BENode.h

//
// BENode.h
//
// This file is part of PeerProject (peerproject.org) © 2008-2012
// Portions copyright Shareaza Development Team, 2002-2008.
//
// PeerProject is free software. You may redistribute and/or modify it
// under the terms of the GNU Affero General Public License
// as published by the Free Software Foundation (fsf.org);
// version 3 or later at your option. (AGPLv3)
//
// PeerProject 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 Affero General Public License 3.0 for details:
// (http://www.gnu.org/licenses/agpl.html)
//

#pragma once

class CBuffer;

typedef const BYTE *LPCBYTE;

class CBENode
{
// Construction
public:
	CBENode();
	~CBENode();

// Attributes
public:
	int			m_nType;
	LPVOID		m_pValue;
	__int64		m_nValue;
	QWORD		m_nSize;
	QWORD		m_nPosition;

	static UINT	m_nDefaultCP;	// User codepage for string decoding

	enum { beNull, beString, beInt, beList, beDict };

// Operations
public:
	void		Clear();
	CBENode*	Add(LPCBYTE pKey, size_t nKey);
	CBENode*	GetNode(LPCSTR pszKey) const;
	CBENode*	GetNode(const LPBYTE pKey, int nKey) const;
	CString		GetStringFromSubNode(LPCSTR pszKey, UINT nEncoding) const;
	CString		GetStringFromSubNode(int nItem, UINT nEncoding) const;
	CSHA		GetSHA1() const;
	void		Encode(CBuffer* pBuffer) const;
	void		Decode(LPCBYTE& pInput, DWORD& nInput, DWORD nSize);
	static CBENode*	Decode(const CBuffer* pBuffer, DWORD *pnReaden = NULL);
	static CBENode* Decode(LPCBYTE pBuffer, DWORD nLength, DWORD *pnReaden = NULL);
private:
	static int	DecodeLen(LPCBYTE& pInput, DWORD& nInput);

// Inline
public:
	inline bool IsType(int nType) const
	{
		if ( this == NULL ) return false;
		return m_nType == nType;
	}

	inline __int64 GetInt() const
	{
		if ( m_nType != beInt ) return 0;
		return m_nValue;
	}

	inline void SetInt(__int64 nValue)
	{
		Clear();
		m_nType  = beInt;
		m_nValue = nValue;
	}

	// If a torrent is badly encoded, you can try forcing a code page.
	// Trying codepages: nCodePage, m_nDefaultCP, OEM, ANSI, as-is
	CString DecodeString(UINT nCodePage) const;

	CString GetString() const;

//	inline void SetString(LPCSTR psz)
//	{
//		SetString( psz, strlen(psz), TRUE );
//	}

//	inline void SetString(LPCWSTR psz)
//	{
//		CW2A pszASCII( psz );
//		SetString( (LPCSTR)pszASCII, strlen( (LPCSTR)pszASCII ), TRUE );
//	}

	inline void SetString(const CString& strInput)
	{
		CStringA strUTF8 = UTF8Encode( strInput );
		SetString( strUTF8, strUTF8.GetLength(), TRUE );
	}

	inline void SetString(LPCVOID pString, size_t nLength, BOOL bNull = FALSE)
	{
		Clear();
		m_nType  = beString;
		m_nValue = (__int64)nLength;
		m_pValue = new BYTE[ nLength + ( bNull ? 1 : 0 ) ];
		CopyMemory( m_pValue, pString, nLength + ( bNull ? 1 : 0 ) );
	}

//#ifdef HASHES_HPP_INCLUDED

	bool GetString(Hashes::BtGuid& oGUID) const;

	inline void SetString(const Hashes::BtGuid& oGUID)
	{
		SetString( &oGUID[0], oGUID.byteCount );
	}

//#endif // HASHES_HPP_INCLUDED

	inline CBENode* Add(LPCSTR pszKey = NULL)
	{
		return Add( (LPBYTE)pszKey, pszKey != NULL ? strlen( pszKey ) : 0 );
	}

	inline int GetCount() const
	{
		if ( m_nType != beList && m_nType != beDict ) return 0;
		return (int)m_nValue;
	}

	inline CBENode* GetNode(int nItem) const
	{
		if ( m_nType != beList && m_nType != beDict ) return NULL;
		if ( m_nType == beDict ) nItem *= 2;
		if ( nItem < 0 || nItem >= m_nValue ) return NULL;
		return *( (CBENode**)m_pValue + nItem );
	}

	// Encode node to human readable string
	const CString Encode() const;
};