/*

'File Association Manager'-Plugin for Miranda IM

Copyright (C) 2005-2007 H. Herkenrath

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 (AssocMgr-License.txt); if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "common.h"

#ifdef _DEBUG
/* Debug: Ensure all registry calls do succeed and have valid parameters. 
 * Shows a details message box otherwise. */
static __inline LONG regchk(LONG res,const char *pszFunc,const void *pszInfo,BOOL fInfoUnicode,const char *pszFile,unsigned int nLine)
{
	if(res!=ERROR_SUCCESS && res!=ERROR_FILE_NOT_FOUND && res!=ERROR_NO_MORE_ITEMS) {
		TCHAR szMsg[1024],*pszInfo2;
		char *pszErr;
		pszErr=GetWinErrorDescription(res);
		pszInfo2=s2t(pszInfo,fInfoUnicode,FALSE);  /* does NULL check */
		mir_sntprintf(szMsg,SIZEOF(szMsg),_T("Access failed:\n%.64hs(%.128s)\n%.250hs(%u)\n%.256hs (%u)"),pszFunc,pszInfo2,pszFile,nLine,pszErr,res);
		MessageBox(NULL,szMsg,_T("Registry Warning"),MB_OK|MB_ICONINFORMATION|MB_SETFOREGROUND|MB_TOPMOST|MB_TASKMODAL);
		if(pszErr!=NULL) LocalFree(pszErr);
		mir_free(pszInfo2);  /* does NULL check */
	}
	return res;
}
#undef  RegCloseKey
#define RegCloseKey(hKey) \
	regchk(RegCloseKey(hKey),"RegCloseKey",NULL,FALSE,__FILE__,__LINE__)
#undef  RegOpenKeyExA
#define RegOpenKeyExA(hKey,szSubkey,opt,rights,phKey) \
	regchk(RegOpenKeyExA(hKey,szSubkey,opt,rights,phKey),"RegOpenKeyExA",szSubkey,FALSE,__FILE__,__LINE__)
#undef  RegCreateKeyExA
#define RegCreateKeyExA(hKey,szSubkey,x,y,opt,rights,sec,phKey,pDisp) \
	regchk(RegCreateKeyExA(hKey,szSubkey,x,y,opt,rights,sec,phKey,pDisp),"RegCreateKeyExA",szSubkey,FALSE,__FILE__,__LINE__)
#undef  RegDeleteKeyA
#define RegDeleteKeyA(hKey,szName) \
	regchk(RegDeleteKeyA(hKey,szName),"RegDeleteKeyA",szName,FALSE,__FILE__,__LINE__)
#undef  RegSetValueExA
#define RegSetValueExA(hSubKey,szName,x,type,pVal,size) \
	regchk(RegSetValueExA(hSubKey,szName,x,type,pVal,size),"RegSetValueExA",szName,FALSE,__FILE__,__LINE__)
#undef  RegQueryValueExA
#define RegQueryValueExA(hKey,szName,x,pType,pVal,pSize) \
	regchk(RegQueryValueExA(hKey,szName,x,pType,pVal,pSize),"RegQueryValueExA",szName,FALSE,__FILE__,__LINE__)
#undef  RegQueryInfoKeyA
#define RegQueryInfoKeyA(hKey,x,y,z,pnKeys,pnKeyLen,a,pnVals,pnNames,pnValLen,sec,pTime) \
	regchk(RegQueryInfoKeyA(hKey,x,y,z,pnKeys,pnKeyLen,a,pnVals,pnNames,pnValLen,sec,pTime),"RegQueryInfoKeyA",NULL,FALSE,__FILE__,__LINE__)
#undef  RegEnumKeyExA
#define RegEnumKeyExA(hKey,idx,pName,pnName,x,y,z,pTime) \
	regchk(RegEnumKeyExA(hKey,idx,pName,pnName,x,y,z,pTime),"RegEnumKeyExA",NULL,FALSE,__FILE__,__LINE__)
#undef  RegDeleteValueA
#define RegDeleteValueA(hKey,szName) \
	regchk(RegDeleteValueA(hKey,szName),"RegDeleteValueA",szName,FALSE,__FILE__,__LINE__)
#undef  RegOpenKeyExW
#define RegOpenKeyExW(hKey,szSubkey,x,sam,phKey) \
	regchk(RegOpenKeyExW(hKey,szSubkey,x,sam,phKey),"RegOpenKeyExW",szSubkey,TRUE,__FILE__,__LINE__)
#undef  RegCreateKeyExW
#define RegCreateKeyExW(hKey,szSubkey,x,y,z,rights,p,phKey,q) \
	regchk(RegCreateKeyExW(hKey,szSubkey,x,y,z,rights,p,phKey,q),"RegCreateKeyExW",szSubkey,TRUE,__FILE__,__LINE__)
#undef  RegDeleteKeyW
#define RegDeleteKeyW(hKey,szName) \
	regchk(RegDeleteKeyW(hKey,szName),"RegDeleteKeyW",szName,TRUE,__FILE__,__LINE__)
#undef  RegSetValueExW
#define RegSetValueExW(hSubKey,szName,x,type,pVal,size) \
	regchk(RegSetValueExW(hSubKey,szName,x,type,pVal,size),"RegSetValueExW",szName,TRUE,__FILE__,__LINE__)
#undef  RegQueryValueExW
#define RegQueryValueExW(hKey,szName,x,pType,pVal,pSize) \
	regchk(RegQueryValueExW(hKey,szName,x,pType,pVal,pSize),"RegQueryValueExW",szName,TRUE,__FILE__,__LINE__)
#undef  RegQueryInfoKeyW
#define RegQueryInfoKeyW(hKey,x,y,z,pnKeys,pnKeyLen,a,pnVals,pnNames,pnValLen,sec,pTime) \
	regchk(RegQueryInfoKeyW(hKey,x,y,z,pnKeys,pnKeyLen,a,pnVals,pnNames,pnValLen,sec,pTime),"RegQueryInfoKeyW",NULL,TRUE,__FILE__,__LINE__)
#undef  RegEnumKeyExW
#define RegEnumKeyExW(hKey,idx,pName,pnName,x,y,z,pTime) \
	regchk(RegEnumKeyExW(hKey,idx,pName,pnName,x,y,z,pTime),"RegEnumKeyExW",NULL,TRUE,__FILE__,__LINE__)
#undef  RegDeleteValueW
#define RegDeleteValueW(hKey,szName) \
	regchk(RegDeleteValueW(hKey,szName),"RegDeleteValueW",szName,TRUE,__FILE__,__LINE__)
#endif // _DEBUG

/************************* Strings ********************************/

// mir_free() the return value
char *MakeFileClassName(const char *pszFileExt)
{
	char *pszClass;
	pszClass=(char*)mir_alloc((lstrlenA(pszFileExt)+12)*sizeof(TCHAR));
	if(pszClass!=NULL)
		/* using correctly formated PROGID */
		wsprintfA(pszClass,"miranda%sfile",pszFileExt); /* includes dot, buffer safe */
	return pszClass;
}

// mir_free() the return value
char *MakeUrlClassName(const char *pszUrl)
{
	char *pszClass;
	pszClass=mir_strdup(pszUrl);
	if(pszClass!=NULL)
		/* remove trailing : */
		pszClass[lstrlenA(pszClass)-1]=0;
	return pszClass;
}

static BOOL IsFileClassName(const char *pszClassName,const char **ppszFileExt)
{
	*ppszFileExt=strchr(pszClassName,'.');
	return *ppszFileExt!=NULL;
}

