/*******************************************************************************
 * You may amend and distribute as you like, but don't remove this header!
 *
 * EPPlus provides server-side generation of Excel 2007/2010 spreadsheets.
 * See http://www.codeplex.com/EPPlus for details.
 *
 * 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       		        2013-03-01 (Prior file history on https://github.com/swmal/ExcelFormulaParser)
 *******************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using OfficeOpenXml.FormulaParsing;
using OfficeOpenXml.FormulaParsing.ExcelUtilities;
using OfficeOpenXml.FormulaParsing.Exceptions;
using OfficeOpenXml.FormulaParsing.LexicalAnalysis;
using OfficeOpenXml.FormulaParsing.Utilities;

namespace OfficeOpenXml.FormulaParsing.ExpressionGraph
{
    public class ExcelAddressExpression : AtomicExpression
    {
        /// <summary>
        /// Gets or sets a value that indicates whether or not to resolve directly to an <see cref="ExcelDataProvider.IRangeInfo"/>
        /// </summary>
        public bool ResolveAsRange { get; set; }

        private readonly ExcelDataProvider _excelDataProvider;
        private readonly ParsingContext _parsingContext;
        private readonly RangeAddressFactory _rangeAddressFactory;
        private readonly bool _negate;

        public ExcelAddressExpression(string expression, ExcelDataProvider excelDataProvider, ParsingContext parsingContext)
            : this(expression, excelDataProvider, parsingContext, new RangeAddressFactory(excelDataProvider), false)
        {

        }
        public ExcelAddressExpression(string expression, ExcelDataProvider excelDataProvider, ParsingContext parsingContext, bool negate)
            : this(expression, excelDataProvider, parsingContext, new RangeAddressFactory(excelDataProvider), negate)
        {

        }

        public ExcelAddressExpression(string expression, ExcelDataProvider excelDataProvider, ParsingContext parsingContext, RangeAddressFactory rangeAddressFactory, bool negate)
            : base(expression)
        {
            Require.That(excelDataProvider).Named("excelDataProvider").IsNotNull();
            Require.That(parsingContext).Named("parsingContext").IsNotNull();
            Require.That(rangeAddressFactory).Named("rangeAddressFactory").IsNotNull();
            _excelDataProvider = excelDataProvider;
            _parsingContext = parsingContext;
            _rangeAddressFactory = rangeAddressFactory;
            _negate = negate;
        }

        public override bool IsGroupedExpression
        {
            get { return false; }
        }

        public override CompileResult Compile()
        {
            if (ParentIsLookupFunction)
            {
                return new CompileResult(ExpressionString, DataType.ExcelAddress);
            }
            else
            {
                return CompileRangeValues();
            }
        }

        private CompileResult CompileRangeValues()
        {
            var c = this._parsingContext.Scopes.Current;
            var result = _excelDataProvider.GetRange(c.Address.Worksheet, c.Address.FromRow, c.Address.FromCol, ExpressionString);
            if (result == null)
            {
                return CompileResult.Empty;
            }
            if (this.ResolveAsRange || result.Address.Rows > 1 || result.Address.Columns > 1)
            {
                return new CompileResult(result, DataType.Enumerable);
            }
            else
            {
                return CompileSingleCell(result);
            }
        }

        private CompileResult CompileSingleCell(ExcelDataProvider.IRangeInfo result)
        {
            var cell = result.FirstOrDefault();
            if (cell == null)
                return CompileResult.Empty;
            var factory = new CompileResultFactory();
            var compileResult = factory.Create(cell.Value);
            if (_negate && compileResult.IsNumeric)
            {
                compileResult = new CompileResult(compileResult.ResultNumeric * -1, compileResult.DataType);
            }
            compileResult.IsHiddenCell = cell.IsHiddenRow;
            return compileResult;
        }
    }
}
