/**********************************************************************

   Audacity: A Digital Audio Editor
   Audacity(R) is copyright (c) 1999-2008 Audacity Team.
   License: GPL v2.  See License.txt.

   DirManager.cpp

   Dominic Mazzoni
   Matt Brubeck
   Michael Chinen
   James Crook
   Al Dimond
   Brian Gunlogson
   Josh Haberman
   Vaughan Johnson
   Leland Lucius
   Monty
   Markus Meyer

*******************************************************************//*!

\class DirManager
\brief Creates and manages BlockFile objects.

  This class manages the files that a project uses to store most
  of its data.  It creates NEW BlockFile objects, which can
  be used to store any type of data.  BlockFiles support all of
  the common file operations, but they also support reference
  counting, so two different parts of a project can point to
  the same block of data.

  For example, a track might contain 10 blocks of data representing
  its audio.  If you copy the last 5 blocks and paste at the
  end of the file, no NEW blocks need to be created - we just store
  pointers to NEW ones.  When part of a track is deleted, the
  affected blocks decrement their reference counts, and when they
  reach zero they are deleted.  This same mechanism is also used
  to implement Undo.

  The DirManager, besides mapping filenames to absolute paths,
  also hashes all of the block names used in a project, so that
  when reading a project from disk, multiple copies of the
  same block still get mapped to the same BlockFile object.

  The blockfile/directory scheme is rather complicated with two different schemes.
  The current scheme uses two levels of subdirectories - up to 256 'eXX' and up to
  256 'dYY' directories within each of the 'eXX' dirs, where XX and YY are hex chars.
  In each of the dXX directories there are up to 256 audio files (e.g. .au or .auf).
  They have a filename scheme of 'eXXYYZZZZ', where XX and YY refers to the
  subdirectories as above.  The 'ZZZZ' component is generated randomly for some reason.
  The XX and YY components are sequential.
  DirManager fills up the current dYY subdir until 256 are created, and moves on to the next one.

  So for example, the first blockfile created may be 'e00/d00/e0000a23b.au' and the next
  'e00/d00/e000015e8.au', and the 257th may be 'e00/d01/e0001f02a.au'.
  On close the blockfiles that are no longer referenced by the project (edited or deleted) are removed,
  along with the consequent empty directories.


*//*******************************************************************/


#include "Audacity.h" // for __UNIX__
#include "DirManager.h"

#include <time.h> // to use time() for srand()

#include <wx/wxcrtvararg.h>
#include <wx/defs.h>
#include <wx/dir.h>
#include <wx/log.h>
#include <wx/filefn.h>
#include <wx/hash.h>
#include <wx/progdlg.h>
#include <wx/timer.h>
#include <wx/intl.h>
#include <wx/file.h>
#include <wx/filename.h>
#include <wx/object.h>

// chmod
#ifdef __UNIX__
#include <sys/types.h>
#include <sys/stat.h>
#endif

#include "BlockFile.h"
#include "FileNames.h"
#include "InconsistencyException.h"
#include "Prefs.h"
#include "Project.h"
#include "widgets/Warning.h"
#include "widgets/AudacityMessageBox.h"
#include "widgets/ProgressDialog.h"

#if defined(__WXMAC__)
#include <mach/mach.h>
#include <mach/vm_statistics.h>
#endif


wxMemorySize GetFreeMemory()
{
   wxMemorySize avail;

#if defined(__WXMAC__)
   mach_port_t port = mach_host_self();
   mach_msg_type_number_t cnt = HOST_VM_INFO_COUNT;
   vm_statistics_data_t	stats;
   vm_size_t pagesize = 0;

   memset(&stats, 0, sizeof(stats));

   host_page_size(port, &pagesize);
   host_statistics(port, HOST_VM_INFO, (host_info_t) &stats, &cnt);
   avail = stats.free_count * pagesize;
#else
   avail = wxGetFreeMemory();
#endif

   return avail;
}

//
// local helper functions for subdirectory traversal
//

// Behavior of RecursivelyEnumerate is tailored to our uses and not
// entirely straightforward.  We use it only for recursing into 
// Audacity projects, but beware that it may be applied to a directory 
// that contains other things too, for example a temp directory.
// It recurses depth-first from the passed-
// in directory into its subdirs according to optional dirspec
// pattern, building a list of directories and (optionally) files
// in the listed order.  
// The dirspec is not applied to subdirs of subdirs. 
// The filespec is applied to all files in subdirectories.
// Files in the passed-in directory will not be
// enumerated.  Also, the passed-in directory is the last entry added
// to the list.
// JKC: Using flag wxDIR_NO_FOLLOW to NOT follow symbolic links.
// Directories and files inside a project should never be symbolic 
// links, so if we find one, do not follow it.
int DirManager::RecursivelyEnumerate(const FilePath &dirPath,
                                  FilePaths& filePathArray,  // output: all files in dirPath tree
                                  wxString dirspec,
                                  wxString filespec,
                                  bool bFiles, bool bDirs,
                                  int progress_count,
                                  int progress_bias,
                                  ProgressDialog* progress)
{
   int count=0;
   bool cont;

   wxDir dir(dirPath);
   if(dir.IsOpened()){
      wxString name;

      // Don't DELETE files from a selective top level, e.g. if handed "projects*" as the
      // directory specifier.
      if (bFiles && dirspec.empty() ){
         cont= dir.GetFirst(&name, filespec, wxDIR_FILES | wxDIR_HIDDEN | wxDIR_NO_FOLLOW);
         while ( cont ){
            FilePath filepath = dirPath + wxFILE_SEP_PATH + name;

            count++;
            filePathArray.push_back(filepath);

            cont = dir.GetNext(&name);

            if (progress)
               progress->Update(count + progress_bias,
                                progress_count);
         }
      }

      cont= dir.GetFirst(&name, dirspec, wxDIR_DIRS | wxDIR_NO_FOLLOW);
      while ( cont ){
         FilePath subdirPath = dirPath + wxFILE_SEP_PATH + name;
         count += RecursivelyEnumerate(
                     subdirPath, filePathArray, wxEmptyString,filespec,
                     bFiles, bDirs,
                     progress_count, count + progress_bias,
                     progress);
         cont = dir.GetNext(&name);
      }
   }

   if (bDirs) {
      filePathArray.push_back(dirPath);
      count++;
   }

   return count;
}

int DirManager::RecursivelyEnumerateWithProgress(const FilePath &dirPath,
                                             FilePaths& filePathArray, // output: all files in dirPath tree
                                             wxString dirspec,
                                             wxString filespec,
                                             bool bFiles, bool bDirs,
                                             int progress_count,
                                             const TranslatableString &message)
{
   Optional<ProgressDialog> progress{};

   if (!message.empty())
      progress.emplace( XO("Progress"), message );

   int count = RecursivelyEnumerate(
                  dirPath, filePathArray, dirspec,filespec,
                  bFiles, bDirs,
                  progress_count, 0,
                  progress ? &*progress : nullptr);

