/*
 *   ORXONOX - the hottest 3D action shooter ever to exist
 *                    > www.orxonox.net <
 *
 *
 *   License notice:
 *
 *   This program 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.
 *
 *   This program 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 this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 *   Author:
 *      Reto Grieder
 *   Co-authors:
 *      ...
 *
 */

#include "OrxonoxStableHeaders.h"
#include "GSGraphics.h"

#include <fstream>
#include <OgreConfigFile.h>
#include <OgreFrameListener.h>
#include <OgreRoot.h>
#include <OgreException.h>
#include <OgreRenderWindow.h>
#include <OgreTextureManager.h>
#include <OgreViewport.h>
#include <OgreWindowEventUtilities.h>

#include "util/Debug.h"
#include "util/Exception.h"
#include "core/ConsoleCommand.h"
#include "core/ConfigValueIncludes.h"
#include "core/CoreIncludes.h"
#include "core/input/InputManager.h"
#include "overlays/console/InGameConsole.h"
#include "gui/GUIManager.h"
#include "tools/WindowEventListener.h"
#include "Settings.h"

// for compatibility
#include "GraphicsEngine.h"

namespace orxonox
{
    GSGraphics::GSGraphics()
        : GameState<GSRoot>("graphics")
        , ogreRoot_(0)
        , inputManager_(0)
        , console_(0)
        , guiManager_(0)
        , frameCount_(0)
        , statisticsRefreshCycle_(0)
        , statisticsStartTime_(0)
        , statisticsStartCount_(0)
        , tickTime_(0)
    {
        RegisterRootObject(GSGraphics);
    }

    GSGraphics::~GSGraphics()
    {
    }

    void GSGraphics::setConfigValues()
    {
        SetConfigValue(resourceFile_, "resources.cfg").description("Location of the resources file in the data path.");
        SetConfigValue(statisticsRefreshCycle_, 200000).description("Sets the time in microseconds interval at which average fps, etc. get updated.");
    }

    void GSGraphics::enter()
    {
        Settings::_getInstance().bShowsGraphics_ = true;

        setConfigValues();

        this->ogreRoot_ = getParent()->getOgreRoot();

        this->declareResources();
        this->loadRenderer();    // creates the render window
        // TODO: Spread this so that this call only initialises things needed for the Console and GUI
        this->initialiseResources();


        // HACK: temporary:
        GraphicsEngine* graphicsEngine = getParent()->getGraphicsEngine();
        graphicsEngine->renderWindow_  = this->renderWindow_;
        graphicsEngine->root_          = this->ogreRoot_;
        graphicsEngine->viewport_      = this->viewport_;


        // Calls the InputManager which sets up the input devices.
        // The render window width and height are used to set up the mouse movement.
        inputManager_ = new InputManager();
        size_t windowHnd = 0;
        this->renderWindow_->getCustomAttribute("WINDOW", &windowHnd);
        inputManager_->initialise(windowHnd, renderWindow_->getWidth(), renderWindow_->getHeight(), true);

        // Load the InGameConsole
        console_ = new InGameConsole();
        console_->initialise();

        // load the CEGUI interface
        guiManager_ = new GUIManager();
        guiManager_->initialise(this->renderWindow_);

        // reset frame counter
        this->frameCount_ = 0;
        this->tickTime_ = 0;
        statisticsStartTime_ = 0;
        statisticsStartCount_ = 0;

        // add console commands
        FunctorMember<GSGraphics>* functor1 = createFunctor(&GSGraphics::printScreen);
        functor1->setObject(this);
        CommandExecutor::addConsoleCommandShortcut(createConsoleCommand(functor1, "printScreen"));
    }

    void GSGraphics::leave()
    {
        delete this->guiManager_;

        delete this->console_;

        delete this->inputManager_;

        this->ogreRoot_->detachRenderTarget(this->renderWindow_);
        delete this->renderWindow_;
        //this->ogreRoot_->shutdown
        // TODO: destroy render window

        Settings::_getInstance().bShowsGraphics_ = false;
    }

    /**
        Main loop of the orxonox game.
        We use the Ogre::Timer to measure time since it uses the most precise
        method an a platform (however the windows timer lacks time when under
        heavy kernel load!).
        There is a simple mechanism to measure the average time spent in our
        ticks as it may indicate performance issues.
        A note about the Ogre::FrameListener: Even though we don't use them,
        they still get called. However, the delta times are not correct (except
        for timeSinceLastFrame, which is the most important). A little research
        as shown that there is probably only one FrameListener that doesn't even
        need the time. So we shouldn't run into problems.
    */
    void GSGraphics::ticked(const Clock& time)
    {
        unsigned long long timeBeforeTick = time.getRealMicroseconds();
        float dt = time.getDeltaTime();

        this->inputManager_->tick(dt);
        // tick console
        this->console_->tick(dt);
        this->tickChild(time);
        
        unsigned long long timeAfterTick = time.getRealMicroseconds();

        tickTime_ += (unsigned int)(timeAfterTick - timeBeforeTick);
        if (timeAfterTick > statisticsStartTime_ + statisticsRefreshCycle_)
        {
            GraphicsEngine::getInstance().setAverageTickTime(
                (float)tickTime_ * 0.001f / (frameCount_ - statisticsStartCount_));
            float avgFPS = (float)(frameCount_ - statisticsStartCount_)
                / (timeAfterTick - statisticsStartTime_) * 1000000.0;
            GraphicsEngine::getInstance().setAverageFramesPerSecond(avgFPS);

            tickTime_ = 0;
            statisticsStartCount_ = frameCount_;
            statisticsStartTime_  = timeAfterTick;
        }