// mir_free() the return value
TCHAR *MakeRunCommand(BOOL fMirExe,BOOL fFixedDbProfile)
{
	extern HINSTANCE hInst;
	TCHAR szExe[MAX_PATH],*pszFmt,*pszRunCmd=NULL;
	char szDbFile[MAX_PATH];
	int cch;
	if(!fFixedDbProfile || !CallService(MS_DB_GETPROFILENAME,SIZEOF(szDbFile),(LPARAM)szDbFile))
		if(GetModuleFileNameWorkaround(fMirExe?NULL:hInst,szExe,SIZEOF(szExe))) {
			/* db file */
			if(!fFixedDbProfile)
				lstrcpyA(szDbFile,"%1"); /* buffer safe */
			/* size */
			cch=lstrlen(szExe)+lstrlenA(szDbFile);
			if(fMirExe) {
				/* run command for miranda32.exe */
				cch+=7;
				pszFmt=_T("\"%s\" \"%hs\"");
			} else {
				DWORD len;
				/* run command for rundll32.exe calling WaitForDDE */
				cch+=28;
				pszFmt=_T("rundll32.exe %s,WaitForDDE \"%hs\"");
				/* ensure the command line is not too long */ 
				GetShortPathName(szExe,szExe,SIZEOF(szExe));
				/* surround by quotes if failed */
				len=lstrlen(szExe);
				if(_tcschr(szExe,_T(' '))!=NULL && (len+2)<SIZEOF(szExe)) {
					MoveMemory(szExe,szExe+1,(len+1)*sizeof(TCHAR));
					szExe[len+2]=szExe[0]=_T('\"');
					szExe[len+3]=0;
				}
			}
			pszRunCmd=(TCHAR*)mir_alloc(cch*sizeof(TCHAR));
			if(pszRunCmd!=NULL)
				mir_sntprintf(pszRunCmd,cch,pszFmt,szExe,szDbFile);
		}
	return pszRunCmd;
}

static BOOL IsValidRunCommand(const TCHAR *pszRunCmd)
{
	TCHAR *buf,*pexe,*pargs;
	TCHAR szFullExe[MAX_PATH],*pszFilePart;
	buf=lstrcpy(_alloca((lstrlen(pszRunCmd)+1)*sizeof(TCHAR)),pszRunCmd);
	/* split into executable path and arguments */
	if(buf[0]==_T('\"')) {
		pargs=_tcschr(&buf[1],_T('\"'));
		if(pargs!=NULL) *(pargs++)=0;
		pexe=&buf[1];
		if(*pargs==_T(' ')) ++pargs;
	} else {
		pargs=_tcschr(buf,_T(' '));
		if(pargs!=NULL) *pargs=0;
		pexe=buf;
	}
	if(SearchPath(NULL,pexe,_T(".exe"),SIZEOF(szFullExe),szFullExe,&pszFilePart)) {
		if(pszFilePart!=NULL)
			if(!lstrcmpi(pszFilePart,_T("rundll32.exe")) || !lstrcmpi(pszFilePart,_T("rundll.exe"))) {
				/* split into dll path and arguments */
				if(pargs[0]==_T('\"')) {
					++pargs;
					pexe=_tcschr(&pargs[1],_T('\"'));
					if(pexe!=NULL) *pexe=0;
				} else {
					pexe=_tcschr(pargs,_T(','));
					if(pexe!=NULL) *pexe=0;
				}
				return SearchPath(NULL,pargs,_T(".dll"),0,NULL,NULL)!=0;
			}
		return TRUE;
	}
	return FALSE;
}

// mir_free() the return value
TCHAR *MakeIconLocation(HMODULE hModule,WORD nIconResID)
{
	TCHAR szModule[MAX_PATH],*pszIconLoc=NULL;
	int cch;
	if((cch=GetModuleFileNameWorkaround(hModule,szModule,SIZEOF(szModule)))!=0) {
		pszIconLoc=(TCHAR*)mir_alloc((cch+=8)*sizeof(TCHAR));
		if(pszIconLoc!=NULL)
			wsprintf(pszIconLoc,_T("%s,%i"),szModule,-(int)nIconResID); /* id may be 0, buffer safe */
	}
	return pszIconLoc;
}

// mir_free() the return value
TCHAR *MakeAppFileName(BOOL fMirExe)
{
	extern HINSTANCE hInst;
	TCHAR szExe[MAX_PATH],*psz;
	if(GetModuleFileNameWorkaround(fMirExe?NULL:hInst,szExe,SIZEOF(szExe))) {
		psz=_tcsrchr(szExe,_T('\\'));
		if(psz!=NULL) ++psz;
		else psz=szExe;
		return mir_tstrdup(psz);
	}
	return NULL;
}

/************************* Helpers ********************************/

static LONG DeleteRegSubTree(HKEY hKey,const TCHAR *pszSubKey)
{
	LONG res;
	DWORD nMaxSubKeyLen,cchSubKey;
	TCHAR *pszSubKeyBuf;
	HKEY hSubKey;
	if((res=RegOpenKeyEx(hKey,pszSubKey,0,KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS|DELETE,&hSubKey))==ERROR_SUCCESS) {
		if((res=RegQueryInfoKey(hSubKey,NULL,NULL,NULL,NULL,&nMaxSubKeyLen,NULL,NULL,NULL,NULL,NULL,NULL))==ERROR_SUCCESS) {
			pszSubKeyBuf=(TCHAR*)mir_alloc((nMaxSubKeyLen+1)*sizeof(TCHAR));
			if(pszSubKeyBuf==NULL) res=ERROR_NOT_ENOUGH_MEMORY;
			while(!res) {
				cchSubKey=nMaxSubKeyLen+1;
				if((res=RegEnumKeyEx(hSubKey,0,pszSubKeyBuf,&cchSubKey,NULL,NULL,NULL,NULL))==ERROR_SUCCESS)
					res=DeleteRegSubTree(hSubKey,pszSubKeyBuf); /* recursion */
			}
			mir_free(pszSubKeyBuf); /* does NULL check */
			if(res==ERROR_NO_MORE_ITEMS) res=ERROR_SUCCESS;
		}
		RegCloseKey(hSubKey);
	}
	if(!res) res=RegDeleteKey(hKey,pszSubKey);
	return res;
}

// hMainKey must have been opened with KEY_CREATE_SUB_KEY access right
static LONG SetRegSubKeyStrDefValue(HKEY hMainKey,const TCHAR *pszSubKey,const TCHAR *pszVal)
{
	HKEY hSubKey;
	LONG res;
	res=RegCreateKeyEx(hMainKey,pszSubKey,0,NULL,0,KEY_SET_VALUE|KEY_QUERY_VALUE,NULL,&hSubKey,NULL);
	if(!res) {
		res=RegSetValueEx(hSubKey,NULL,0,REG_SZ,(BYTE*)pszVal,(lstrlen(pszVal)+1)*sizeof(TCHAR));
		RegCloseKey(hSubKey);
	}
	return res;
}

// hKey must have been opened with KEY_SET_VALUE access right
static void SetRegStrPrefixValue(HKEY hKey,const TCHAR *pszValPrefix,const TCHAR *pszVal)
{
	TCHAR *pszStr;
	DWORD dwSize;
	dwSize=(lstrlen(pszVal)+lstrlen(pszValPrefix)+1)*sizeof(TCHAR);
	pszStr=(TCHAR*)mir_alloc(dwSize);
	if(pszStr==NULL) return;
	lstrcat(lstrcpy(pszStr,pszValPrefix),pszVal); /* buffer safe */
	RegSetValueEx(hKey,NULL,0,REG_SZ,(BYTE*)pszStr,dwSize);
	mir_free(pszStr);
}

