#pragma once
#ifndef REAL_BUILD
# include "externals.hh"
#endif


/*= COMMON PROPERTIES ========================================================*/

// Type of shader
enum class E_ShaderType {
	VERTEX , FRAGMENT , GEOMETRY ,
	COMPUTE ,
	__COUNT__
};

// Errors in shader code - the errors it represents may come from either
// the input loader, the shader loader or the driver.
struct T_ShaderError
{
	T_FSPath source;
	uint32_t line;
	T_String error;

	T_ShaderError( ) = default;

	T_ShaderError( T_FSPath source ,
			const uint32_t line ,
			T_String error )
		: source( std::move( source ) ) , line( line ) ,
			error( std::move( error ) )
	{ }

	T_ShaderError( T_FSPath source ,
			const uint32_t line ,
			T_StringBuilder& error )
		: source( std::move( source ) ) , line( line ) ,
			error( std::move( error ) )
	{ }
};


/*= INPUT FILES ==============================================================*/

// Type of input chunk
enum class E_ShaderInputChunk {
	CODE ,
	INCLUDE ,
};

// Input chunk data
struct T_ShaderInputChunk
{
	E_ShaderInputChunk type;
	T_Union< T_String , T_FSPath > data;
	uint32_t lines;

	T_ShaderInputChunk( ) = default;

	T_ShaderInputChunk(
			T_String text ,
			const uint32_t lines )
		: type( E_ShaderInputChunk::CODE ) ,
			data( std::move( text ) ) ,
			lines( lines )
	{ }

	T_ShaderInputChunk(
			T_FSPath path ,
			const uint32_t lines )
		: type( E_ShaderInputChunk::INCLUDE ) ,
			data( std::move( path ) ) ,
			lines( lines )
	{ }
};

// Input file type
enum class E_ShaderInput {
	CHUNK ,			// Chunk that may be repeated
	LIBRARY ,		// Library (will only be loaded once)

	// "Main" shader source files
	VERTEX , FRAGMENT , GEOMETRY ,
	COMPUTE
};

// Preprocessing errors
struct T_ShaderInputError
{
	uint32_t line;
	T_String error;

	T_ShaderInputError(
			const uint32_t line ,
			T_String error )
		: line( line ) , error( std::move( error ) )
	{ }
};

// Source file
struct T_ShaderInput
{
	E_ShaderInput type = E_ShaderInput::CHUNK;
	T_Array< T_ShaderInputChunk > chunks;
	T_Array< T_ShaderInputError > errors;

	bool load( T_FSPath const& path );
};
using P_ShaderInput = T_OwnPtr< T_ShaderInput >;