   return count;
}

int DirManager::RecursivelyCountSubdirs( const FilePath &dirPath )
{
   bool bContinue;
   int nCount = 0;
   wxDir dir(dirPath);
   if (dir.IsOpened() && dir.HasSubDirs())
   {
      wxString name;
      bContinue = dir.GetFirst(&name, wxEmptyString, wxDIR_DIRS);
      while (bContinue)
      {
         nCount++;
         FilePath subdirPath = dirPath + wxFILE_SEP_PATH + name;
         nCount += RecursivelyCountSubdirs(subdirPath);
         bContinue = dir.GetNext(&name);
      }
   }
   return nCount;
}

int DirManager::RecursivelyRemoveEmptyDirs(const FilePath &dirPath,
                                       int nDirCount,
                                       ProgressDialog* pProgress)
{
   bool bContinue;
   wxDir dir(dirPath);
   int nCount = 0;
   if (dir.IsOpened())
   {
      if (dir.HasSubDirs())
      {
         wxString name;
         bContinue = dir.GetFirst(&name, wxEmptyString, wxDIR_DIRS);
         while (bContinue)
         {
            FilePath subdirPath = dirPath + wxFILE_SEP_PATH + name;
            nCount += RecursivelyRemoveEmptyDirs(subdirPath, nDirCount, pProgress);
            bContinue = dir.GetNext(&name);
         }
      }
      // Have to recheck dir.HasSubDirs() again, in case they all were deleted in recursive calls.
      if (!dir.HasSubDirs() && !dir.HasFiles() && (dirPath.Right(5) != wxT("_data")))
      {
         // No subdirs or files. It's empty so DELETE it.
         // Vaughan, 2010-07-07:
         // Note that, per http://src.chromium.org/svn/trunk/src/base/file_util_win.cc, among others,
         // "Some versions of Windows return ERROR_FILE_NOT_FOUND (0x2) when deleting
         // an empty directory..." Supposedly fixed in Vista and up.
         // I discovered this on WinXP. I tried several other Windows SDK functions (e.g., _rmdir
         // and RemoveDirectory), and they all give same results.
         // I noticed dirs get deleted in RecursivelyRemove, maybe because it doesn't
         // consider whether the path is a directory or a file and wxRemoveFile()'s it first.
         // Tried it here on WinXP, but no joy. Leave the code in case it works on other Win systems.
         #ifdef __WXMSW__
            ::wxRemoveFile(dirPath);
         #endif
         ::wxRmdir(dirPath);
      }
      nCount++; // Count dirPath in progress.
      if (pProgress)
         pProgress->Update(nCount, nDirCount);
   }
   return nCount;
}

void DirManager::RecursivelyRemove(const FilePaths& filePathArray, int count, int bias,
                              int flags, const TranslatableString &message)
{
   bool bFiles= (flags & kCleanFiles) != 0;
   bool bDirs = (flags & kCleanDirs) != 0;
   bool bDirsMustBeEmpty = (flags & kCleanDirsOnlyIfEmpty) != 0;
   Optional<ProgressDialog> progress{};


   if (!message.empty())
      progress.emplace( XO("Progress"), message );

   auto nn = filePathArray.size();
   for ( size_t ii = 0; ii < nn; ++ii ) {
      const auto &file = filePathArray[ ii ];
      if (bFiles)
         ::wxRemoveFile(file);
      if (bDirs) {
         // continue will go to the next item, and skip
         // attempting to delete the directory.
         if( bDirsMustBeEmpty ){
            wxDir dir( file );
            if( !dir.IsOpened() )
               continue;
            if( dir.HasFiles() )
               continue;
            if( dir.HasSubDirs() )
               continue;
         }

#ifdef __WXMSW__
         if (!bFiles)
            ::wxRemoveFile(file); // See note above about wxRmdir sometimes incorrectly failing on Windows.
#endif

         if (! ::wxRmdir(file) ) {
            wxDir dir(file);
            if(dir.IsOpened()) {
               wxLogMessage(file + wxString(" still contains:"));
               wxString name;
               auto cont = dir.GetFirst(&name);
               while ( cont ) {
                  wxLogMessage(file + wxString(wxFILE_SEP_PATH) + name );
                  cont = dir.GetNext(&name);
               }
            }
            else
               wxLogMessage(wxString("Can't enumerate directory ") + file);
         }
      }
      if (progress)
         progress->Update((int) ii + bias, count);
   }
}


//
// DirManager
//

// Static class variables
wxString DirManager::globaltemp;
int DirManager::numDirManagers = 0;
bool DirManager::dontDeleteTempFiles = false;

namespace {

// Global tracking of all outstanding DirManagers
std::vector< std::weak_ptr< DirManager > > sDirManagers;

}

std::shared_ptr<DirManager> DirManager::Create()
{
   auto result = std::shared_ptr< DirManager >( safenew DirManager );
   sDirManagers.push_back( result );
   return result;
}

static const AudacityProject::AttachedObjects::RegisteredFactory key{
   [](AudacityProject&) { return DirManager::Create(); }
};

DirManager &DirManager::Get( AudacityProject &project )
{
   return project.AttachedObjects::Get< DirManager >( key );
}

const DirManager &DirManager::Get( const AudacityProject &project )
{
   return Get( const_cast< AudacityProject & >( project ) );
}

DirManager &DirManager::Reset( AudacityProject &project )
{
   auto dirManager = DirManager::Create();
   project.AttachedObjects::Assign( key, dirManager );
   return *dirManager;
}

void DirManager::Destroy( AudacityProject &project )
{
   project.AttachedObjects::Assign( key, nullptr );
}

DirManager::DirManager()
{
   wxLogDebug(wxT("DirManager: Created new instance."));

   mLastBlockFileDestructionCount = BlockFile::gBlockFileDestructionCount;

   // Seed the random number generator.
   // this need not be strictly uniform or random, but it should give
   // unclustered numbers
   srand(time(NULL));

   // Set up local temp subdir
   // Previously, Audacity just named project temp directories "project0",
   // "project1" and so on. But with the advent of recovery code, we need a
   // unique name even after a crash. So we create a random project index
   // and make sure it is not used already. This will not pose any performance
   // penalties as long as the number of open Audacity projects is much
   // lower than RAND_MAX.
   do {
      mytemp = globaltemp + wxFILE_SEP_PATH +
               wxString::Format(wxT("project%d"), rand());
   } while (wxDirExists(mytemp));

   numDirManagers++;

   projPath = wxT("");
   projName = wxT("");

   mMaxSamples = ~size_t(0);

   // toplevel pool hash is fully populated to begin
   {
      // We can bypass the accessor function while initializing
      auto &balanceInfo = mBalanceInfo;
      auto &dirTopPool = balanceInfo.dirTopPool;
      for(int i = 0; i < 256; ++i)
         dirTopPool[i] = 0;
   }

   // Make sure there is plenty of space for temp files
   wxLongLong freeSpace = 0;
   if (wxGetDiskSpace(globaltemp, NULL, &freeSpace)) {
      if (freeSpace < wxLongLong(wxLL(100 * 1048576))) {
         ShowWarningDialog(NULL, wxT("DiskSpaceWarning"),
                           XO("There is very little free disk space left on this volume.\nPlease select another temporary directory in Preferences."));
      }
   }
}