// hKey must have been opened with KEY_QUERY_VALUE access right
// mir_free() the return value
static TCHAR *GetRegStrValue(HKEY hKey,const TCHAR *pszValName)
{
	TCHAR *pszVal,*pszVal2;
	DWORD dwSize,dwType;
	/* get size */
	if(!RegQueryValueEx(hKey,pszValName,NULL,NULL,NULL,&dwSize) && dwSize>sizeof(TCHAR)) {
		pszVal=(TCHAR*)mir_alloc(dwSize+sizeof(TCHAR));
		if(pszVal!=NULL) {
			/* get value */
			if(!RegQueryValueEx(hKey,pszValName,NULL,&dwType,(BYTE*)pszVal,&dwSize)) {
				pszVal[dwSize/sizeof(TCHAR)]=0;
				if(dwType==REG_EXPAND_SZ) {
					dwSize=MAX_PATH;
					pszVal2=(TCHAR*)mir_alloc(dwSize*sizeof(TCHAR));
					if(ExpandEnvironmentStrings(pszVal,pszVal2,dwSize)) {
						mir_free(pszVal);
						return pszVal2;
					}
					mir_free(pszVal2);
				} else if(dwType==REG_SZ)
					return pszVal;
			}
			mir_free(pszVal);
		}
	}
	return NULL;
}

// hKey must have been opened with KEY_QUERY_VALUE access right
static BOOL IsRegStrValue(HKEY hKey,const TCHAR *pszValName,const TCHAR *pszCmpVal)
{
	BOOL fSame=FALSE;
	TCHAR *pszVal;
	pszVal=GetRegStrValue(hKey,pszValName);
	if(pszVal!=NULL) {
		fSame=!lstrcmp(pszVal,pszCmpVal);
		mir_free(pszVal);
	}
	return fSame;
}

// hKey must have been opened with KEY_QUERY_VALUE access right
static BOOL IsRegStrValueA(HKEY hKey,const TCHAR *pszValName,const char *pszCmpVal)
{
	BOOL fSame=FALSE;
	TCHAR *pszVal;
	char *pszValA;
	pszVal=GetRegStrValue(hKey,pszValName);
	if(pszVal!=NULL) {
		pszValA=t2a(pszVal);
		if(pszValA!=NULL)
			fSame=!lstrcmpA(pszValA,pszCmpVal);
		mir_free(pszValA); /* does NULL check */
		mir_free(pszVal);
	}
	return fSame;
}

/************************* Backup to DB ***************************/

#define REGF_ANSI  0x80000000 /* this bit is set in dwType for ANSI registry data */ 

// pData must always be Unicode data, registry supports Unicode even on Win95
static void WriteDbBackupData(const char *pszSetting,DWORD dwType,BYTE *pData,DWORD cbData)
{
	DBCONTACTWRITESETTING dbcws;
	dbcws.szModule="AssocMgr";
	dbcws.szSetting=pszSetting;
	dbcws.value.type=DBVT_BLOB;
	dbcws.value.cpbVal=(WORD)(cbData+sizeof(DWORD));
	dbcws.value.pbVal=(BYTE*)mir_alloc(cbData+sizeof(DWORD));
	if(dbcws.value.pbVal==NULL) return;
	*(DWORD*)dbcws.value.pbVal=dwType;
	CopyMemory(dbcws.value.pbVal+sizeof(DWORD),pData,cbData);
	CallService(MS_DB_CONTACT_WRITESETTING,0,(LPARAM)&dbcws);
	mir_free(dbcws.value.pbVal);
}

// mir_free() the value returned in ppData 
static BOOL ReadDbBackupData(const char *pszSetting,DWORD *pdwType,BYTE **ppData,DWORD *pcbData)
{
	DBCONTACTGETSETTING dbcgs;
	DBVARIANT dbv;
	dbcgs.szModule="AssocMgr";
	dbcgs.szSetting=pszSetting;
	dbcgs.pValue=&dbv;
	if(!CallService(MS_DB_CONTACT_GETSETTING,0,(LPARAM)&dbcgs)) {
		if(dbv.type==DBVT_BLOB && dbv.cpbVal>=sizeof(DWORD)) {
			*pdwType=*(DWORD*)dbv.pbVal;
			*ppData=dbv.pbVal;
			*pcbData=dbv.cpbVal-sizeof(DWORD);
			MoveMemory(*ppData,*ppData+sizeof(DWORD),*pcbData);
			return TRUE;
		}
		CallService(MS_DB_CONTACT_FREEVARIANT,0,(LPARAM)&dbv);
	}
	return FALSE;
}

struct BackupRegTreeParam {
	char **ppszDbPrefix;
	DWORD *pdwDbPrefixSize;
	int level;
};

static void BackupRegTree_Worker(HKEY hKey,const char *pszSubKey,struct BackupRegTreeParam *param)
{
	LONG res;
	DWORD nMaxSubKeyLen,nMaxValNameLen,nMaxValSize;
	DWORD index,cchName,dwType,cbData;
	BYTE *pData;
	char *pszName;
	register TCHAR *ptszName;
	DWORD nDbPrefixLen;
	if((res=RegOpenKeyExA(hKey,pszSubKey,0,KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS,&hKey))==ERROR_SUCCESS) {
		if((res=RegQueryInfoKey(hKey,NULL,NULL,NULL,NULL,&nMaxSubKeyLen,NULL,NULL,&nMaxValNameLen,&nMaxValSize,NULL,NULL))==ERROR_SUCCESS) {
			if(nMaxSubKeyLen>nMaxValNameLen) nMaxValNameLen=nMaxSubKeyLen;
			/* prepare buffer */
			nDbPrefixLen=(DWORD)lstrlenA(*param->ppszDbPrefix)+lstrlenA(pszSubKey)+1;
			cchName=nDbPrefixLen+nMaxValNameLen+3;
			if(cchName>*param->pdwDbPrefixSize) {
				pszName=(char*)mir_realloc(*param->ppszDbPrefix,cchName);
				if(pszName==NULL) return;
				*param->ppszDbPrefix=pszName;
				*param->pdwDbPrefixSize=cchName;
			}
			lstrcatA(lstrcatA(*param->ppszDbPrefix,pszSubKey),"\\"); /* buffer safe */
			/* enum values */
			pszName=(char*)mir_alloc(nMaxValNameLen+1);
			if(nMaxValSize==0) nMaxValSize=1;
			pData=(BYTE*)mir_alloc(nMaxValSize);
			if(pszName!=NULL && pData!=NULL) {
				index=0;
				while(!res) {
					cchName=nMaxValNameLen+1;
					cbData=nMaxValSize;
					if((res=RegEnumValueA(hKey,index++,pszName,&cchName,NULL,NULL,NULL,NULL))==ERROR_SUCCESS) {
						(*param->ppszDbPrefix)[nDbPrefixLen]=0;
						lstrcatA(*param->ppszDbPrefix,pszName); /* buffer safe */
						ptszName=a2t(pszName);
						if(ptszName!=NULL) {
							if(!RegQueryValueEx(hKey,ptszName,NULL,&dwType,pData,&cbData)) {
								#ifdef _UNICODE
								WriteDbBackupData(*param->ppszDbPrefix,dwType,pData,cbData);
								#else
								if(!(dwType&REGF_ANSI)) /* sanity check, never happens */
									WriteDbBackupData(*param->ppszDbPrefix,dwType&REGF_ANSI,pData,cbData);
								#endif
							}
							mir_free(ptszName);
						}
					}
				}
				if(res==ERROR_NO_MORE_ITEMS) res=ERROR_SUCCESS;
			}
			mir_free(pData); /* does NULL check */
			/* enum subkeys */
			if(param->level<32 && pszName!=NULL) {
				++param->level; /* can be max 32 levels deep (after prefix), restriction of RegCreateKeyEx() */
				index=0;
				while(!res) {
					cchName=nMaxSubKeyLen+1;
					if((res=RegEnumKeyExA(hKey,index++,pszName,&cchName,NULL,NULL,NULL,NULL))==ERROR_SUCCESS) {
						(*param->ppszDbPrefix)[nDbPrefixLen]=0;
						BackupRegTree_Worker(hKey,pszName,param); /* recursion */
					}
				}
			}
			if(res==ERROR_NO_MORE_ITEMS) res=ERROR_SUCCESS;
			mir_free(pszName); /* does NULL check */
		}
		RegCloseKey(hKey);
	}
}

