// Copyright (C) 2015-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/engine/material_manager.hh"

#include "nv/io/c_file_system.hh"
#include "nv/image/png_loader.hh"

using namespace nv;


nv::gpu_material_manager::gpu_material_manager( context* context, material_manager* matmgr, image_manager* imgmgr )
	: dependant_resource_manager( matmgr ), m_context( context )
	, m_image_manager( imgmgr )
{
	uint8 data[2 * 2 * 4];
	nv::raw_fill_n( data, 2 * 2 * 4, 0 );
	m_default = m_context->create_texture( ivec2(2,2), nv::RGBA8, nv::sampler(), data );
}

nv::resource< nv::gpu_material > nv::gpu_material_manager::create_resource( resource< material > m )
{
	resource_id id = m.id();
	if ( auto mat = m.lock() )
	{
		gpu_material* result = new gpu_material;
		sampler smp( sampler::LINEAR_MIPMAP_LINEAR, sampler::REPEAT );
		for ( uint32 i = 0; i < size( mat->paths ); ++i )
			if ( !mat->paths[i].empty() )
			{
				if ( auto data = m_image_manager->get( mat->paths[i] ).lock() )
				{
					result->textures[i] = m_context->create_texture( &*data, smp );
				}
			}

		// HACK
 		for ( uint32 i = 0; i < 5; ++i )
 			if ( result->textures[i].is_nil() )
 				result->textures[i] = m_default;

		return add( id, result );
	}
	return resource< nv::gpu_material >();
}

void gpu_material_manager::release( gpu_material* m )
{
	for ( const texture& t : m->textures )
	{
		m_context->release( t );
	}
}

bool material_manager::load_resource( nv::lua::table_guard& table, nv::shash64 id )
{
	c_file_system fs;
	material* m = new material;

	if ( table["path"].is_string() )
	{
		m->id = table["id"].get_string128();
		string128 path = table["path"].get_string128();
		for ( uint32 i = 0; i < 5; ++i )
			m->paths[i] = path;
		m->paths[TEX_DIFFUSE].append( "_diffuse.png" );
		m->paths[TEX_NORMAL].append( "_normal.png" );
		m->paths[TEX_METALLIC].append( "_metallic.png" );
		m->paths[TEX_ROUGHNESS].append( "_roughness.png" );
		m->paths[TEX_EMISSIVE].append( "_emissive.png" );
		for ( uint32 i = 0; i < 5; ++i )
		{
			if ( !fs.exists( m->paths[i] ) )
			{
				if ( i != TEX_EMISSIVE )
					NV_LOG_ERROR( "Texture file not found! : ", m->paths[i] );
				if ( m_clear_paths )
					m->paths[i].clear();
			}
		}
	}
	else
	{
		m->paths[ TEX_DIFFUSE  ] = table[ "diffuse"   ].get_string128();
		m->paths[ TEX_NORMAL   ] = table[ "normal"    ].get_string128();
		m->paths[ TEX_METALLIC ] = table[ "metallic"  ].get_string128();
		m->paths[ TEX_ROUGHNESS] = table[ "roughness" ].get_string128();
		m->paths[ TEX_EMISSIVE ] = table[ "emissive"  ].get_string128();
	}
	add( id, m );
	return true;
}