/* Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied. 
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 * 
 * Author							Change						Date
 *******************************************************************************
 * Mats Alm   		                Added		                2013-12-03
 *******************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using OfficeOpenXml.FormulaParsing.ExpressionGraph;
using OfficeOpenXml.Utils;
using OfficeOpenXml.FormulaParsing.Exceptions;

namespace OfficeOpenXml.FormulaParsing.Excel.Functions.Math
{
    public class Sum : HiddenValuesHandlingFunction
    {
        public override CompileResult Execute(IEnumerable<FunctionArgument> arguments, ParsingContext context)
        {
            var retVal = 0d;
            if (arguments != null)
            {
                foreach (var arg in arguments)
                {
                    retVal += Calculate(arg, context);                    
                }
            }
            return CreateResult(retVal, DataType.Decimal);
        }

        
        private double Calculate(FunctionArgument arg, ParsingContext context)
        {
            var retVal = 0d;
            if (ShouldIgnore(arg))
            {
                return retVal;
            }
            if (arg.Value is IEnumerable<FunctionArgument>)
            {
                foreach (var item in (IEnumerable<FunctionArgument>)arg.Value)
                {
                    retVal += Calculate(item, context);
                }
            }
            else if (arg.Value is ExcelDataProvider.IRangeInfo)
            {
                foreach (var c in (ExcelDataProvider.IRangeInfo)arg.Value)
                {
                    if (ShouldIgnore(c, context) == false)
                    {
                        CheckForAndHandleExcelError(c);
                        retVal += c.ValueDouble;
                    }
                }
            }
            else
            {
                CheckForAndHandleExcelError(arg);
                retVal += ConvertUtil.GetValueDouble(arg.Value, true);
            }
            return retVal;
        }
    }
}
