AppsheetEpplus/Packaging/ZipPackage.cs - epplus - Git at Google

 /*******************************************************************************
  * 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		Added		25-Oct-2012
  *******************************************************************************/

 using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
 using System.Runtime.InteropServices;
 using System.Text;
 using System.Xml;

 namespace AppsheetEpplus;

 /// <summary>
 /// Specifies whether the target is inside or outside the System.IO.Packaging.Package.
 /// </summary>
 public enum TargetMode {
   /// <summary>
   /// The relationship references a part that is inside the package.
   /// </summary>
   Internal = 0,

   /// <summary>
   /// The relationship references a resource that is external to the package.
   /// </summary>
   External = 1,
 }

 /// <summary>
 /// Represent an OOXML Zip package.
 /// </summary>
 internal class ZipPackage : ZipPackageRelationshipBase {
   internal class ContentType {
     internal string Name;
     internal bool IsExtension;
     internal string Match;

     public ContentType(string name, bool isExtension, string match) {
       Name = name;
       IsExtension = isExtension;
       Match = match;
     }
   }

   private readonly Dictionary<string, ZipPackagePart> Parts = new(
       StringComparer.InvariantCultureIgnoreCase);
   internal Dictionary<string, ContentType> _contentTypes = new(
       StringComparer.InvariantCultureIgnoreCase);

   internal ZipPackage() {
     AddNew();
   }

   private void AddNew() {
     _contentTypes.Add("xml", new(ExcelPackage._schemaXmlExtension, true, "xml"));
     _contentTypes.Add("rels", new(ExcelPackage._schemaRelsExtension, true, "rels"));
   }

   internal ZipPackage(Stream stream) {
     bool hasContentTypeXml = false;
     if (stream == null || stream.Length == 0) {
       AddNew();
     } else {
       var rels = new Dictionary<string, ZipArchiveEntry>();
       stream.Seek(0, SeekOrigin.Begin);
       using var zip = new ZipArchive(stream, ZipArchiveMode.Read, leaveOpen: true);
       foreach (var e in zip.Entries) {
         if (e.Length > 0) {
           if (e.FullName.Equals(
               "[content_types].xml",
               StringComparison.InvariantCultureIgnoreCase)) {
             using var inputStream = e.Open();
             AddContentTypes(inputStream);
             hasContentTypeXml = true;
           } else if (e.FullName.Equals(
               "_rels/.rels",
               StringComparison.InvariantCultureIgnoreCase)) {
             using var inputStream = e.Open();
             ReadRelation(inputStream, "");
           } else {
             if (e.FullName.EndsWith(".rels", StringComparison.InvariantCultureIgnoreCase)) {
               rels.Add(GetUriKey(e.FullName), e);
             } else {
               var data = new byte[e.Length];
               using var inputStream = e.Open();
               inputStream.ReadExactly(data);
               var part = new ZipPackagePart(
                   this,
                   e,
                   ImmutableCollectionsMarshal.AsImmutableArray(data));
               Parts.Add(GetUriKey(e.FullName), part);
             }
           }
         }
       }
       foreach (var p in Parts) {
         string name = Path.GetFileName(p.Key);
         string extension = Path.GetExtension(p.Key);
         string relFile = string.Format(
             "{0}_rels/{1}.rels",
             p.Key.Substring(0, p.Key.Length - name.Length),
             name);
         if (rels.TryGetValue(relFile, out var zipArchiveEntry)) {
           using var inputStream = zipArchiveEntry.Open();
           p.Value.ReadRelation(inputStream, p.Value.Uri.OriginalString);
         }
         if (_contentTypes.TryGetValue(p.Key, out var type)) {
           p.Value.ContentType = type.Name;
         } else if (extension.Length > 1 && _contentTypes.ContainsKey(extension.Substring(1))) {
           p.Value.ContentType = _contentTypes[extension.Substring(1)].Name;
         }
       }
       if (!hasContentTypeXml) {
         throw new InvalidDataException("The file is not an valid Package file.");
       }
     }
   }

   private void AddContentTypes(Stream inputStream) {
     var doc = new XmlDocument();
     XmlHelper.LoadXmlSafe(doc, inputStream);

