content: /*******************************************************************************
   * 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.model.expr;
  
  import com.bstek.ureport.build.Context;
  import com.bstek.ureport.exception.ReportComputeException;
  import com.bstek.ureport.expression.ExpressionUtils;
  import com.bstek.ureport.expression.function.Function;
  import com.bstek.ureport.expression.function.page.PageFunction;
  import com.bstek.ureport.expression.model.Expression;
  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 com.bstek.ureport.expression.model.expr.set.CellExpression;
  import com.bstek.ureport.model.Cell;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  /**
   * @author
   * @since 2016年11月18日
   */
  public class FunctionExpression extends BaseExpression {
  	private static final long serialVersionUID = -6981657541024043558L;
  	private String name;
  	private List<BaseExpression> expressions;
  
  	@Override
  	public ExpressionData<?> compute(Cell cell,Cell currentCell,Context context) {
  		Map<String, Function> functions=ExpressionUtils.getFunctions();
  		Function targetFunction=functions.get(name);
  		if(targetFunction==null){
  			throw new ReportComputeException("Function ["+name+"] not exist.");
  		}
  		List<ExpressionData<?>> dataList=new ArrayList<ExpressionData<?>>();
  		if(expressions!=null){
  			for(BaseExpression expr:expressions){
  				if(targetFunction instanceof PageFunction){
  					ExpressionData<?> data=buildPageExpressionData(expr,cell,currentCell, context);
  					dataList.add(data);
  				}else{
  					ExpressionData<?> data=expr.execute(cell,currentCell, context);
  					dataList.add(data);
  				}
  			}
  		}
  		Object obj=targetFunction.execute(dataList, context,currentCell);
  		if(obj instanceof List){
  			return new ObjectListExpressionData((List<?>)obj);
  		}
  		return new ObjectExpressionData(obj);
  	}
  
  	private ExpressionData<?> buildPageExpressionData(Expression expr,Cell cell,Cell currentCell,Context context){
  		if(expr instanceof CellExpression){
  			CellExpression cellExpr=(CellExpression)expr;
  			if(cellExpr.supportPaging()){
  				return cellExpr.computePageCells(cell, currentCell, context);
  			}else{
  				return cellExpr.execute(cell, currentCell, context);
  			}
  		}else{
  			return expr.execute(cell, currentCell, context);
  		}
  	}
  
  
  	public String getName() {
  		return name;
  	}
  
  	public void setName(String name) {
  		this.name = name;
  	}
  	public void setExpressions(List<BaseExpression> expressions) {
  		this.expressions = expressions;
  	}
  	public List<BaseExpression> getExpressions() {
  		return expressions;
  	}
  }
  