DirManager::~DirManager()
{
   auto start = sDirManagers.begin(), finish = sDirManagers.end(),
      iter = std::remove_if( start, finish,
         [=]( const std::weak_ptr<DirManager> &ptr ){
            return ptr.expired() || ptr.lock().get() == this;
         } );
   sDirManagers.erase( iter, finish );

   numDirManagers--;
   if (numDirManagers == 0) {
      CleanTempDir();
      //::wxRmdir(temp);
   } else if( projFull.empty() && !mytemp.empty()) {
      CleanDir(mytemp, wxEmptyString, ".DS_Store", XO("Cleaning project temporary files"), kCleanTopDirToo | kCleanDirsOnlyIfEmpty );
   }
}


// static
// This is quite a dangerous function.  In the temp dir it will DELETE every directory
// recursively, that has 'project*' as the name - EVEN if it happens not to be an Audacity
// project but just something else called project.
void DirManager::CleanTempDir()
{
   // with default flags (none) this does not clean the top directory, and may remove non-empty 
   // directories.
   CleanDir(globaltemp, wxT("project*"), wxEmptyString, XO("Cleaning up temporary files"));
}

// static
void DirManager::CleanDir(
   const FilePath &path,
   const wxString &dirSpec, 
   const wxString &fileSpec, 
   const TranslatableString &msg,
   int flags)
{
   if (dontDeleteTempFiles)
      return; // do nothing

   FilePaths filePathArray, dirPathArray;

   int countFiles =
      RecursivelyEnumerate(path, filePathArray, dirSpec, fileSpec, true, false);
   int countDirs =
      RecursivelyEnumerate(path, dirPathArray, dirSpec, fileSpec, false, true);

   // Subtract 1 because we don't want to DELETE the global temp directory,
   // which this will find and list last.
   if ((flags & kCleanTopDirToo)==0) {
      // Remove the globaltemp itself from the array so that it is not deleted.
      --countDirs;
      dirPathArray.resize(countDirs);
   }

   auto count = countFiles + countDirs;
   if (count == 0)
      return;

   RecursivelyRemove(filePathArray, count, 0, flags | kCleanFiles, msg);
   RecursivelyRemove(dirPathArray, count, countFiles, flags | kCleanDirs, msg);
}

namespace {
   struct PathRestorer {
      PathRestorer(
         bool &commitFlag, FilePath &path, FilePath &name, FilePath &full )
         : committed( commitFlag )

         , projPath( path )
         , projName( name )
         , projFull( full )

         , oldPath( path )
         , oldName( name )
         , oldFull( full )
      {}
      
      ~PathRestorer()
      {
         if (!committed)
            projFull = oldFull, projName = oldName, projPath = oldPath;
      }

      bool &committed;
      FilePath &projPath, &projName, &projFull;
      const FilePath oldPath, oldName, oldFull;
   };

   struct DirCleaner {
      DirCleaner( bool &commitFlag, const FilePath &path )
         : committed( commitFlag )
         , fullPath( path )
      {}
      ~DirCleaner()
      {
         if (!committed)
            DirManager::CleanDir(
               fullPath,
               wxEmptyString,
               wxEmptyString,
               XO("Cleaning up after failed save"),
               kCleanTopDirToo);
      }

      bool &committed;
      FilePath fullPath;
   };
}

struct DirManager::ProjectSetter::Impl
{
   Impl(
      DirManager &dm,
      FilePath& newProjPath, const FilePath& newProjName, const bool bCreate,
      bool moving );

   void Commit();

   DirManager &dirManager;
   bool committed{ false };

   // RAII object
   // Save old state of paths in case of failure
   PathRestorer pathRestorer{
      committed,
      dirManager.projPath, dirManager.projName, dirManager.projFull };

   // Another RAII object
   // Be prepared to un-create directory on failure
   Optional<DirCleaner> dirCleaner;
   
   // State variables to carry over into Commit()
   // Remember old path to be cleaned up in case of successful move
   FilePath oldFull{ dirManager.projFull };
   FilePaths newPaths;
   size_t trueTotal{ 0 };
   bool moving{ true };

   // Make this true only after successful construction
   bool ok{ false };
};

DirManager::ProjectSetter::ProjectSetter(
   DirManager &dirManager,
   FilePath& newProjPath, const FilePath& newProjName, const bool bCreate,
   bool moving )
   : mpImpl{
      std::make_unique<Impl>( dirManager, newProjPath, newProjName, bCreate,
      moving )
   }
{
   
}

DirManager::ProjectSetter::~ProjectSetter()
{
}

bool DirManager::ProjectSetter::Ok()
{
   return mpImpl->ok;
}


void DirManager::ProjectSetter::Commit()
{
   mpImpl->Commit();
}

DirManager::ProjectSetter::Impl::Impl(
   DirManager &dm,
   FilePath& newProjPath, const FilePath& newProjName, const bool bCreate,
   bool moving_ )
: dirManager{ dm }
, moving{ moving_ }
{
   // Choose new paths
   if (newProjPath.empty())
      newProjPath = ::wxGetCwd();

   dirManager.projPath = newProjPath;
   dirManager.projName = newProjName;
   if (newProjPath.Last() == wxFILE_SEP_PATH)
      dirManager.projFull = newProjPath + newProjName;
   else
      dirManager.projFull = newProjPath + wxFILE_SEP_PATH + newProjName;

   // Verify new paths, maybe creating a directory
   if (bCreate) {
      if (!wxDirExists(dirManager.projFull) &&
          !wxMkdir(dirManager.projFull))
         return;

      #ifdef __UNIX__
      chmod(OSFILENAME(dirManager.projFull), 0775);
      #endif

      #ifdef __WXMAC__
      chmod(OSFILENAME(dirManager.projFull), 0775);
      #endif

   }
   else if (!wxDirExists(dirManager.projFull))
      return;

   // Be prepared to un-create directory on failure
   if (bCreate)
      dirCleaner.emplace( committed, dirManager.projFull );

   /* Hard-link or copy all files into this NEW directory.

      If any files are "locked" then all get copied.  (This happens when
      we perform a Save As - the files which belonged to the last
      saved version of the old project must not be removed because of operations
      on the NEW project, otherwise the old project would not be safe.)

      Copy also happens anyway when hard file links are not possible, as when
      saving the project for the first time out of temporary storage and onto
      some other storage device.

      Renaming would also be cheap like hard-linking, but linking is better
      because it builds up a new tree of files without destroying anything in
      the old tree.  That destruction can be left to a commit phase which
      proceeds only when all the building of the new tree has succeeded.
      */

   /* Bug2059:  Don't deduce whether moving or copying just from the block
      files, because an empty project, or one that was empty in its last saved
      state, may have had no block files to lock.
      Must treat as a copy if any is locked, but may also treat as copy if
      the constructor argument tells us so.
      With this change, the empty _data folder of the empty source project
      will not be deleted in Commit().
   */

   moving = moving && ! std::any_of(
      dirManager.mBlockFileHash.begin(), dirManager.mBlockFileHash.end(),
      []( const BlockHash::value_type &pair ){
         auto b = pair.second.lock();
         return b && b->IsLocked();
      }
   );

   trueTotal = 0;

   {
      /* i18n-hint: This title appears on a dialog that indicates the progress
         in doing something.*/
      ProgressDialog progress(XO("Progress"),
         XO("Saving project data files"));

      int total = dirManager.mBlockFileHash.size();

      bool link = moving;
      for (const auto &pair : dirManager.mBlockFileHash) {
         if( progress.Update((int) newPaths.size(), total) != ProgressResult::Success )
            return;

         FilePath newPath;
         if (auto b = pair.second.lock()) {
            auto result =
               dirManager.LinkOrCopyToNewProjectDirectory( &*b, link );
            if (!result.first)
               return;
            newPath = result.second;
            ++trueTotal;
         }
         newPaths.push_back( newPath );
      }
   }

   ok = true;
}

void DirManager::ProjectSetter::Impl::Commit()
{
   wxASSERT( ok );

   // We have built all of the new file tree.
   // So cancel the destructor actions of the RAII objects.
   committed = true;

   auto size = newPaths.size();
   wxASSERT( size == dirManager.mBlockFileHash.size() );

   // Commit changes to filenames in the BlockFile objects, and removal
   // of files at old paths, ONLY NOW!  This must be nothrow.

