//
// This file is part of the aMule Project.
//
// Copyright (c) 2003-2009 Angel Vidal (Kry) ( kry@amule.org )
// Copyright (c) 2003-2009 aMule Team ( admin@amule.org / http://www.amule.org )
// Copyright (c) 2002 Merkur ( devs@emule-project.net / http://www.emule-project.net )
//
// Any parts of this program derived from the xMule, lMule or eMule project,
// or contributed by third-party developers are copyrighted by their
// respective authors.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
//

/* 
 SHA hashset basically exists of 1 Tree for all Parts (9.28MB) + n Trees
 for all blocks (180KB) while n is the number of Parts.
 This means it is NOT a complete hashtree, since the 9.28MB is a given level, in order
 to be able to create a hashset format similar to the MD4 one.

 If the number of elements for the next level are odd (for example 21 blocks to spread into 2 hashs)
 the majority of elements will go into the left branch if the parent node was a left branch
 and into the right branch if the parent node was a right branch. The first node is always
 taken as a left branch.

Example tree:
	FileSize: 19506000 Bytes = 18,6 MB

              X(18,6 MB)                               		MasterHash
             /          \
          X(18,55)       \
         /        \       \
  X(9,28)         X(9,28)  X(0,05MB)				PartHashs
 /     \         /     \          \
X(4,75) X(4,57) X(4,57) X(4,57)    X(4,75)
[...............]
X(180KB)   X(180KB)  [...] X(140KB) | X(180KB) X(180KB) [...]	BlockHashs
                                    v
                                    Border between first and second Part (9.28MB)

HashsIdentifier:
When sending hashes, they are sent with a 16bit identifier which specifies its position in the
tree (so StartPosition + HashDataSize would lead to the same hash)
The identifier basically describes the way from the top of the tree to the hash. a set bit (1)
means follow the left branch, a 0 means follow the right. The highest bit which is set is seen as the start-
position (since the first node is always seen as left).

Example

    x                   0000000000000001
   / \		
  x   \			0000000000000011
 / \   \
x  _X_  x 	        0000000000000110


Version 2 of AICH also supports 32bit identifiers to support large files, check CAICHHashSet::CreatePartRecoveryData
*/

#ifndef __SHAHAHSET_H__
#define __SHAHAHSET_H__

#include <deque>
#include <set>

#include "Types.h"

#define HASHSIZE			20
#define KNOWN2_MET_FILENAME		wxT("known2_64.met")
#define OLD_KNOWN2_MET_FILENAME		wxT("known2.met")
#define KNOWN2_MET_VERSION		0x02

enum EAICHStatus {
	AICH_ERROR = 0,
	AICH_EMPTY,
	AICH_UNTRUSTED,
	AICH_TRUSTED,
	AICH_VERIFIED,
	AICH_HASHSETCOMPLETE
};

class CFileDataIO;
class CKnownFile;
class CMemFile;
class CPartFile;
class CUpDownClient;


/////////////////////////////////////////////////////////////////////////////////////////
///CAICHHash
class CAICHHash 
{
private:
	byte m_abyBuffer[HASHSIZE];

public:
	CAICHHash() 				{ memset(m_abyBuffer, 0, HASHSIZE); }
	CAICHHash(CFileDataIO* file)		{ Read(file); }
	CAICHHash(byte* data)			{ Read(data); }
	CAICHHash(const CAICHHash& k1)		{ *this = k1; }
	~CAICHHash() {}
	CAICHHash& operator=(const CAICHHash& k1)
	{
		memcpy(m_abyBuffer, k1.m_abyBuffer, HASHSIZE);
		return *this;
	}
	friend bool operator==(const CAICHHash& k1,const CAICHHash& k2)
	{
		return memcmp(k1.m_abyBuffer, k2.m_abyBuffer, HASHSIZE) == 0;
	}
	friend bool operator!=(const CAICHHash& k1,const CAICHHash& k2)	{ return !(k1 == k2); }
	void Read(CFileDataIO* file);
	void Write(CFileDataIO* file) const;
	void Read(byte* data)			{ memcpy(m_abyBuffer, data, HASHSIZE); }
	wxString GetString() const;
	byte* GetRawHash()			{ return m_abyBuffer; }
	static uint32 GetHashSize()		{ return HASHSIZE;}
	unsigned int DecodeBase32(const wxString &base32);
};

/////////////////////////////////////////////////////////////////////////////////////////
///CAICHHashAlgo
class CAICHHashAlgo 
{
public:
	virtual ~CAICHHashAlgo() {};
	virtual void Reset() = 0;
	virtual void Add(const void* pData, uint32 nLength) = 0;
	virtual void Finish(CAICHHash& Hash) = 0;
	virtual void GetHash(CAICHHash& Hash) = 0;
};

