sub BackToForwardSlash
{
	my( $path ) = shift;
	$path =~ s,\\,/,g;
	return $path;
}

sub RemoveFileName
{
	my( $in ) = shift;
	$in = &BackToForwardSlash( $in );
	$in =~ s,/[^/]*$,,;
	return $in;
}

sub RemovePath
{
	my( $in ) = shift;
	$in = &BackToForwardSlash( $in );
	$in =~ s,^(.*)/([^/]*)$,$2,;
	return $in;
}

sub MakeDirHier
{
	my( $in ) = shift;
#	print "MakeDirHier( $in )\n";
	$in = &BackToForwardSlash( $in );
	my( @path );
	while( $in =~ m,/, ) # while $in still has a slash
	{
		my( $end ) = &RemovePath( $in );
		push @path, $end;
#		print $in . "\n";
		$in = &RemoveFileName( $in );
	}
	my( $i );
	my( $numelems ) = scalar( @path );
	my( $curpath );
	for( $i = $numelems - 1; $i >= 0; $i-- )
	{
		$curpath .= "/" . $path[$i];
		my( $dir ) = $in . $curpath;
		if( !stat $dir )
		{
			print "mkdir $dir\n";
			mkdir $dir, 0777;
		}
	}
}

sub BuildDefineOptions
{
	local( $output );
	local( $combo ) = shift;
	local( $i );
	for( $i = 0; $i < scalar( @dynamicDefineNames ); $i++ )
	{
		local( $val ) = ( $combo % ( $dynamicDefineMax[$i] - $dynamicDefineMin[$i] + 1 ) ) + $dynamicDefineMin[$i];
		if ( $g_xbox )
		{
			# xsasm can only support "ifdef" compilation directive form
			# so symbol encodes value and shader uses "ifdef <MySymbol_MyValue>"
			# xsasm mandates space for /D argument definitions
			$output .= "/D $dynamicDefineNames[$i]_$val ";
		}
		else
		{
			# symbol encodes value and shader uses "ifdef <MySymbol_MyValue>"
			# psa crashes without the explicit symbol=value format
			# encode both flavors for backwards compatibility
			$output .= "/D$dynamicDefineNames[$i]_$val=$val ";
			$output .= "/D$dynamicDefineNames[$i]=$val ";
		}
		$combo = $combo / ( $dynamicDefineMax[$i] - $dynamicDefineMin[$i] + 1 );
	}
	for( $i = 0; $i < scalar( @staticDefineNames ); $i++ )
	{
		local( $val ) = ( $combo % ( $staticDefineMax[$i] - $staticDefineMin[$i] + 1 ) ) + $staticDefineMin[$i];
		if ( $g_xbox )
		{
			# xsasm can only support "ifdef" compilation directive form
			# so symbol encodes value and shader uses "ifdef <MySymbol_MyValue>"
			# xsasm mandates space for /D argument definitions
			$output .= "/D $staticDefineNames[$i]_$val ";
		}
		else
		{
			# symbol encodes value and shader uses "ifdef <MySymbol_MyValue>"
			# psa crashes without the explicit symbol=value format
			# encode both flavors for backwards compatibility
			$output .= "/D$staticDefineNames[$i]_$val=$val ";
			$output .= "/D$staticDefineNames[$i]=$val ";
		}
		$combo = $combo / ( $staticDefineMax[$i] - $staticDefineMin[$i] + 1 );
	}
	return $output;
}

sub CalcNumCombos
{
	local( $i, $numCombos );
	$numCombos = 1;
	for( $i = 0; $i < scalar( @dynamicDefineNames ); $i++ )
	{
		$numCombos *= $dynamicDefineMax[$i] - $dynamicDefineMin[$i] + 1;
	}
	for( $i = 0; $i < scalar( @staticDefineNames ); $i++ )
	{
		$numCombos *= $staticDefineMax[$i] - $staticDefineMin[$i] + 1;
	}
	return $numCombos;
}

sub CalcNumDynamicCombos
{
	local( $i, $numCombos );
	$numCombos = 1;
	for( $i = 0; $i < scalar( @dynamicDefineNames ); $i++ )
	{
		$numCombos *= $dynamicDefineMax[$i] - $dynamicDefineMin[$i] + 1;
	}
	return $numCombos;
}