   // This copy-then-delete procedure is needed to make it safe to
   // attempt save to another storage device, but fail.

   // It has the consequence that saving a project from one part of
   // the device to another will not succeed unless there is sufficient
   // space to hold originals and copies at the same time.  Perhaps the
   // extra cautions are not needed in that case, and the old procedure
   // of renaming first, and reversing the renamings in case of failure,
   // could still work safely.

   // But I don't know whether wxWidgets gives us a reliable means to
   // distinguish that case.

   // I will err on the side of safety and simplicity and follow the
   // same procedure in all cases.

   size_t ii = 0;
   for (const auto &pair : dirManager.mBlockFileHash)
   {
      BlockFilePtr b = pair.second.lock();

      if (b) {
         if (moving || !b->IsLocked()) {
            auto result = b->GetFileName();
            auto oldPath = result.name.GetFullPath();
            if (!oldPath.empty())
               wxRemoveFile( oldPath );
         }

         if (ii < size)
            b->SetFileName(
               wxFileNameWrapper{ wxFileName{ newPaths[ii] } } );
      }

      ++ii;
   }

   // Some subtlety; SetProject is used both to move a temp project
   // into a permanent home as well as just set up path variables when
   // loading a project; in this latter case, the movement code does
   // nothing because SetProject is called before there are any
   // blockfiles.  Cleanup code trigger is the same

   // Do the cleanup of the temporary directory only if not saving-as, which we
   // detect by having done copies rather than moves.
   if (moving && trueTotal > 0) {
      // Clean up after ourselves; boldly remove all files and directories
      // in the tree.  (Unlike what the earlier version of this comment said.)
      // Because this is a relocation of the project, not the case of closing
      // a persistent project.

      // You may think the loops above guarantee that all files we put in the
      // folders have been moved away already, but:
      // to fix bug1567 on Mac, we need to find the extraneous .DS_Store files
      // that we didn't put there, but that Finder may insert into the folders,
      // and mercilessly remove them, in addition to removing the directories.

      auto cleanupLoc1 = oldFull.empty() ? dirManager.mytemp : oldFull;
      CleanDir(
         cleanupLoc1, 
         wxEmptyString, // EmptyString => ALL directories.
         // If the next line were wxEmptyString, ALL files would be removed.
         ".DS_Store",   // Other project files should already have been removed.
         XO("Cleaning up cache directories"), 
         kCleanTopDirToo);

      //This destroys the empty dirs of the OD block files, which are yet to come.
      //Dont know if this will make the project dirty, but I doubt it. (mchinen)
      //      count += RecursivelyEnumerate(cleanupLoc2, dirlist, wxEmptyString, false, true);
   }
}

bool DirManager::SetProject(
   FilePath& newProjPath, const FilePath& newProjName, const bool bCreate)
{
   ProjectSetter setter{ *this, newProjPath, newProjName, bCreate, true };
   if (!setter.Ok())
      return false;
   setter.Commit();
   return true;
}

FilePath DirManager::GetProjectDataDir()
{
   return projFull;
}

FilePath DirManager::GetProjectName()
{
   return projName;
}

wxLongLong DirManager::GetFreeDiskSpace()
{
   wxLongLong freeSpace = -1;
   wxFileName path;

   path.SetPath(projPath.empty() ? mytemp : projPath);

   // Use the parent directory if the project directory hasn't yet been created
   if (!path.DirExists())
   {
      path.RemoveLastDir();
   }

   if (!wxGetDiskSpace(path.GetFullPath(), NULL, &freeSpace))
   {
      freeSpace = -1;
   }

   return freeSpace;
}

FilePath DirManager::GetDataFilesDir() const
{
   return !projFull.empty()? projFull: mytemp;
}

void DirManager::SetLocalTempDir(const wxString &path)
{
   mytemp = path;
}

wxFileNameWrapper DirManager::MakeBlockFilePath(const wxString &value) {

   wxFileNameWrapper dir;
   dir.AssignDir(GetDataFilesDir());

   if(value.GetChar(0)==wxT('d')){
      // this file is located in a subdirectory tree
      int location=value.Find(wxT('b'));
      wxString subdir=value.Mid(0,location);
      dir.AppendDir(subdir);

      if(!dir.DirExists())
         dir.Mkdir();
   }

   if(value.GetChar(0)==wxT('e')){
      // this file is located in a NEW style two-deep subdirectory tree
      wxString topdir=value.Mid(0,3);
      wxString middir=wxT("d");
      middir.Append(value.Mid(3,2));

      dir.AppendDir(topdir);
      dir.AppendDir(middir);

      if(!dir.DirExists() && !dir.Mkdir(0777,wxPATH_MKDIR_FULL))
      { // need braces to avoid compiler warning about ambiguous else, see the macro
         wxLogSysError(_("mkdir in DirManager::MakeBlockFilePath failed."));
      }
   }
   return dir;
}

bool DirManager::AssignFile(wxFileNameWrapper &fileName,
                            const wxString &value,
                            bool diskcheck)
{
   wxFileNameWrapper dir{ MakeBlockFilePath(value) };

   if(diskcheck){
      // verify that there's no possible collision on disk.  If there
      // is, log the problem and return FALSE so that MakeBlockFileName
      // can try again

      wxDir checkit(dir.GetFullPath());
      if(!checkit.IsOpened()) return FALSE;

      // this code is only valid if 'value' has no extention; that
      // means, effectively, AssignFile may be called with 'diskcheck'
      // set to true only if called from MakeFileBlockName().

      wxString filespec;
      filespec.Printf(wxT("%s.*"),value);
      if(checkit.HasFiles(filespec)){
         // collision with on-disk state!
         wxString collision;
         checkit.GetFirst(&collision,filespec);

         wxLogWarning(_("Audacity found an orphan block file: %s. \nPlease consider saving and reloading the project to perform a complete project check."),
                      collision);

         return FALSE;
      }
   }
   fileName.Assign(dir.GetFullPath(),value);
   return fileName.IsOk();
}

static inline unsigned int hexchar_to_int(unsigned int x)
{
   if(x<48U)return 0;
   if(x<58U)return x-48U;
   if(x<65U)return 10U;
   if(x<71U)return x-55U;
   if(x<97U)return 10U;
   if(x<103U)return x-87U;
   return 15U;
}

int DirManager::BalanceMidAdd(int topnum, int midkey)
{
   // enter the midlevel directory if it doesn't exist

   auto &balanceInfo = GetBalanceInfo();
   auto &dirMidPool = balanceInfo.dirMidPool;
   auto &dirMidFull = balanceInfo.dirMidFull;
   auto &dirTopPool = balanceInfo.dirTopPool;
   auto &dirTopFull = balanceInfo.dirTopFull;

   if(dirMidPool.find(midkey) == dirMidPool.end() &&
         dirMidFull.find(midkey) == dirMidFull.end()){
      dirMidPool[midkey]=0;

