/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "scenegraph.h"

#include "debugging/debugging.h"

#include <map>
#include <set>
#include <vector>

#include "string/string.h"
#include "signal/signal.h"
#include "scenelib.h"
#include "instancelib.h"
#include "treemodel.h"

class StringEqualPredicate
{
const char* m_string;
public:
StringEqualPredicate( const char* string ) : m_string( string ){
}
bool operator()( const char* other ) const {
	return string_equal( m_string, other );
}
};

template<std::size_t SIZE>
class TypeIdMap
{
typedef const char* TypeName;
typedef TypeName TypeNames[SIZE];
TypeNames m_typeNames;
TypeName* m_typeNamesEnd;

public:
TypeIdMap() : m_typeNamesEnd( m_typeNames ){
}
TypeId getTypeId( const char* name ){
	TypeName* i = std::find_if( m_typeNames, m_typeNamesEnd, StringEqualPredicate( name ) );
	if ( i == m_typeNamesEnd ) {
		ASSERT_MESSAGE( m_typeNamesEnd != m_typeNames + SIZE, "reached maximum number of type names supported (" << Unsigned( SIZE ) << ")" );
		*m_typeNamesEnd++ = name;
	}
	return i - m_typeNames;
}
};

class CompiledGraph : public scene::Graph, public scene::Instantiable::Observer
{
typedef std::map<PathConstReference, scene::Instance*> InstanceMap;

InstanceMap m_instances;
scene::Instantiable::Observer* m_observer;
Signal0 m_boundsChanged;
scene::Path m_rootpath;
Signal0 m_sceneChangedCallbacks;

TypeIdMap<NODETYPEID_MAX> m_nodeTypeIds;
TypeIdMap<INSTANCETYPEID_MAX> m_instanceTypeIds;

public:

CompiledGraph( scene::Instantiable::Observer* observer )
	: m_observer( observer ){
}

void addSceneChangedCallback( const SignalHandler& handler ){
	m_sceneChangedCallbacks.connectLast( handler );
}
void sceneChanged(){
	m_sceneChangedCallbacks();
}

scene::Node& root(){
	ASSERT_MESSAGE( !m_rootpath.empty(), "scenegraph root does not exist" );
	return m_rootpath.top();
}
void insert_root( scene::Node& root ){
	//globalOutputStream() << "insert_root\n";

	ASSERT_MESSAGE( m_rootpath.empty(), "scenegraph root already exists" );

	root.IncRef();

	Node_traverseSubgraph( root, InstanceSubgraphWalker( this, scene::Path(), 0 ) );

	m_rootpath.push( makeReference( root ) );
}
void erase_root(){
	//globalOutputStream() << "erase_root\n";

	ASSERT_MESSAGE( !m_rootpath.empty(), "scenegraph root does not exist" );

	scene::Node& root = m_rootpath.top();

	m_rootpath.pop();

	Node_traverseSubgraph( root, UninstanceSubgraphWalker( this, scene::Path() ) );

	root.DecRef();
}
void boundsChanged(){
	m_boundsChanged();
}

void traverse( const Walker& walker ){
	traverse_subgraph( walker, m_instances.begin() );
}

void traverse_subgraph( const Walker& walker, const scene::Path& start ){
	if ( !m_instances.empty() ) {
		traverse_subgraph( walker, m_instances.find( PathConstReference( start ) ) );
	}
}

scene::Instance* find( const scene::Path& path ){
	InstanceMap::iterator i = m_instances.find( PathConstReference( path ) );
	if ( i == m_instances.end() ) {
		return 0;
	}
	return ( *i ).second;
}

void insert( scene::Instance* instance ){
	m_instances.insert( InstanceMap::value_type( PathConstReference( instance->path() ), instance ) );

	m_observer->insert( instance );
}
void erase( scene::Instance* instance ){
	m_observer->erase( instance );

	m_instances.erase( PathConstReference( instance->path() ) );
}

SignalHandlerId addBoundsChangedCallback( const SignalHandler& boundsChanged ){
	return m_boundsChanged.connectLast( boundsChanged );
}
void removeBoundsChangedCallback( SignalHandlerId id ){
	m_boundsChanged.disconnect( id );
}

TypeId getNodeTypeId( const char* name ){
	return m_nodeTypeIds.getTypeId( name );
}

TypeId getInstanceTypeId( const char* name ){
	return m_instanceTypeIds.getTypeId( name );
}

private:

bool pre( const Walker& walker, const InstanceMap::iterator& i ){
	return walker.pre( i->first, *i->second );
}

void post( const Walker& walker, const InstanceMap::iterator& i ){
	walker.post( i->first, *i->second );
}

void traverse_subgraph( const Walker& walker, InstanceMap::iterator i ){
	Stack<InstanceMap::iterator> stack;
	if ( i != m_instances.end() ) {
		const std::size_t startSize = ( *i ).first.get().size();
		do
		{
			if ( i != m_instances.end()
				 && stack.size() < ( ( *i ).first.get().size() - startSize + 1 ) ) {
				stack.push( i );
				++i;
				if ( !pre( walker, stack.top() ) ) {
					// skip subgraph
					while ( i != m_instances.end()
							&& stack.size() < ( ( *i ).first.get().size() - startSize + 1 ) )
					{
						++i;
					}
				}
			}
			else
			{
				post( walker, stack.top() );
				stack.pop();
			}
		}
		while ( !stack.empty() );
	}
}
};

namespace
{
CompiledGraph* g_sceneGraph;
GraphTreeModel* g_tree_model;
}

GraphTreeModel* scene_graph_get_tree_model(){
	return g_tree_model;
}


class SceneGraphObserver : public scene::Instantiable::Observer
{
public:
void insert( scene::Instance* instance ){
	g_sceneGraph->sceneChanged();
	graph_tree_model_insert( g_tree_model, *instance );
}
void erase( scene::Instance* instance ){
	g_sceneGraph->sceneChanged();
	graph_tree_model_erase( g_tree_model, *instance );
}
};

SceneGraphObserver g_SceneGraphObserver;

void SceneGraph_Construct(){
	g_tree_model = graph_tree_model_new();

	g_sceneGraph = new CompiledGraph( &g_SceneGraphObserver );
}

void SceneGraph_Destroy(){
	delete g_sceneGraph;

	graph_tree_model_delete( g_tree_model );
}


#include "modulesystem/singletonmodule.h"
#include "modulesystem/moduleregistry.h"

class SceneGraphAPI
{
scene::Graph* m_scenegraph;
public:
typedef scene::Graph Type;
STRING_CONSTANT( Name, "*" );

SceneGraphAPI(){
	SceneGraph_Construct();

	m_scenegraph = g_sceneGraph;
}
~SceneGraphAPI(){
	SceneGraph_Destroy();
}
scene::Graph* getTable(){
	return m_scenegraph;
}
};

typedef SingletonModule<SceneGraphAPI> SceneGraphModule;
typedef Static<SceneGraphModule> StaticSceneGraphModule;
StaticRegisterModule staticRegisterSceneGraph( StaticSceneGraphModule::instance() );