 : 1;
}
if (column2 == null) {
return -1;
}
AbstractType<?> type = column1.getType();
ByteBuffer value1 = column1.getDecomposedValue();
ByteBuffer value2 = column2.getDecomposedValue();
return reverse ? type.compare(value2, value1) : type.compare(value1, value2);
}
};
}
/** {@inheritDoc} */
@Override
public String toString() {
return Objects.toStringHelper(this).add("field", field).add("reverse", reverse).toString();
}
}