$g_dx9 = 1;
$shaderoutputdir = "shaders";

while( 1 )
{
	$psh_filename = shift;

	if( $psh_filename =~ m/-source/ )
	{
		$g_SourceDir = shift;
	}
	elsif( $psh_filename =~ m/-xbox/ )
	{
		$g_xbox = 1;
		$g_dx9 = 0;
	}
	elsif( $psh_filename =~ m/-shaderoutputdir/i )
	{
		$shaderoutputdir = shift;
	}
	else
	{
		last;
	}
}


# Get the shader binary version number from a header file.
open FILE, "<$g_SourceDir\\public\\materialsystem\\shader_vcs_version.h" || die;
while( $line = <FILE> )
{
	if( $line =~ m/^\#define\s+SHADER_VCS_VERSION_NUMBER\s+(\d+)\s*$/ )
	{
		$shaderVersion = $1;
		last;
	}
}
if( !defined $shaderVersion )
{
	die "couldn't get shader version from shader_vcs_version.h";
}
close FILE;



local( @staticDefineNames );
local( @staticDefineMin );
local( @staticDefineMax );
local( @dynamicDefineNames );
local( @dynamicDefineMin );
local( @dynamicDefineMax );

# Parse the combos.
open PSH, "<$psh_filename";
while( <PSH> )
{
	last if( !m,^;, );
	s,^;\s*,,;
	if( m/\s*STATIC\s*\:\s*\"(.*)\"\s+\"(\d+)\.\.(\d+)\"/ )
	{
		local( $name, $min, $max );
		$name = $1;
		$min = $2;
		$max = $3;
#		print "\"STATIC: $name\" \"$min..$max\"\n";
		push @staticDefineNames, $name;
		push @staticDefineMin, $min;
		push @staticDefineMax, $max;
	}
	elsif( m/\s*DYNAMIC\s*\:\s*\"(.*)\"\s+\"(\d+)\.\.(\d+)\"/ )
	{
		local( $name, $min, $max );
		$name = $1;
		$min = $2;
		$max = $3;
#		print "\"DYNAMIC: $name\" \"$min..$max\"\n";
		push @dynamicDefineNames, $name;
		push @dynamicDefineMin, $min;
		push @dynamicDefineMax, $max;
	}
}
close PSH;

$numCombos = &CalcNumCombos();
$numDynamicCombos = &CalcNumDynamicCombos();
print "$psh_filename\n";
#print "$numCombos combos\n";
#print "$numDynamicCombos dynamic combos\n";

if( $g_xbox )
{
	$pshtmp = "pshtmp_xbox";
}
elsif( $g_dx9 )
{
	$pshtmp = "pshtmp9";
}
else
{
	$pshtmp = "pshtmp8";
}
$basename = $psh_filename;
$basename =~ s/\.psh$//i;

for( $shaderCombo = 0; $shaderCombo < $numCombos; $shaderCombo++ )
{
	my $tempFilename = "shader$shaderCombo.o";
	unlink $tempFilename;
	
	if( $g_xbox )
	{
		$cmd = "xsasm /nologo /D _XBOX=1 " . &BuildDefineOptions( $shaderCombo ) . "$psh_filename shader$shaderCombo.o > NIL 2>&1";
	}
	else
	{
		$cmd = "psa /Foshader$shaderCombo.o /nologo " . &BuildDefineOptions( $shaderCombo ) . "$psh_filename";
	}

	if( !stat $pshtmp )
	{
		mkdir $pshtmp, 0777 || die $!;
	}

#	print $cmd . "\n";
	system $cmd || die $!;

	# Make sure a file got generated because sometimes the die above won't happen on compile errors.
	my $filesize = (stat $tempFilename)[7];
	if ( !$filesize )
	{
		die "Error compiling shader$shaderCombo.o";
	}

	push @outputHeader, @hdr;
}

$basename =~ s/\.fxc//gi;
push @outputHeader, "static PrecompiledShaderByteCode_t " . $basename . "_pixel_shaders[" . $numCombos . "] = \n";
push @outputHeader, "{\n";
local( $j );
for( $j = 0; $j < $numCombos; $j++ )
{
	local( $thing ) = "pixelShader_" . $basename . "_" . $j;
	push @outputHeader, "\t{ " . "$thing, sizeof( $thing ) },\n";
}
push @outputHeader, "};\n";