static void BackupRegTree(HKEY hKey,const char *pszSubKey,const char *pszDbPrefix)
{
	struct BackupRegTreeParam param;
	DWORD dwDbPrefixSize;
	param.level=0;
	param.pdwDbPrefixSize=&dwDbPrefixSize;
	param.ppszDbPrefix=(char**)&pszDbPrefix;
	pszDbPrefix=mir_strdup(pszDbPrefix);
	if(pszDbPrefix!=NULL) {
		dwDbPrefixSize=lstrlenA(pszDbPrefix)+1;
		BackupRegTree_Worker(hKey,pszSubKey,&param);
		mir_free((char*)pszDbPrefix);
	}
}

static LONG RestoreRegTree(HKEY hKey,const char *pszSubKey,const char *pszDbPrefix)
{
	char **ppszSettings,*pszSuffix,*pszPrefixWithSubKey;
	int nSettingsCount,i,nDbPrefixLen,nPrefixWithSubKeyLen;
	char *pslash=NULL,*pnext,*pkeys;
	char *pszValName;
	WCHAR *pwszValName;
	HKEY hSubKey;
	DWORD dwType,cbData;
	BYTE *pData;
	LONG res;

	nDbPrefixLen=lstrlenA(pszDbPrefix);
	nPrefixWithSubKeyLen=nDbPrefixLen+lstrlenA(pszSubKey)+1;
	pszPrefixWithSubKey=(char*)mir_alloc(nPrefixWithSubKeyLen+1);
	if(pszPrefixWithSubKey==NULL) return ERROR_OUTOFMEMORY;
	lstrcatA(lstrcatA(lstrcpyA(pszPrefixWithSubKey,pszDbPrefix),pszSubKey),"\\"); /* buffer safe */
	res=ERROR_NO_MORE_ITEMS;
	if(pszPrefixWithSubKey!=NULL) {
		if(EnumDbPrefixSettings("AssocMgr",pszPrefixWithSubKey,&ppszSettings,&nSettingsCount)) {
			for(i=0;i<nSettingsCount;++i) {
				pszSuffix=&ppszSettings[i][nDbPrefixLen];
				/* key hierachy */
				pkeys=lstrcpyA((char*)_alloca(lstrlenA(pszSuffix)+1),pszSuffix);
				pnext=pkeys;
				while((pnext=strchr(pnext+1,_T('\\')))!=NULL) pslash=pnext;
				if(pslash!=NULL) {
					/* create subkey */
					*(pslash++)=0;
					hSubKey=hKey;
					if(pslash!=pkeys+1)
						if((res=RegCreateKeyExA(hKey,pkeys,0,NULL,0,KEY_SET_VALUE,NULL,&hSubKey,NULL))!=ERROR_SUCCESS)
							break;
					pszValName=pslash;
					/* read data */
					if(ReadDbBackupData(ppszSettings[i],&dwType,&pData,&cbData)) {
						/* set value */
						if(!(dwType&REGF_ANSI)) {
							pwszValName=a2u(pszValName,FALSE);
							if(pwszValName!=NULL) res=RegSetValueExW(hSubKey,pwszValName,0,dwType,pData,cbData);
							else res=ERROR_NOT_ENOUGH_MEMORY;
							mir_free(pwszValName); /* does NULL check */
						} else res=RegSetValueExA(hSubKey,pszValName,0,dwType&~REGF_ANSI,pData,cbData);
						mir_free(pData);
					} else res=ERROR_INVALID_DATA;
					if(res) break;
					DBDeleteContactSetting(NULL,"AssocMgr",ppszSettings[i]);
					if(hSubKey!=hKey) RegCloseKey(hSubKey);
				}
				mir_free(ppszSettings[i]);
			}
			mir_free(ppszSettings);
		}
		mir_free(pszPrefixWithSubKey);
	}
	return res;
}

static void DeleteRegTreeBackup(const char *pszSubKey,const char *pszDbPrefix)
{
	char **ppszSettings,*pszPrefixWithSubKey;
	int nSettingsCount,i;

	pszPrefixWithSubKey=(char*)mir_alloc(lstrlenA(pszDbPrefix)+lstrlenA(pszSubKey)+2);
	if(pszPrefixWithSubKey==NULL) return;
	lstrcatA(lstrcatA(lstrcpyA(pszPrefixWithSubKey,pszDbPrefix),pszSubKey),"\\"); /* buffer safe */
	if(pszPrefixWithSubKey!=NULL) {
		if(EnumDbPrefixSettings("AssocMgr",pszPrefixWithSubKey,&ppszSettings,&nSettingsCount)) {
			for(i=0;i<nSettingsCount;++i) {
				DBDeleteContactSetting(NULL,"AssocMgr",ppszSettings[i]);
				mir_free(ppszSettings[i]);
			}
			mir_free(ppszSettings);
		}
		mir_free(pszPrefixWithSubKey);
	}
}

void CleanupRegTreeBackupSettings(void)
{
	int nSettingsCount;
	char **ppszSettings;
	char *pszClassName,*pszBuf,*pszFileExt;
	int i,j;

	/* delete old bak_* settings and try to restore backups */
	if(EnumDbPrefixSettings("AssocMgr","bak_",&ppszSettings,&nSettingsCount)) {
		for(i=0;i<nSettingsCount;++i) {
			pszClassName=&ppszSettings[i][4];
			pszBuf=strchr(pszClassName,'\\');
			if(pszBuf!=NULL) {
				*pszBuf='\0';
				/* remove others in list with same class name */
				for(j=i;j<nSettingsCount;++j) {
					pszBuf=strchr(&ppszSettings[j][4],'\\');
					if(pszBuf!=NULL) *pszBuf='\0';
					if(lstrcmpA(pszClassName,&ppszSettings[j][4])) continue;
					MoveMemory(&ppszSettings[j],&ppszSettings[j+1],((--nSettingsCount)-j)*sizeof(TCHAR*));
					--j; /* reiterate current index */
				}
				/* no longer registered? */
				if(!IsRegisteredAssocItem(pszClassName)) {
					if(IsFileClassName(pszClassName,&pszFileExt))
						RemoveRegFileExt(pszFileExt,pszClassName);
					else RemoveRegClass(pszClassName);
				}
			}
			mir_free(ppszSettings[i]);
		}
		mir_free(ppszSettings);
	}
}

/************************* Opera Support **************************/

/*
 * These are helpers accessing the Opera settings file.
 * Should work with Opera 6 up to 9.10 (current)
 */

static BOOL Opera6_GetIniFilePath(TCHAR *szIniFile)
{
	HKEY hExeKey;
	TCHAR szPath[MAX_PATH],*p;
	BOOL fSuccess=FALSE;
	DWORD len;