     foreach (XmlElement c in doc.DocumentElement.ChildNodes) {
       ContentType ct;
       if (string.IsNullOrEmpty(c.GetAttribute("Extension"))) {
         ct = new(c.GetAttribute("ContentType"), false, c.GetAttribute("PartName"));
       } else {
         ct = new(c.GetAttribute("ContentType"), true, c.GetAttribute("Extension"));
       }
       _contentTypes.Add(GetUriKey(ct.Match), ct);
     }
   }

   internal void CreatePart(Uri partUri, string contentType, Action<StreamWriter> saveHandler) {
     if (PartExists(partUri)) {
       throw (new InvalidOperationException("Part already exist"));
     }

     var part = new ZipPackagePart(this, partUri, contentType, saveHandler);
     _contentTypes.Add(
         GetUriKey(part.Uri.OriginalString),
         new(contentType, false, part.Uri.OriginalString));
     Parts.Add(GetUriKey(part.Uri.OriginalString), part);
   }

   internal ZipPackagePart GetPart(Uri partUri) {
     if (PartExists(partUri)) {
       return Parts
           .Single(x =>
               x.Key.Equals(
                   GetUriKey(partUri.OriginalString),
                   StringComparison.InvariantCultureIgnoreCase))
           .Value;
     }
     throw (new InvalidOperationException("Part does not exist."));
   }

   internal string GetUriKey(string uri) {
     string ret = uri;
     if (ret[0] != '/') {
       ret = "/" + ret;
     }
     return ret;
   }

   internal bool PartExists(Uri partUri) {
     var uriKey = GetUriKey(partUri.OriginalString.ToLower(CultureInfo.InvariantCulture));
     return Parts.Keys.Any(x => x.Equals(uriKey, StringComparison.InvariantCultureIgnoreCase));
   }

   internal void DeletePart(Uri uri) {
     var delList = new List<object[]>();
     foreach (var p in Parts.Values) {
       foreach (var r in p.GetRelationships()) {
         if (UriHelper
             .ResolvePartUri(p.Uri, r.TargetUri)
             .OriginalString.Equals(
                 uri.OriginalString,
                 StringComparison.InvariantCultureIgnoreCase)) {
           delList.Add([r.Id, p]);
         }
       }
     }
     foreach (var o in delList) {
       ((ZipPackagePart)o[1]).DeleteRelationship(o[0].ToString());
     }
     var rels = GetPart(uri).GetRelationships();
     while (rels.Count > 0) {
       rels.Remove(rels.First().Id);
     }
     _contentTypes.Remove(GetUriKey(uri.OriginalString));
     //remove all relations
     Parts.Remove(GetUriKey(uri.OriginalString));
   }

   internal void Save(Stream stream) {
     using var zipArchive = new ZipArchive(stream, ZipArchiveMode.Create, leaveOpen: true);
     // Content types
     var contentTypesEntry = zipArchive.CreateEntry("[Content_Types].xml");
     using (var contentTypesWriter = new StreamWriter(contentTypesEntry.Open())) {
       contentTypesWriter.Write(GetContentTypeXml());
     }
     // Top Rels
     _rels.WriteZip(zipArchive, "_rels/.rels");
     ZipPackagePart ssPart = null;
     foreach (var part in Parts.Values) {
       if (part.ContentType != ExcelPackage._contentTypeSharedString) {
         part.WriteZip(zipArchive);
       } else {
         ssPart = part;
       }
     }
     //Shared strings must be saved after all worksheets. The ss dictionary is populated when that workheets are saved (to get the best performance).
     if (ssPart != null) {
       ssPart.WriteZip(zipArchive);
     }
   }

   private string GetContentTypeXml() {
     StringBuilder xml = new StringBuilder(
         "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><Types xmlns=\"http://schemas.openxmlformats.org/package/2006/content-types\">");
     foreach (ContentType ct in _contentTypes.Values) {
       if (ct.IsExtension) {
         xml.Append($"<Default ContentType=\"{ct.Name}\" Extension=\"{ct.Match}\"/>");
       } else {
         xml.Append($"<Override ContentType=\"{ct.Name}\" PartName=\"{GetUriKey(ct.Match)}\" />");
       }
     }
     xml.Append("</Types>");
     return xml.ToString();
   }
 }
	/*******************************************************************************
	* 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 Added 25-Oct-2012
	*******************************************************************************/

	using System;
	using System.Collections.Generic;
	using System.Globalization;
	using System.IO;
	using System.IO.Compression;
	using System.Linq;
	using System.Runtime.InteropServices;
	using System.Text;
	using System.Xml;

	namespace AppsheetEpplus;

