// Copyright (C) 2014 ChaosForge / Kornel Kisielewicz
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/formats/nmd_loader.hh"
#include "nv/io/std_stream.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 );
	for ( uint32 i = 0; i < root_header.elements; ++i )
	{
		nmd_element_header element_header;
		source.read( &element_header, sizeof( element_header ), 1 );
		switch ( element_header.type )
		{
		case nmd_type::MESH           : load_mesh( source, element_header.children ); break;
		case nmd_type::ANIMATION      : load_animation( source, element_header.children ); break;
		case nmd_type::BONE_ARRAY     : load_bones( source, element_header.children ); break;
		case nmd_type::STRING_TABLE   : load_strings( source ); break;
		default: NV_ASSERT( false, "UNKNOWN NMD ELEMENT!" ); break;
		}
	}
	return true;
}

bool nv::nmd_loader::load_mesh( stream& source, uint32 children )
{
	mesh_data* mesh = new mesh_data();
	for ( uint32 s = 0; s < children; ++s )
	{
		nmd_element_header element_header;
		source.read( &element_header, sizeof( element_header ), 1 );
		NV_ASSERT( element_header.type == nmd_type::STREAM, "STREAM expected!" );

		nmd_stream_header stream_header;
		source.read( &stream_header, sizeof( stream_header ), 1 );
		mesh_raw_channel* channel = mesh_raw_channel::create( stream_header.format, stream_header.count );
		source.read( channel->data, stream_header.format.size, stream_header.count );
		mesh->add_channel( channel );
	}
	m_meshes.push_back( mesh );
	return true;
}

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

void nv::nmd_loader::reset()
{
	for ( auto mesh : m_meshes ) if ( mesh ) delete mesh;
	if ( m_animation ) delete m_animation;
	if ( m_strings )   delete m_strings;
	if ( m_bone_data ) delete m_bone_data;
	m_meshes.clear();
	m_animation = nullptr;
	m_bone_data = nullptr;
	m_strings   = nullptr;
}

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

bool nv::nmd_loader::load_strings( stream& source )
{
	NV_ASSERT( m_strings == nullptr, "MULTIPLE STRING ENTRIES!" );
	m_strings = new string_table( &source );
	return true;
}

bool nv::nmd_loader::load_bones( stream& source, uint32 children )
{
	NV_ASSERT( m_bone_data == nullptr, "MULTIPLE BONE ENTRIES!" );
	m_bone_data = new nmd_bone_data;
	m_bone_data->bones = new nmd_bone[ children ];
	m_bone_data->count = (uint16)children;
	source.read( m_bone_data->bones, sizeof( nmd_bone ), children );
	return true;
}

nmd_animation* nv::nmd_loader::release_animation()
{
	nmd_animation* result = m_animation;
	m_animation = nullptr;
	return result;
}

nmd_bone_data* nv::nmd_loader::release_bone_data()
{
	nmd_bone_data* result = m_bone_data;
	m_bone_data = nullptr;
	return result;
}

string_table* nv::nmd_loader::release_string_table()
{
	string_table* result = m_strings;
	m_strings = nullptr;
	return result;
}


bool nv::nmd_loader::load_animation( stream& source, uint32 children )
{
	NV_ASSERT( m_animation == nullptr, "MULTIPLE ANIMATION ENTRIES!" );
	nmd_animation_header header;
	source.read( &header, sizeof( header ), 1 );
	m_animation = new nmd_animation;
	m_animation->fps        = header.fps;
	m_animation->duration   = header.duration;
	m_animation->flat       = header.flat;
	m_animation->node_count = (uint16)children;
	m_animation->nodes      = new nmd_node[ children ];
	for ( uint32 i = 0; i < children; ++i )
	{
		nmd_element_header element_header;
		source.read( &element_header, sizeof( element_header ), 1 );
		NV_ASSERT( element_header.type == nmd_type::ANIMATION_NODE, "ANIMATION_NODE expected!" );

		uint16 ch_count = element_header.children;

		nmd_animation_node_header node_header;
		source.read( &node_header, sizeof( node_header ), 1 );
		m_animation->nodes[i].name          = node_header.name;
		m_animation->nodes[i].parent_id     = node_header.parent_id;
		m_animation->nodes[i].transform     = node_header.transform;
		m_animation->nodes[i].channel_count = ch_count;
		m_animation->nodes[i].channels      = nullptr;
		if ( ch_count > 0 )
		{
			m_animation->nodes[i].channels      = new key_raw_channel* [ch_count];
			for ( uint32 c = 0; c < ch_count; ++c )
			{
				source.read( &element_header, sizeof( element_header ), 1 );
				NV_ASSERT( element_header.type == nmd_type::ANIMATION_CHANNEL, "ANIMATION_CHANNEL expected!" );
				nv::nmd_animation_channel_header cheader;
				source.read( &cheader, sizeof( cheader ), 1 );
				key_raw_channel* channel = key_raw_channel::create( cheader.format, cheader.count );
				source.read( channel->data, channel->desc.size, channel->count );
				m_animation->nodes[i].channels[c] = channel;
			}
		}
	}
	return true;
}