      // increment toplevel directory fill
      dirTopPool[topnum]++;
      if(dirTopPool[topnum]>=256){
         // this toplevel is now full; move it to the full hash
         dirTopPool.erase(topnum);
         dirTopFull[topnum]=256;
      }
      return 1;
   }
   return 0;
}

void DirManager::BalanceFileAdd(int midkey)
{
   auto &balanceInfo = GetBalanceInfo();
   auto &dirMidPool = balanceInfo.dirMidPool;
   auto &dirMidFull = balanceInfo.dirMidFull;

   // increment the midlevel directory usage information
   if(dirMidPool.find(midkey) != dirMidPool.end()){
      dirMidPool[midkey]++;
      if(dirMidPool[midkey]>=256){
         // this middir is now full; move it to the full hash
         dirMidPool.erase(midkey);
         dirMidFull[midkey]=256;
      }
   }else{
      // this case only triggers in absurdly large projects; we still
      // need to track directory fill even if we're over 256/256/256
      dirMidPool[midkey]++;
   }
}

void DirManager::BalanceInfoAdd(const wxString &file)
{
   const wxChar *s=file;
   if(s[0]==wxT('e')){
      // this is one of the modern two-deep managed files
      // convert filename to keys
      unsigned int topnum = (hexchar_to_int(s[1]) << 4) |
         hexchar_to_int(s[2]);
      unsigned int midnum = (hexchar_to_int(s[3]) << 4) |
         hexchar_to_int(s[4]);
      unsigned int midkey=topnum<<8|midnum;

      BalanceMidAdd(topnum,midkey);
      BalanceFileAdd(midkey);
   }
}

auto DirManager::GetBalanceInfo() -> BalanceInfo &
{
   // Before returning the map,
   // see whether any block files have disappeared,
   // and if so update

   auto count = BlockFile::gBlockFileDestructionCount;
   if ( mLastBlockFileDestructionCount != count ) {
      auto it = mBlockFileHash.begin(), end = mBlockFileHash.end();
      while (it != end)
      {
         BlockFilePtr ptr { it->second.lock() };
         if (!ptr) {
            auto name = it->first;
            mBlockFileHash.erase( it++ );
            BalanceInfoDel( name );
         }
         else
            ++it;
      }
   }

   mLastBlockFileDestructionCount = count;

   return mBalanceInfo;
}

// Note that this will try to clean up directories out from under even
// locked blockfiles; this is actually harmless as the rmdir will fail
// on non-empty directories.
void DirManager::BalanceInfoDel(const wxString &file)
{
   // do not use GetBalanceInfo(),
   // rather this function will be called from there.
   auto &balanceInfo = mBalanceInfo;
   auto &dirMidPool = balanceInfo.dirMidPool;
   auto &dirMidFull = balanceInfo.dirMidFull;
   auto &dirTopPool = balanceInfo.dirTopPool;
   auto &dirTopFull = balanceInfo.dirTopFull;

   const wxChar *s=file;
   if(s[0]==wxT('e')){
      // this is one of the modern two-deep managed files

      unsigned int topnum = (hexchar_to_int(s[1]) << 4) |
         hexchar_to_int(s[2]);
      unsigned int midnum = (hexchar_to_int(s[3]) << 4) |
         hexchar_to_int(s[4]);
      unsigned int midkey=topnum<<8|midnum;

      // look for midkey in the mid pool
      if(dirMidFull.find(midkey) != dirMidFull.end()){
         // in the full pool

         if(--dirMidFull[midkey]<256){
            // move out of full into available
            dirMidPool[midkey]=dirMidFull[midkey];
            dirMidFull.erase(midkey);
         }
      }else{
         if(--dirMidPool[midkey]<1){
            // erasing the key here is OK; we have provision to add it
            // back if its needed (unlike the dirTopPool hash)
            dirMidPool.erase(midkey);

            // DELETE the actual directory
            auto dir = !projFull.empty() ? projFull : mytemp;
            dir += wxFILE_SEP_PATH;
            dir += file.Mid(0,3);
            dir += wxFILE_SEP_PATH;
            dir += wxT("d");
            dir += file.Mid(3,2);
            wxFileName::Rmdir(dir);

            // also need to remove from toplevel
            if(dirTopFull.find(topnum) != dirTopFull.end()){
               // in the full pool
               if(--dirTopFull[topnum]<256){
                  // move out of full into available
                  dirTopPool[topnum]=dirTopFull[topnum];
                  dirTopFull.erase(topnum);
               }
            }else{
               if(--dirTopPool[topnum]<1){
                  // do *not* erase the hash entry from dirTopPool
                  // *do* DELETE the actual directory
                  dir=(!projFull.empty()? projFull: mytemp);
                  dir += wxFILE_SEP_PATH;
                  dir += file.Mid(0,3);
                  wxFileName::Rmdir(dir);
               }
            }
         }
      }
   }
}

// only determines appropriate filename and subdir balance; does not
// perform maintainence
wxFileNameWrapper DirManager::MakeBlockFileName()
{
   auto &balanceInfo = GetBalanceInfo();
   auto &dirMidPool = balanceInfo.dirMidPool;
   auto &dirTopPool = balanceInfo.dirTopPool;
   auto &dirTopFull = balanceInfo.dirTopFull;

   wxFileNameWrapper ret;
   wxString baseFileName;

   unsigned int filenum,midnum,topnum,midkey;

   while(1){

      /* blockfiles are divided up into heirarchical directories.
         Each toplevel directory is represented by "e" + two unique
         hexadecimal digits, for a total possible number of 256
         toplevels.  Each toplevel contains up to 256 subdirs named
         "d" + two hex digits.  Each subdir contains 'a number' of
         files.  */

      filenum=0;
      midnum=0;
      topnum=0;

      // first action: if there is no available two-level directory in
      // the available pool, try to make one

      if(dirMidPool.empty()){

         // is there a toplevel directory with space for a NEW subdir?

         if(!dirTopPool.empty()){

            // there's still a toplevel with room for a subdir

            DirHash::iterator iter = dirTopPool.begin();
            int newcount           = 0;
            topnum                 = iter->first;


            // search for unused midlevels; linear search adequate
            // add 32 NEW topnum/midnum dirs full of  prospective filenames to midpool
            for(midnum=0;midnum<256;midnum++){
               midkey=(topnum<<8)+midnum;
               if(BalanceMidAdd(topnum,midkey)){
                  newcount++;
                  if(newcount>=32)break;
               }
            }

            if(dirMidPool.empty()){
               // all the midlevels in this toplevel are in use yet the
               // toplevel claims some are free; this implies multiple
               // internal logic faults, but simply giving up and going
               // into an infinite loop isn't acceptible.  Just in case,
               // for some reason, we get here, dynamite this toplevel so
               // we don't just fail.

