/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * 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.bstek.ureport.expression.function.math;

import com.bstek.ureport.Utils;
import com.bstek.ureport.build.Context;
import com.bstek.ureport.exception.ReportComputeException;
import com.bstek.ureport.expression.model.data.ExpressionData;
import com.bstek.ureport.expression.model.data.ObjectExpressionData;
import com.bstek.ureport.model.Cell;

import java.math.BigDecimal;
import java.util.List;

/**
 * @author Jacky.gao
 * @since 2017年1月23日
 */
public class PowFunction extends MathFunction {

    @Override
    public Object execute(List<ExpressionData<?>> dataList, Context context, Cell currentCell) {
        BigDecimal data = buildBigDecimal(dataList);
        int pos = 0;
        if (dataList.size() == 2) {
            ExpressionData<?> exprData = dataList.get(1);
            if (exprData instanceof ObjectExpressionData) {
                ObjectExpressionData objData = (ObjectExpressionData) exprData;
                Object obj = objData.getData();
                if (obj == null) {
                    throw new ReportComputeException("Pow Function second parameter can not be null.");
                }
                pos = Utils.toBigDecimal(obj).intValue();
            }
        }
        return Math.pow(data.doubleValue(), pos);
    }

    @Override
    public String name() {
        return "pow";
    }
}
