/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Benjamin Grauer
   co-programmer: ...
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_GRAPHICS

#include "graphics_engine.h"
#include "util/loading/resource_manager.h"
#include "state.h"

#include "world_entity.h"

#include "render_2d.h"
#include "text_engine.h"
#include "light.h"
#include "shader.h"
#include "debug.h"

#include "util/preferences.h"
#include "substring.h"
#include "text.h"

#include "globals.h"
#include "texture.h"

#include "effects/graphics_effect.h"
#include "effects/fog_effect.h"
#include "effects/lense_flare.h"

#include "shell_command.h"


#include "parser/tinyxml/tinyxml.h"
#include "util/loading/load_param.h"
#include "util/loading/factory.h"
#include "class_list.h"

#ifdef __WIN32__
 #include "static_model.h"
#endif

SHELL_COMMAND(wireframe, GraphicsEngine, wireframe);
SHELL_COMMAND(fps, GraphicsEngine, toggleFPSdisplay);

/**
 * @brief standard constructor
 */
GraphicsEngine::GraphicsEngine ()
{
  this->setClassID(CL_GRAPHICS_ENGINE, "GraphicsEngine");
  this->setName("GraphicsEngine");

  this->isInit = false;

  this->bDisplayFPS = false;
  this->bAntialiasing = false;
  this->minFPS = 9999;
  this->maxFPS = 0;

  this->geTextCFPS = NULL;
  this->geTextMaxFPS = NULL;
  this->geTextMinFPS = NULL;

  this->fullscreenFlag = 0;
  this->videoFlags = 0;
  this->screen = NULL;

  // initialize the Modules
  TextEngine::getInstance();
  this->graphicsEffects = NULL;

}

/**
 * @brief The Pointer to this GraphicsEngine
 */
GraphicsEngine* GraphicsEngine::singletonRef = NULL;

/**
 * @brief destructs the graphicsEngine.
*/
GraphicsEngine::~GraphicsEngine ()
{
  // delete what has to be deleted here
  this->displayFPS( false );

  //TextEngine
  delete TextEngine::getInstance();
  // render 2D
  delete Render2D::getInstance();

  SDL_QuitSubSystem(SDL_INIT_VIDEO);
  //   if (this->screen != NULL)
  //     SDL_FreeSurface(this->screen);

  GraphicsEngine::singletonRef = NULL;
}


/**
 * @brief loads the GraphicsEngine Specific Parameters.
 * @param root: the XML-Element to load the Data From
 */
void GraphicsEngine::loadParams(const TiXmlElement* root)
{
  LoadParamXML(root, "GraphicsEffect", this, GraphicsEngine, loadGraphicsEffects)
  .describe("loads a graphics effect");
}




/**
 * @param root The XML-element to load GraphicsEffects from
 */
void GraphicsEngine::loadGraphicsEffects(const TiXmlElement* root)
{
  LOAD_PARAM_START_CYCLE(root, element);
  {
    PRINTF(4)("element is: %s\n", element->Value());
    Factory::fabricate(element);
  }
  LOAD_PARAM_END_CYCLE(element);
}



/**
 * @brief initializes the GraphicsEngine with default settings.
 */
int GraphicsEngine::init()
{
  if (this->isInit)
    return -1;
  this->initVideo(640, 480, 16);
  return 1;
}

/**
 * @brief loads the GraphicsEngine's settings from a given ini-file and section
 * @returns nothing usefull
 */
int GraphicsEngine::initFromPreferences()
{
  // looking if we are in fullscreen-mode
  MultiType fullscreen = Preferences::getInstance()->getString(CONFIG_SECTION_VIDEO, CONFIG_NAME_FULLSCREEN, "0");

  if (fullscreen.getBool())
    this->fullscreenFlag = SDL_FULLSCREEN;

  // looking if we are in fullscreen-mode
  MultiType textures = Preferences::getInstance()->getString(CONFIG_SECTION_VIDEO_ADVANCED, CONFIG_NAME_TEXTURES, "1");
  Texture::setTextureEnableState(textures.getBool());

  // searching for a usefull resolution
  SubString resolution(Preferences::getInstance()->getString(CONFIG_SECTION_VIDEO, CONFIG_NAME_RESOLUTION, "640x480").c_str(), 'x'); ///FIXME
  //resolution.debug();
  MultiType x = resolution.getString(0), y = resolution.getString(1);
  return this->initVideo(x.getInt(), y.getInt(), 16);

