/*
* Copyright 2016 the original author or authors.
*
* 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 org.springframework.data.mongodb.core.aggregation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.springframework.data.mongodb.core.aggregation.BucketOperation.BucketOperationOutputBuilder;
import org.springframework.util.Assert;
import org.bson.Document;
/**
* Encapsulates the aggregation framework {@code $bucket}-operation. <br />
*
* Bucket stage is typically used with {@link Aggregation} and {@code $facet}. Categorizes incoming documents into
* groups, called buckets, based on a specified expression and bucket boundaries. <br />
*
* We recommend to use the static factory method {@link Aggregation#bucket(String)} instead of creating instances of
* this class directly.
*
* @see <a href="https://docs.mongodb.org/manual/reference/aggregation/bucket/">https://docs.mongodb.org/manual/reference/aggregation/bucket/</a>
* @see BucketOperationSupport
* @author Mark Paluch
* @since 1.10
*/
public class BucketOperation extends BucketOperationSupport<BucketOperation, BucketOperationOutputBuilder>
implements FieldsExposingAggregationOperation {
private final List<Object> boundaries;
private final Object defaultBucket;
/**
* Creates a new {@link BucketOperation} given a {@link Field group-by field}.
*
* @param groupByField must not be {@literal null}.
*/
public BucketOperation(Field groupByField) {
super(groupByField);
this.boundaries = Collections.emptyList();
this.defaultBucket = null;
}
/**
* Creates a new {@link BucketOperation} given a {@link AggregationExpression group-by expression}.
*
* @param groupByExpression must not be {@literal null}.
*/
public BucketOperation(AggregationExpression groupByExpression) {
super(groupByExpression);
this.boundaries = Collections.emptyList();
this.defaultBucket = null;
}
private BucketOperation(BucketOperation bucketOperation, Outputs outputs) {
super(bucketOperation, outputs);
this.boundaries = bucketOperation.boundaries;
this.defaultBucket = bucketOperation.defaultBucket;
}
private BucketOperation(BucketOperation bucketOperation, List<Object> boundaries, Object defaultBucket) {
super(bucketOperation);
this.boundaries = new ArrayList<Object>(boundaries);
this.defaultBucket = defaultBucket;
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport#toDocument(org.springframework.data.mongodb.core.aggregation.AggregationOperationContext)
*/
@Override
public Document toDocument(AggregationOperationContext context) {
Document options = new Document();
options.put("boundaries", context.getMappedObject(new Document("$set", boundaries)).get("$set"));
if (defaultBucket != null) {
options.put("default", context.getMappedObject(new Document("$set", defaultBucket)).get("$set"));
}
options.putAll(super.toDocument(context));
return new Document("$bucket", options);
}
/**
* Configures a default bucket {@literal literal} and return a new {@link BucketOperation}.
*
* @param literal must not be {@literal null}.
* @return
*/
public BucketOperation withDefaultBucket(Object literal) {
Assert.notNull(literal, "Default bucket literal must not be null!");
return new BucketOperation(this, boundaries, literal);
}
/**
* Configures {@literal boundaries} and return a new {@link BucketOperation}. Existing {@literal boundaries} are
* preserved and the new {@literal boundaries} are appended.
*
* @param boundaries must not be {@literal null}.
* @return
*/
public BucketOperation withBoundaries(Object... boundaries) {
Assert.notNull(boundaries, "Boundaries must not be null!");
Assert.noNullElements(boundaries, "Boundaries must not contain null values!");
List<Object> newBoundaries = new ArrayList<Object>(this.boundaries.size() + boundaries.length);
newBoundaries.addAll(this.boundaries);
newBoundaries.addAll(Arrays.asList(boundaries));
return new BucketOperation(this, newBoundaries, defaultBucket);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport#newBucketOperation(org.springframework.data.mongodb.core.aggregation.BucketOperationSupport.Outputs)
*/
@Override
protected BucketOperation newBucketOperation(Outputs outputs) {
return new BucketOperation(this, outputs);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport#andOutputExpression(java.lang.String, java.lang.Object[])
*/
@Override
public ExpressionBucketOperationBuilder andOutputExpression(String expression, Object... params) {
return new ExpressionBucketOperationBuilder(expression, this, params);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport#andOutput(org.springframework.data.mongodb.core.aggregation.AggregationExpression)
*/
@Override
public BucketOperationOutputBuilder andOutput(AggregationExpression expression) {
return new BucketOperationOutputBuilder(expression, this);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport#andOutput(java.lang.String)
*/
@Override
public BucketOperationOutputBuilder andOutput(String fieldName) {
return new BucketOperationOutputBuilder(Fields.field(fieldName), this);
}
/**
* {@link OutputBuilder} implementation for {@link BucketOperation}.
*/
public static class BucketOperationOutputBuilder
extends BucketOperationSupport.OutputBuilder<BucketOperationOutputBuilder, BucketOperation> {
/**
* Creates a new {@link BucketOperationOutputBuilder} fot the given value and {@link BucketOperation}.
*
* @param value must not be {@literal null}.
* @param operation must not be {@literal null}.
*/
protected BucketOperationOutputBuilder(Object value, BucketOperation operation) {
super(value, operation);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport.OutputBuilder#apply(org.springframework.data.mongodb.core.aggregation.BucketOperationSupport.OperationOutput)
*/
@Override
protected BucketOperationOutputBuilder apply(OperationOutput operationOutput) {
return new BucketOperationOutputBuilder(operationOutput, this.operation);
}
}
/**
* {@link ExpressionBucketOperationBuilderSupport} implementation for {@link BucketOperation} using SpEL expression
* based {@link Output}.
*
* @author Mark Paluch
*/
public static class ExpressionBucketOperationBuilder
extends ExpressionBucketOperationBuilderSupport<BucketOperationOutputBuilder, BucketOperation> {
/**
* Creates a new {@link ExpressionBucketOperationBuilderSupport} for the given value, {@link BucketOperation}
* and parameters.
*
* @param expression must not be {@literal null}.
* @param operation must not be {@literal null}.
* @param parameters
*/
protected ExpressionBucketOperationBuilder(String expression, BucketOperation operation, Object[] parameters) {
super(expression, operation, parameters);
}
/* (non-Javadoc)
* @see org.springframework.data.mongodb.core.aggregation.BucketOperationSupport.OutputBuilder#apply(org.springframework.data.mongodb.core.aggregation.BucketOperationSupport.OperationOutput)
*/
@Override
protected BucketOperationOutputBuilder apply(OperationOutput operationOutput) {
return new BucketOperationOutputBuilder(operationOutput, this.operation);
}
}
}