EPPlus/FormulaParsing/ExcelUtilities/AddressTranslator.cs

/*******************************************************************************
 * 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.Globalization;
using System.Text.RegularExpressions;
using OfficeOpenXml.FormulaParsing.Utilities;

namespace OfficeOpenXml.FormulaParsing.ExcelUtilities;

/// <summary>
/// Handles translations from Spreadsheet addresses to 0-based numeric index.
/// </summary>
public class AddressTranslator {
  public enum RangeCalculationBehaviour {
    FirstPart,
    LastPart,
  }

  private readonly ExcelDataProvider _excelDataProvider;

  public AddressTranslator(ExcelDataProvider excelDataProvider) {
    Require.That(excelDataProvider).Named("excelDataProvider").IsNotNull();
    _excelDataProvider = excelDataProvider;
  }

  /// <summary>
  /// Translates an address in format "A1" to col- and rowindex.
  ///
  /// If the supplied address is a range, the address of the first part will be calculated.
  /// </summary>
  /// <param name="address"></param>
  /// <param name="col"></param>
  /// <param name="row"></param>
  public virtual void ToColAndRow(string address, out int col, out int row) {
    ToColAndRow(address, out col, out row, RangeCalculationBehaviour.FirstPart);
  }

  /// <summary>
  /// Translates an address in format "A1" to col- and rowindex.
  /// </summary>
  /// <param name="address"></param>
  /// <param name="col"></param>
  /// <param name="row"></param>
  /// <param name="behaviour"></param>
  public virtual void ToColAndRow(
      string address,
      out int col,
      out int row,
      RangeCalculationBehaviour behaviour) {
    address = address.ToUpper(CultureInfo.InvariantCulture);
    var alphaPart = GetAlphaPart(address);
    col = 0;
    var nLettersInAlphabet = 26;
    for (int x = 0; x < alphaPart.Length; x++) {
      var pos = alphaPart.Length - x - 1;
      var currentNumericValue = GetNumericAlphaValue(alphaPart[x]);
      col += (nLettersInAlphabet * pos * currentNumericValue);
      if (pos == 0) {
        col += currentNumericValue;
      }
    }
    //col--;
    //row = GetIntPart(address) - 1 ?? GetRowIndexByBehaviour(behaviour);
    row = GetIntPart(address) ?? GetRowIndexByBehaviour(behaviour);
  }

  private int GetRowIndexByBehaviour(RangeCalculationBehaviour behaviour) {
    if (behaviour == RangeCalculationBehaviour.FirstPart) {
      return 1;
    }
    return _excelDataProvider.ExcelMaxRows;
  }

  private int GetNumericAlphaValue(char c) {
    return c - 64;
  }

  private string GetAlphaPart(string address) {
    return Regex.Match(address, "[A-Z]+").Value;
  }

  private int? GetIntPart(string address) {
    if (Regex.IsMatch(address, "[0-9]+")) {
      return int.Parse(Regex.Match(address, "[0-9]+").Value);
    }
    return null;
  }
}