	/* Info: http://opera-info.de/forum/thread.php?threadid=2905 */
	/* app path */
	if(!RegOpenKeyExA(HKEY_LOCAL_MACHINE,"Software\\Microsoft\\Windows\\CurrentVersion\\App Paths\\Netscape.exe",0,KEY_QUERY_VALUE,&hExeKey)) {
		/* exe name */
		p=GetRegStrValue(hExeKey,NULL);
		if(p!=NULL && _tcsstr(p,_T("Opera.exe"))!=NULL) {
			/* path */
			mir_free(p);
			p=GetRegStrValue(hExeKey,_T("Path"));
			len=lstrlen(p);
			if(p[len-1]==_T('\\')) p[len-1]=0;
			fSuccess=(p!=NULL && ExpandEnvironmentStrings(p,szPath,MAX_PATH));
		}
		mir_free(p); /* does NULL check */
		RegCloseKey(hExeKey);
	}
	if(fSuccess) {
		TCHAR szFileBuf[MAX_PATH+34];
		/* operadef6.ini */
		lstrcat(lstrcpy(szFileBuf,szPath),_T("\\operadef6.ini")); /* buffer safe */
		/* If enabled Opera will use Windows profiles to store individual user settings */
		if(GetPrivateProfileInt(_T("System"),_T("Multi User"),0,szFileBuf)==1) {
			p=_tcsrchr(szPath,'\\');
			lstrcpy(szFileBuf,_T("%APPDATA%\\Opera")); /* buffer safe */
			if(p!=NULL) lstrcat(szFileBuf,p);  /* buffer safe */
		} else lstrcpy(szFileBuf,szPath);
		/* opera6.ini */
		lstrcat(szFileBuf,_T("\\profile\\opera6.ini")); /* buffer safe */
		fSuccess=ExpandEnvironmentStrings(szFileBuf,szIniFile,MAX_PATH)!=0;
	}
	/* check file existstance */
	if(fSuccess) {
		HANDLE hFile;
		hFile=CreateFile(szIniFile,0,FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,OPEN_EXISTING,0,NULL);
		if(hFile==INVALID_HANDLE_VALUE) fSuccess=FALSE;
		else CloseHandle(hFile);
	}
	return fSuccess;
}

// pszProtoPrefix is expected to have no trailing :
static void Opera6_AddTrustedProto(const char *pszProtoPrefix)
{
	TCHAR szIniFile[MAX_PATH],*ptszProtoPrefix;
	if(Opera6_GetIniFilePath(szIniFile)) {
		/* trusted protocols */
		ptszProtoPrefix=a2t(pszProtoPrefix);
		if(ptszProtoPrefix!=NULL) {
			WritePrivateProfileString(_T("Trusted Protocols"),ptszProtoPrefix,_T("1,0,"),szIniFile);
			mir_free(ptszProtoPrefix);
		}
	}
}

static void Opera6_AddKnownMimeType(const char *pszMimeType,const char *pszFileExt,const TCHAR *pszDescription)
{
	TCHAR szIniFile[MAX_PATH],szVal[256],*ptszMimeType;
	if(Opera6_GetIniFilePath(szIniFile)) {
		/* section version */
		if(GetPrivateProfileInt(_T("File Types Section Info"),_T("Version"),0,szIniFile)==2) {
			ptszMimeType=a2t(pszMimeType);
			if(ptszMimeType!=NULL) {
				/* file type */
				mir_sntprintf(szVal,SIZEOF(szVal),_T("4,,,,%.15hs,|%.128s (%.16hs)"),&pszFileExt[1],pszDescription,pszFileExt);
				WritePrivateProfileString(_T("File Types"),ptszMimeType,szVal,szIniFile);
				/* file type extension */
				WritePrivateProfileString(_T("File Types Extension"),ptszMimeType,_T(",0"),szIniFile);
				mir_free(ptszMimeType);
			}
		}
	}
}

/************************* Class **********************************/

/*
 * Add a new file class to the class list.
 * This either represents a superclass for several file extensions or
 * the the url object.
 * Urls just need a class named after their prefix e.g. "http".
 * File extensions should follow the rule "appname.extension". 
 */

// pszIconLoc, pszVerbDesc and pszDdeCmd are allowed to be NULL
// call GetLastError() on error to get more error details
BOOL AddRegClass(const char *pszClassName,const TCHAR *pszTypeDescription,const TCHAR *pszIconLoc,const TCHAR *pszAppName,const TCHAR *pszRunCmd,const TCHAR *pszDdeCmd,const TCHAR *pszDdeApp,const TCHAR *pszDdeTopic,const TCHAR *pszVerbDesc,BOOL fBrowserAutoOpen,BOOL fUrlProto,BOOL fIsShortcut)
{
	LONG res;
	HKEY hRootKey,hClassKey,hShellKey,hVerbKey,hDdeKey;

	/* some error checking for disallowed values (to avoid errors in registry) */
	if(strchr(pszClassName,'\\')!=NULL || strchr(pszClassName,' ')!=NULL) {
		SetLastError(ERROR_INVALID_PARAMETER);
		return FALSE;
	}
	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_CREATE_SUB_KEY,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT; /* might be write protected by security settings */

	/* class */
	if((res=RegCreateKeyExA(hRootKey,pszClassName,0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY|DELETE|KEY_QUERY_VALUE,NULL,&hClassKey,NULL))==ERROR_SUCCESS) {
		/* backup class if shared */
		if(fUrlProto) BackupRegTree(hRootKey,pszClassName,"bak_");
		/* type description */
		if(fUrlProto) SetRegStrPrefixValue(hClassKey,_T("URL:"),pszTypeDescription);
		else RegSetValueEx(hClassKey,NULL,0,REG_SZ,(BYTE*)pszTypeDescription,(lstrlen(pszTypeDescription)+1)*sizeof(TCHAR));
		/* default icon */
		if(pszIconLoc!=NULL) SetRegSubKeyStrDefValue(hClassKey,_T("DefaultIcon"),pszIconLoc);
		/* url protocol */
		if(!fUrlProto) RegDeleteValue(hClassKey,_T("URL Protocol"));
		else RegSetValueEx(hClassKey,_T("URL Protocol"),0,REG_SZ,NULL,0);
		/* moniker clsid */
		RegDeleteKey(hClassKey,_T("CLSID"));
		/* edit flags */
		{	DWORD dwFlags=0,dwSize=sizeof(dwFlags);
			RegQueryValueEx(hClassKey,_T("EditFlags"),NULL,NULL,(BYTE*)&dwFlags,&dwSize);
			if(fBrowserAutoOpen) dwFlags=(dwFlags&~FTA_AlwaysUnsafe)|FTA_OpenIsSafe;
			if(!fUrlProto) dwFlags|=FTA_HasExtension;
			else dwFlags=(dwFlags&~FTA_HasExtension)|FTA_Show; /* show classes without extension */
			RegSetValueEx(hClassKey,_T("EditFlags"),0,REG_DWORD,(BYTE*)&dwFlags,sizeof(dwFlags));
		}
		if(fIsShortcut) {
			RegSetValueExA(hClassKey,"IsShortcut",0,REG_SZ,NULL,0);
			RegSetValueExA(hClassKey,"NeverShowExt",0,REG_SZ,NULL,0);
		}
		/* shell */
		if((res=RegCreateKeyEx(hClassKey,_T("shell"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY,NULL,&hShellKey,NULL))==ERROR_SUCCESS) {
			/* default verb (when empty "open" is used) */
			RegSetValueEx(hShellKey,NULL,0,REG_SZ,(BYTE*)_T("open"),5*sizeof(TCHAR));
			/* verb */
			if((res=RegCreateKeyEx(hShellKey,_T("open"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY|DELETE,NULL,&hVerbKey,NULL))==ERROR_SUCCESS) {
				/* verb description */
				if(pszVerbDesc==NULL) RegDeleteValue(hVerbKey,NULL);
				else RegSetValueEx(hVerbKey,NULL,0,REG_SZ,(BYTE*)pszVerbDesc,(lstrlen(pszVerbDesc)+1)*sizeof(TCHAR));
				/* friendly appname (mui string) */
				RegSetValueEx(hVerbKey,_T("FriendlyAppName"),0,REG_SZ,(BYTE*)pszAppName,(lstrlen(pszAppName)+1)*sizeof(TCHAR));
				/* command */
				SetRegSubKeyStrDefValue(hVerbKey,_T("command"),pszRunCmd);
				/* ddeexec */
				if(pszDdeCmd!=NULL) {
					if(!RegCreateKeyEx(hVerbKey,_T("ddeexec"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY|DELETE,NULL,&hDdeKey,NULL)) {
						/* command */
						RegSetValueEx(hDdeKey,NULL,0,REG_SZ,(BYTE*)pszDdeCmd,(lstrlen(pszDdeCmd)+1)*sizeof(TCHAR));
						/* application */
						SetRegSubKeyStrDefValue(hDdeKey,_T("application"),pszDdeApp);
						/* topic */
						SetRegSubKeyStrDefValue(hDdeKey,_T("topic"),pszDdeTopic);
						/* ifexec */
						RegDeleteKey(hDdeKey,_T("ifexec"));
						RegCloseKey(hDdeKey);
					}
				} else {
					if(!RegOpenKeyEx(hVerbKey,_T("ddeexec"),0,DELETE,&hDdeKey)) {
						/* application */
						RegDeleteKey(hDdeKey,_T("application"));
						/* topic */
						RegDeleteKey(hDdeKey,_T("topic"));
						/* ifexec */
						RegDeleteKey(hDdeKey,_T("ifexec"));
						RegCloseKey(hDdeKey);
					}
					RegDeleteKey(hVerbKey,_T("ddeexec"));
				}
				/* drop target (WinXP+) */
				RegDeleteKey(hVerbKey,_T("DropTarget"));
				RegCloseKey(hVerbKey);
			}
			RegCloseKey(hShellKey);
			/* Opera support */
			if(fUrlProto) Opera6_AddTrustedProto(pszClassName);
		}
		RegCloseKey(hClassKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);

