/*
 * Copyright 2021-2023 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.repository.support;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.springframework.data.domain.Sort;
import org.springframework.data.repository.query.FluentQuery;
import org.springframework.util.Assert;

/**
 * Support class for {@link org.springframework.data.repository.query.FluentQuery.ReactiveFluentQuery} implementations.
 *
 * @author Mark Paluch
 * @since 3.3
 */
abstract class ReactiveFluentQuerySupport<P, T> implements FluentQuery.ReactiveFluentQuery<T> {

	private final P predicate;
	private final Sort sort;
	private final int limit;
	private final Class<T> resultType;
	private final List<String> fieldsToInclude;

	ReactiveFluentQuerySupport(P predicate, Sort sort, int limit, Class<T> resultType, List<String> fieldsToInclude) {
		this.predicate = predicate;
		this.sort = sort;
		this.limit = limit;
		this.resultType = resultType;
		this.fieldsToInclude = fieldsToInclude;
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.query.FluentQuery.ReactiveFluentQuery#sortBy(org.springframework.data.domain.Sort)
	 */
	@Override
	public ReactiveFluentQuery<T> sortBy(Sort sort) {

		Assert.notNull(sort, "Sort must not be null");

		return create(predicate, sort, limit, resultType, fieldsToInclude);
	}

	@Override
	public ReactiveFluentQuery<T> limit(int limit) {

		Assert.isTrue(limit > 0, "Limit must be greater zero");

		return create(predicate, sort, limit, resultType, fieldsToInclude);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.query.FluentQuery.ReactiveFluentQuery#as(java.lang.Class)
	 */
	@Override
	public <R> ReactiveFluentQuery<R> as(Class<R> projection) {

		Assert.notNull(projection, "Projection target type must not be null");

		return create(predicate, sort, limit, projection, fieldsToInclude);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.query.FluentQuery.ReactiveFluentQuery#project(java.util.Collection)
	 */
	@Override
	public ReactiveFluentQuery<T> project(Collection<String> properties) {

		Assert.notNull(properties, "Projection properties must not be null");

		return create(predicate, sort, limit, resultType, new ArrayList<>(properties));
	}

	protected abstract <R> ReactiveFluentQuerySupport<P, R> create(P predicate, Sort sort, int limit, Class<R> resultType,
			List<String> fieldsToInclude);

	P getPredicate() {
		return predicate;
	}

	Sort getSort() {
		return sort;
	}

	int getLimit() {
		return limit;
	}

	Class<T> getResultType() {
		return resultType;
	}

	List<String> getFieldsToInclude() {
		return fieldsToInclude;
	}
}
