/*******************************************************************************
 * 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		License changed GPL-->LGPL 2011-12-27
 *******************************************************************************/

using System;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using OfficeOpenXml.Packaging;
using OfficeOpenXml.Utils;

namespace OfficeOpenXml;

/// <summary>
/// Collection of Excelcomment objects
/// </summary>
public class ExcelCommentCollection : IEnumerable, IDisposable {
  internal RangeCollection _comments;

  internal ExcelCommentCollection(ExcelPackage pck, ExcelWorksheet ws, XmlNamespaceManager ns) {
    CommentXml.PreserveWhitespace = false;
    NameSpaceManager = ns;
    Worksheet = ws;
    CreateXml(pck);
    AddCommentsFromXml();
  }

  private void CreateXml(ExcelPackage pck) {
    var commentParts = Worksheet.Part.GetRelationshipsByType(ExcelPackage._schemaComment);
    bool isLoaded = false;
    CommentXml = new();
    foreach (var commentPart in commentParts) {
      Uri = UriHelper.ResolvePartUri(commentPart.SourceUri, commentPart.TargetUri);
      Part = pck.Package.GetPart(Uri);
      XmlHelper.LoadXmlSafe(CommentXml, Part.GetStream());
      RelId = commentPart.Id;
      isLoaded = true;
    }
    //Create a new document
    if (!isLoaded) {
      CommentXml.LoadXml(
          "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\" ?><comments xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\"><authors /><commentList /></comments>");
      Uri = null;
    }
  }

  private void AddCommentsFromXml() {
    var lst = new List<IRangeId>();
    foreach (XmlElement node in CommentXml.SelectNodes(
        "//d:commentList/d:comment",
        NameSpaceManager)) {
      var comment = new ExcelComment(
          NameSpaceManager,
          node,
          new(Worksheet, node.GetAttribute("ref")));
      lst.Add(comment);
    }
    _comments = new(lst);
  }

  /// <summary>
  /// Access to the comment xml document
  /// </summary>
  public XmlDocument CommentXml { get; set; } = new();

  internal Uri Uri { get; set; }

  internal string RelId { get; set; }

  internal XmlNamespaceManager NameSpaceManager { get; set; }

  internal ZipPackagePart Part { get; set; }

  /// <summary>
  /// A reference to the worksheet object
  /// </summary>
  public ExcelWorksheet Worksheet { get; set; }

  /// <summary>
  /// Number of comments in the collection
  /// </summary>
  public int Count => _comments.Count;

  /// <summary>
  /// Indexer for the comments collection
  /// </summary>
  /// <param name="index">The index</param>
  /// <returns>The comment</returns>
  public ExcelComment this[int index] {
    get {
      if (index < 0 || index >= _comments.Count) {
        throw (new ArgumentOutOfRangeException("Comment index out of range"));
      }
      return _comments[index] as ExcelComment;
    }
  }

  /// <summary>
  /// Indexer for the comments collection
  /// </summary>
  /// <param name="cell">The cell</param>
  /// <returns>The comment</returns>
  public ExcelComment this[ExcelCellAddress cell] {
    get {
      ulong cellId = ExcelCellBase.GetCellId(Worksheet.SheetID, cell.Row, cell.Column);
      if (_comments.IndexOf(cellId) >= 0) {
        return _comments[cellId] as ExcelComment;
      }
      return null;
    }
  }

  void IDisposable.Dispose() {}

  IEnumerator IEnumerable.GetEnumerator() {
    return _comments;
  }
}