#include "rar.hpp"

// If NewFile==NULL, we delete created file after user confirmation.

// It is useful if we need to overwrite an existing folder or file,

// but need user confirmation for that.

bool FileCreate(CommandData *Cmd,File *NewFile,wchar *Name,size_t MaxNameSize,

                bool *UserReject,int64 FileSize,RarTime *FileTime,bool WriteOnly)

{

  if (UserReject!=NULL)

    *UserReject=false;

#ifdef _WIN_ALL

  bool ShortNameChanged=false;

#endif

  while (FileExist(Name))

  {

#if defined(_WIN_ALL)

    if (!ShortNameChanged)

    {

      // Avoid the infinite loop if UpdateExistingShortName returns

      // the same name.

      ShortNameChanged=true;

      // Maybe our long name matches the short name of existing file.

      // Let's check if we can change the short name.

      if (UpdateExistingShortName(Name))

        continue;

    }

    // Allow short name check again. It is necessary, because rename and

    // autorename below can change the name, so we need to check it again.

    ShortNameChanged=false;

#endif

    UIASKREP_RESULT Choice=uiAskReplaceEx(Cmd,Name,MaxNameSize,FileSize,FileTime,(NewFile==NULL ? UIASKREP_F_NORENAME:0));

    if (Choice==UIASKREP_R_REPLACE)

      break;

    if (Choice==UIASKREP_R_SKIP)

    {

      if (UserReject!=NULL)

        *UserReject=true;

      return false;

    }

    if (Choice==UIASKREP_R_CANCEL)

      ErrHandler.Exit(RARX_USERBREAK);

  }

  // Try to truncate the existing file first instead of delete,

  // so we preserve existing file permissions, such as NTFS permissions,

  // also as "Compressed" attribute and hard links. In GUI version we avoid

  // deleting an existing file for non-.rar archive formats as well.

  uint FileMode=WriteOnly ? FMF_WRITE|FMF_SHAREREAD:FMF_UPDATE|FMF_SHAREREAD;

  if (NewFile!=NULL && NewFile->Create(Name,FileMode))

    return true;

  CreatePath(Name,true,Cmd->DisableNames);

  return NewFile!=NULL ? NewFile->Create(Name,FileMode):DelFile(Name);

}

bool GetAutoRenamedName(wchar *Name,size_t MaxNameSize)

{

  wchar NewName[NM];

  size_t NameLength=wcslen(Name);

  wchar *Ext=GetExt(Name);

  if (Ext==NULL)

    Ext=Name+NameLength;

  for (uint FileVer=1;;FileVer++)

  {

    swprintf(NewName,ASIZE(NewName),L"%.*ls(%u)%ls",uint(Ext-Name),Name,FileVer,Ext);

    if (!FileExist(NewName))

    {

      wcsncpyz(Name,NewName,MaxNameSize);

      break;

    }

    if (FileVer>=1000000)

      return false;

  }

  return true;

}

#if defined(_WIN_ALL)

// If we find a file, which short name is equal to 'Name', we try to change

// its short name, while preserving the long name. It helps when unpacking

// an archived file, which long name is equal to short name of already

// existing file. Otherwise we would overwrite the already existing file,

// even though its long name does not match the name of unpacking file.

bool UpdateExistingShortName(const wchar *Name)

{

  wchar LongPathName[NM];

  DWORD Res=GetLongPathName(Name,LongPathName,ASIZE(LongPathName));

  if (Res==0 || Res>=ASIZE(LongPathName))

    return false;

  wchar ShortPathName[NM];

  Res=GetShortPathName(Name,ShortPathName,ASIZE(ShortPathName));

  if (Res==0 || Res>=ASIZE(ShortPathName))

    return false;

  wchar *LongName=PointToName(LongPathName);

  wchar *ShortName=PointToName(ShortPathName);

  // We continue only if file has a short name, which does not match its

  // long name, and this short name is equal to name of file which we need

  // to create.

  if (*ShortName==0 || wcsicomp(LongName,ShortName)==0 ||

      wcsicomp(PointToName(Name),ShortName)!=0)

    return false;

  // Generate the temporary new name for existing file.

  wchar NewName[NM];

  *NewName=0;

  for (int I=0;I<10000 && *NewName==0;I+=123)

  {

    // Here we copy the path part of file to create. We'll make the temporary

    // file in the same folder.

    wcsncpyz(NewName,Name,ASIZE(NewName));

    // Here we set the random name part.

    swprintf(PointToName(NewName),ASIZE(NewName),L"rtmp%d",I);

    // If such file is already exist, try next random name.

    if (FileExist(NewName))

      *NewName=0;

  }

  // If we could not generate the name not used by any other file, we return.

  if (*NewName==0)

    return false;

  // FastFind returns the name without path, but we need the fully qualified

  // name for renaming, so we use the path from file to create and long name

  // from existing file.

  wchar FullName[NM];

  wcsncpyz(FullName,Name,ASIZE(FullName));

  SetName(FullName,LongName,ASIZE(FullName));

  // Rename the existing file to randomly generated name. Normally it changes

  // the short name too.

  if (!MoveFile(FullName,NewName))

    return false;

  // Now we need to create the temporary empty file with same name as

  // short name of our already existing file. We do it to occupy its previous

  // short name and not allow to use it again when renaming the file back to

  // its original long name.

  File KeepShortFile;

  bool Created=false;

  if (!FileExist(Name))

    Created=KeepShortFile.Create(Name,FMF_WRITE|FMF_SHAREREAD);

  // Now we rename the existing file from temporary name to original long name.

  // Since its previous short name is occupied by another file, it should

  // get another short name.

  MoveFile(NewName,FullName);

  if (Created)

  {

    // Delete the temporary zero length file occupying the short name,

    KeepShortFile.Close();

    KeepShortFile.Delete();

  }

  // We successfully changed the short name. Maybe sometimes we'll simplify

  // this function by use of SetFileShortName Windows API call.

  // But SetFileShortName is not available in older Windows.

  return true;

}

#endif