// Copyright (C) 2014-2015 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/formats/nmd_loader.hh"
#include "nv/io/std_stream.hh"
#include "nv/stl/string.hh"
#include "nv/interface/data_channel_access.hh"

using namespace nv;

bool nv::nmd_loader::load( stream& source )
{
	// TODO: proper error handling
	reset();
	nmd_header root_header;
	source.read( &root_header, sizeof( root_header ), 1 );
	skip_attributes( source, root_header.attributes );
	for ( uint32 i = 0; i < root_header.elements; ++i )
	{
		nmd_element_header element_header;
		source.read( &element_header, sizeof( element_header ), 1 );
		skip_attributes( source, element_header.attributes );
		switch ( element_header.type )
		{
		case nmd_type::MESH           : load_mesh( source, element_header ); break;
		case nmd_type::ANIMATION      : load_animation( source, element_header ); break;
		case nmd_type::STRINGS        : load_strings( source ); break;
		default: NV_ASSERT( false, "UNKNOWN NMD ELEMENT!" ); break;
		}
	}
	return true;
}

bool nv::nmd_loader::load_mesh( stream& source, const nmd_element_header& e )
{
	data_channel_set* mesh = data_channel_set_creator::create_set( e.children );
	load_channel_set( source, mesh, e );
//	m_mesh_names.push_back( e.name );
	m_meshes.push_back( mesh );
	return true;
}

data_channel_set* nv::nmd_loader::release_mesh_data( size_t index )
{
	data_channel_set* result = m_meshes[ index ];
	m_meshes[ index ] = nullptr;
	return result;
}

mesh_data_pack* nv::nmd_loader::release_mesh_data_pack()
{
	uint32 size = m_meshes.size();
	data_channel_set* meshes = data_channel_set_creator::create_set_array( size, 0 );
	for ( uint32 i = 0; i < size; ++i )
	{
		meshes[i] = move( *m_meshes[i] );
		delete m_meshes[i];
	}
	m_meshes.clear();
	return new mesh_data_pack( size, meshes, release_mesh_nodes_data() );
}

void nv::nmd_loader::reset()
{
	for ( auto mesh : m_meshes ) if ( mesh ) delete mesh;
	if ( m_node_data ) delete m_node_data;
	m_meshes.clear();

	m_node_data  = nullptr;
}

void nv::nmd_loader::skip_attributes( stream& source, uint32 count )
{
	if ( count == 0 ) return;
	source.seek( count * sizeof( nmd_attribute ), origin::CUR );
}

nv::nmd_loader::~nmd_loader()
{
	reset();
}

bool nv::nmd_loader::load_strings( stream& source )
{
	if ( !m_strings ) return true;
	// TODO: load strings optionally
	string_table* strings = new string_table( source );
	m_strings->insert( strings );
	delete strings;
	return true;
}

bool nv::nmd_loader::load_animation( stream& source, const nmd_element_header& e )
{
	NV_ASSERT( m_node_data == nullptr, "MULTIPLE NODE ENTRIES!" );
	nmd_animation_header animation_header;
	source.read( &animation_header, sizeof( animation_header ), 1 );
	m_node_data = new mesh_nodes_data( e.name, animation_header.frame_rate, animation_header.duration, animation_header.flat );
	for ( uint32 i = 0; i < e.children; ++i )
	{
		nmd_element_header element_header;
		source.read( &element_header, sizeof( element_header ), 1 );
		skip_attributes( source, element_header.attributes );
		NV_ASSERT( element_header.type == nmd_type::NODE, "NODE expected!" );
		data_channel_set* set = data_channel_set_creator::create_set( element_header.children );
		load_channel_set( source, set, element_header );
		m_node_data->push_back( set );
	}
	return true;
}

bool nv::nmd_loader::load_channel( stream& source, data_channel_set* channel_set )
{
	data_channel_set_creator kaccess( channel_set );
	nmd_channel_header cheader;
	source.read( &cheader, sizeof( cheader ), 1 );
	raw_data_channel_access channel( kaccess.add_channel( cheader.format, cheader.count ) );
	source.read( channel.raw_data(), channel.element_size(), channel.size() );
	return true;
}

bool nv::nmd_loader::load_channel_set( stream& source, data_channel_set* channel_set, const nmd_element_header& e )
{
	data_channel_set_creator kaccess( channel_set );
	for ( uint32 c = 0; c < e.children; ++c )
	{
		load_channel( source, channel_set );
	}
	data_channel_set_creator access( channel_set );
	access.set_name( e.name );
	access.set_parent_id( e.parent_id );
	access.set_transform( e.transform );
	return true;
}

mesh_nodes_data* nv::nmd_loader::release_mesh_nodes_data( size_t )
{
	if ( m_node_data )
	{
		mesh_nodes_data* result = m_node_data;
		m_node_data = nullptr;
		return result;
	}
	return nullptr;
}