        // don't forget to call _fireFrameStarted in ogre to make sure
        // everything goes smoothly
        Ogre::FrameEvent evt;
        evt.timeSinceLastFrame = dt;
        evt.timeSinceLastEvent = dt; // note: same time, but shouldn't matter anyway
        ogreRoot_->_fireFrameStarted(evt);

        // Pump messages in all registered RenderWindows
        // This calls the WindowEventListener objects.
        Ogre::WindowEventUtilities::messagePump();
        // make sure the window stays active even when not focused
        // (probably only necessary on windows)
        this->renderWindow_->setActive(true);

        // render
        ogreRoot_->_updateAllRenderTargets();

        // again, just to be sure ogre works fine
        ogreRoot_->_fireFrameEnded(evt); // note: uses the same time as _fireFrameStarted

        ++frameCount_;
    }

    void GSGraphics::declareResources()
    {
        CCOUT(4) << "Declaring Resources" << std::endl;
        //TODO: Specify layout of data file and maybe use xml-loader
        //TODO: Work with ressource groups (should be generated by a special loader)

        if (resourceFile_ == "")
        {
            COUT(2) << "Warning: Ogre resource file set to \"\". Defaulting to resources.cfg" << std::endl;
            ModifyConfigValue(resourceFile_, tset, "resources.cfg");
        }

        // Load resource paths from data file using configfile ressource type
        Ogre::ConfigFile cf;
        try
        {
            cf.load(Settings::getDataPath() + resourceFile_);
        }
        catch (...)
        {
            //COUT(1) << ex.getFullDescription() << std::endl;
            COUT(0) << "Have you forgotten to set the data path in orxnox.ini?" << std::endl;
            throw;
        }

        // Go through all sections & settings in the file
        Ogre::ConfigFile::SectionIterator seci = cf.getSectionIterator();

        std::string secName, typeName, archName;
        while (seci.hasMoreElements())
        {
            try
            {
                secName = seci.peekNextKey();
                Ogre::ConfigFile::SettingsMultiMap *settings = seci.getNext();
                Ogre::ConfigFile::SettingsMultiMap::iterator i;
                for (i = settings->begin(); i != settings->end(); ++i)
                {
                    typeName = i->first; // for instance "FileSystem" or "Zip"
                    archName = i->second; // name (and location) of archive

                    Ogre::ResourceGroupManager::getSingleton().addResourceLocation(
                        std::string(Settings::getDataPath() + archName), typeName, secName);
                }
            }
            catch (Ogre::Exception& ex)
            {
                COUT(1) << ex.getFullDescription() << std::endl;
            }
        }
    }

    void GSGraphics::loadRenderer()
    {
        CCOUT(4) << "Configuring Renderer" << std::endl;

        if (!ogreRoot_->restoreConfig())
            if (!ogreRoot_->showConfigDialog())
                ThrowException(InitialisationFailed, "Could not show Ogre configuration dialogue.");

        CCOUT(4) << "Creating render window" << std::endl;

        this->renderWindow_ = ogreRoot_->initialise(true, "OrxonoxV2");

        Ogre::WindowEventUtilities::addWindowEventListener(this->renderWindow_, this);

        //Ogre::TextureManager::getSingleton().setDefaultNumMipmaps(5);

        // create a full screen default viewport
        this->viewport_ = this->renderWindow_->addViewport(0, 0);
    }

    void GSGraphics::initialiseResources()
    {
        CCOUT(4) << "Initialising resources" << std::endl;
        //TODO: Do NOT load all the groups, why are we doing that? And do we really do that? initialise != load...
        try
        {
            Ogre::ResourceGroupManager::getSingleton().initialiseAllResourceGroups();
            /*Ogre::StringVector str = Ogre::ResourceGroupManager::getSingleton().getResourceGroups();
            for (unsigned int i = 0; i < str.size(); i++)
            {
            Ogre::ResourceGroupManager::getSingleton().loadResourceGroup(str[i]);
            }*/
        }
        catch (...)
        {
            CCOUT(2) << "Error: There was a serious error when initialising the resources." << std::endl;
            throw;
        }
    }


    /**
    @brief
        Window has moved.
    @param rw
        The render window it occured in
    */
    void GSGraphics::windowMoved(Ogre::RenderWindow *rw)
    {
        for (ObjectList<orxonox::WindowEventListener>::iterator it = ObjectList<orxonox::WindowEventListener>::begin(); it; ++it)
            it->windowMoved();
    }

    /**
    @brief
        Window has resized.
    @param rw
        The render window it occured in
    @note
        GraphicsEngine has a render window stored itself. This is the same
        as rw. But we have to be careful when using multiple render windows!
    */
    void GSGraphics::windowResized(Ogre::RenderWindow *rw)
    {
        for (ObjectList<orxonox::WindowEventListener>::iterator it = ObjectList<orxonox::WindowEventListener>::begin(); it; ++it)
            it->windowResized(this->renderWindow_->getWidth(), this->renderWindow_->getHeight());
    }

    /**
    @brief
        Window focus has changed.
    @param rw
        The render window it occured in
    */
    void GSGraphics::windowFocusChanged(Ogre::RenderWindow *rw)
    {
        for (ObjectList<orxonox::WindowEventListener>::iterator it = ObjectList<orxonox::WindowEventListener>::begin(); it; ++it)
            it->windowFocusChanged();
    }

    /**
    @brief
        Window was closed.
    @param rw
        The render window it occured in
    */
    void GSGraphics::windowClosed(Ogre::RenderWindow *rw)
    {
        // using CommandExecutor in order to avoid depending on Orxonox.h.
        //CommandExecutor::execute("exit", false);
        this->requestState("root");
    }

    void GSGraphics::printScreen()
    {
        if (this->renderWindow_)
        {
            this->renderWindow_->writeContentsToTimestampedFile("shot_", ".jpg");
        }
    }
}