﻿/* 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.Exceptions;

namespace OfficeOpenXml.FormulaParsing.Excel.Functions
{
    /// <summary>
    /// Base class for functions that needs to handle cells that is not visible.
    /// </summary>
    public abstract class HiddenValuesHandlingFunction : ExcelFunction
    {
        /// <summary>
        /// Set to true or false to indicate whether the function should ignore hidden values.
        /// </summary>
        public bool IgnoreHiddenValues
        {
            get;
            set;
        }

        protected override IEnumerable<double> ArgsToDoubleEnumerable(IEnumerable<FunctionArgument> arguments, ParsingContext context)
        {
            return ArgsToDoubleEnumerable(arguments, context, true);
        }

        protected IEnumerable<double> ArgsToDoubleEnumerable(IEnumerable<FunctionArgument> arguments, ParsingContext context, bool ignoreErrors)
        {
            if (!arguments.Any())
            {
                return Enumerable.Empty<double>();
            }
            if (IgnoreHiddenValues)
            {
                var nonHidden = arguments.Where(x => !x.ExcelStateFlagIsSet(ExcelCellState.HiddenCell));
                return base.ArgsToDoubleEnumerable(IgnoreHiddenValues, nonHidden, context);
            }
            return base.ArgsToDoubleEnumerable(IgnoreHiddenValues, ignoreErrors, arguments, context);
        }

        protected bool ShouldIgnore(ExcelDataProvider.ICellInfo c, ParsingContext context)
        {
            return CellStateHelper.ShouldIgnore(IgnoreHiddenValues, c, context);
        }
        protected bool ShouldIgnore(FunctionArgument arg)
        {
            if (IgnoreHiddenValues && arg.ExcelStateFlagIsSet(ExcelCellState.HiddenCell))
            {
                return true;
            }
            return false;
        }

    }
}