/*
 Derived from source code of TrueCrypt 7.1a, which is
 Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
 by the TrueCrypt License 3.0.

 Modifications and additions to the original source code (contained in this file)
 and all other portions of this file are Copyright (c) 2013-2017 IDRIX
 and are governed by the Apache License 2.0 the full text of which is
 contained in the file License.txt included in VeraCrypt binary and source
 code distribution packages.
*/

#include "System.h"
#include <wx/tokenzr.h>
#include "Platform/FileStream.h"
#include "Xml.h"

namespace VeraCrypt
{
	XmlParser::XmlParser (const FilePath &fileName)
	{
		make_shared_auto (File, file);
		file->Open (fileName);
		FileStream stream (file);

		XmlText = wxString::FromUTF8 (stream.ReadToEnd().c_str());
	}

	wxString XmlParser::ConvertEscapedChars (wxString xmlString) const
	{
		xmlString.Replace (L"&lt;", L"<");
		xmlString.Replace (L"&gt;", L">");
		xmlString.Replace (L"&amp;", L"&");
		xmlString.Replace (L"&quot;", L"\"");
		return xmlString;
	}

	XmlNodeList XmlParser::GetNodes (const wxString &nodeName) const
	{
		XmlNodeList nodeList;

		size_t nodePos = 0;
		while ((nodePos = XmlText.find (L"<" + nodeName, nodePos)) != string::npos)
		{
			XmlNode xmlNode;
			xmlNode.Name = nodeName;

			size_t nodeEnd = XmlText.find (L">", nodePos);
			if (nodeEnd == string::npos)
				throw ParameterIncorrect (SRC_POS);

			wxString nodeTagText = XmlText.substr (nodePos + 1, nodeEnd - nodePos - 1);
			nodePos = nodeEnd;

			if (nodeTagText.size() > nodeName.size() && nodeTagText[nodeName.size()] != L' ' && nodeTagText[nodeName.size()] != L'/')
				continue;

			nodeTagText = nodeTagText.substr (nodeName.size());


			// Attributes
			wxStringTokenizer tokenizer (nodeTagText, L"\"", wxTOKEN_RET_EMPTY);
			while (tokenizer.HasMoreTokens())
			{
				wxString attributeName = tokenizer.GetNextToken();
				attributeName.Replace (L" ", L"", true);
				attributeName.Replace (L"=", L"");

				if (!attributeName.empty() && tokenizer.HasMoreTokens())
				{
					wxString attributeText = tokenizer.GetNextToken();
					xmlNode.Attributes[attributeName] = ConvertEscapedChars (attributeText);
				}
			}

			// Inner text
			if (!nodeTagText.EndsWith (L"/"))
			{
				size_t innerTextPos = nodeEnd + 1;
				size_t innerTextEnd = XmlText.find (L"</" + nodeName + L">", innerTextPos);
				if (innerTextEnd == string::npos)
					throw ParameterIncorrect (SRC_POS);

				xmlNode.InnerText = ConvertEscapedChars (XmlText.substr (innerTextPos, innerTextEnd - innerTextPos));
				nodePos = innerTextEnd;
			}

			nodeList.push_back (xmlNode);
		}

		return nodeList;
	}

	XmlWriter::XmlWriter (const FilePath &fileName)
	{
		MemOutStream.reset (new wxMemoryOutputStream);
		TextOutStream.reset (new wxTextOutputStream (*MemOutStream));
		OutFile.Open (fileName, File::CreateWrite);

		*TextOutStream << L"<?xml version=\"1.0\" encoding=\"utf-8\"?>" << endl << L"<VeraCrypt>" << endl;
		CurrentIndentLevel = 0;
	}

	void XmlWriter::Close()
	{
		if (MemOutStream.get())
		{
			*TextOutStream << L"</VeraCrypt>" << endl;

			wxStreamBuffer *buf = MemOutStream->GetOutputStreamBuffer();
			OutFile.Write (ConstBufferPtr (reinterpret_cast <byte *> (buf->GetBufferStart()), buf->GetBufferSize()));
			OutFile.Close();

			TextOutStream.reset();
			MemOutStream.reset();
		}
	}

	wxString XmlWriter::EscapeChars (wxString rawString) const
	{
		rawString.Replace (L"<", L"&lt;");
		rawString.Replace (L">", L"&gt;");
		rawString.Replace (L"&", L"&amp;");
		rawString.Replace (L"\"", L"&quot;");
		return rawString;
	}

	void XmlWriter::WriteNode (const XmlNode &xmlNode)
	{
		XmlNodeList nodes;
		nodes.push_back (xmlNode);
		WriteNodes (nodes);
	}

	void XmlWriter::WriteNodes (const XmlNodeList &xmlNodes)
	{
		CurrentIndentLevel++;
		wxString indent;
		for (int i = 0; i < CurrentIndentLevel; ++i)
			indent += L"\t";

		foreach (const XmlNode &node, xmlNodes)
		{
			*TextOutStream << indent << L"<" << node.Name;

			typedef pair <wxString, wxString> AttribPair;
			foreach (AttribPair attrib, node.Attributes)
			{
				*TextOutStream << L" " << attrib.first << L"=\"" << EscapeChars (attrib.second) << L"\"";
			}

			if (!node.InnerNodes.empty())
			{
				*TextOutStream << L">" << endl;
				WriteNodes (node.InnerNodes);
				*TextOutStream << indent;
			}
			else if (!node.InnerText.empty())
			{
				*TextOutStream << L">" << EscapeChars (node.InnerText);
			}
			else
			{
				*TextOutStream << L"/>" << endl;
				continue;
			}

			*TextOutStream << L"</" << node.Name << L">" << endl;
		}

		CurrentIndentLevel--;
	}

	XmlWriter::~XmlWriter ()
	{
		try
		{
			Close();
		}
		catch (...) { }
	}
}
