/******************************************************************************/
/* STREAMS ********************************************************************/
/******************************************************************************/

#pragma once
#include <lw/lib/Externals.hh>
#include <lw/lib/Utilities.hh>
#include <lw/lib/Pointers.hh>
#include <lw/lib/Buffers.hh>
namespace lw {


/*= STREAM ERRORS ============================================================*/

enum class E_StreamError {
	NOT_SUPPORTED ,                 // Operation not supported
	INVALID_POSITION ,
	END ,                           // End of stream
	BAD_DATA ,                      // Invalid data read from the stream
	SYSTEM_ERROR ,
	UNAVAILABLE ,			// Stream is no longer available
};


class X_StreamError : public std::exception
{
   private:
	E_StreamError error_;
	int sysError_;

   public:
	explicit X_StreamError( E_StreamError e );
	explicit X_StreamError( int error );

	X_StreamError( ) = delete;
	X_StreamError( X_StreamError const& ) = default;
	X_StreamError( X_StreamError&& ) noexcept = default;
	virtual X_StreamError& operator= ( X_StreamError const& ) = default;
	virtual X_StreamError& operator= ( X_StreamError&& ) = default;

	E_StreamError code( ) const;
	int systemError( ) const;

	char const * what( ) const noexcept;
};


/*= BASE ABSTRACT CLASSES FOR STREAMS ========================================*/

class A_Stream
{
   private:
	const bool isInput_;
	const bool knownSize_;

   protected:
	size_t size_;
	size_t position_;

	A_Stream( bool isInput , size_t position ) noexcept;
	A_Stream( bool isInput , size_t position , size_t size ) noexcept;

   public:
	A_Stream( ) = delete;
	A_Stream( A_Stream const& ) = delete;
	A_Stream( A_Stream&& ) = delete;
	virtual ~A_Stream( ) = 0;

	bool isInput( ) const;
	bool isSizeKnown( ) const;
	size_t position( ) const;
	size_t size( ) const;
};


M_ABSTRACT_POINTERS( Stream );

/*----------------------------------------------------------------------------*/

class A_InputStream : public A_Stream
{
   protected:
	explicit A_InputStream( size_t position ) noexcept;
	A_InputStream( size_t position , size_t size ) noexcept;

   public:
	virtual size_t read( void* data , size_t size ) = 0;
};


M_ABSTRACT_POINTERS( InputStream );

/*----------------------------------------------------------------------------*/

class A_OutputStream : public A_Stream
{
   protected:
	A_OutputStream( size_t position ) noexcept;
	A_OutputStream( size_t position , size_t size ) noexcept;

   public:
	virtual size_t write( void const* data , size_t size ) = 0;
	virtual void flush( );
};


M_ABSTRACT_POINTERS( OutputStream );

} // namespace
#include <lw/lib/inline/Streams.hh>