/*******************************************************************************
 * 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 = new();
    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; }

  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;
    }
  }

  /// <summary>
  /// Adds a comment to the top left cell of the range
  /// </summary>
  /// <param name="cell">The cell</param>
  /// <param name="text">The comment text</param>
  /// <param name="author">Author</param>
  /// <returns>The comment</returns>
  public ExcelComment Add(ExcelRangeBase cell, string text, string author) {
    var elem = CommentXml.CreateElement("comment", ExcelPackage._schemaMain);
    int ix = _comments.IndexOf(
        ExcelCellBase.GetCellId(Worksheet.SheetID, cell._fromRow, cell._fromCol));
    //Make sure the nodes come on order.
    if (ix < 0 && (~ix < _comments.Count)) {
      ix = ~ix;
      var preComment = _comments[ix] as ExcelComment;
      preComment._commentHelper.TopNode.ParentNode.InsertBefore(
          elem,
          preComment._commentHelper.TopNode);
    } else {
      CommentXml.SelectSingleNode("d:comments/d:commentList", NameSpaceManager).AppendChild(elem);
    }
    elem.SetAttribute("ref", cell.Start.Address);
    ExcelComment comment = new ExcelComment(NameSpaceManager, elem, cell);
    comment.RichText.Add(text);
    if (author != "") {
      comment.Author = author;
    }
    _comments.Add(comment);
    //Check if a value exists otherwise add one so it is saved when the cells collection is iterated
    if (!Worksheet._values.Exists(cell._fromRow, cell._fromCol)) {
      Worksheet._values.SetValue(cell._fromRow, cell._fromCol, null);
    }
    return comment;
  }

  /// <summary>
  /// Removes the comment
  /// </summary>
  /// <param name="comment">The comment to remove</param>
  public void Remove(ExcelComment comment) {
    ulong id = ExcelCellBase.GetCellId(
        Worksheet.SheetID,
        comment.Range._fromRow,
        comment.Range._fromCol);
    int ix = _comments.IndexOf(id);
    if (ix >= 0 && comment == _comments[ix]) {
      comment.TopNode.ParentNode.RemoveChild(comment.TopNode); //Remove VML
      comment._commentHelper.TopNode.ParentNode.RemoveChild(comment._commentHelper.TopNode); //Remove Comment

      Worksheet.VmlDrawingsComments._drawings.Delete(id);
      _comments.Delete(id);
    } else {
      throw (new ArgumentException("Comment does not exist in the worksheet"));
    }
  }

  void IDisposable.Dispose() {}

  /// <summary>
  /// Removes the comment at the specified position
  /// </summary>
  /// <param name="index">The index</param>
  public void RemoveAt(int index) {
    Remove(this[index]);
  }

  IEnumerator IEnumerable.GetEnumerator() {
    return _comments;
  }

  internal void Clear() {
    while (Count > 0) {
      RemoveAt(0);
    }
  }
}