               // this is 'wrong', but the best we can do given that
               // something else is also wrong.  It will contain the
               // problem so we can keep going without worry.
               dirTopPool.erase(topnum);
               dirTopFull[topnum]=256;
            }
            continue;
         }
      }

      if(dirMidPool.empty()){
         // still empty, thus an absurdly large project; all dirs are
         // full to 256/256/256; keep working, but fall back to 'big
         // filenames' and randomized placement

         filenum = rand();
         midnum  = (int)(256.*rand()/(RAND_MAX+1.));
         topnum  = (int)(256.*rand()/(RAND_MAX+1.));
         midkey=(topnum<<8)+midnum;


      }else{

         DirHash::iterator iter = dirMidPool.begin();
         midkey                 = iter->first;

         // split the retrieved 16 bit directory key into two 8 bit numbers
         topnum = midkey >> 8;
         midnum = midkey & 0xff;
         filenum = (int)(4096.*rand()/(RAND_MAX+1.));

      }

      baseFileName.Printf(wxT("e%02x%02x%03x"),topnum,midnum,filenum);

      if (!ContainsBlockFile(baseFileName)) {
         // not in the hash, good.
         if (!this->AssignFile(ret, baseFileName, true))
         {
            // this indicates an on-disk collision, likely due to an
            // orphan blockfile.  We should try again, but first
            // alert the balancing info there's a phantom file here;
            // if the directory is nearly full of orphans we neither
            // want performance to suffer nor potentially get into an
            // infinite loop if all possible filenames are taken by
            // orphans (unlikely but possible)
            BalanceFileAdd(midkey);

         }else break;
      }
   }
   // FIXME: Might we get here without midkey having been set?
   //    Seemed like a possible problem in these changes in .aup directory hierarchy.
   BalanceFileAdd(midkey);
   return ret;
}

BlockFilePtr DirManager::NewBlockFile( const BlockFileFactory &factory )
{
   wxFileNameWrapper filePath{ MakeBlockFileName() };
   const wxString fileName{ filePath.GetName() };
   auto newBlockFile = factory( std::move(filePath) );
   mBlockFileHash[fileName] = newBlockFile;
   auto &aliasName = newBlockFile->GetExternalFileName();
   if ( aliasName.IsOk() )
      //OD TODO: check to see if we need to remove this when done decoding.
      //I don't immediately see a place where aliased files remove when a file is closed.
      aliasList.push_back( aliasName.GetFullPath() );
   return newBlockFile;
}

bool DirManager::ContainsBlockFile(const BlockFile *b) const
{
   if (!b)
      return false;
   auto result = b->GetFileName();
   BlockHash::const_iterator it = mBlockFileHash.find(result.name.GetName());
   if (it == mBlockFileHash.end())
      return false;
   BlockFilePtr ptr = it->second.lock();
   return ptr && (b == &*ptr);
}

bool DirManager::ContainsBlockFile(const wxString &filepath) const
{
   // check what the hash returns in case the blockfile is from a different project
   BlockHash::const_iterator it = mBlockFileHash.find(filepath);
   return it != mBlockFileHash.end() &&
      BlockFilePtr{ it->second.lock() };
}

// Adds one to the reference count of the block file,
// UNLESS it is "locked", then it makes a NEW copy of
// the BlockFile.
// This function returns non-NULL, or else throws
BlockFilePtr DirManager::CopyBlockFile(const BlockFilePtr &b)
{
   if (!b)
      THROW_INCONSISTENCY_EXCEPTION;

   auto result = b->GetFileName();
   const auto &fn = result.name;

   if (!b->IsLocked()) {
      //mchinen:July 13 2009 - not sure about this, but it needs to be added to the hash to be able to save if not locked.
      //note that this shouldn't hurt mBlockFileHash's that already contain the filename, since it should just overwrite.
      //but it's something to watch out for.
      //
      // LLL: Except for silent block files which have uninitialized filename.
      if (fn.IsOk())
         mBlockFileHash[fn.GetName()] = b;
      return b;
   }

   // Copy the blockfile
   BlockFilePtr b2;
   if (!fn.IsOk())
      // Block files with uninitialized filename (i.e. SilentBlockFile)
      // just need an in-memory copy.
      b2 = b->Copy(wxFileNameWrapper{});
   else
   {
      wxFileNameWrapper newFile{ MakeBlockFileName() };
      const wxString newName{newFile.GetName()};
      const wxString newPath{ newFile.GetFullPath() };

      // We assume that the NEW file should have the same extension
      // as the existing file
      newFile.SetExt(fn.GetExt());

      //some block files such as ODPCMAliasBlockFIle don't always have
      //a summary file, so we should check before we copy.
      if(b->IsSummaryAvailable())
      {
         if( !FileNames::CopyFile(fn.GetFullPath(),
                  newFile.GetFullPath()) )
            // Disk space exhaustion, maybe
            throw FileException{
               FileException::Cause::Write, newFile };
      }

      // Done with fn
      result.mLocker.reset();

      b2 = b->Copy(std::move(newFile));

      mBlockFileHash[newName] = b2;
      aliasList.push_back(newPath);
   }

   if (!b2)
      THROW_INCONSISTENCY_EXCEPTION;

   return b2;
}

namespace {

using Deserializers =
   std::unordered_map< wxString, DirManager::BlockFileDeserializer >;
Deserializers &GetDeserializers()
{
   static Deserializers sDeserializers;
   return sDeserializers;
}

}

DirManager::RegisteredBlockFileDeserializer::RegisteredBlockFileDeserializer(
   const wxString &tag, BlockFileDeserializer function )
{
   GetDeserializers()[tag] = function;
}

bool DirManager::HandleXMLTag(const wxChar *tag, const wxChar **attrs)
{
   if( !mLoadingTarget )
      return false;

   BlockFilePtr pBlockFile {};

   BlockFilePtr &target = mLoadingTarget();
   mLoadingTarget = nullptr;
   
   auto &table = GetDeserializers();
   auto iter = table.find( tag );
   if ( iter == table.end() )
      return false;
   pBlockFile = iter->second( *this, attrs );

   if (!pBlockFile)
      // BuildFromXML failed, or we didn't find a valid blockfile tag.
      return false;

   if (!pBlockFile->GetFileName().name.IsOk()) {
     // Silent blocks don't actually have a file associated, so
     // we don't need to worry about the hash table at all
     target = pBlockFile;
     return true;
   }

   // Check the length here so we don't have to do it in each BuildFromXML method.
   if ((mMaxSamples != ~size_t(0)) && // is initialized
         (pBlockFile->GetLength() > mMaxSamples))
   {
      // See http://bugzilla.audacityteam.org/show_bug.cgi?id=451#c13.
      // Lock pBlockFile so that the ~BlockFile() will not DELETE the file on disk.
      pBlockFile->Lock();
      return false;
   }
   else
      target = pBlockFile;

   //
   // If the block we loaded is already in the hash table, then the
   // object we just loaded is a duplicate, so we DELETE it and
   // return a reference to the existing object instead.
   //

   wxString name = target->GetFileName().name.GetName();
   auto &wRetrieved = mBlockFileHash[name];
   BlockFilePtr retrieved = wRetrieved.lock();
   if (retrieved) {
      // Lock it in order to DELETE it safely, i.e. without having
      // it DELETE the file, too...
      target->Lock();

      target = retrieved;
      return true;
   }

   // This is a NEW object
   wRetrieved = target;
   // MakeBlockFileName wasn't used so we must add the directory
   // balancing information
   BalanceInfoAdd(name);

   return true;
}

std::pair<bool, FilePath> DirManager::LinkOrCopyToNewProjectDirectory(
   BlockFile *f, bool &link )
{
   FilePath newPath;
   auto result = f->GetFileName();
   const auto &oldFileNameRef = result.name;

