/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2014 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/
#ifndef __OverlayManager_H__
#define __OverlayManager_H__

#include "OgreOverlayPrerequisites.h"
#include "OgreSingleton.h"
#include "OgreStringVector.h"
#include "OgreScriptLoader.h"
#include "OgreFrustum.h"
#include "OgreScriptTranslator.h"

namespace Ogre {
    class Overlay;
    class OverlayContainer;
    class OverlayElement;
    class OverlayElementFactory;
    template <typename T> class MapIterator;

    /** \addtogroup Optional
    *  @{
    */
    /** \addtogroup Overlays
    *  @{
    */
    /** Manages Overlay objects, parsing them from .overlay files and
        storing a lookup library of them. Also manages the creation of 
        OverlayContainers and OverlayElements, used for non-interactive 2D 
        elements such as HUDs.
    */
    class _OgreOverlayExport OverlayManager : public Singleton<OverlayManager>, public ScriptLoader, public OverlayAlloc
    {
    public:
        typedef std::map<String, Overlay*> OverlayMap;
        typedef std::map<String, OverlayElement*> ElementMap;
        typedef std::map<String, OverlayElementFactory*> FactoryMap;
    private:
        OverlayMap mOverlayMap;
        StringVector mScriptPatterns;

        int mLastViewportWidth, mLastViewportHeight;
        float mPixelRatio;

        bool parseChildren( DataStreamPtr& chunk, const String& line, int& l,
            Overlay* pOverlay, bool isTemplate, OverlayContainer* parent = NULL);

        FactoryMap mFactories;

        ElementMap mElements;

        typedef std::set<String> LoadedScripts;
        LoadedScripts mLoadedScripts;

        std::unique_ptr<ScriptTranslatorManager> mTranslatorManager;

    public:
        OverlayManager();
        virtual ~OverlayManager();

        /** Notifies that hardware resources were lost */
        void _releaseManualHardwareResources();
        /** Notifies that hardware resources should be restored */
        void _restoreManualHardwareResources();

        /// @copydoc ScriptLoader::getScriptPatterns
        const StringVector& getScriptPatterns(void) const override;
        /// @copydoc ScriptLoader::parseScript
        void parseScript(DataStreamPtr& stream, const String& groupName) override;
        /// @copydoc ScriptLoader::getLoadingOrder
        Real getLoadingOrder(void) const override;

        void addOverlay(Overlay* overlay);

        /** Create a new Overlay. */
        Overlay* create(const String& name);
        /** Retrieve an Overlay by name. For example, one defined in some .overlay file.
        @return A pointer to the Overlay, or 0 if not found
        */
        Overlay* getByName(const String& name);
        /** Destroys an existing overlay by name */
        void destroy(const String& name);
        /** Destroys an existing overlay */
        void destroy(Overlay* overlay);
        /** Destroys all existing overlays */
        void destroyAll(void);
        typedef MapIterator<OverlayMap> OverlayMapIterator;
        OverlayMapIterator getOverlayIterator(void);

        /** Internal method for queueing the visible overlays for rendering. */
        void _queueOverlaysForRendering(Camera* cam, RenderQueue* pQueue, Viewport *vp);

        /** Gets the height of the destination viewport in pixels. */
        int getViewportHeight(void) const;
        
        /** Gets the width of the destination viewport in pixels. */
        int getViewportWidth(void) const;
        Real getViewportAspectRatio(void) const;

       /** Sets the pixel ratio: how many viewport pixels represent a single overlay pixel (in one dimension).

       By default this is an 1:1 mapping. However on HiDPI screens you want to increase that to scale up your Overlay.
       @see RenderWindow::getViewPointToPixelScale */
       void setPixelRatio(float ratio);
       float getPixelRatio() const;

        /** Creates a new OverlayElement of the type requested.

        The type of element to create is passed in as a string because this
        allows plugins to register new types of component.
        @param typeName The type of element to create.
        @param instanceName The name to give the new instance.
        */
        OverlayElement* createOverlayElement(const String& typeName, const String& instanceName, bool = false);

        /** Gets a reference to an existing element. */
        OverlayElement* getOverlayElement(const String& name, bool = false);

        /** Tests if an element exists. */
        bool hasOverlayElement(const String& name, bool = false);
        
        /** Destroys a OverlayElement. 

        Make sure you're not still using this in an Overlay. If in
        doubt, let OGRE destroy elements on shutdown.
        */
        void destroyOverlayElement(const String& instanceName, bool = false);

        /** Destroys a OverlayElement. 

        Make sure you're not still using this in an Overlay. If in
        doubt, let OGRE destroy elements on shutdown.
        */
        void destroyOverlayElement(OverlayElement* pInstance, bool = false);

        /** Destroys all the OverlayElement  created so far.

        Best to leave this to the engine to call internally, there
        should rarely be a need to call it yourself.
        */
        void destroyAllOverlayElements(bool = false);

        /** Registers a new OverlayElementFactory with this manager.

        Should be used by plugins or other apps wishing to provide
        a new OverlayElement subclass.
        */
        void addOverlayElementFactory(OverlayElementFactory* elemFactory);
        
        /** Get const access to the list of registered OverlayElement factories. */
        const FactoryMap& getOverlayElementFactoryMap() const {
            return mFactories;
        }

        OverlayElement* createOverlayElementFromTemplate(const String& templateName, const String& typeName, const String& instanceName, bool = false);
        /**
        *  Creates a new OverlayElement object from the specified template name.  The new
        *  object's name, and all of it's children, will be instanceName/orignalName.
        */
        OverlayElement* cloneOverlayElementFromTemplate(const String& templateName, const String& instanceName);

        OverlayElement* createOverlayElementFromFactory(const String& typeName, const String& instanceName);

        /** Override standard Singleton retrieval.

        Why do we do this? Well, it's because the Singleton
        implementation is in a .h file, which means it gets compiled
        into anybody who includes it. This is needed for the
        Singleton template to work, but we actually only want it
        compiled into the implementation of the class based on the
        Singleton, not all of them. If we don't change this, we get
        link errors when trying to use the Singleton-based class from
        an outside dll.
        @par
        This method just delegates to the template version anyway,
        but the implementation stays in this single compilation unit,
        preventing link errors.
        */
        static OverlayManager& getSingleton(void);
        /// @copydoc Singleton::getSingleton()
        static OverlayManager* getSingletonPtr(void);
    };


    /** @} */
    /** @} */

}


#endif