  //   GraphicsEffect* fe = new FogEffect(NULL);
  //   this->loadGraphicsEffect(fe);
  //   fe->activate();
  //   PRINTF(0)("--------------------------------------------------------------\n");

  //LenseFlare* ge = new LenseFlare();
  //this->loadGraphicsEffect(ge);

  //ge->addFlare("pictures/lense_flare/sun.png"); //sun
  //ge->addFlare("pictures/lense_flare/lens2.png"); //first halo
  //ge->addFlare("pictures/lense_flare/lens1.png"); //small birst
  //ge->addFlare("pictures/lense_flare/lens3.png"); //second halo
  //ge->addFlare("pictures/lense_flare/lens4.png");
  //ge->addFlare("pictures/lense_flare/lens1.png");
  //ge->addFlare("pictures/lense_flare/lens3.png");

  //ge->activate();
}



/**
 * @brief initializes the Video for openGL.
 *
 * This has to be done only once when starting orxonox.
 */
int GraphicsEngine::initVideo(unsigned int resX, unsigned int resY, unsigned int bbp)
{
  if (this->isInit)
    return -1;
  //   initialize SDL_VIDEO
  if (SDL_InitSubSystem(SDL_INIT_VIDEO) == -1)
  {
    PRINTF(1)("could not initialize SDL Video\n");
    return -1;
  }
  // initialize SDL_GL-settings
  this->setGLattribs();

  // setting the Video Flags.
  this->videoFlags = SDL_OPENGL | SDL_HWPALETTE | SDL_RESIZABLE ;

  /* query SDL for information about our video hardware */
  const SDL_VideoInfo* videoInfo = SDL_GetVideoInfo ();
  if( videoInfo == NULL)
  {
    PRINTF(1)("Failed getting Video Info :%s\n", SDL_GetError());
    SDL_Quit ();
  }
  if( videoInfo->hw_available)
    this->videoFlags |= SDL_HWSURFACE;
  else
    this->videoFlags |= SDL_SWSURFACE;
  /*
  if(VideoInfo -> blit_hw)
    VideoFlags |= SDL_HWACCEL;
  */
  // setting up the Resolution
  this->setResolution(resX, resY, bbp);

  // GRABBING ALL GL-extensions
  this->grabHardwareSettings();

  // Enable default GL stuff
  glEnable(GL_DEPTH_TEST);

  Render2D::getInstance();

  this->isInit = true;
  return 1;
}

/**
 * @brief sets the Window Captions and the Name of the icon.
 * @param windowName The name of the Window
 * @param icon The name of the Icon on the Disc
 */
void GraphicsEngine::setWindowName(const std::string& windowName, const std::string& icon)
{
  SDL_Surface* iconSurf = SDL_LoadBMP(icon.c_str());
  if (iconSurf != NULL)
  {
    Uint32 colorkey = SDL_MapRGB(iconSurf->format, 0, 0, 0);
    SDL_SetColorKey(iconSurf, SDL_SRCCOLORKEY, colorkey);
    SDL_WM_SetIcon(iconSurf, NULL);
    SDL_FreeSurface(iconSurf);
  }

  SDL_WM_SetCaption (windowName.c_str(), icon.c_str());
}


/**
 * @brief Sets the GL-attributes
 */
void GraphicsEngine::setGLattribs()
{
  // Set video mode
  // TO DO: parse arguments for settings
  //SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
  //SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5);
  //SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
  //SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);


  SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
  SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16);
  SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 0);
  SDL_GL_SetAttribute( SDL_GL_ACCUM_RED_SIZE, 0);
  SDL_GL_SetAttribute( SDL_GL_ACCUM_GREEN_SIZE, 0);
  SDL_GL_SetAttribute( SDL_GL_ACCUM_BLUE_SIZE, 0);
  SDL_GL_SetAttribute( SDL_GL_ACCUM_ALPHA_SIZE, 0);

  SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);      //Use at least 5 bits of Red
  SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5);    //Use at least 5 bits of Green
  SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);     //Use at least 5 bits of Blue
  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);   //Use at least 16 bits for the depth buffer
  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);  //Enable double buffering