   // Check that this BlockFile corresponds to a file on disk
   //ANSWER-ME: Is this checking only for SilentBlockFiles, in which case
   //    (!oldFileName.IsOk()) is a more correct check?
   if (oldFileNameRef.GetName().empty()) {
      return { true, newPath };
   }

   wxFileNameWrapper newFileName;
   if (!this->AssignFile(newFileName, oldFileNameRef.GetFullName(), false)
       // Another sanity check against blockfiles getting reassigned an empty
       // name, as apparently happened in
       // http://forum.audacityteam.org/viewtopic.php?f=47&t=97787 :
       || newFileName.GetFullName().empty() )
      return { false, {} };

   newPath = newFileName.GetFullPath();

   if (newFileName != oldFileNameRef) {
      //check to see that summary exists before we copy.
      bool summaryExisted = f->IsSummaryAvailable();
      auto oldPath = oldFileNameRef.GetFullPath();
      if (summaryExisted) {
         bool success = false;
         if (link)
            success = FileNames::HardLinkFile( oldPath, newPath );
         if (!success)
             link = false,
             success = FileNames::CopyFile( oldPath, newPath );
         if (!success)
            return { false, {} };
      }

      if (!summaryExisted && (f->IsSummaryAvailable() || f->IsSummaryBeingComputed())) {
         // PRL:  These steps apply only in case of "on-demand" files that have
         // not completed their asynchronous loading yet -- a very unusual
         // circumstance.

         // We will need to remember the old file name, so copy it
         wxFileName oldFileName{ oldFileNameRef };

         // Now we can free any lock (and should, if as the comment below says, we need
         // the other threads to progress)
         result.mLocker.reset();

         f->SetFileName(std::move(newFileName));

         //there is a small chance that the summary has begun to be computed on a different thread with the
         //original filename.  we need to catch this case by waiting for it to finish and then copy.

         //block to make sure OD files don't get written while we are changing file names.
         //(It is important that OD files set this lock while computing their summary files.)
         while(f->IsSummaryBeingComputed() && !f->IsSummaryAvailable())
            ::wxMilliSleep(50);

         //check to make sure the oldfile exists.
         //if it doesn't, we can assume it was written to the NEW name, which is fine.
         if (oldFileName.FileExists())
         {
            bool ok = FileNames::CopyFile(oldPath, newPath);
            if (!ok)
               return { false, {} };
         }
      }
   }

   return { true, newPath };
}

bool DirManager::EnsureSafeFilename(const wxFileName &fName)
{
   // Quick check: If it's not even in our alias list,
   // then the file name is A-OK.

   const wxString fullPath{fName.GetFullPath()};
   if ( !make_iterator_range( aliasList ).contains( fullPath ) )
      return true;

   /* i18n-hint: 'old' is part of a filename used when a file is renamed. */
   // Figure out what the NEW name for the existing file would be.
   /* i18n-hint: e.g. Try to go from "mysong.wav" to "mysong-old1.wav". */
   // Keep trying until we find a filename that doesn't exist.

   wxFileNameWrapper renamedFileName{ fName };
   int i = 0;
   do {
      i++;
      /* i18n-hint: This is the pattern for filenames that are created
       * when a file needs to be backed up to a different name.  For
       * example, mysong would become mysong-old1, mysong-old2, etc. */
      renamedFileName.SetName(wxString::Format(_("%s-old%d"), fName.GetName(), i));
   } while (renamedFileName.FileExists());

   // Test creating a file by that name to make sure it will
   // be possible to do the rename

   const wxString renamedFullPath{ renamedFileName.GetFullPath() };
   wxFile testFile(renamedFullPath, wxFile::write);
   if (!testFile.IsOpened()) {
      { // need braces to avoid compiler warning about ambiguous else, see the macro
         wxLogSysError(_("Unable to open/create test file."),
               renamedFullPath);
      }
      return false;
   }

   // Close the file prior to renaming.
   testFile.Close();

   if (!wxRemoveFile(renamedFullPath)) {
      /* i18n-hint: %s is the name of a file.*/
      { // need braces to avoid compiler warning about ambiguous else, see the macro
         wxLogSysError(_("Unable to remove '%s'."),
            renamedFullPath);
      }
      return false;
   }

   wxPrintf(_("Renamed file: %s\n"), renamedFullPath);

   // Go through our block files and see if any indeed point to
   // the file we're concerned about.  If so, point the block file
   // to the renamed file and when we're done, perform the rename.

   bool needToRename = false;
   wxBusyCursor busy;
   BlockHash::iterator iter = mBlockFileHash.begin();
   std::vector< BlockFile::ReadLock > readLocks;
   while (iter != mBlockFileHash.end())
   {
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (fName.IsOk() && b->GetExternalFileName() == fName) {
            needToRename = true;

            //ODBlocks access the aliased file on another thread, so we need to pause them before this continues.
            readLocks.push_back( b->LockForRead() );
         }
      }
      ++iter;
   }

   if (needToRename) {
      if (!wxRenameFile(fullPath,
                        renamedFullPath))
      {
         // ACK!!! The renaming was unsuccessful!!!
         // (This shouldn't happen, since we tried creating a
         // file of this name and then deleted it just a
         // second earlier.)  But we'll handle this scenario
         // just in case!!!

         // Print error message and cancel the export
         wxLogSysError(_("Unable to rename '%s' to '%s'."),
                       fullPath,
                       renamedFullPath);

         // Destruction of readLocks puts things back where they were
         return false;
      }
      else
      {
         //point the aliases to the NEW filename.
         BlockHash::iterator iter2 = mBlockFileHash.begin();
         while (iter2 != mBlockFileHash.end())
         {
            BlockFilePtr b = iter2->second.lock();
            if (b) {
               if (fName.IsOk() && b->GetExternalFileName() == fName) {
                  b->SetExternalFileName(wxFileNameWrapper{ renamedFileName });
                  wxPrintf(_("Changed block %s to new alias name\n"),
                           b->GetFileName().name.GetFullName());

               }
            }
            ++iter2;
         }

      }

      aliasList.erase(
         std::find( aliasList.begin(), aliasList.end(), fullPath ) );
      aliasList.push_back(renamedFullPath);
   }

