/*
   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 "resource_manager.h"
#include "event_handler.h"

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


using namespace std;

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

  this->isInit = false;

  this->bDisplayFPS = 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;


  // Hardware
  this->hwRenderer = NULL;
  this->hwVendor = NULL;
  this->hwVersion = NULL;
  this->hwExtensions = NULL;

  // initialize the TextEngine
  TextEngine::getInstance();
}

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

/**
 *  destructs the graphicsEngine.
*/
GraphicsEngine::~GraphicsEngine ()
{
  // delete what has to be deleted here
  delete this->geTextCFPS;
  delete this->geTextMaxFPS;
  delete this->geTextMinFPS;

  delete[] this->hwRenderer;
  delete[] this->hwVendor;
  delete[] this->hwVersion;
  delete this->hwExtensions;

  delete Render2D::getInstance();
  //TextEngine
  delete TextEngine::getInstance();

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

  GraphicsEngine::singletonRef = NULL;
}

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

/**
 * loads the GraphicsEngine's settings from a given ini-file and section
 * @param iniParser the iniParser to load from
 * @param section the Section in the ini-file to load from
 * @returns nothing usefull
 */
int GraphicsEngine::initFromIniFile(IniParser* iniParser)
{
  // looking if we are in fullscreen-mode
  const char* fullscreen = iniParser->getVar(CONFIG_NAME_FULLSCREEN, CONFIG_SECTION_VIDEO, "0");
  if (strchr(fullscreen, '1'))
    this->fullscreenFlag = SDL_FULLSCREEN;



  // looking if we are in fullscreen-mode
  const char* textures = iniParser->getVar(CONFIG_NAME_TEXTURES, CONFIG_SECTION_VIDEO_ADVANCED, "0");
  if (strchr(textures, '1'))
    this->texturesEnabled = true;
  else
    this->texturesEnabled = false;

  // searching for a usefull resolution
  SubString resolution(iniParser->getVar(CONFIG_NAME_RESOLUTION, CONFIG_SECTION_VIDEO, "640x480"), 'x');
  //resolution.debug();

  this->initVideo(atoi(resolution.getString(0)), atoi(resolution.getString(1)), 16);
}



/**
 *  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 | SDL_DOUBLEBUF | SDL_GL_DOUBLEBUFFER;

  /* 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;
}

/**
 * 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 char* windowName, const char* icon)
{
  SDL_Surface* iconSurf = SDL_LoadBMP(icon);
  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, icon);

}


/**
 *  Sets the GL-attributes
*/
int 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);
}

/**
 * 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 (this->hwRenderer == NULL && renderer != NULL)
  {
    this->hwRenderer = new char[strlen(renderer)+1];
    strcpy(this->hwRenderer, renderer);
  }
  if (this->hwVendor == NULL && vendor != NULL)
  {
    this->hwVendor = new char[strlen(vendor)+1];
    strcpy(this->hwVendor, vendor);
  }
  if (this->hwVersion == NULL && version != NULL)
  {
    this->hwVersion = new char[strlen(version)+11];
    strcpy(this->hwVersion, version);
  }

  if (this->hwExtensions == NULL && extensions != NULL)
    this->hwExtensions = new SubString((char*)glGetString(GL_EXTENSIONS), true);

  PRINT(4)("Running on : %s %s %s\n", vendor, renderer, version);
  PRINT(4)("Extensions:\n");
  if (this->hwExtensions != NULL)
    for (unsigned int i = 0; i < this->hwExtensions->getCount(); i++)
      PRINT(4)("%d: %s\n", i, this->hwExtensions->getString(i));


  // 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));

}

/**
 *  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;

  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;
    }
    glMatrixMode(GL_PROJECTION_MATRIX);
    glLoadIdentity();
    glViewport(0,0,width,height);                                                   // Reset The Current Viewport
}

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

/**
 *  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);
}

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

/**
 * if Textures should be enabled
*/
bool GraphicsEngine::texturesEnabled = true;