// ----------------------------------------------------------------
// nmd format dump
// HACK : TEMPORARY - will go to it's own file, probably nmd_io

void nv::nmd_dump_header( stream& stream_out, uint32 elements, uint64 name )
{
	nmd_header header;
	header.id = four_cc<'n', 'm', 'f', '1'>::value;
	header.elements = elements; // +1 string array
	header.name = name;
	header.version = 1;
	header.attributes = 0;
	stream_out.write( &header, sizeof( header ), 1 );
}

void nv::nmd_dump_element( stream& stream_out, const data_channel_set& data, nmd_type type )
{
	uint32 size = 0;
	for ( auto& chan : data )
	{
		size += sizeof( nmd_channel_header );
		size += chan.raw_size();
	}

	nmd_element_header eheader;
	eheader.type       = type;
	eheader.children   = static_cast<uint16>( data.size() );
	eheader.size       = size;
	eheader.name       = data.get_name();
	eheader.transform  = data.get_transform();
	eheader.parent_id  = data.get_parent_id();
	eheader.attributes = 0;
	stream_out.write( &eheader, sizeof( eheader ), 1 );
	for ( auto& channel : data )
	{
		nmd_channel_header cheader;
		cheader.format = channel.descriptor();
		cheader.count = channel.size();
		stream_out.write( &cheader, sizeof( cheader ), 1 );
		stream_out.write( channel.raw_data(), channel.element_size(), channel.size() );
	}
}

void nv::nmd_dump_nodes( stream& stream_out, const mesh_nodes_data& nodes )
{
	uint32 total = sizeof( nmd_animation_header );
	for ( auto node : nodes )
	{
		total += sizeof( nmd_element_header );
		for ( uint32 c = 0; c < node->size(); ++c )
		{
			total += sizeof( nmd_channel_header );
			total += node->get_channel( c )->raw_size();
		}
	}

	nmd_element_header header;
	header.type = nmd_type::ANIMATION;
	header.children = static_cast<uint16>( nodes.get_count() );
	header.size = total;
	header.name = nodes.get_name();
	header.transform = mat4();
	header.parent_id = -1;
	header.attributes = 0;

	stream_out.write( &header, sizeof( header ), 1 );

	nmd_animation_header aheader;
	aheader.frame_rate = nodes.get_frame_rate();
	aheader.duration = nodes.get_duration();
	aheader.flat = nodes.is_flat();
	stream_out.write( &aheader, sizeof( aheader ), 1 );

	for ( auto node : nodes )
	{
		nmd_dump_element( stream_out, *node, nv::nmd_type::NODE );
	}
}

void nv::nmd_dump_strings( stream& stream_out, const string_table& strings )
{
	nmd_element_header sheader;
	sheader.type       = nv::nmd_type::STRINGS;
	sheader.children   = 0;
	sheader.size       = strings.dump_size();
	sheader.name       = 0;
	sheader.parent_id  = -1;
    sheader.attributes = 0;
	stream_out.write( &sheader, sizeof( sheader ), 1 );
	strings.dump( stream_out );
}

void nv::nmd_dump( stream& stream_out, const mesh_data_pack* model, const string_table* strings, uint64 name )
{
	uint32 elements = ( strings ? 1 : 0 ) // +1 string array
		+ model->get_count() // meshes
		+ ( model->get_node_count() > 0 ? 1 : 0 ); // nodes
	nmd_dump_header( stream_out, elements, name );

	for ( uint32 i = 0; i < model->get_count(); ++i )
	{
		nmd_dump_element( stream_out, *model->get_mesh( i ), nv::nmd_type::MESH );
	}

	if ( model->get_node_count() > 0 )
	{
		nmd_dump_nodes( stream_out, *model->get_nodes() );
	}

	if ( strings )
	{
		nmd_dump_strings( stream_out, *strings );
	}
}