/*

Miranda NG: the free IM client for Microsoft* Windows*

Copyright 2012-14 Miranda NG project,
all portions of this codebase are copyrighted to the people
listed in contributors.txt.

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include <m_db_int.h>

/* tree diagram

DBHeader
 |-->end of file (plain offset)
 |-->first contact (DBContact)
 |   |-->next contact (DBContact)
 |   |   \--> ...
 |   |-->first settings (DBContactSettings)
 |   |	 |-->next settings (DBContactSettings)
 |   |   |   \--> ...
 |   |   \-->module name (DBModuleName)
 |   \-->first/last/firstunread event
 |-->user contact (DBContact)
 |   |-->next contact = NULL
 |   |-->first settings	as above
 |   \-->first/last/firstunread event as above
 \-->first module name (DBModuleName)
     \-->next module name (DBModuleName)
	     \--> ...
*/

#define DB_OLD_VERSION   0x00000700u
#define DB_094_VERSION   0x00000701u
#define DB_095_VERSION   0x00000800u

#define DB_SETTINGS_RESIZE_GRANULARITY  128

#define WSOFS_END   0xFFFFFFFF
#define WS_ERROR    0xFFFFFFFF

#define DBVT_ENCRYPTED   250
#define DBVT_UNENCRYPTED 251

#define NeedBytes(n)   if (bytesRemaining<(n)) pBlob = (PBYTE)DBRead(ofsBlobPtr,(n),&bytesRemaining)
#define MoveAlong(n)   {int x = n; pBlob += (x); ofsBlobPtr += (x); bytesRemaining -= (x);}

DWORD __forceinline GetSettingValueLength(PBYTE pSetting)
{
	if (pSetting[0] & DBVTF_VARIABLELENGTH)
		return 2 + *(PWORD)(pSetting + 1);
	return pSetting[0];
}

struct DBSignature
{
	char name[15];
	BYTE eof;
};

struct ModuleName
{
	char *name;
	DWORD ofs;
};

#include <pshpack1.h>
struct DBHeader
{
	BYTE signature[16];      // 'Miranda ICQ DB',0,26
	DWORD version;		   //as 4 bytes, ie 1.2.3.10 = 0x0102030a
	//this version is 0x00000700
	DWORD ofsFileEnd;		   //offset of the end of the database - place to write
	//new structures
	DWORD slackSpace;		   //a counter of the number of bytes that have been
	//wasted so far due to deleting structures and/or
	//re-making them at the end. We should compact when
	//this gets above a threshold
	DWORD contactCount;	   //number of contacts in the chain,excluding the user
	DWORD ofsFirstContact;   //offset to first DBContact in the chain
	DWORD ofsUser;		   //offset to DBContact representing the user
	DWORD ofsFirstModuleName;	//offset to first struct DBModuleName in the chain
};

#define DBCONTACT_SIGNATURE   0x43DECADEu

struct DBContact
{
	DWORD signature;
	DWORD ofsNext;			 //offset to the next contact in the chain. zero if
	//this is the 'user' contact or the last contact
	//in the chain
	DWORD ofsFirstSettings;	 //offset to the first DBContactSettings in the
	//chain for this contact.
	DWORD eventCount;			 //number of events in the chain for this contact
	DWORD ofsFirstEvent, ofsLastEvent;	 //offsets to the first and last DBEvent in
	//the chain for this contact
	DWORD ofsFirstUnreadEvent; //offset to the first (chronological) unread event
	//in the chain, 0 if all are read
	DWORD timestampFirstUnread; //timestamp of the event at ofsFirstUnreadEvent
	DWORD dwContactID;
};

#define DBMODULENAME_SIGNATURE  0x4DDECADEu
struct DBModuleName
{
	DWORD signature;
	DWORD ofsNext;		//offset to the next module name in the chain
	BYTE cbName;			//number of characters in this module name
	char name[1];			//name, no nul terminator
};

#define DBCONTACTSETTINGS_SIGNATURE  0x53DECADEu
struct DBContactSettings
{
	DWORD signature;
	DWORD ofsNext;		 //offset to the next contactsettings in the chain
	DWORD ofsModuleName;	 //offset to the DBModuleName of the owner of these
	//settings
	DWORD cbBlob;			 //size of the blob in bytes. May be larger than the
	//actual size for reducing the number of moves
	//required using granularity in resizing
	BYTE blob[1];			 //the blob. a back-to-back sequence of DBSetting
	//structs, the last has cbName = 0
};

#define DBEVENT_SIGNATURE  0x45DECADEu
struct DBEvent
{
	DWORD signature;
	DWORD ofsPrev, ofsNext;	 //offset to the previous and next events in the
	//chain. Chain is sorted chronologically
	DWORD ofsModuleName;		 //offset to a DBModuleName struct of the name of
	//the owner of this event
	DWORD timestamp;			 //seconds since 00:00:00 01/01/1970
	DWORD flags;				 //see m_database.h, db/event/add
	WORD eventType;			 //module-defined event type
	DWORD cbBlob;				 //number of bytes in the blob
	BYTE blob[1];				 //the blob. module-defined formatting
};

