/*******************************************************************************
 * 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.string;

import com.bstek.ureport.exception.ReportComputeException;
import com.bstek.ureport.expression.function.Function;
import com.bstek.ureport.expression.model.data.ExpressionData;
import com.bstek.ureport.expression.model.data.ObjectExpressionData;
import com.bstek.ureport.expression.model.data.ObjectListExpressionData;

import java.util.List;

/**
 * @author Jacky.gao
 * @since 2017年1月24日
 */
public abstract class StringFunction implements Function {
    protected String buildString(List<ExpressionData<?>> dataList) {
        if (dataList == null || dataList.size() == 0) {
            throw new ReportComputeException("Function [" + name() + "] need a data of string parameter.");
        }
        String result;
        ExpressionData<?> data = dataList.get(0);
        if (data instanceof ObjectListExpressionData) {
            ObjectListExpressionData listData = (ObjectListExpressionData) data;
            List<?> list = listData.getData();
            if (list == null || list.size() != 1) {
                throw new ReportComputeException("Function [" + name() + "] need a data of number parameter.");
            }
            Object obj = list.get(0);
            if (obj == null) {
                throw new ReportComputeException("Function [" + name() + "] parameter can not be null.");
            }
            result = obj.toString();
        } else if (data instanceof ObjectExpressionData) {
            ObjectExpressionData objData = (ObjectExpressionData) data;
            Object obj = objData.getData();
            if (obj == null) {
                throw new ReportComputeException("Function [" + name() + "] parameter can not be null.");
            }
            result = obj.toString();
        } else {
            throw new ReportComputeException("Function [" + name() + "] need a data of number parameter.");
        }
        return result;
    }
}
