/*
 * Copyright 2022-2023 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
 *
 *      https://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.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * {@link Collation} allows to define the rules used for language-specific string comparison.
 *
 * @see <a href="https://www.mongodb.com/docs/manual/reference/collation/">https://www.mongodb.com/docs/manual/reference/collation/</a>
 * @author Christoph Strobl
 * @since 4.0
 */
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.METHOD })
public @interface Collation {

	/**
	 * The actual collation definition in JSON format or a
	 * {@link org.springframework.expression.spel.standard.SpelExpression template expression} resolving to either a JSON
	 * String or a {@link org.bson.Document}. The keys of the JSON document are configuration options for the collation.
	 *
	 * @return an empty {@link String} by default.
	 */
	String value() default "";
}