#include <poppack.h>

struct CDb3Mmap : public MIDatabase, public MIDatabaseChecker, public MZeroedObject
{
	CDb3Mmap(const TCHAR* tszFileName, bool bReadOnly);
	~CDb3Mmap();

	int Load(bool bSkipInit);
	int Create(void);
	int CreateDbHeaders(const DBSignature&);
	int CheckDbHeaders();

	void ToggleEncryption(void);
	void StoreKey(void);
	void SetPassword(const TCHAR *ptszPassword);
	void UpdateMenuItem(void);

	int  PrepareCheck(void);

	__forceinline LPSTR GetMenuTitle() const { return m_bUsesPassword ? LPGEN("Change/remove password") : LPGEN("Set password"); }

	void DatabaseCorruption(TCHAR *text);
	void WriteSignature(DBSignature&);

	__forceinline HANDLE getFile() const { return m_hDbFile; }
	__forceinline bool isEncrypted() const { return m_bEncrypted; }
	__forceinline bool usesPassword() const { return m_bUsesPassword; }

public:
	STDMETHODIMP_(void)   SetCacheSafetyMode(BOOL);

	STDMETHODIMP_(LONG)     GetContactCount(void);
	STDMETHODIMP_(MCONTACT) FindFirstContact(const char* szProto = NULL);
	STDMETHODIMP_(MCONTACT) FindNextContact(MCONTACT contactID, const char* szProto = NULL);
	STDMETHODIMP_(LONG)     DeleteContact(MCONTACT contactID);
	STDMETHODIMP_(HANDLE)   AddContact(void);
	STDMETHODIMP_(BOOL)     IsDbContact(MCONTACT contactID);

	STDMETHODIMP_(LONG)     GetEventCount(MCONTACT contactID);
	STDMETHODIMP_(HANDLE)   AddEvent(MCONTACT contactID, DBEVENTINFO *dbe);
	STDMETHODIMP_(BOOL)     DeleteEvent(MCONTACT contactID, HANDLE hDbEvent);
	STDMETHODIMP_(LONG)     GetBlobSize(HANDLE hDbEvent);
	STDMETHODIMP_(BOOL)     GetEvent(HANDLE hDbEvent, DBEVENTINFO *dbe);
	STDMETHODIMP_(BOOL)     MarkEventRead(MCONTACT contactID, HANDLE hDbEvent);
	STDMETHODIMP_(MCONTACT) GetEventContact(HANDLE hDbEvent);
	STDMETHODIMP_(HANDLE)   FindFirstEvent(MCONTACT contactID);
	STDMETHODIMP_(HANDLE)   FindFirstUnreadEvent(MCONTACT contactID);
	STDMETHODIMP_(HANDLE)   FindLastEvent(MCONTACT contactID);
	STDMETHODIMP_(HANDLE)   FindNextEvent(HANDLE hDbEvent);
	STDMETHODIMP_(HANDLE)   FindPrevEvent(HANDLE hDbEvent);

	STDMETHODIMP_(BOOL)     EnumModuleNames(DBMODULEENUMPROC pFunc, void *pParam);

	STDMETHODIMP_(BOOL)     GetContactSetting(MCONTACT contactID, LPCSTR szModule, LPCSTR szSetting, DBVARIANT *dbv);
	STDMETHODIMP_(BOOL)     GetContactSettingStr(MCONTACT contactID, LPCSTR szModule, LPCSTR szSetting, DBVARIANT *dbv);
	STDMETHODIMP_(BOOL)     GetContactSettingStatic(MCONTACT contactID, LPCSTR szModule, LPCSTR szSetting, DBVARIANT *dbv);
	STDMETHODIMP_(BOOL)     FreeVariant(DBVARIANT *dbv);
	STDMETHODIMP_(BOOL)     WriteContactSetting(MCONTACT contactID, DBCONTACTWRITESETTING *dbcws);
	STDMETHODIMP_(BOOL)     DeleteContactSetting(MCONTACT contactID, LPCSTR szModule, LPCSTR szSetting);
	STDMETHODIMP_(BOOL)     EnumContactSettings(MCONTACT contactID, DBCONTACTENUMSETTINGS* dbces);
	STDMETHODIMP_(BOOL)     SetSettingResident(BOOL bIsResident, const char *pszSettingName);
	STDMETHODIMP_(BOOL)     EnumResidentSettings(DBMODULEENUMPROC pFunc, void *pParam);
	STDMETHODIMP_(BOOL)     IsSettingEncrypted(LPCSTR szModule, LPCSTR szSetting);