  // enable antialiasing?
  if( this->bAntialiasing)
  {
    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES,4);
    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS,1);
  }

  glEnable(GL_CULL_FACE);
  glCullFace(GL_FRONT);
}

/**
 * @brief grabs the Hardware Specifics
 *
 * checks for all the different HW-types
 */
void GraphicsEngine::grabHardwareSettings()
{
  const char* renderer = (const char*) glGetString(GL_RENDERER);
  const char* vendor   = (const char*) glGetString(GL_VENDOR);
  const char* version  = (const char*) glGetString(GL_VERSION);
  const char* extensions = (const char*) glGetString(GL_EXTENSIONS);

  //  printf("%s %s %s\n %s", renderer, vendor, version, extensions);

  if (renderer != NULL)
  {
    this->hwRenderer == renderer;
  }
  if (vendor != NULL)
  {
    this->hwVendor == vendor;
  }
  if (version != NULL)
  {
    this->hwVersion == version;
  }

  if (extensions != NULL)
    this->hwExtensions.split(extensions, " \n\t,");

  PRINT(4)("Running on : vendor: %s,  renderer: %s,  version:%s\n", vendor, renderer, version);
  PRINT(4)("Extensions:\n");
  for (unsigned int i = 0; i < this->hwExtensions.size(); i++)
    PRINT(4)("%d: %s\n", i, this->hwExtensions[i].c_str());


  // inizializing GLEW
  GLenum err = glewInit();
  if (GLEW_OK != err)
  {
    /* Problem: glewInit failed, something is seriously wrong. */
    PRINTF(1)("%s\n", glewGetErrorString(err));
  }
  PRINTF(4)("Status: Using GLEW %s\n", glewGetString(GLEW_VERSION));
}


/**
 * @brief sets the Resolution of the Screen to display the Graphics to.
 * @param width The width of the window
 * @param height The height of the window
 * @param bpp bits per pixel
 */
int GraphicsEngine::setResolution(int width, int height, int bpp)
{
  this->resolutionX = width;
  this->resolutionY = height;
  this->bitsPerPixel = bpp;
  State::setResolution( width, height);

  if (this->screen != NULL)
    SDL_FreeSurface(screen);
  if((this->screen = SDL_SetVideoMode(this->resolutionX, this->resolutionY, this->bitsPerPixel, this->videoFlags | this->fullscreenFlag)) == NULL)
  {
    PRINTF(1)("Could not SDL_SetVideoMode(%d, %d, %d, %d): %s\n", this->resolutionX, this->resolutionY, this->bitsPerPixel, this->videoFlags, SDL_GetError());
    //    SDL_Quit();
    //    return -1;
    return -1;
  }
  glViewport(0, 0, width, height);                     // Reset The Current Viewport

#ifdef __WIN32__
  // REBUILDING TEXTURES (ON WINDOWS CONTEXT SWITCH)
  const std::list<BaseObject*>* texList = ClassList::getList(CL_TEXTURE);
  if (texList != NULL)
  {
    std::list<BaseObject*>::const_iterator reTex;
    for (reTex = texList->begin(); reTex != texList->end(); reTex++)
      dynamic_cast<Texture*>(*reTex)->rebuild();
  }
  // REBUILDING MODELS
  const std::list<BaseObject*>* modelList = ClassList::getList(CL_STATIC_MODEL);
  if (texList != NULL)
  {
    std::list<BaseObject*>::const_iterator reModel;
    for (reModel = modelList->begin(); reModel != modelList->end(); reModel++)
      dynamic_cast<StaticModel*>(*reModel)->rebuild();
  }
#endif /* __WIN32__ */
  return 1;
}

/**
 * @brief sets Fullscreen mode
 * @param fullscreen true if fullscreen, false if windowed
*/
void GraphicsEngine::setFullscreen(bool fullscreen)
{
  if (fullscreen)
    this->fullscreenFlag = SDL_FULLSCREEN;
  else
    this->fullscreenFlag = 0;
  this->setResolution(this->resolutionX, this->resolutionY, this->bitsPerPixel);
}

void GraphicsEngine::toggleFullscreen()
{
  if (this->fullscreenFlag == SDL_FULLSCREEN)
    this->fullscreenFlag = 0;
  else
    this->fullscreenFlag = SDL_FULLSCREEN;
  this->setResolution(this->resolutionX, this->resolutionY, this->bitsPerPixel);
}


