/* 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
 * Eric Beiler                      Enable Multiple Selections  2015-09-01
 *******************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using OfficeOpenXml.FormulaParsing.ExpressionGraph;

namespace OfficeOpenXml.FormulaParsing.Excel.Functions.RefAndLookup
{
    public class Choose : ExcelFunction
    {
        public override CompileResult Execute(IEnumerable<FunctionArgument> arguments, ParsingContext context)
        {
            ValidateArguments(arguments, 2);
            var items = new List<object>();
            for (int x = 0; x < arguments.Count(); x++)
            {
                items.Add(arguments.ElementAt(x).ValueFirst);
            }

            var chooseIndeces = arguments.ElementAt(0).ValueFirst as IEnumerable<FunctionArgument>;
            if (chooseIndeces != null && chooseIndeces.Count() > 1)
            {
                IntArgumentParser intParser = new IntArgumentParser();
                object[] values = chooseIndeces.Select(chosenIndex => items[(int)intParser.Parse(chosenIndex.ValueFirst)]).ToArray();
                return CreateResult(values, DataType.Enumerable);
            }
            else
            {
                var index = ArgToInt(arguments, 0);
                return CreateResult(items[index].ToString(), DataType.String);
            }
        }
    }

    public class ChoosenInfo : ExcelDataProvider.IRangeInfo
    {
        private string[] chosenIndeces = null;

        public ChoosenInfo(string[] chosenIndeces)
        {
            this.chosenIndeces = chosenIndeces;
        }

        public bool IsEmpty
        {
            get { return false; }
        }

        public bool IsMulti
        {
            get { return true; }
        }

        public int GetNCells()
        {
            return 0;
        }

        public ExcelAddressBase Address
        {
            get { return null; }
        }

        public object GetValue(int row, int col)
        {
            return null;
        }

        public object GetOffset(int rowOffset, int colOffset)
        {
            return null;
        }

        public ExcelWorksheet Worksheet
        {
            get { return null; }
        }

        public ExcelDataProvider.ICellInfo Current
        {
            get { return null; }
        }

        public void Dispose()
        {
        }

        object System.Collections.IEnumerator.Current
        {
            get { return chosenIndeces[0]; }
        }

        public bool MoveNext()
        {
            throw new NotImplementedException();
        }

        public void Reset()
        {
            throw new NotImplementedException();
        }

        public IEnumerator<ExcelDataProvider.ICellInfo> GetEnumerator()
        {
            throw new NotImplementedException();
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            throw new NotImplementedException();
        }
    }
}
