/******************************************************************************/
/* DYNAMIC LIBRARIES **********************************************************/
/******************************************************************************/

#include <ebcl/DynLib.hh>
#include <ebcl/Threading.hh>
using namespace ebcl;

#ifdef _WIN32

/*= T_DynLibWindows ==========================================================*/

namespace {
struct T_DynLibWindows_
{
	T_Buffer< char > path;
	T_String error;
	HMODULE lib;

	explicit T_DynLibWindows_( T_String const& path ) noexcept;
	explicit T_DynLibWindows_( char const* const path ) noexcept;
	~T_DynLibWindows_( ) noexcept;

	bool load( ) noexcept;
	void unload( ) noexcept;

	bool isLoaded( ) const noexcept;

	void* getSymbol( char const* const symbol ) noexcept;
};
} // namespace

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

inline T_DynLibWindows_::T_DynLibWindows_(
		T_String const& path ) noexcept
	: path( path.toOSString( ) ) , lib( nullptr )
{ }

inline T_DynLibWindows_::T_DynLibWindows_(
		char const* const path ) noexcept
	: path( path , strlen( path ) ) , lib( nullptr )
{ }

inline T_DynLibWindows_::~T_DynLibWindows_( ) noexcept
{
	unload( );
}

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

inline bool T_DynLibWindows_::load( ) noexcept
{
	lib = LoadLibraryW( (wchar_t const*) path.data( ) );
	return lib != nullptr;
}

inline void T_DynLibWindows_::unload( ) noexcept
{
	if ( lib != nullptr ) {
		FreeLibrary( lib );
		lib = nullptr;
	}
}

inline bool T_DynLibWindows_::isLoaded( ) const noexcept
{
	return lib != nullptr;
}

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

inline void* T_DynLibWindows_::getSymbol(
		char const* const symbol ) noexcept
{
	return (void*) GetProcAddress( lib , symbol );
}

using T_DynLibImpl_ = T_DynLibWindows_;


#else // ifdef _WIN32

/*= T_DynLibLinux_ ===========================================================*/

#include <dlfcn.h>
#include <atomic>

namespace {
struct T_DynLibLinux_
{
	T_Buffer< char > path;
	T_String error;
	void* lib;

	explicit T_DynLibLinux_( T_String const& path ) noexcept;
	explicit T_DynLibLinux_( char const* const path ) noexcept;
	~T_DynLibLinux_( ) noexcept;

	bool load( ) noexcept;
	void unload( ) noexcept;

	bool isLoaded( ) const noexcept;

	void* getSymbol( char const* const symbol ) noexcept;
};
} // namespace

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

inline T_DynLibLinux_::T_DynLibLinux_(
		T_String const& path ) noexcept
	: path( path.toOSString( ) ) , lib( nullptr )
{ }

inline T_DynLibLinux_::T_DynLibLinux_(
		char const* const path ) noexcept
	: path( path , strlen( path ) ) , lib( nullptr )
{ }

inline T_DynLibLinux_::~T_DynLibLinux_( ) noexcept
{
	unload( );
}

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

inline bool T_DynLibLinux_::load( ) noexcept
{
	if ( lib != nullptr ) {
		return true;
	}
	lib = dlopen( &path[ 0 ] , RTLD_LOCAL | RTLD_NOW );
	error = lib ? T_String{} : T_String{ dlerror( ) };
	return lib != nullptr;
}

inline void T_DynLibLinux_::unload( ) noexcept
{
	if ( lib != nullptr ) {
		dlclose( lib );
		lib = nullptr;
	}
}

inline bool T_DynLibLinux_::isLoaded( ) const noexcept
{
	return lib != nullptr;
}

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

inline void* T_DynLibLinux_::getSymbol(
		char const* const symbol ) noexcept
{
	assert( lib != nullptr );
	void* const ptr( dlsym( lib , symbol ) );
	error = ( ptr == nullptr ) ? T_String{ dlerror( ) } : T_String{};
	return ptr;
}

using T_DynLibImpl_ = T_DynLibLinux_;

#endif // ifdef _WIN32

/*= T_DynLib =================================================================*/

T_DynLib::T_DynLib(
		T_String const& name )
	: A_PrivateImplementation( new T_DynLibImpl_( name ) )
{ }

T_DynLib::T_DynLib(
		char const* const name )
	: A_PrivateImplementation( new T_DynLibImpl_( name ) )
{ }

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

bool T_DynLib::load( )
{
	return p< T_DynLibImpl_ >( ).load( );
}

void T_DynLib::unload( )
{
	p< T_DynLibImpl_ >( ).unload( );
}

bool T_DynLib::isLoaded( ) const noexcept
{
	return p< T_DynLibImpl_ >( ).isLoaded( );
}

T_String T_DynLib::lastError( ) const noexcept
{
	return p< T_DynLibImpl_ >( ).error;
}

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

void* T_DynLib::getRawSymbol(
		char const* const name ) const noexcept
{
	return p< T_DynLibImpl_ >( ).getSymbol( name );
}