/**
 * @brief sets the background color
 * @param red the red part of the background
 * @param blue the blue part of the background
 * @param green the green part of the background
 * @param alpha the alpha part of the background
 */
void GraphicsEngine::setBackgroundColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
{
  glClearColor(red, green, blue, alpha);
}

/**
 * @brief Signalhandler, for when the resolution has changed
 * @param resizeInfo SDL information about the size of the new screen size
 */
void GraphicsEngine::resolutionChanged(const SDL_ResizeEvent& resizeInfo)
{
  this->setResolution(resizeInfo.w, resizeInfo.h, this->bitsPerPixel);
}

/**
 * @brief entering 2D Mode
 * this is a GL-Projection-mode, that is orthogonal, for placing the font in fron of everything else
 */
void GraphicsEngine::enter2DMode()
{
  //GraphicsEngine::storeMatrices();
  SDL_Surface *screen = SDL_GetVideoSurface();

  /* Note, there may be other things you need to change,
     depending on how you have your OpenGL state set up.
  */
  glPushAttrib(GL_ENABLE_BIT);
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_CULL_FACE);
  glDisable(GL_LIGHTING);  // will be set back when leaving 2D-mode

  glMatrixMode(GL_PROJECTION);
  glPushMatrix();
  glLoadIdentity();
  glOrtho(0.0, (GLdouble)screen->w, (GLdouble)screen->h, 0.0, 0.0, 1.0);

  glMatrixMode(GL_MODELVIEW);
  glPushMatrix();
  glLoadIdentity();
}

/**
 * @brief leaves the 2DMode again also @see Font::enter2DMode()
 */
void GraphicsEngine::leave2DMode()
{

  glMatrixMode(GL_MODELVIEW);
  glPopMatrix();

  glMatrixMode(GL_PROJECTION);
  glPopMatrix();

  glPopAttrib();
}

/**
 * @brief changes to wireframe-mode.
 */
void GraphicsEngine::wireframe()
{
  glPolygonMode(GL_FRONT, GL_LINE);
}

/**
 * @brief stores the GL_matrices
 */
void GraphicsEngine::storeMatrices()
{
  glGetDoublev(GL_PROJECTION_MATRIX, GraphicsEngine::projMat);
  glGetDoublev(GL_MODELVIEW_MATRIX, GraphicsEngine::modMat);
  glGetIntegerv(GL_VIEWPORT, GraphicsEngine::viewPort);
}

//! the stored ModelView Matrix.
GLdouble GraphicsEngine::modMat[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//! the stored Projection Matrix
GLdouble GraphicsEngine::projMat[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//! The ViewPort
GLint GraphicsEngine::viewPort[4] = {0,0,0,0};



/**
 * @brief outputs all the Fullscreen modes.
 */
void GraphicsEngine::listModes()
{
  /* Get available fullscreen/hardware modes */
  this->videoModes=SDL_ListModes(NULL, SDL_FULLSCREEN|SDL_HWSURFACE);

  /* Check is there are any modes available */
  if(this->videoModes == (SDL_Rect **)0)
  {
    PRINTF(1)("No modes available!\n");
    exit(-1);
  }

  /* Check if our resolution is restricted */
  if(this->videoModes == (SDL_Rect **)-1)
  {
    PRINTF(2)("All resolutions available.\n");
  }
  else
  {
    /* Print valid modes */
    PRINT(0)("Available Resoulution Modes are\n");
    for(int i = 0; this->videoModes[i]; ++i)
      PRINT(4)(" |  %d x %d\n", this->videoModes[i]->w, this->videoModes[i]->h);
  }
}

/**
 * @brief checks wether a certain extension is availiable
 * @param extension the Extension to check for (ex. GL_ARB_texture_env_dot3)
 * @return true if it is, false otherwise
 */
bool GraphicsEngine::hwSupportsEXT(const std::string& extension)
{
  for (unsigned int i = 0; i < this->hwExtensions.size(); i++)
    if ( this->hwExtensions.getString(i) == extension)
      return true;
  return false;
}

/**
 * @brief updates everything that is to be updated in the GraphicsEngine
 */
void GraphicsEngine::update(float dt)
{
  Render2D::getInstance()->update(dt);
}


