/*******************************************************************************
 * 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
 *******************************************************************************
 * Jan Källman		                Initial Release		        2009-10-01
 * Jan Källman                      Total rewrite               2010-03-01
 * Jan Källman		License changed GPL-->LGPL 2011-12-27
 * *******************************************************************************/

using System.Xml;

namespace OfficeOpenXml;

/// <summary>
/// Print header and footer
/// </summary>
public class ExcelHeaderFooterText {
  private ExcelWorksheet _ws;
  private string _hf;

  internal ExcelHeaderFooterText(XmlNode textNode, ExcelWorksheet ws, string hf) {
    _ws = ws;
    _hf = hf;
    if (textNode == null || string.IsNullOrEmpty(textNode.InnerText)) {
      return;
    }
    string text = textNode.InnerText;
    string code = text.Substring(0, 2);
    int startPos = 2;
    for (int pos = startPos; pos < text.Length - 2; pos++) {
      string newCode = text.Substring(pos, 2);
      if (newCode == "&C" || newCode == "&R") {
        SetText(code, text.Substring(startPos, pos - startPos));
        startPos = pos + 2;
        pos = startPos;
        code = newCode;
      }
    }
    SetText(code, text.Substring(startPos, text.Length - startPos));
  }

  private void SetText(string code, string text) {
    switch (code) {
      case "&L":
        LeftAlignedText = text;
        break;
      case "&C":
        CenteredText = text;
        break;
      default:
        RightAlignedText = text;
        break;
    }
  }

  /// <summary>
  /// Get/set the text to appear on the left hand side of the header (or footer) on the worksheet.
  /// </summary>
  public string LeftAlignedText;

  /// <summary>
  /// Get/set the text to appear in the center of the header (or footer) on the worksheet.
  /// </summary>
  public string CenteredText;

  /// <summary>
  /// Get/set the text to appear on the right hand side of the header (or footer) on the worksheet.
  /// </summary>
  public string RightAlignedText;
}

/// <summary>
/// Represents the Header and Footer on an Excel Worksheet
/// </summary>
public sealed class ExcelHeaderFooter : XmlHelper {
  /// <summary>
  /// The code for "current page #"
  /// </summary>
  public const string PageNumber = "&P";

  /// <summary>
  /// The code for "total pages"
  /// </summary>
  public const string NumberOfPages = "&N";

  /// <summary>
  /// The code for "text font color"
  /// RGB Color is specified as RRGGBB
  /// Theme Color is specified as TTSNN where TT is the theme color Id, S is either "+" or "-" of the tint/shade value, NN is the tint/shade value.
  /// </summary>
  public const string FontColor = "&K";

  /// <summary>
  /// The code for "sheet tab name"
  /// </summary>
  public const string SheetName = "&A";

  /// <summary>
  /// The code for "this workbook's file path"
  /// </summary>
  public const string FilePath = "&Z";

  /// <summary>
  /// The code for "this workbook's file name"
  /// </summary>
  public const string FileName = "&F";

  /// <summary>
  /// The code for "date"
  /// </summary>
  public const string CurrentDate = "&D";

  /// <summary>
  /// The code for "time"
  /// </summary>
  public const string CurrentTime = "&T";

  /// <summary>
  /// The code for "picture as background"
  /// </summary>
  public const string Image = "&G";

  /// <summary>
  /// The code for "outline style"
  /// </summary>
  public const string OutlineStyle = "&O";

  /// <summary>
  /// The code for "shadow style"
  /// </summary>
  public const string ShadowStyle = "&H";

  internal ExcelHeaderFooterText _oddHeader;
  internal ExcelHeaderFooterText _oddFooter;
  internal ExcelHeaderFooterText _evenHeader;
  internal ExcelHeaderFooterText _evenFooter;
  internal ExcelHeaderFooterText _firstHeader;
  internal ExcelHeaderFooterText _firstFooter;
  private readonly ExcelWorksheet _ws;

  /// <summary>
  /// ExcelHeaderFooter Constructor
  /// </summary>
  /// <param name="nameSpaceManager"></param>
  /// <param name="topNode"></param>
  /// <param name="ws">The worksheet</param>
  internal ExcelHeaderFooter(
      XmlNamespaceManager nameSpaceManager,
      XmlNode topNode,
      ExcelWorksheet ws)
      : base(nameSpaceManager, topNode) {
    _ws = ws;
    SchemaNodeOrder = new[] {
      "headerFooter",
      "oddHeader",
      "oddFooter",
      "evenHeader",
      "evenFooter",
      "firstHeader",
      "firstFooter",
    };
  }

  private const string _alignWithMarginsPath = "@alignWithMargins";

  /// <summary>
  /// Gets/sets the alignWithMargins attribute
  /// </summary>
  public bool AlignWithMargins {
    get => GetXmlNodeBool(_alignWithMarginsPath);
    set => SetXmlNodeString(_alignWithMarginsPath, value ? "1" : "0");
  }

  private const string _differentOddEvenPath = "@differentOddEven";

