//====== Copyright © 1996-2006, Valve Corporation, All rights reserved. =======//
//
// Purpose: D3DX command implementation.
//
// $NoKeywords: $
//
//=============================================================================//

#include "shadercompile.h"

#include "d3dxfxc.h"
#include "cmdsink.h"

// Required to compile using D3DX* routines in the same process
#include <d3dx9shader.h>
#include "dx_proxy/dx_proxy.h"

#include <tier0/icommandline.h>
#include <tier1/strtools.h>

#define D3DXSHADER_MICROCODE_BACKEND_OLD_DEPRECATED ( 1 << 25 )

namespace InterceptFxc
{

	// The command that is intercepted by this namespace routines
	enum ExecutableEnum
	{
		EXEC_FXC,
		EXEC_SCE_CGC,
		EXEC_COUNT
	};
	static const char * g_pExecutables[EXEC_COUNT] = 
	{
		"fxc.exe",
		"sce-cgc.exe"
	};

	namespace Private		 
	{
		//
		// Response implementation
		//
		class CResponse : public CmdSink::IResponse
		{
		public:
			explicit CResponse( LPD3DXBUFFER pShader, LPD3DXBUFFER pListing, HRESULT hr );
			~CResponse( void );

		public:
			virtual bool Succeeded( void ) { return m_pShader && (m_hr == D3D_OK); }
			virtual size_t GetResultBufferLen( void ) { return ( Succeeded() ? m_pShader->GetBufferSize() : 0 ); }
			virtual const void * GetResultBuffer( void ) { return ( Succeeded() ? m_pShader->GetBufferPointer() : NULL ); }
			virtual const char * GetListing( void ) { return (const char *) ( m_pListing ? m_pListing->GetBufferPointer() : NULL ); }

		protected:
			LPD3DXBUFFER m_pShader;
			LPD3DXBUFFER m_pListing;
			HRESULT m_hr;
		};

		CResponse::CResponse( LPD3DXBUFFER pShader, LPD3DXBUFFER pListing, HRESULT hr ) :
			m_pShader(pShader),
			m_pListing(pListing),
			m_hr(hr)
		{
			NULL;
		}

		CResponse::~CResponse( void )
		{
			if ( m_pShader )
				m_pShader->Release();

			if ( m_pListing )
				m_pListing->Release();
		}

		//
		// Perform a fast shader file compilation.
		//		TODO: avoid writing "shader.o" and "output.txt" files to avoid extra filesystem access.
		//
		// @param pszFilename		the filename to compile (e.g. "debugdrawenvmapmask_vs20.fxc")
		// @param pMacros			null-terminated array of macro-defines
		// @param pszModel			shader model for compilation
		//
		void FastShaderCompile( ExecutableEnum nExecutable, const char *pszFilename, const D3DXMACRO *pMacros, const char *pszModel, CmdSink::IResponse **ppResponse )
		{
			LPD3DXBUFFER pShader = NULL; // NOTE: Must release the COM interface later
			LPD3DXBUFFER pErrorMessages = NULL; // NOTE: Must release COM interface later
			
			HRESULT hresult = S_OK;

			static DxProxyModule s_dxModule;
			hresult = s_dxModule.D3DXCompileShaderFromFile( pszFilename, pMacros, NULL /* LPD3DXINCLUDE */,
				"main",	pszModel, 0, &pShader, &pErrorMessages,
				NULL /* LPD3DXCONSTANTTABLE *ppConstantTable */ );

			if ( ppResponse )
			{
				*ppResponse = new CResponse( pShader, pErrorMessages, hresult );
			}
			else
			{
				if ( pShader )
				{
					pShader->Release();
				}

				if ( pErrorMessages )
				{
					pErrorMessages->Release();
				}
			}
		}

	}; // namespace Private

	// return the next option (starting with -D or /D), or NULL
	inline char * FindOptionD( char * pCommand )
	{
		char * p = pCommand;
		while( V_isspace(*p) )
			++p;
		while( *p )
		{
			if( ( *p == '/' || *p == '-' ) && p[1] == 'D' )
			{
				return p + 2;
			}
			++p;
		}
		return NULL;
	}
	
	