/**
 * @brief ticks the Text
 * @param dt the time passed
 */
void GraphicsEngine::tick(float dt)
{
  if( unlikely(this->bDisplayFPS))
  {
    this->currentFPS = 1.0/dt;
    if( unlikely(this->currentFPS > this->maxFPS)) this->maxFPS = this->currentFPS;
    if( unlikely(this->currentFPS < this->minFPS)) this->minFPS = this->currentFPS;

#ifndef NO_TEXT
    char tmpChar1[20];
    sprintf(tmpChar1, "Current:  %4.0f", this->currentFPS);
    this->geTextCFPS->setText(tmpChar1);
    char tmpChar2[20];
    sprintf(tmpChar2, "Max:    %4.0f", this->maxFPS);
    this->geTextMaxFPS->setText(tmpChar2);
    char tmpChar3[20];
    sprintf(tmpChar3, "Min:    %4.0f", this->minFPS);
    this->geTextMinFPS->setText(tmpChar3);
#endif /* NO_TEXT */

  }

  Render2D::getInstance()->tick(dt);

  // tick the graphics effects
  if (this->graphicsEffects != NULL || (this->graphicsEffects = ClassList::getList(CL_GRAPHICS_EFFECT)) != NULL)
  {
    std::list<BaseObject*>::const_iterator it;
    for (it = this->graphicsEffects->begin(); it != this->graphicsEffects->end(); it++)
      dynamic_cast<GraphicsEffect*>(*it)->tick(dt);
  }
}

/**
 * @brief draws all Elements that should be displayed on the Background.
 */
void GraphicsEngine::drawBackgroundElements() const
{
  GraphicsEngine::storeMatrices();

  Render2D::getInstance()->draw(E2D_LAYER_BELOW_ALL, E2D_LAYER_BELOW_ALL);
}

void GraphicsEngine::draw() const
{
  //  LightManager::getInstance()->draw();

  if (this->graphicsEffects != NULL)
  {
    //draw the graphics effects
    std::list<BaseObject*>::const_iterator it;
    for (it = this->graphicsEffects->begin(); it != this->graphicsEffects->end(); it++)
      dynamic_cast<GraphicsEffect*>(*it)->draw();
  }
  Shader::suspendShader();
  Render2D::getInstance()->draw(E2D_LAYER_BOTTOM, E2D_LAYER_ABOVE_ALL);
  Shader::restoreShader();
}


void GraphicsEngine::toggleFPSdisplay()
{
  this->displayFPS(!this->bDisplayFPS);
}


/**
 * @brief displays the Frames per second
 * @param display if the text should be displayed
*/
void GraphicsEngine::displayFPS(bool display)
{
#ifndef NO_TEXT
  if( display )
  {
    if (this->geTextCFPS == NULL)
    {
      this->geTextCFPS = new Text("fonts/arial_black.ttf", 15);
      this->geTextCFPS->setName("curFPS");
      this->geTextCFPS->setAlignment(TEXT_ALIGN_LEFT);
      this->geTextCFPS->setAbsCoor2D(5, 0);
    }
    if (this->geTextMaxFPS == NULL)
    {
      this->geTextMaxFPS = new Text("fonts/arial_black.ttf", 15);
      this->geTextMaxFPS->setName("MaxFPS");
      this->geTextMaxFPS->setAlignment(TEXT_ALIGN_LEFT);
      this->geTextMaxFPS->setAbsCoor2D(5, 20);
    }
    if (this->geTextMinFPS == NULL)
    {
      this->geTextMinFPS = new Text("fonts/arial_black.ttf", 15);
      this->geTextMinFPS->setName("MinFPS");
      this->geTextMinFPS->setAlignment(TEXT_ALIGN_LEFT);
      this->geTextMinFPS->setAbsCoor2D(5, 40);
    }
  }
  else
  {
    delete this->geTextCFPS;
    this->geTextCFPS = NULL;
    delete this->geTextMaxFPS;
    this->geTextMaxFPS = NULL;
    delete this->geTextMinFPS;
    this->geTextMinFPS = NULL;
  }
  this->bDisplayFPS = display;
#else
  this->bDisplayFPS = false;
#endif /* NO_TEXT */
}


/**
 * @brief processes the events for the GraphicsEngine class
 * @param the event to handle
 */
void GraphicsEngine::process(const Event &event)
{
  switch (event.type)
  {
    case EV_VIDEO_RESIZE:
      this->resolutionChanged(event.resize);
      break;
  }
}