	if(res) SetLastError(res);
	return !res;
}

BOOL RemoveRegClass(const char *pszClassName)
{
	LONG res;
	HKEY hRootKey,hClassKey,hShellKey,hVerbKey;
	TCHAR *ptszClassName,*ptszPrevRunCmd;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,DELETE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* class name */
	ptszClassName=a2t(pszClassName);
	if(ptszClassName!=NULL)
		res=DeleteRegSubTree(hRootKey,ptszClassName);
	else res=ERROR_OUTOFMEMORY;
	mir_free(ptszClassName); /* does NULL check */

	/* backup only saved/restored for fUrlProto */
	if(!res) {
		if((res=RestoreRegTree(hRootKey,pszClassName,"bak_"))==ERROR_SUCCESS)
			/* class */
			if(!RegOpenKeyExA(hRootKey,pszClassName,0,KEY_QUERY_VALUE,&hClassKey)) {
				/* shell */
				if(!RegOpenKeyEx(hClassKey,_T("shell"),0,KEY_QUERY_VALUE,&hShellKey)) {
					/* verb */
					if(!RegOpenKeyEx(hShellKey,_T("open"),0,KEY_QUERY_VALUE,&hVerbKey)) {
						/* command */
						ptszPrevRunCmd=GetRegStrValue(hVerbKey,_T("command"));
						if(ptszPrevRunCmd!=NULL && !IsValidRunCommand(ptszPrevRunCmd))
							res=DeleteRegSubTree(hRootKey,ptszClassName); /* backup outdated, remove all */
						mir_free(ptszPrevRunCmd); /* does NULL check */
						RegCloseKey(hShellKey);
					}
					RegCloseKey(hVerbKey);
				}
				RegCloseKey(hClassKey);
			}
	} else DeleteRegTreeBackup(pszClassName,"bak_");

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);

	if(res==ERROR_SUCCESS || res==ERROR_FILE_NOT_FOUND || res==ERROR_NO_MORE_ITEMS) return TRUE;
	SetLastError(res);
	return FALSE;
}

/*
 * Test if a given class belongs to the current process
 * specified via its run command.
 * This is especially needed for Urls where the same class name "http" can be
 * registered and thus be overwritten by multiple applications.
 */

BOOL IsRegClass(const char *pszClassName,const TCHAR *pszRunCmd)
{
	BOOL fSuccess=FALSE;
	HKEY hClassKey,hShellKey,hVerbKey,hCmdKey;

	/* using the merged view classes key for reading */
	/* class */
	if(!RegOpenKeyExA(HKEY_CLASSES_ROOT,pszClassName,0,KEY_QUERY_VALUE,&hClassKey)) {
		/* shell */
		if(!RegOpenKeyEx(hClassKey,_T("shell"),0,KEY_QUERY_VALUE,&hShellKey)) {
			/* verb */
			if(!RegOpenKeyEx(hShellKey,_T("open"),0,KEY_QUERY_VALUE,&hVerbKey)) {
				/* command */
				if(!RegOpenKeyEx(hVerbKey,_T("command"),0,KEY_QUERY_VALUE,&hCmdKey)) {
					/* it is enough to check if the command is right */
					fSuccess=IsRegStrValue(hCmdKey,NULL,pszRunCmd);
					RegCloseKey(hCmdKey);
				}
				RegCloseKey(hVerbKey);
			}
			RegCloseKey(hShellKey);
		}
		RegCloseKey(hClassKey);
	}
	return fSuccess;
}

/*
 * Extract the icon name of the class from the registry and load it.
 * For uses especially with url classes.
 */

// DestroyIcon() the return value
HICON LoadRegClassSmallIcon(const char *pszClassName)
{
	HICON hIcon=NULL;
	HKEY hClassKey,hIconKey;
	TCHAR *pszIconLoc,*p;

	/* using the merged view classes key for reading */
	/* class */
	if(!RegOpenKeyExA(HKEY_CLASSES_ROOT,pszClassName,0,KEY_QUERY_VALUE,&hClassKey)) {
		/* default icon */
		if(!RegOpenKeyEx(hClassKey,_T("DefaultIcon"),0,KEY_QUERY_VALUE,&hIconKey)) {
			/* extract icon */
			pszIconLoc=GetRegStrValue(hIconKey,NULL);
			if(pszIconLoc!=NULL) {
				p=_tcsrchr(pszIconLoc,_T(','));
				if(p!=NULL) {
					*(p++)=0;
					ExtractIconEx(pszIconLoc,_ttoi(p),NULL,&hIcon,1);
				}
				mir_free(pszIconLoc);
			}
			RegCloseKey(hIconKey);
		}
		RegCloseKey(hClassKey);
	}

	return hIcon;
}

/************************* Extension ******************************/

/*
 * Add a new file extension to the class list.
 * The file extension needs to be associated with a class
 * that has been registered previously.
 * Multiple file extensions can be assigned to the same class.
 * The class contains most settings as the run command etc.
 */

// pszMimeType is allowed to be NULL
BOOL AddRegFileExt(const char *pszFileExt,const char *pszClassName,const char *pszMimeType,BOOL fIsText)
{
	BOOL fSuccess=FALSE;
	HKEY hRootKey,hExtKey,hOpenWithKey;

	/* some error checking for disallowed values (to avoid errors in registry) */
	if(strchr(pszFileExt,'\\')!=NULL || strchr(pszFileExt,' ')!=NULL)
		return FALSE;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_CREATE_SUB_KEY,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* file ext */
	if(!RegCreateKeyExA(hRootKey,pszFileExt,0,NULL,0,KEY_SET_VALUE|KEY_QUERY_VALUE|KEY_CREATE_SUB_KEY,NULL,&hExtKey,NULL)) {
		TCHAR *pszPrevClass;
		/* backup previous app */
		BackupRegTree(hRootKey,pszFileExt,"bak_");
		/* remove any no-open flag */
		RegDeleteValue(hExtKey,_T("NoOpen"));
		/* open with progids */
		pszPrevClass=GetRegStrValue(hExtKey,NULL);
		if(pszPrevClass!=NULL && !IsRegStrValueA(hExtKey,NULL,pszClassName))
			if(!RegCreateKeyEx(hExtKey,_T("OpenWithProgids"),0,NULL,0,KEY_SET_VALUE,NULL,&hOpenWithKey,NULL)) {
				/* previous class (backup) */
				RegSetValueEx(hOpenWithKey,pszPrevClass,0,REG_NONE,NULL,0);
				RegCloseKey(hOpenWithKey);
			}
		mir_free(pszPrevClass); /* does NULL check */
		/* class name */
		fSuccess=!RegSetValueExA(hExtKey,NULL,0,REG_SZ,(BYTE*)pszClassName,lstrlenA(pszClassName)+1);
		/* mime type e.g. "application/x-icq" */
		if(pszMimeType!=NULL) RegSetValueExA(hExtKey,"Content Type",0,REG_SZ,(BYTE*)pszMimeType,lstrlenA(pszMimeType)+1);
		/* perceived type e.g. text (WinXP+) */
		if(fIsText) RegSetValueEx(hExtKey,_T("PerceivedType"),0,REG_SZ,(BYTE*)_T("text"),5*sizeof(TCHAR));
		RegCloseKey(hExtKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
	return fSuccess;
}