	/// <summary>
	/// Specifies whether the target is inside or outside the System.IO.Packaging.Package.
	/// </summary>
	public enum TargetMode {
	/// <summary>
	/// The relationship references a part that is inside the package.
	/// </summary>
	Internal = 0,

	/// <summary>
	/// The relationship references a resource that is external to the package.
	/// </summary>
	External = 1,
	}

	/// <summary>
	/// Represent an OOXML Zip package.
	/// </summary>
	internal class ZipPackage : ZipPackageRelationshipBase {
	internal class ContentType {
	internal string Name;
	internal bool IsExtension;
	internal string Match;

	public ContentType(string name, bool isExtension, string match) {
	Name = name;
	IsExtension = isExtension;
	Match = match;
	}
	}

	private readonly Dictionary<string, ZipPackagePart> Parts = new(
	StringComparer.InvariantCultureIgnoreCase);
	internal Dictionary<string, ContentType> _contentTypes = new(
	StringComparer.InvariantCultureIgnoreCase);

	internal ZipPackage() {
	AddNew();
	}

	private void AddNew() {
	_contentTypes.Add("xml", new(ExcelPackage._schemaXmlExtension, true, "xml"));
	_contentTypes.Add("rels", new(ExcelPackage._schemaRelsExtension, true, "rels"));
	}

	internal ZipPackage(Stream stream) {
	bool hasContentTypeXml = false;
	if (stream == null \|\| stream.Length == 0) {
	AddNew();
	} else {
	var rels = new Dictionary<string, ZipArchiveEntry>();
	stream.Seek(0, SeekOrigin.Begin);
	using var zip = new ZipArchive(stream, ZipArchiveMode.Read, leaveOpen: true);
	foreach (var e in zip.Entries) {
	if (e.Length > 0) {
	if (e.FullName.Equals(
	"[content_types].xml",
	StringComparison.InvariantCultureIgnoreCase)) {
	using var inputStream = e.Open();
	AddContentTypes(inputStream);
	hasContentTypeXml = true;
	} else if (e.FullName.Equals(
	"_rels/.rels",
	StringComparison.InvariantCultureIgnoreCase)) {
	using var inputStream = e.Open();
	ReadRelation(inputStream, "");
	} else {
	if (e.FullName.EndsWith(".rels", StringComparison.InvariantCultureIgnoreCase)) {
	rels.Add(GetUriKey(e.FullName), e);
	} else {
	var data = new byte[e.Length];
	using var inputStream = e.Open();
	inputStream.ReadExactly(data);
	var part = new ZipPackagePart(
	this,
	e,
	ImmutableCollectionsMarshal.AsImmutableArray(data));
	Parts.Add(GetUriKey(e.FullName), part);
	}
	}
	}
	}
	foreach (var p in Parts) {
	string name = Path.GetFileName(p.Key);
	string extension = Path.GetExtension(p.Key);
	string relFile = string.Format(
	"{0}_rels/{1}.rels",
	p.Key.Substring(0, p.Key.Length - name.Length),
	name);
	if (rels.TryGetValue(relFile, out var zipArchiveEntry)) {
	using var inputStream = zipArchiveEntry.Open();
	p.Value.ReadRelation(inputStream, p.Value.Uri.OriginalString);
	}
	if (_contentTypes.TryGetValue(p.Key, out var type)) {
	p.Value.ContentType = type.Name;
	} else if (extension.Length > 1 && _contentTypes.ContainsKey(extension.Substring(1))) {
	p.Value.ContentType = _contentTypes[extension.Substring(1)].Name;
	}
	}
	if (!hasContentTypeXml) {
	throw new InvalidDataException("The file is not an valid Package file.");
	}
	}
	}

	private void AddContentTypes(Stream inputStream) {
	var doc = new XmlDocument();
	XmlHelper.LoadXmlSafe(doc, inputStream);

