/*
 * Copyright 2011-2024 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.batch.extensions.excel;

import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Workbook;

import org.springframework.lang.Nullable;

/**
 * Factory interface for creating a {@code FormulaEvaluator}, the default will return {@code null} as to re-use the
 * cached formula result in the workbooks.
 *
 * @author Marten Deinum
 * @since 0.2.0
 *
 */
@FunctionalInterface
public interface FormulaEvaluatorFactory {

	/** Return {@code null} for the {@code FormulaEvaluator}, used by default. **/
	FormulaEvaluatorFactory NOOP = (wb) -> null;

	/** Delegate the creation of the {@code FormulaEvaluator} to the workbook. **/
	FormulaEvaluatorFactory SIMPLE = (wb) -> wb.getCreationHelper().createFormulaEvaluator();

	/**
	 * Create the {@code FormulaEvaluator} for the given {@code Workbook}.
	 * @param workbook the workbook
	 * @return the {@code FormulaEvaluator}, can be {@code null}.
	 */
	@Nullable
	FormulaEvaluator create(Workbook workbook);
}