// TEMPORARY
nv::nmd_temp_animation::nmd_temp_animation( nmd_loader* loader )
{
	m_animation = loader->release_animation();
	m_strings   = loader->release_string_table();

	for ( uint32 n = 0; n < m_animation->node_count; ++n )
	{
		nmd_node& node = m_animation->nodes[n];
		key_animation_data* keys = nullptr;
		if ( node.channel_count > 1 )
		{
			keys = new nv::key_vectors_prs( node.channels[0], node.channels[1], node.channels[2] );
		}
		else if ( node.channel_count == 1 )
		{
			keys      =  new nv::transform_vector( node.channels[0] );
			node.channels[0] = nullptr;
			node.channel_count = 0;
		}
		m_data.push_back( keys );
	}

	if ( !m_animation->flat )
	{
		m_children.resize( m_animation->node_count );
		for ( nv::uint32 n = 0; n < m_animation->node_count; ++n )
		{
			const nmd_node& node = m_animation->nodes[n];
			if ( node.parent_id != -1 )
			{
				m_children[ node.parent_id ].push_back( n );
			}
		}
	}

	m_bone_ids.resize( m_animation->node_count );
}

nv::nmd_temp_animation::~nmd_temp_animation()
{
	for ( auto node : m_data ) delete node;
	delete m_animation;
	delete m_strings;
}

void nv::nmd_temp_animation::prepare( const nmd_temp_model* model )
{
	m_offsets = model->m_bone_offsets.data();
	for ( uint32 n = 0; n < m_animation->node_count; ++n )
	{
		const nmd_node& node = m_animation->nodes[n];
		sint16 bone_id = -1;

		auto bi = model->m_bone_names.find( m_strings->get( node.name ) );
		if ( bi != model->m_bone_names.end() )
		{
			bone_id = bi->second;
		}
		m_bone_ids[n] = bone_id;
	}
}

void nv::nmd_temp_animation::animate( mat4* data, uint32 time )
{
	float tick_time = ( time / 1000.0f ) * m_animation->fps;
	float anim_time = fmodf( tick_time, m_animation->duration );

	if ( !m_animation->flat )
	{
		animate_rec( data, anim_time, 0, mat4() );
		return;
	}

	for ( uint32 n = 0; n < m_animation->node_count; ++n )
		if ( m_bone_ids[n] >= 0 )
		{
			const nmd_node* node = &m_animation->nodes[ n ];
			nv::mat4 node_mat( node->transform );

			if ( m_data[n] && !m_data[n]->empty() )
			{
				node_mat = m_data[n]->get_matrix( anim_time );
			}

			sint16 bone_id = m_bone_ids[n];
			data[ bone_id ] = node_mat * m_offsets[ bone_id ];
		}

}

void nv::nmd_temp_animation::animate_rec( mat4* data, float time, uint32 node_id, const mat4& parent_mat )
{
	// TODO: fix transforms, which are now embedded,
	//       see note in assimp_loader.cc:load_node
	const nmd_node* node = &m_animation->nodes[ node_id ];
	mat4 node_mat( node->transform );

	if ( m_data[ node_id ] && !m_data[ node_id ]->empty() )
	{
		node_mat = m_data[ node_id ]->get_matrix( time );
	}

	mat4 global_mat = parent_mat * node_mat;

	sint16 bone_id = m_bone_ids[ node_id ];
	if ( bone_id >= 0 )
	{
		data[ bone_id ] = global_mat * m_offsets[ bone_id ];
	}

	for ( auto child : m_children[ node_id ] )
	{
		animate_rec( data, time, child, global_mat );
	}
}

nv::nmd_temp_model::nmd_temp_model( nmd_loader* loader )
{
	for ( unsigned m = 0; m < loader->get_mesh_count(); ++m )
	{
		m_mesh_data.push_back(loader->release_mesh_data(m));
	}
	nmd_bone_data* bone_data = loader->release_bone_data();
	string_table*  strings   = loader->release_string_table();

	for ( nv::uint16 bi = 0; bi < bone_data->count; ++bi )
	{
		m_bone_names[ strings->get( bone_data->bones[bi].name ) ] = bi;
		m_bone_offsets.push_back( bone_data->bones[bi].offset );
	}

	delete bone_data;
	delete strings;
}

nv::nmd_temp_model::~nmd_temp_model()
{
	for ( unsigned m = 0; m < m_mesh_data.size(); ++m )
	{
		delete m_mesh_data[m];
	}
}