	//
	// Completely mimic the behaviour of "fxc.exe" in the specific cases related
	// to shader compilations.
	//
	// @param pCommand       the command in form
	//		"fxc.exe /DSHADERCOMBO=1 /DTOTALSHADERCOMBOS=4 /DCENTROIDMASK=0 /DNUMDYNAMICCOMBOS=4 /DFLAGS=0x0 /DNUM_BONES=1 /Dmain=main /Emain /Tvs_2_0 /DSHADER_MODEL_VS_2_0=1 /D_X360=1 /nologo /Foshader.o debugdrawenvmapmask_vs20.fxc>output.txt 2>&1"
	//
	void ExecuteCommand( ExecutableEnum nExecutable, const char *pCommand, CmdSink::IResponse **ppResponse )
	{
		// A duplicate portion of memory for modifications
		void *bufEditableCommand = alloca( strlen( pCommand ) + 1 );
		char *pEditableCommand = strcpy( (char *) bufEditableCommand, pCommand );

		// Macros to be defined for D3DX
		CUtlVector<D3DXMACRO> macros;

		// Shader model (determined when parsing "/D" flags)
		const char *pszShaderModel = NULL;

		// Iterate over the command line and find all "/D...=..." settings
		for ( char *pszFlag = pEditableCommand;
			( pszFlag = FindOptionD( pszFlag ) ) != NULL;
			/* advance inside */ )
		{
			// Name is immediately after "/D" or "-D", which is taken care of by FindOptionD
			char *pszFlagName = pszFlag ;
			
			// Value will be determined later
			char *pszValue = "";

			if ( char *pchEq = strchr( pszFlag, '=' ) )
			{
				// Value is after '=' sign
				*pchEq = 0;
				pszValue = pchEq + 1;
				pszFlag = pszValue;
			}

			if ( char *pchSpace = strchr( pszFlag, ' ' ) )
			{
				// Space is designating the end of the flag
				*pchSpace = 0;
				pszFlag = pchSpace + 1;
			}
			else
			{
				// Reached end of command line
				pszFlag = "";
			}

			// Shader model extraction; see src\devtools\bin\fxc_prep.pl for details how this is generated;
			// for PS3, it'll be sce_vp_rsx or sce_fp_rsx
			if ( !strncmp(pszFlagName, "SHADER_MODEL_", 13) )
			{
				pszShaderModel = pszFlagName + 13;
			}

			// Add the macro definition to the macros array
			int iMacroIdx = macros.AddToTail();
			D3DXMACRO &m = macros[iMacroIdx];

			// Fill the macro data
			m.Name = pszFlagName;
			m.Definition = pszValue;
		}

		// Add a NULL-terminator
		{
			D3DXMACRO nullTerminatorMacro = { NULL, NULL };
			macros.AddToTail( nullTerminatorMacro );
		}

		// Convert shader model to lowercase
		char chShaderModel[20] = {0};
		if(pszShaderModel)
		{
			Q_strncpy( chShaderModel, pszShaderModel, sizeof(chShaderModel) - 1 );
		}
		Q_strlower( chShaderModel );

		// Determine the file name (at the end of the command line before redirection)
		char const *pszFilename = "";
		if ( const char *pchCmdRedirect = strstr( pCommand, ">output.txt " ) )
		{
			size_t uCmdEndOffset = ( pchCmdRedirect - pCommand );

			pEditableCommand[uCmdEndOffset] = 0;
			pszFilename = &pEditableCommand[uCmdEndOffset];

			while ( pszFilename > pEditableCommand &&
				pszFilename[-1] &&
				' ' != pszFilename[-1] )
			{
				-- pszFilename;
			}
		}

		// Compile the stuff
		Private::FastShaderCompile( nExecutable, pszFilename, macros.Base(), chShaderModel, ppResponse );
	}

	bool TryExecuteCommand( const char *pCommand, CmdSink::IResponse **ppResponse )
	{
		{
			static bool s_bNoIntercept = ( CommandLine()->FindParm("-nointercept") != 0 );
			if ( !s_bNoIntercept )
			{
				const char * pExecutable = pCommand;
				while( *pExecutable && V_isspace(*pExecutable) )
					++pExecutable;
				const char *pExecutableEnd = pExecutable;
				while( *pExecutableEnd && !V_isspace(*pExecutableEnd) )
					++pExecutableEnd;

				for( int i = 0;i < EXEC_COUNT; ++i )
				{
					if( pExecutable == strstr( pExecutable, g_pExecutables[i] ) )
					{
						
						// Trap "???.exe" so that we did not spawn extra process 
						//Msg( "[shadercompile] Intercepting call to %s\n", g_pExecutables[i] );
						
						const char *pParameters = pExecutableEnd;
						while( *pParameters && V_isspace(*pParameters) )
							++pParameters ;
						
						InterceptFxc::ExecuteCommand( ( ExecutableEnum )i, pParameters, ppResponse );
						return true;
					}
				}
			}
		}

		return false;
	}

}; // namespace InterceptFxc