protected:
	STDMETHODIMP_(BOOL)     Start(DBCHeckCallback *callback);
	STDMETHODIMP_(BOOL)     CheckDb(int phase, int firstTime);
	STDMETHODIMP_(VOID)     Destroy();

protected:
	DWORD GetSettingsGroupOfsByModuleNameOfs(DBContact *dbc, DWORD ofsContact, DWORD ofsModuleName);
	void  InvalidateSettingsGroupOfsCacheEntry(DWORD ofsSettingsGroup) {}
	int   WorkInitialCheckHeaders(void);

	void  DBMoveChunk(DWORD ofsDest, DWORD ofsSource, int bytes);
	PBYTE DBRead(DWORD ofs, int bytesRequired, int *bytesAvail);
	void  DBWrite(DWORD ofs, PVOID pData, int bytes);
	void  DBFill(DWORD ofs, int bytes);
	void  DBFlush(int setting);
	int   InitMap(void);
	void  FillContacts(void);

	PBYTE m_pNull;

	void  Map();
	void  ReMap(DWORD needed);

public:  // Check functions
	int WorkInitialChecks(int);
	int WorkModuleChain(int);
	int WorkUser(int);
	int WorkContactChain(int);
	int WorkAggressive(int);
	int WorkFinalTasks(int);

protected:
	TCHAR*   m_tszProfileName;
	HANDLE   m_hDbFile;
	DBHeader m_dbHeader;
	DWORD    m_ChunkSize;
	bool     m_safetyMode, m_bReadOnly, m_bEncrypted, m_bUsesPassword;

	////////////////////////////////////////////////////////////////////////////
	// database stuff
public:
	UINT_PTR m_flushBuffersTimerId;
	DWORD    m_flushFailTick;
	PBYTE    m_pDbCache;
	HANDLE   m_hMap;

	MICryptoEngine *m_crypto;

protected:
	DWORD    m_dwFileSize, m_dwMaxContactId;
	HANDLE   hSettingChangeEvent, hContactDeletedEvent, hContactAddedEvent, hEventMarkedRead;

	CRITICAL_SECTION m_csDbAccess;

	int   CheckProto(DBCachedContact *cc, const char *proto);
	DWORD CreateNewSpace(int bytes);
	void  DeleteSpace(DWORD ofs, int bytes);
	DWORD ReallocSpace(DWORD ofs, int oldSize, int newSize);
	DWORD GetContactOffset(MCONTACT contactID);

	////////////////////////////////////////////////////////////////////////////
	// settings 

	int m_codePage;

	////////////////////////////////////////////////////////////////////////////
	// modules

	HANDLE m_hModHeap;
	LIST<ModuleName> m_lMods, m_lOfs;
	LIST<char> m_lResidentSettings;
	HANDLE hEventAddedEvent, hEventDeletedEvent, hEventFilterAddedEvent;
	MCONTACT m_hLastCachedContact;
	ModuleName *m_lastmn;

	void  AddToList(char *name, DWORD len, DWORD ofs);
	DWORD FindExistingModuleNameOfs(const char *szName);
	int   InitModuleNames(void);
	DWORD GetModuleNameOfs(const char *szName);
	char *GetModuleNameByOfs(DWORD ofs);

	////////////////////////////////////////////////////////////////////////////
	// checker

	int PeekSegment(DWORD ofs, PVOID buf, int cbBytes);
	int ReadSegment(DWORD ofs, PVOID buf, int cbBytes);
	int ReadWrittenSegment(DWORD ofs, PVOID buf, int cbBytes);
	int SignatureValid(DWORD ofs, DWORD signature);
	void FreeModuleChain();

	DWORD ConvertModuleNameOfs(DWORD ofsOld);
	void ConvertOldEvent(DBEvent*& dbei);

	int GetContactSettingWorker(MCONTACT contactID, LPCSTR szModule, LPCSTR szSetting, DBVARIANT *dbv, int isStatic);
	int WorkSettingsChain(DWORD ofsContact, DBContact *dbc, int firstTime);
	int WorkEventChain(DWORD ofsContact, DBContact *dbc, int firstTime);

	DWORD WriteSegment(DWORD ofs, PVOID buf, int cbBytes);
	DWORD WriteEvent(DBEvent *dbe);
	void WriteOfsNextToPrevious(DWORD ofsPrev, DBContact *dbc, DWORD ofsNext);
	void FinishUp(DWORD ofsLast, DBContact *dbc);

	DBCHeckCallback *cb;
	DWORD sourceFileSize, ofsAggrCur;

	////////////////////////////////////////////////////////////////////////////
	// encryption

	void ConvertContacts(void);
	int  InitCrypt(void);
	void ToggleEventsEncryption(MCONTACT contactID);
	void ToggleSettingsEncryption(MCONTACT contactID);

	void InitDialogs();
	bool EnterPassword(const BYTE *pKey, const size_t keyLen);
};