  /// <summary>
  /// Gets/sets the flag that tells Excel to display different headers and footers on odd and even pages.
  /// </summary>
  public bool differentOddEven {
    get => GetXmlNodeBool(_differentOddEvenPath);
    set => SetXmlNodeString(_differentOddEvenPath, value ? "1" : "0");
  }

  private const string _differentFirstPath = "@differentFirst";

  /// <summary>
  /// Gets/sets the flag that tells Excel to display different headers and footers on the first page of the worksheet.
  /// </summary>
  public bool differentFirst {
    get => GetXmlNodeBool(_differentFirstPath);
    set => SetXmlNodeString(_differentFirstPath, value ? "1" : "0");
  }

  /// <summary>
  /// Provides access to the header on odd numbered pages of the document.
  /// If you want the same header on both odd and even pages, then only set values in this ExcelHeaderFooterText class.
  /// </summary>
  public ExcelHeaderFooterText OddHeader {
    get {
      if (_oddHeader == null) {
        _oddHeader = new(TopNode.SelectSingleNode("d:oddHeader", NameSpaceManager), _ws, "H");
      }
      return _oddHeader;
    }
  }

  /// <summary>
  /// Provides access to the footer on odd numbered pages of the document.
  /// If you want the same footer on both odd and even pages, then only set values in this ExcelHeaderFooterText class.
  /// </summary>
  public ExcelHeaderFooterText OddFooter {
    get {
      if (_oddFooter == null) {
        _oddFooter = new(TopNode.SelectSingleNode("d:oddFooter", NameSpaceManager), _ws, "F");
        ;
      }
      return _oddFooter;
    }
  }

  // evenHeader and evenFooter set differentOddEven = true
  /// <summary>
  /// Provides access to the header on even numbered pages of the document.
  /// </summary>
  public ExcelHeaderFooterText EvenHeader {
    get {
      if (_evenHeader == null) {
        _evenHeader = new(TopNode.SelectSingleNode("d:evenHeader", NameSpaceManager), _ws, "HEVEN");
        differentOddEven = true;
      }
      return _evenHeader;
    }
  }

  /// <summary>
  /// Provides access to the footer on even numbered pages of the document.
  /// </summary>
  public ExcelHeaderFooterText EvenFooter {
    get {
      if (_evenFooter == null) {
        _evenFooter = new(TopNode.SelectSingleNode("d:evenFooter", NameSpaceManager), _ws, "FEVEN");
        differentOddEven = true;
      }
      return _evenFooter;
    }
  }

  /// <summary>
  /// Provides access to the header on the first page of the document.
  /// </summary>
  public ExcelHeaderFooterText FirstHeader {
    get {
      if (_firstHeader == null) {
        _firstHeader = new(
            TopNode.SelectSingleNode("d:firstHeader", NameSpaceManager),
            _ws,
            "HFIRST");
        differentFirst = true;
      }
      return _firstHeader;
    }
  }

  /// <summary>
  /// Provides access to the footer on the first page of the document.
  /// </summary>
  public ExcelHeaderFooterText FirstFooter {
    get {
      if (_firstFooter == null) {
        _firstFooter = new(
            TopNode.SelectSingleNode("d:firstFooter", NameSpaceManager),
            _ws,
            "FFIRST");
        differentFirst = true;
      }
      return _firstFooter;
    }
  }

  /// <summary>
  /// Saves the header and footer information to the worksheet XML
  /// </summary>
  internal void Save() {
    if (_oddHeader != null) {
      SetXmlNodeString("d:oddHeader", GetText(OddHeader));
    }
    if (_oddFooter != null) {
      SetXmlNodeString("d:oddFooter", GetText(OddFooter));
    }

    // only set evenHeader and evenFooter
    if (differentOddEven) {
      if (_evenHeader != null) {
        SetXmlNodeString("d:evenHeader", GetText(EvenHeader));
      }
      if (_evenFooter != null) {
        SetXmlNodeString("d:evenFooter", GetText(EvenFooter));
      }
    }

    // only set firstHeader and firstFooter
    if (differentFirst) {
      if (_firstHeader != null) {
        SetXmlNodeString("d:firstHeader", GetText(FirstHeader));
      }
      if (_firstFooter != null) {
        SetXmlNodeString("d:firstFooter", GetText(FirstFooter));
      }
    }
  }

  private string GetText(ExcelHeaderFooterText headerFooter) {
    string ret = "";
    if (headerFooter.LeftAlignedText != null) {
      ret += "&L" + headerFooter.LeftAlignedText;
    }
    if (headerFooter.CenteredText != null) {
      ret += "&C" + headerFooter.CenteredText;
    }
    if (headerFooter.RightAlignedText != null) {
      ret += "&R" + headerFooter.RightAlignedText;
    }
    return ret;
  }
}