/////////////////////////////////////////////////////////////////////////////////////////
///CAICHHashTree
class CAICHHashTree
{
	friend class CAICHHashSet;
private:
	CAICHHash m_Hash;
	uint64 m_nDataSize;	// size of data which is covered by this hash
	uint64 m_nBaseSize;	// blocksize on which the lowest hash is based on
	bool m_bIsLeftBranch;	// left or right branch of the tree
	bool m_bHashValid;	// the hash is valid and not empty
	CAICHHashTree* m_pLeftTree;
	CAICHHashTree* m_pRightTree;
	
public:
	CAICHHashTree(uint64 nDataSize, bool bLeftBranch, uint64 nBaseSize);
	~CAICHHashTree();

	const CAICHHash &GetHash() const	{ return m_Hash; }
	uint64 GetNDataSize() const		{ return m_nDataSize; }
	uint64 GetNBaseSize() const		{ return m_nBaseSize; }
	bool GetIsLeftBranch() const		{ return m_bIsLeftBranch; }
	bool GetHashValid() const		{ return m_bHashValid; }
	
	void SetBlockHash(uint64 nSize, uint64 nStartPos, CAICHHashAlgo* pHashAlg);
	bool ReCalculateHash(CAICHHashAlgo* hashalg, bool bDontReplace );
	bool VerifyHashTree(CAICHHashAlgo* hashalg, bool bDeleteBadTrees);
	CAICHHashTree* FindHash(uint64 nStartPos, uint64 nSize)
	{
		uint8 buffer = 0;
		return FindHash(nStartPos, nSize, &buffer);
	}

protected:
	CAICHHashTree* FindHash(uint64 nStartPos, uint64 nSize, uint8* nLevel);
	bool CreatePartRecoveryData(uint64 nStartPos, uint64 nSize,
		CFileDataIO* fileDataOut, uint32 wHashIdent, bool b32BitIdent);
	void WriteHash(CFileDataIO* fileDataOut, uint32 wHashIdent, bool b32BitIdent) const;
	bool WriteLowestLevelHashs(CFileDataIO* fileDataOut,
		uint32 wHashIdent, bool bNoIdent, bool b32BitIdent) const;
	bool LoadLowestLevelHashs(CFileDataIO* fileInput);
	bool SetHash(CFileDataIO* fileInput, uint32 wHashIdent, sint8 nLevel = (-1), bool bAllowOverwrite = true);
};

/////////////////////////////////////////////////////////////////////////////////////////
///CAICHUntrustedHashs
class CAICHUntrustedHash {
public:
	CAICHUntrustedHash& operator=(const CAICHUntrustedHash& k1)
	{
		m_adwIpsSigning = k1.m_adwIpsSigning;
		m_Hash = k1.m_Hash ;
		return *this;
	}
	bool AddSigningIP(uint32 dwIP);	

	CAICHHash m_Hash;
	std::set<uint32> m_adwIpsSigning;
};

/////////////////////////////////////////////////////////////////////////////////////////
///CAICHUntrustedHashs
class CAICHRequestedData {
public:
	CAICHRequestedData()
	{
		m_nPart = 0;
		m_pPartFile = NULL;
		m_pClient= NULL;
	}
	CAICHRequestedData& operator=(const CAICHRequestedData& k1)
	{
		m_nPart = k1.m_nPart;
		m_pPartFile = k1.m_pPartFile;
		m_pClient = k1.m_pClient;
		return *this;
	}
	uint16 m_nPart;
	CPartFile* m_pPartFile;
	CUpDownClient* m_pClient;
};


using namespace std;
	
typedef std::list<CAICHRequestedData> CAICHRequestedDataList;

/////////////////////////////////////////////////////////////////////////////////////////
///CAICHHashSet
class CAICHHashSet
{
private:
	CKnownFile* m_pOwner;
	EAICHStatus m_eStatus;
	deque<CAICHUntrustedHash> m_aUntrustedHashs;
	
public:
	static CAICHRequestedDataList m_liRequestedData;
	CAICHHashTree m_pHashTree;
	
	CAICHHashSet(CKnownFile* pOwner);
	~CAICHHashSet(void);
	bool CreatePartRecoveryData(uint64 nPartStartPos, CFileDataIO* fileDataOut, bool bDbgDontLoad = false);
	bool ReadRecoveryData(uint64 nPartStartPos, CMemFile* fileDataIn);
	bool ReCalculateHash(bool bDontReplace = false);
	bool VerifyHashTree(bool bDeleteBadTrees);
	void UntrustedHashReceived(const CAICHHash& Hash, uint32 dwFromIP);
	bool IsPartDataAvailable(uint64 nPartStartPos);
	void SetStatus(EAICHStatus bNewValue)	{ m_eStatus = bNewValue; }
	EAICHStatus GetStatus()	const		{ return m_eStatus; }
	
	void FreeHashSet();
	void SetFileSize(uint64 nSize);
	
	CAICHHash& GetMasterHash()		{ return m_pHashTree.m_Hash; } 
	void SetMasterHash(const CAICHHash& Hash, EAICHStatus eNewStatus);
	bool HasValidMasterHash()		{ return m_pHashTree.m_bHashValid; }

	bool SaveHashSet();
	bool LoadHashSet(); // only call directly when debugging

	static CAICHHashAlgo* GetNewHashAlgo();
	static void ClientAICHRequestFailed(CUpDownClient* pClient);
	static void RemoveClientAICHRequest(const CUpDownClient* pClient);
	static bool IsClientRequestPending(const CPartFile* pForFile, uint16 nPart);
	static CAICHRequestedData GetAICHReqDetails(const  CUpDownClient* pClient);
	void DbgTest();
	
	void SetOwner(CKnownFile* owner)	{ m_pOwner = owner; }
};

#endif  //__SHAHAHSET_H__

// File_checked_for_headers
