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

  Audacity: A Digital Audio Editor

  Import.h

  Dominic Mazzoni

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

#ifndef _IMPORT_
#define _IMPORT_

#include "ImportForwards.h"
#include "Identifier.h"
#include <vector>
#include <wx/tokenzr.h> // for enum wxStringTokenizerMode

#include "FileNames.h" // for FileType

#include "Registry.h"

class wxArrayString;
class AudacityProject;
class Tags;
class WaveTrackFactory;
class Track;
class TrackList;
class ImportPlugin;
class ImportProgressListener;
class UnusableImportPlugin;
typedef bool (*progress_callback_t)( void *userData, float percent );

class ExtImportItem;
class WaveTrack;

using ExtImportItems = std::vector<std::unique_ptr<ExtImportItem>>;
using TrackHolders = std::vector<std::shared_ptr<TrackList>>;

class ExtImportItem
{
  public:
  /**
   * Unique string ID exists for each filter, it is not translateable
   * and can be stored in config. This ID is matched internally with a
   * translated name of a filter.
   * Unknown IDs will be presented and saved as-is.
   * Unused filters will not be used for matching files, unless forced.
   */
  wxArrayString filters;

  /**
   * The index of first unused filter in @filters array
   * 0 - divider is at the top of the list (in the list control
   * it will be the highest item), all filters are unused
   * -1 - divider is at the bottom of the list (in the list control
   * it will be the lowest item), all filters are used
   */
  int divider;

  /**
   * Array of pointers to import plugins (members of FormatList)
   */
  std::vector<ImportPlugin*> filter_objects;

  /**
   * File extensions. Each one is a string with simple wildcards,
   * i.e. "*.wav".
   */
  wxArrayString extensions;

  /**
   * Mime-types. Each one is a string in form of "foo/bar-baz" or
   * something like that.
   */
  wxArrayString mime_types;
};

class IMPORT_EXPORT_API Importer {
   struct ImporterItem;
public:

   // Objects of this type are statically constructed in files implementing
   // subclasses of ImportPlugin
   struct IMPORT_EXPORT_API RegisteredImportPlugin final
      : public Registry::RegisteredItem<ImporterItem>
   {
      RegisteredImportPlugin(
         const Identifier &id, // an internal string naming the plug-in
         std::unique_ptr<ImportPlugin>,
         const Registry::Placement &placement = { wxEmptyString, {} } );
   };

   // Objects of this type are statically constructed in files, to identify
   // unsupported import formats; typically in a conditional compilation
   struct RegisteredUnusableImportPlugin{
      RegisteredUnusableImportPlugin( std::unique_ptr<UnusableImportPlugin> );
   };

   Importer();
   ~Importer();

   Importer( const Importer& ) = delete;
   Importer &operator=( Importer& ) = delete;

   /**
    * Return instance reference
    */
   static Importer & Get();

   /**
    * Initialization/Termination
    */
   bool Initialize();
   bool Terminate();

   /**
    * Constructs a list of types, for use by file opening dialogs, that includes
    * all supported file types
    */
   FileNames::FileTypes
   GetFileTypes( const FileNames::FileType &extraType = {} );

   /**
    * Remember a file type in preferences
    */
   static void
   SetLastOpenType( const FileNames::FileType &type );

   /**
    * Remember a file type in preferences
    */
   static void
   SetDefaultOpenType( const FileNames::FileType &type );

   /**
    * Choose index of preferred type
    */
   static size_t
   SelectDefaultOpenType( const FileNames::FileTypes &fileTypes );

   /**
    * Reads extended import filters from gPrefs into internal
    * list mExtImportItems
    */
   void ReadImportItems();

   /**
    * Writes mExtImportItems into gPrefs
    */
   void WriteImportItems();

   /**
    * Helper function - uses wxStringTokenizer to tokenize
    * @str string and appends string-tokens to a list @list.
    * @mod defines tokenizer's behaviour.
    */
   void StringToList(wxString &str, wxString &delims, wxArrayString &list, wxStringTokenizerMode mod = wxTOKEN_RET_EMPTY_ALL);

   /**
    * Returns a pointer to internal items array.
    * External objects are allowed to change the array contents.
    */
   ExtImportItems &GetImportItems() { return mExtImportItems; }

   /**
    * Allocates NEW ExtImportItem, fills it with default data
    * and returns a pointer to it.
    */
    std::unique_ptr<ExtImportItem> CreateDefaultImportItem();

   // if false, the import failed and errorMessage will be set.
   bool Import( AudacityProject &project,
              const FilePath &fName,
              ImportProgressListener* importProgressListener,
              WaveTrackFactory *trackFactory,
              TrackHolders &tracks,
              Tags *tags,
              TranslatableString &errorMessage);

private:
   struct IMPORT_EXPORT_API ImporterItem final : Registry::SingleItem {
      static Registry::GroupItemBase &Registry();

      ImporterItem( const Identifier &id, std::unique_ptr<ImportPlugin> pPlugin );
      ~ImporterItem();
      std::unique_ptr<ImportPlugin> mpPlugin;
   };

   static Importer mInstance;

   ExtImportItems mExtImportItems;
   static ImportPluginList &sImportPluginList();
   static UnusableImportPluginList &sUnusableImportPluginList();
};

extern IMPORT_EXPORT_API BoolSetting NewImportingSession;

#endif