/**
 *
 * @param show if The mouse-cursor should be visible
 */
void GraphicsEngine::showMouse(bool show)
{
  if (show)
    SDL_ShowCursor(SDL_ENABLE);
  else
    SDL_ShowCursor(SDL_DISABLE);
}

/**
 *
 * @returns The Visinility of the mouse-cursor (true if visible, false if it is invisible)
 */
bool GraphicsEngine::isMouseVisible()
{
  if (SDL_ShowCursor(SDL_QUERY) == SDL_ENABLE)
    return true;
  else
    return false;
}

/**
 *
 * @param steal If the Winodow-Managers Events should be stolen to this app
 * (steals the mouse, and all WM-clicks)
 *
 * This only happens, if the HARD-Debug-level is set to 0,1,2, because otherwise a Segfault could
 * result in the loss of System-controll
 */
void GraphicsEngine::stealWMEvents(bool steal)
{
#if DEBUG < 3
   if (steal)
     SDL_WM_GrabInput(SDL_GRAB_ON);
   else
     SDL_WM_GrabInput(SDL_GRAB_OFF);
#endif
}

/**
 *
 * @returns true if Events are stolen from the WM, false if not.
 */
bool GraphicsEngine::isStealingEvents()
{
   if (SDL_WM_GrabInput(SDL_GRAB_QUERY) == SDL_GRAB_ON)
     return true;
   else
     return false;
};

/**
 *  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

  glViewport(0, 0, screen->w, screen->h);

  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();

  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}

/**
 *  leaves the 2DMode again also \see Font::enter2DMode()
*/
void GraphicsEngine::leave2DMode()
{
  glMatrixMode(GL_PROJECTION);
  glPopMatrix();

  glMatrixMode(GL_MODELVIEW);
  glPopMatrix();

  glPopAttrib();
}

/**
 *  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};



/**
 *  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);
  }
}

/**
 * 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 char* extension)
{
  if (this->hwExtensions != NULL)
    for (unsigned int i = 0; i < this->hwExtensions->getCount(); i++)
      if (!strcmp(extension, this->hwExtensions->getString(i)))
        return true;
  return false;
}

/**
 * updates everything that is to be updated in the GraphicsEngine
 */
void GraphicsEngine::update(float dt)
{
  NullElement2D::getInstance()->update2D(dt);
}


/**
 *  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);
}


void GraphicsEngine::draw() const
{
  GraphicsEngine::storeMatrices();
  Shader::suspendShader();
  Render2D::getInstance()->draw(E2D_ALL_LAYERS);
  Shader::restoreShader();
  LightManager::getInstance()->draw();
}

/**
 *  displays the Frames per second
 * @param display if the text should be displayed

   @todo this is dangerous
*/
void GraphicsEngine::displayFPS(bool display)
{
  if( display)
    {
#ifndef NO_TEXT
if (this->geTextCFPS == NULL)
{
  this->geTextCFPS = TextEngine::getInstance()->createText("fonts/arial_black.ttf", 15, TEXT_RENDER_DYNAMIC);
  this->geTextCFPS->setName("curFPS");
  this->geTextCFPS->setAlignment(TEXT_ALIGN_LEFT);
  this->geTextCFPS->setAbsCoor2D(5, 15);
}
if (this->geTextMaxFPS == NULL)
{
      this->geTextMaxFPS = TextEngine::getInstance()->createText("fonts/arial_black.ttf", 15, TEXT_RENDER_DYNAMIC);
      this->geTextMaxFPS->setName("MaxFPS");
      this->geTextMaxFPS->setAlignment(TEXT_ALIGN_LEFT);
      this->geTextMaxFPS->setAbsCoor2D(5, 40);
}
if (this->geTextMinFPS == NULL)
{
      this->geTextMinFPS = TextEngine::getInstance()->createText("fonts/arial_black.ttf", 15, TEXT_RENDER_DYNAMIC);
      this->geTextMinFPS->setName("MinFPS");
      this->geTextMinFPS->setAlignment(TEXT_ALIGN_LEFT);
      this->geTextMinFPS->setAbsCoor2D(5, 65);
}
#endif /* NO_TEXT */
    }
  this->bDisplayFPS = display;
}


/**
  \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;
  }

}