	foreach (XmlElement c in doc.DocumentElement.ChildNodes) {
	ContentType ct;
	if (string.IsNullOrEmpty(c.GetAttribute("Extension"))) {
	ct = new(c.GetAttribute("ContentType"), false, c.GetAttribute("PartName"));
	} else {
	ct = new(c.GetAttribute("ContentType"), true, c.GetAttribute("Extension"));
	}
	_contentTypes.Add(GetUriKey(ct.Match), ct);
	}
	}

	internal void CreatePart(Uri partUri, string contentType, Action<StreamWriter> saveHandler) {
	if (PartExists(partUri)) {
	throw (new InvalidOperationException("Part already exist"));
	}

	var part = new ZipPackagePart(this, partUri, contentType, saveHandler);
	_contentTypes.Add(
	GetUriKey(part.Uri.OriginalString),
	new(contentType, false, part.Uri.OriginalString));
	Parts.Add(GetUriKey(part.Uri.OriginalString), part);
	}

	internal ZipPackagePart GetPart(Uri partUri) {
	if (PartExists(partUri)) {
	return Parts
	.Single(x =>
	x.Key.Equals(
	GetUriKey(partUri.OriginalString),
	StringComparison.InvariantCultureIgnoreCase))
	.Value;
	}
	throw (new InvalidOperationException("Part does not exist."));
	}

	internal string GetUriKey(string uri) {
	string ret = uri;
	if (ret[0] != '/') {
	ret = "/" + ret;
	}
	return ret;
	}

	internal bool PartExists(Uri partUri) {
	var uriKey = GetUriKey(partUri.OriginalString.ToLower(CultureInfo.InvariantCulture));
	return Parts.Keys.Any(x => x.Equals(uriKey, StringComparison.InvariantCultureIgnoreCase));
	}

	internal void DeletePart(Uri uri) {
	var delList = new List<object[]>();
	foreach (var p in Parts.Values) {
	foreach (var r in p.GetRelationships()) {
	if (UriHelper
	.ResolvePartUri(p.Uri, r.TargetUri)
	.OriginalString.Equals(
	uri.OriginalString,
	StringComparison.InvariantCultureIgnoreCase)) {
	delList.Add([r.Id, p]);
	}
	}
	}
	foreach (var o in delList) {
	((ZipPackagePart)o[1]).DeleteRelationship(o[0].ToString());
	}
	var rels = GetPart(uri).GetRelationships();
	while (rels.Count > 0) {
	rels.Remove(rels.First().Id);
	}
	_contentTypes.Remove(GetUriKey(uri.OriginalString));
	//remove all relations
	Parts.Remove(GetUriKey(uri.OriginalString));
	}

	internal void Save(Stream stream) {
	using var zipArchive = new ZipArchive(stream, ZipArchiveMode.Create, leaveOpen: true);
	// Content types
	var contentTypesEntry = zipArchive.CreateEntry("[Content_Types].xml");
	using (var contentTypesWriter = new StreamWriter(contentTypesEntry.Open())) {
	contentTypesWriter.Write(GetContentTypeXml());
	}
	// Top Rels
	_rels.WriteZip(zipArchive, "_rels/.rels");
	ZipPackagePart ssPart = null;
	foreach (var part in Parts.Values) {
	if (part.ContentType != ExcelPackage._contentTypeSharedString) {
	part.WriteZip(zipArchive);
	} else {
	ssPart = part;
	}
	}
	//Shared strings must be saved after all worksheets. The ss dictionary is populated when that workheets are saved (to get the best performance).
	if (ssPart != null) {
	ssPart.WriteZip(zipArchive);
	}
	}

	private string GetContentTypeXml() {
	StringBuilder xml = new StringBuilder(
	"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><Types xmlns=\"http://schemas.openxmlformats.org/package/2006/content-types\">");
	foreach (ContentType ct in _contentTypes.Values) {
	if (ct.IsExtension) {
	xml.Append($"<Default ContentType=\"{ct.Name}\" Extension=\"{ct.Match}\"/>");
	} else {
	xml.Append($"<Override ContentType=\"{ct.Name}\" PartName=\"{GetUriKey(ct.Match)}\" />");
	}
	}
	xml.Append("</Types>");
	return xml.ToString();
	}
	}