   // Success!!!  Either we successfully renamed the file,
   // or we didn't need to!
   return true;
}

void DirManager::FindMissingAliasFiles(
      BlockHash& missingAliasFilesAUFHash,     // output: (.auf) AliasBlockFiles whose aliased files are missing
      BlockHash& missingAliasFilesPathHash)    // output: full paths of missing aliased files
{
   BlockHash::iterator iter = mBlockFileHash.begin();
   while (iter != mBlockFileHash.end())
   {
      wxString key = iter->first;   // file name and extension
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->IsAlias())
         {
            const wxFileName &aliasedFileName =
            static_cast< AliasBlockFile* > ( &*b )->GetAliasedFileName();
            wxString aliasedFileFullPath = aliasedFileName.GetFullPath();
            // wxEmptyString can happen if user already chose to "replace... with silence".
            if ((!aliasedFileFullPath.empty()) &&
                !aliasedFileName.FileExists())
            {
               missingAliasFilesAUFHash[key] = b;
               if (missingAliasFilesPathHash.find(aliasedFileFullPath) ==
                   missingAliasFilesPathHash.end()) // Add it only once.
                  // Not actually using the block here, just the path,
                  // so set the block to NULL to create the entry.
                  missingAliasFilesPathHash[aliasedFileFullPath] = {};
            }
         }
      }
      ++iter;
   }

   iter = missingAliasFilesPathHash.begin();
   while (iter != missingAliasFilesPathHash.end())
   {
      wxLogWarning(_("Missing aliased audio file: '%s'"), iter->first);
      ++iter;
   }
}

void DirManager::FindMissingAUFs(
      BlockHash& missingAUFHash)                // output: missing (.auf) AliasBlockFiles
{
   BlockHash::iterator iter = mBlockFileHash.begin();
   while (iter != mBlockFileHash.end())
   {
      const wxString &key = iter->first;
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->IsAlias() && b->IsSummaryAvailable())
         {
            /* don't look in hash; that might find files the user moved
             that the Blockfile abstraction can't find itself */
            wxFileNameWrapper fileName{ MakeBlockFilePath(key) };
            fileName.SetName(key);
            fileName.SetExt(wxT("auf"));
            if (!fileName.FileExists())
            {
               missingAUFHash[key] = b;
               wxLogWarning(_("Missing alias (.auf) block file: '%s'"),
                            fileName.GetFullPath());
            }
         }
      }
      ++iter;
   }
}

void DirManager::FindMissingAUs(
      BlockHash& missingAUHash)                 // missing data (.au) blockfiles
{
   BlockHash::iterator iter = mBlockFileHash.begin();
   while (iter != mBlockFileHash.end())
   {
      const wxString &key = iter->first;
      BlockFilePtr b = iter->second.lock();
      // TODO key can be empty in doing a ProjectFSK
      // In which case MakeFilePath will fail.  Bail out?
      if (b) {
         if (!b->IsAlias())
         {
            wxFileNameWrapper fileName{ MakeBlockFilePath(key) };
            fileName.SetName(key);
            fileName.SetExt(wxT("au"));
            const auto path = fileName.GetFullPath();
            if (!fileName.FileExists() ||
                wxFile{ path }.Length() == 0)
            {
               missingAUHash[key] = b;
               wxLogWarning(_("Missing data block file: '%s'"), path);
            }
         }
      }
      ++iter;
   }
}

// Find .au and .auf files that are not in the project.
void DirManager::FindOrphanBlockFiles(
      const FilePaths &filePathArray,       // input: all files in project directory
      FilePaths &orphanFilePathArray)       // output: orphan files
{
   std::vector< std::shared_ptr<DirManager> > otherDirManagers;
   for ( auto &wPtr : sDirManagers ) {
      auto sPtr = wPtr.lock();
      if ( sPtr && sPtr.get() != this )
         otherDirManagers.push_back( sPtr );
   }

   for (size_t i = 0; i < filePathArray.size(); i++)
   {
      const wxFileName &fullname = filePathArray[i];
      wxString basename = fullname.GetName();
      const wxString ext{fullname.GetExt()};
      if ((mBlockFileHash.find(basename) == mBlockFileHash.end()) && // is orphan
            // Consider only Audacity data files.
            // Specifically, ignore <branding> JPG and <import> OGG ("Save Compressed Copy").
            (ext.IsSameAs(wxT("au"), false) ||
               ext.IsSameAs(wxT("auf"), false)))
      {
         // Ignore it if it exists in the clipboard (from a previously closed project)
         if ( std::any_of( otherDirManagers.begin(), otherDirManagers.end(),
            [&]( const std::shared_ptr< DirManager > &ptr ){
               return ptr->ContainsBlockFile( basename );
            }
         ) )
            continue;

         orphanFilePathArray.push_back(fullname.GetFullPath());
      }
   }
   for ( const auto &orphan : orphanFilePathArray )
      wxLogWarning(_("Orphan block file: '%s'"), orphan);
}


void DirManager::RemoveOrphanBlockfiles()
{
   FilePaths filePathArray; // *all* files in the project directory/subdirectories
   auto dirPath = (!projFull.empty() ? projFull : mytemp);
   RecursivelyEnumerateWithProgress(
      dirPath,
      filePathArray,          // output: all files in project directory tree
      wxEmptyString,          // All dirs
      wxEmptyString,          // All files
      true, false,
      mBlockFileHash.size(),  // rough guess of how many BlockFiles will be found/processed, for progress
      XO("Inspecting project file data"));

   FilePaths orphanFilePathArray;
   this->FindOrphanBlockFiles(
            filePathArray,          // input: all files in project directory tree
            orphanFilePathArray);   // output: orphan files

   // Remove all orphan blockfiles.
   for ( const auto &orphan : orphanFilePathArray )
      wxRemoveFile(orphan);
}

void DirManager::FillBlockfilesCache()
{
#ifdef DEPRECATED_AUDIO_CACHE
   // See http://bugzilla.audacityteam.org/show_bug.cgi?id=545.
   bool cacheBlockFiles = false;
   gPrefs->Read(wxT("/Directories/CacheBlockFiles"), &cacheBlockFiles);

   if (!cacheBlockFiles)
      return; // user opted not to cache block files

   int lowMem = gPrefs->Read(wxT("/Directories/CacheLowMem"), 16l);
   if (lowMem < 16) {
      lowMem = 16;
   }
   lowMem <<= 20;

   BlockHash::iterator iter;
   int numNeed = 0;

   iter = mBlockFileHash.begin();
   while (iter != mBlockFileHash.end())
   {
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->GetNeedFillCache())
            numNeed++;
      }
      ++iter;
   }

   if (numNeed == 0)
      return;

   ProgressDialog progress(XO("Caching audio"),
                           XO("Caching audio into memory"));

   iter = mBlockFileHash.begin();
   int current = 0;
   while (iter != mBlockFileHash.end())
   {
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->GetNeedFillCache() && (GetFreeMemory() > lowMem)) {
            b->FillCache();
         }

         if (!progress.Update(current, numNeed))
            break; // user cancelled progress dialog, stop caching
         current++;
      }
      ++iter;
   }
#endif // DEPRECATED_AUDIO_CACHE
}

void DirManager::WriteCacheToDisk()
{
   BlockHash::iterator iter;
   int numNeed = 0;

   iter = mBlockFileHash.begin();
   while (iter != mBlockFileHash.end())
   {
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->GetNeedWriteCacheToDisk())
            numNeed++;
      }
      ++iter;
   }

   if (numNeed == 0)
      return;

   ProgressDialog progress(XO("Saving recorded audio"),
                           XO("Saving recorded audio to disk"));

   iter = mBlockFileHash.begin();
   int current = 0;
   while (iter != mBlockFileHash.end())
   {
      BlockFilePtr b = iter->second.lock();
      if (b) {
         if (b->GetNeedWriteCacheToDisk())
         {
            b->WriteCacheToDisk();
            progress.Update(current, numNeed);
         }
         current++;
      }
      ++iter;
   }
}

