const long file_handle_timeout = 30;

class FileHandle;
	
// base class for file handles
class FileHandle
{
public:
	virtual ~FileHandle();

	FileHandle(const char* name, const char* real_name);	// assigns name
	virtual int Open()=0;				// opens (maybe fails)
	virtual int Close()=0;
	virtual int Stat(struct lufs_fattr *fattr)=0;
	virtual int Read(long long pos, unsigned long length, char* buf)=0;
	virtual const char* Identity() { return "FileHandle"; }
	typedef vector<FileHandle*> Array;

    string name;		// virtual name
	string real_name;	// name of the real file on disk
	
	// don't close this before time(0)>timeout
	void KeepAlive();
	bool IsTimedOut(time_t t);
protected:
	time_t timeout;
};

class FileHandleArray : public FileHandle::Array
{
public:
	FileHandleArray() {}
	virtual ~FileHandleArray() {}
		
	// finds handle by name, returns 0 if no handle in stock
    FileHandle* Find( const char* name );

	// Deletes a named handle, does nothing fi it does not exist
	int Delete( const char* name );

	// Inserts a named handle
	void Insert( FileHandle* handle );
		
	// removes timed out handles
	void Cleanup();
};


class FileHandle_Default : public FileHandle
{
public:
	FileHandle_Default(const char* name, const char* real_name);
	~FileHandle_Default();

	int Open();
	int Stat(struct lufs_fattr *fattr);
	int Read(long long pos, unsigned long length, char* buf);
	int Close();
	virtual const char* Identity() { return "FileHandle_Default"; }

protected:
	int handle;
};

// pipes the output from a command (typically a decompressor) and caches it
// so that we can seek it afterwards.
class SeekablePipe: public FileHandle
{
public:
	// name and real_name are inherited from FileHandle
	SeekablePipe(const char* name, const char* real_name, const char* cmd);
	~SeekablePipe();

	int Open();
	int Stat(struct lufs_fattr *fattr);
	int Read(long long pos, unsigned long length, char* buf);
	int Close();
	virtual const char* Identity() { return "SeekablePipe"; }

protected:
	int Cache(long long upto);

	long long already_read;
	bool eof;
	FILE *pipe;
	FILE *tmp_file;

	string command;
};

// handles a compressed wave file
class FileHandle_XWav : public SeekablePipe
{
public:
	FileHandle_XWav(const char* name, const char* real_name, const char* cmd);
	~FileHandle_XWav();
	int Stat(struct lufs_fattr *fattr);
	virtual const char* Identity() { return "FileHandle_XWav"; }

protected:
};

class FileHandle_Flac : public FileHandle_XWav
{
public:
	FileHandle_Flac(const char* name, const char* real_name);
	virtual const char* Identity() { return "FileHandle_Flac"; }

protected:
};

/*
class FileHandle_Ogg : public FileHandle_XWav
{
public:
	FileHandle_Ogg(const char* name, const char* real_name);
	virtual const char* Identity() { return "FileHandle_Ogg"; }

protected:
};

class FileHandle_MP3 : public FileHandle_XWav
{
public:
	FileHandle_MP3(const char* name, const char* real_name);
	virtual const char* Identity() { return "FileHandle_MP3"; }

protected:
};
*/