push @outputHeader, "struct $basename" . "PixelShader_t : public PrecompiledShader_t\n";
push @outputHeader, "{\n";
push @outputHeader, "\t$basename" . "PixelShader_t()\n";
push @outputHeader, "\t{\n";
push @outputHeader, "\t\tm_nFlags = 0;\n";
push @outputHeader, "\t\tm_pByteCode = " . $basename . "_pixel_shaders;\n";
push @outputHeader, "\t\tm_nShaderCount = $numCombos;\n";
#push @outputHeader, "\t\tm_nDynamicCombos = m_nShaderCount;\n";
push @outputHeader, "\t\t// NOTE!!!  psh_prep.pl shaders are always static combos!\n";
push @outputHeader, "\t\tm_nDynamicCombos = 1;\n";
push @outputHeader, "\t\tm_pName = \"$basename\";\n";
if( $basename =~ /vs\d\d/ ) # hack
{
	push @outputHeader, "\t\tGetShaderDLL()->InsertPrecompiledShader( PRECOMPILED_VERTEX_SHADER, this );\n";
}
else
{
	push @outputHeader, "\t\tGetShaderDLL()->InsertPrecompiledShader( PRECOMPILED_PIXEL_SHADER, this );\n";
}
push @outputHeader, "\t}\n";
push @outputHeader, "\tvirtual const PrecompiledShaderByteCode_t &GetByteCode( int shaderID )\n";
push @outputHeader, "\t{\n";
push @outputHeader, "\t\treturn m_pByteCode[shaderID];\n";
push @outputHeader, "\t}\n";
push @outputHeader, "};\n";

push @outputHeader, "static $basename" . "PixelShader_t $basename" . "_PixelShaderInstance;\n";


&MakeDirHier( "$shaderoutputdir/psh" );
open COMPILEDSHADER, ">$shaderoutputdir/psh/$basename.vcs";
binmode( COMPILEDSHADER );

#
# Write out the part of the header that we know. . we'll write the rest after writing the object code.
#

#print $numCombos . "\n";

# version
print COMPILEDSHADER pack "i", $shaderVersion;
# totalCombos
print COMPILEDSHADER pack "i", $numCombos;
# dynamic combos
print COMPILEDSHADER pack "i", $numDynamicCombos;
# flags
print COMPILEDSHADER pack "I", 0x0; # nothing here for now.
# centroid mask
print COMPILEDSHADER pack "I", 0;
# reference size for diffs
print COMPILEDSHADER pack "I", 0;

my $beginningOfDir = tell COMPILEDSHADER;

# Write out a blank directionary. . we'll fill it in later.
for( $i = 0; $i < $numCombos; $i++ )
{
	# offset from beginning of file.
	print COMPILEDSHADER pack "i", 0;
	# size
	print COMPILEDSHADER pack "i", 0;
}

my $startByteCode = tell COMPILEDSHADER;
my @byteCodeStart;
my @byteCodeSize;

# Write out the shader object code.
for( $shaderCombo = 0; $shaderCombo < $numCombos; $shaderCombo++ )
{
	my $filename = "shader$shaderCombo\.o";
	my $filesize = (stat $filename)[7];
	if( $g_xbox )
	{
		# ignore binary signature
		$filesize = $filesize - 4;
	}
	$byteCodeStart[$shaderCombo] = tell COMPILEDSHADER;
	$byteCodeSize[$shaderCombo] = $filesize;
	open SHADERBYTECODE, "<$filename";
	binmode SHADERBYTECODE;
	if( $g_xbox )
	{
		# ignore binary signature
		seek SHADERBYTECODE, 4, 0;
	}
	my $bin;
	my $numread = read SHADERBYTECODE, $bin, $filesize;
#	print "filename: $filename numread: $numread filesize: $filesize\n";
	close SHADERBYTECODE;
	unlink $filename;

	print COMPILEDSHADER $bin;
}

# Seek back to the directory and write it out.
seek COMPILEDSHADER, $beginningOfDir, 0;
for( $i = 0; $i < $numCombos; $i++ )
{
	# offset from beginning of file.
	print COMPILEDSHADER pack "i", $byteCodeStart[$i];
	# size
	print COMPILEDSHADER pack "i", $byteCodeSize[$i];
}

close COMPILEDSHADER;