void RemoveRegFileExt(const char *pszFileExt,const char *pszClassName)
{
	HKEY hRootKey,hExtKey,hSubKey;
	DWORD nOpenWithCount;
	TCHAR *pszPrevClassName=NULL;
	BOOL fRestored=FALSE;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,DELETE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* file ext */
	if(!RegOpenKeyExA(hRootKey,pszFileExt,0,KEY_QUERY_VALUE|KEY_SET_VALUE|DELETE,&hExtKey)) {
		/* class name (the important part) */
		if(!RestoreRegTree(hRootKey,pszFileExt,"bak_")) {
			pszPrevClassName=GetRegStrValue(hExtKey,NULL);
			if(pszPrevClassName!=NULL) {
				/* previous class name still exists? */
				/* using the merged view classes key for reading */
				if(!RegOpenKeyEx(HKEY_CLASSES_ROOT,pszPrevClassName,0,KEY_QUERY_VALUE,&hSubKey)) {
					fRestored=TRUE;
					RegCloseKey(hSubKey);
				} else RegDeleteValue(hExtKey,NULL);
				mir_free(pszPrevClassName);
			}
		}
		if(pszPrevClassName==NULL) RegDeleteValue(hExtKey,NULL);
		/* open with progids (remove if empty) */
		nOpenWithCount=0;
		if(!RegOpenKeyEx(hExtKey,_T("OpenWithProgids"),0,KEY_SET_VALUE|KEY_QUERY_VALUE,&hSubKey)) {
			/* remove current class (if set by another app) */
			RegDeleteValueA(hSubKey,pszClassName);
			RegQueryInfoKey(hSubKey,NULL,NULL,NULL,NULL,NULL,NULL,NULL,&nOpenWithCount,NULL,NULL,NULL);
			RegCloseKey(hSubKey);
		}
		if(!nOpenWithCount) RegDeleteKey(hExtKey,_T("OpenWithProgids")); /* delete if no values */
		RegCloseKey(hExtKey);
	} else DeleteRegTreeBackup(pszFileExt,"bak_");
	if(!fRestored) RegDeleteKeyA(hRootKey,pszFileExt); /* try to remove it all */

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

/*
 * Test if a given file extension belongs to the given class name.
 * If it does not belong to the class name, it got reassigned and thus
 * overwritten by another application.
 */

BOOL IsRegFileExt(const char *pszFileExt,const char *pszClassName)
{
	BOOL fSuccess=FALSE;
	HKEY hExtKey;

	/* using the merged view classes key for reading */
	/* file ext */
	if(!RegOpenKeyExA(HKEY_CLASSES_ROOT,pszFileExt,0,KEY_QUERY_VALUE,&hExtKey)) {
		/* class name */
		/* it is enough to check if the class is right */
		fSuccess=IsRegStrValueA(hExtKey,NULL,pszClassName);
		RegCloseKey(hExtKey);
	}
	return fSuccess;
}

/************************* Mime Type ******************************/

/*
 * Add a given mime type to the global mime database.
 */

// returns TRUE if the mime type was not yet registered on the system,
// it needs to be removed when the file extension gets removed
BOOL AddRegMimeType(const char *pszMimeType,const char *pszFileExt,const TCHAR *pszDescription)
{
	BOOL fSuccess=FALSE;
	HKEY hRootKey,hDbKey,hTypeKey;

	/* some error checking for disallowed values (to avoid errors in registry) */
	if(strchr(pszMimeType,'\\')!=NULL || strchr(pszMimeType,' ')!=NULL)
		return FALSE;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* database */
	if(!RegOpenKeyEx(hRootKey,_T("MIME\\Database\\Content Type"),0,KEY_CREATE_SUB_KEY,&hDbKey)) {
		/* mime type */
		if(!RegCreateKeyExA(hDbKey,pszMimeType,0,NULL,0,KEY_QUERY_VALUE|KEY_SET_VALUE,NULL,&hTypeKey,NULL)) {
			/* file ext */
			if(RegQueryValueExA(hTypeKey,"Extension",NULL,NULL,NULL,NULL)) /* only set if not present */
				fSuccess=!RegSetValueExA(hTypeKey,"Extension",0,REG_SZ,(BYTE*)pszFileExt,lstrlenA(pszFileExt)+1);
			RegCloseKey(hTypeKey);
			/* Opera support */
			Opera6_AddKnownMimeType(pszMimeType,pszFileExt,pszDescription);
		}
		RegCloseKey(hDbKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
	return fSuccess;
}

void RemoveRegMimeType(const char *pszMimeType,const char *pszFileExt)
{
	HKEY hRootKey,hDbKey,hTypeKey;
	BOOL fDelete=TRUE;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* database */
	if(!RegOpenKeyEx(hRootKey,_T("MIME\\Database\\Content Type"),0,DELETE,&hDbKey)) {
		/* mime type */
		if(!RegOpenKeyExA(hDbKey,pszMimeType,0,KEY_QUERY_VALUE,&hTypeKey)) {
			/* file ext */
			fDelete=IsRegStrValueA(hTypeKey,_T("Extension"),pszFileExt);
			RegCloseKey(hTypeKey);
		}
		if(fDelete) RegDeleteKeyA(hDbKey,pszMimeType);
		RegCloseKey(hDbKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

/************************* Open-With App **************************/

/*
 * Add Miranda as an option to the advanced "Open With..." dialog.
 */

// pszDdeCmd is allowed to be NULL
void AddRegOpenWith(const TCHAR *pszAppFileName,BOOL fAllowOpenWith,const TCHAR *pszAppName,const TCHAR *pszIconLoc,const TCHAR *pszRunCmd,const TCHAR *pszDdeCmd,const TCHAR *pszDdeApp,const TCHAR *pszDdeTopic)
{
	HKEY hRootKey,hAppsKey,hExeKey,hShellKey,hVerbKey,hDdeKey;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* database */
	if(!RegCreateKeyEx(hRootKey,_T("Applications"),0,NULL,0,KEY_CREATE_SUB_KEY,NULL,&hAppsKey,NULL)) {
		/* filename */
		if(!RegCreateKeyEx(hAppsKey,pszAppFileName,0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY,NULL,&hExeKey,NULL)) {
			/* appname */
			RegSetValueEx(hExeKey,NULL,0,REG_SZ,(BYTE*)pszAppName,(lstrlen(pszAppName)+1)*sizeof(TCHAR));
			/* no open-with flag */
			if(fAllowOpenWith) RegDeleteValue(hExeKey,_T("NoOpenWith"));
			else RegSetValueEx(hExeKey,_T("NoOpenWith"),0,REG_SZ,NULL,0);
			/* default icon */
			if(pszIconLoc!=NULL) SetRegSubKeyStrDefValue(hExeKey,_T("DefaultIcon"),pszIconLoc);
			/* shell */
			if(!RegCreateKeyEx(hExeKey,_T("shell"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY,NULL,&hShellKey,NULL)) {
				/* default verb (when empty "open" is used) */
				RegSetValueEx(hShellKey,NULL,0,REG_SZ,(BYTE*)_T("open"),5*sizeof(TCHAR));
				/* verb */
				if(!RegCreateKeyEx(hShellKey,_T("open"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY,NULL,&hVerbKey,NULL)) {
					/* friendly appname (mui string) */
					RegSetValueEx(hVerbKey,_T("FriendlyAppName"),0,REG_SZ,(BYTE*)pszAppName,(lstrlen(pszAppName)+1)*sizeof(TCHAR));
					/* command */
					SetRegSubKeyStrDefValue(hVerbKey,_T("command"),pszRunCmd);
					/* ddeexec */
					if(pszDdeCmd!=NULL)
						if(!RegCreateKeyEx(hVerbKey,_T("ddeexec"),0,NULL,0,KEY_SET_VALUE|KEY_CREATE_SUB_KEY,NULL,&hDdeKey,NULL)) {
							/* command */
							RegSetValueEx(hDdeKey,NULL,0,REG_SZ,(BYTE*)pszDdeCmd,(lstrlen(pszDdeCmd)+1)*sizeof(TCHAR));
							/* application */
							SetRegSubKeyStrDefValue(hDdeKey,_T("application"),pszDdeApp);
							/* topic */
							SetRegSubKeyStrDefValue(hDdeKey,_T("topic"),pszDdeTopic);
							RegCloseKey(hDdeKey);
						}
					RegCloseKey(hVerbKey);
				}
				RegCloseKey(hShellKey);
			}
			RegCloseKey(hExeKey);
		}
		RegCloseKey(hAppsKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

