/*
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
*/

#if !defined (INCLUDED_INSTANCELIB_H)
#define INCLUDED_INSTANCELIB_H

#include "debugging/debugging.h"

#include "iscenegraph.h"

#include "scenelib.h"
#include "generic/reference.h"
#include "generic/callback.h"
#include <map>

class InstanceSubgraphWalker : public scene::Traversable::Walker
{
  scene::Instantiable::Observer* m_observer;
  mutable scene::Path m_path;
  mutable Stack<scene::Instance*> m_parent;
public:
  InstanceSubgraphWalker(scene::Instantiable::Observer* observer, const scene::Path& path, scene::Instance* parent)
    : m_observer(observer), m_path(path), m_parent(parent)
  {
  }
  bool pre(scene::Node& node) const
  {
    m_path.push(makeReference(node));
    scene::Instance* instance = Node_getInstantiable(node)->create(m_path, m_parent.top());
    m_observer->insert(instance);
    Node_getInstantiable(node)->insert(m_observer, m_path, instance);
    m_parent.push(instance);
    return true;
  }
  void post(scene::Node& node) const
  {
    m_path.pop();
    m_parent.pop();
  }
};

class UninstanceSubgraphWalker : public scene::Traversable::Walker
{
  scene::Instantiable::Observer* m_observer;
  mutable scene::Path m_path;
public:
  UninstanceSubgraphWalker(scene::Instantiable::Observer* observer, const scene::Path& parent)
    : m_observer(observer), m_path(parent)
  {
  }
  bool pre(scene::Node& node) const
  {
    m_path.push(makeReference(node));
    return true;
  }
  void post(scene::Node& node) const
  {
    scene::Instance* instance = Node_getInstantiable(node)->erase(m_observer, m_path);
    m_observer->erase(instance);
    delete instance;
    m_path.pop();
  }
};

class InstanceSet : public scene::Traversable::Observer
{
  typedef std::pair<scene::Instantiable::Observer*, PathConstReference> CachePath;

  typedef CachePath key_type;

  typedef std::map<key_type, scene::Instance*> InstanceMap;
  InstanceMap m_instances;
public:

  typedef InstanceMap::iterator iterator;

  iterator begin()
  {
    return m_instances.begin();
  }
  iterator end()
  {
    return m_instances.end();
  }

  // traverse observer
  void insert(scene::Node& child)
  {
    for(iterator i = begin(); i != end(); ++i)
    {
      Node_traverseSubgraph(child, InstanceSubgraphWalker((*i).first.first, (*i).first.second, (*i).second));
      (*i).second->boundsChanged();
    }
  }
  void erase(scene::Node& child)
  {
    for(iterator i = begin(); i != end(); ++i)
    {
      Node_traverseSubgraph(child, UninstanceSubgraphWalker((*i).first.first, (*i).first.second));
      (*i).second->boundsChanged();
    }
  }

  // instance
  void forEachInstance(const scene::Instantiable::Visitor& visitor)
  {
    for(iterator i = begin(); i != end(); ++i)
    {
      visitor.visit(*(*i).second);
    }
  }

  void insert(scene::Instantiable::Observer* observer, const scene::Path& path, scene::Instance* instance)
  {
    ASSERT_MESSAGE(m_instances.find(key_type(observer, PathConstReference(instance->path()))) == m_instances.end(), "InstanceSet::insert - element already exists");
    m_instances.insert(InstanceMap::value_type(key_type(observer, PathConstReference(instance->path())), instance));
  }
  scene::Instance* erase(scene::Instantiable::Observer* observer, const scene::Path& path)
  {
    ASSERT_MESSAGE(m_instances.find(key_type(observer, PathConstReference(path))) != m_instances.end(), "InstanceSet::erase - failed to find element");
    InstanceMap::iterator i = m_instances.find(key_type(observer, PathConstReference(path)));
    scene::Instance* instance = i->second;
    m_instances.erase(i);
    return instance;
  }

  void transformChanged()
  {
    for(InstanceMap::iterator i = m_instances.begin(); i != m_instances.end(); ++i)
    {
      (*i).second->transformChanged();
    }
  }
  typedef MemberCaller<InstanceSet, &InstanceSet::transformChanged> TransformChangedCaller;
  void boundsChanged()
  {
    for(InstanceMap::iterator i = m_instances.begin(); i != m_instances.end(); ++i)
    {
      (*i).second->boundsChanged();
    }
  }
  typedef MemberCaller<InstanceSet, &InstanceSet::boundsChanged> BoundsChangedCaller;
};

template<typename Functor>
inline void InstanceSet_forEach(InstanceSet& instances, const Functor& functor)
{
  for(InstanceSet::iterator i = instances.begin(), end = instances.end(); i != end; ++i)
  {
    functor(*(*i).second);
  }
}

template<typename Type>
class InstanceEvaluateTransform
{
public:
  inline void operator()(scene::Instance& instance) const
  {
    InstanceTypeCast<Type>::cast(instance)->evaluateTransform();
  }
};

template<typename Type>
class InstanceSetEvaluateTransform
{
public:
  static void apply(InstanceSet& instances)
  {
    InstanceSet_forEach(instances, InstanceEvaluateTransform<Type>());
  }
  typedef ReferenceCaller<InstanceSet, &InstanceSetEvaluateTransform<Type>::apply> Caller;
};

#endif