void RemoveRegOpenWith(const TCHAR *pszAppFileName)
{
	HKEY hRootKey,hAppsKey,hExeKey,hShellKey,hVerbKey,hDdeKey;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* applications */
	if(!RegOpenKeyEx(hRootKey,_T("Applications"),0,DELETE,&hAppsKey)) {
		/* filename */
		if(!RegOpenKeyEx(hAppsKey,pszAppFileName,0,DELETE,&hExeKey)) {
			/* default icon */
			RegDeleteKey(hExeKey,_T("DefaultIcon"));
			/* shell */
			if(!RegOpenKeyEx(hExeKey,_T("shell"),0,DELETE,&hShellKey)) {
				/* verb */
				if(!RegOpenKeyEx(hShellKey,_T("open"),0,DELETE,&hVerbKey)) {
					/* command */
					RegDeleteKey(hVerbKey,_T("command"));
					/* ddeexec */
					if(!RegOpenKeyEx(hVerbKey,_T("ddeexec"),0,DELETE,&hDdeKey)) {
						/* application */
						RegDeleteKey(hDdeKey,_T("application"));
						/* topic */
						RegDeleteKey(hDdeKey,_T("topic"));
						RegCloseKey(hDdeKey);
					}
					RegDeleteKey(hVerbKey,_T("ddeexec"));
					RegCloseKey(hVerbKey);
				}
				RegDeleteKey(hShellKey,_T("open"));
				RegCloseKey(hShellKey);
			}
			RegDeleteKey(hExeKey,_T("shell"));
			/* supported types */
			RegDeleteKey(hExeKey,_T("SupportedTypes"));
			RegCloseKey(hExeKey);
		}
		RegDeleteKey(hAppsKey,pszAppFileName);
		RegCloseKey(hAppsKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

/*
 * Tell the "Open With..." dialog we support a given file extension.
 */

void AddRegOpenWithExtEntry(const TCHAR *pszAppFileName,const char *pszFileExt,const TCHAR *pszFileDesc)
{
	HKEY hRootKey,hAppsKey,hExeKey,hTypesKey;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* applications */
	if(!RegOpenKeyEx(hRootKey,_T("Applications"),0,KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS,&hAppsKey)) {
		/* filename */
		if(!RegOpenKeyEx(hAppsKey,pszAppFileName,0,KEY_CREATE_SUB_KEY,&hExeKey)) {
			/* supported types */
			if(!RegCreateKeyEx(hExeKey,_T("SupportedTypes"),0,NULL,0,KEY_SET_VALUE,NULL,&hTypesKey,NULL)) {	
				TCHAR *ptszFileExt;
				ptszFileExt=a2t(pszFileExt);
				if(ptszFileExt!=NULL)
					RegSetValueEx(hTypesKey,ptszFileExt,0,REG_SZ,(BYTE*)pszFileDesc,(lstrlen(pszFileDesc)+1)*sizeof(TCHAR));
				mir_free(ptszFileExt); /* does NULL check */
				RegCloseKey(hTypesKey);
			}
			RegCloseKey(hExeKey);
		}
		RegCloseKey(hAppsKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

void RemoveRegOpenWithExtEntry(const TCHAR *pszAppFileName,const char *pszFileExt)
{
	HKEY hRootKey,hAppsKey,hExeKey,hTypesKey;

	/* try to open interactive user's classes key */
	if(!IsWinVer2000Plus() || RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Classes"),0,KEY_QUERY_VALUE,&hRootKey))
		hRootKey=HKEY_CLASSES_ROOT;

	/* applications */
	if(!RegOpenKeyEx(hRootKey,_T("Applications"),0,KEY_QUERY_VALUE,&hAppsKey)) {
		/* filename */
		if(!RegOpenKeyEx(hAppsKey,pszAppFileName,0,KEY_QUERY_VALUE,&hExeKey)) {
			/* supported types */
			if(!RegOpenKeyEx(hExeKey,_T("SupportedTypes"),0,KEY_SET_VALUE,&hTypesKey)) {	
				RegDeleteValueA(hTypesKey,pszFileExt);
				RegCloseKey(hTypesKey);
			}
			RegCloseKey(hExeKey);
		}
		RegCloseKey(hAppsKey);
	}

	if(hRootKey!=HKEY_CLASSES_ROOT)
		RegCloseKey(hRootKey);
}

/************************* Autostart ******************************/

/*
 * Add Miranda to the autostart list in the registry.
 */

BOOL AddRegRunEntry(const TCHAR *pszAppName,const TCHAR *pszRunCmd)
{
	BOOL fSuccess=FALSE;
	HKEY hRunKey;

	/* run */
	if(!RegCreateKeyEx(HKEY_CURRENT_USER,_T("Software\\Microsoft\\Windows\\CurrentVersion\\Run"),0,NULL,0,KEY_SET_VALUE,NULL,&hRunKey,NULL)) {
		/* appname */
		fSuccess=!RegSetValueEx(hRunKey,pszAppName,0,REG_SZ,(BYTE*)pszRunCmd,(lstrlen(pszRunCmd)+1)*sizeof(TCHAR));
		RegCloseKey(hRunKey);
	}
	return fSuccess;
}

BOOL RemoveRegRunEntry(const TCHAR *pszAppName,const TCHAR *pszRunCmd)
{
	LONG res;
	HKEY hRunKey;

	/* run */
	res=RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Microsoft\\Windows\\CurrentVersion\\Run"),0,KEY_QUERY_VALUE|KEY_SET_VALUE,&hRunKey);
	if(!res) {
		/* appname */
		if(IsRegStrValue(hRunKey,pszAppName,pszRunCmd))
			res=RegDeleteValue(hRunKey,pszAppName); /* only remove if current */
		RegCloseKey(hRunKey);
	}
	return res==ERROR_SUCCESS || res==ERROR_FILE_NOT_FOUND;
}

/*
 * Check if the autostart item belongs to the current instance of Miranda.
 */

BOOL IsRegRunEntry(const TCHAR *pszAppName,const TCHAR *pszRunCmd)
{
	BOOL fState=FALSE;
	HKEY hRunKey;

	/* Run */
	if(!RegOpenKeyEx(HKEY_CURRENT_USER,_T("Software\\Microsoft\\Windows\\CurrentVersion\\Run"),0,KEY_QUERY_VALUE,&hRunKey)) {
		/* appname */
		fState=IsRegStrValue(hRunKey,pszAppName,pszRunCmd);
		RegCloseKey(hRunKey);
	}
	return fState;
}