/***************************************************************************
                          Engine.cpp  -  description
                             -------------------
    begin                : Wed Jan 26 2000
    copyright            : (C) 2000 by Henrik Enqvist, GPL
    email                : henqvist@excite.com
***************************************************************************/

#include <cstdlib>
#include <cmath>
#include <cstring>
#include <ctime>

#if EM_THREADS
#include <sched.h>
#endif

#include "Private.h"
#include "Engine.h"
#include "Camera.h"
#include "Keyboard.h"
#include "AlignVisitor.h"
#include "AllegroVisitor.h"
#include "AmbientLightVisitor.h"
#include "BehaviorVisitor.h"
#include "CollisionVisitor.h"
#include "OpenGLVisitor.h"
//#include "PointLightVisitor.h"
//#include "PNormalVisitor.h"
#include "SoundVisitor.h"
#include "SignalSender.h"
#include "TransformVisitor.h"
#include "Config.h"
#include "SoundUtil.h"
#include "TextureUtil.h"
#include "Profiler.h"

// TODO Remove glu
#if EM_USE_SDL
#if EM_DEBUG
#include <GL/glu.h>
#endif
#endif

volatile int g_iStartTime = -1;
//volatile int g_iDesiredTime = -1;
volatile int g_iLastRender = 0;

volatile unsigned int g_iLoops = 0;
volatile unsigned int g_iMSeconds = 0;
//volatile float g_fFps = 0.0f;

#if EM_DEBUG
#define StartProfile(a) Profiler::getInstance()->startProfile(a)
#define StopProfile() Profiler::getInstance()->stopProfile()
#else
#define StartProfile(a)
#define StopProfile()
#endif

#if EM_USE_ALLEGRO
extern "C" {
  void fctCallBack() {
    g_iMSeconds += 10;
  }
  END_OF_FUNCTION(fctCallBack)
}
#endif

#if EM_USE_SDL
#define GET_TIME (signed)SDL_GetTicks()
#endif

#if EM_USE_ALLEGRO
#define GET_TIME g_iMSeconds
#endif

float Engine::m_fFps = 0.0f;

Engine * Engine::p_Engine = NULL;

Engine::Engine(int & argc, char *argv[]) {
  Config * config = Config::getInstance();
  config->loadArgs(argc, argv);
  
  if (!config->useExternGL()) {
#if EM_USE_SDL
    SDL_Init(SDL_INIT_TIMER);
#endif
    TextureUtil::getInstance()->initGrx();
#if EM_USE_ALLEGRO
    LOCK_VARIABLE(g_iStartTime);
    //LOCK_VARIABLE(g_iDesiredTime);
    LOCK_VARIABLE(g_iLastRender);
    LOCK_VARIABLE(g_iLoops);
    LOCK_VARIABLE(g_iMSeconds);
    LOCK_VARIABLE(g_fFps);
    LOCK_FUNCTION(fctCallBack);
    install_int(fctCallBack, 10); // 100 tick per sec
#endif
  }
	
  SoundUtil::getInstance()->applyConfigVolume();
  //  	if (config->getSound() != 0 || config->getMusic() != 0) {
  //  		SoundUtil::getInstance()->initSound();
  //  	} else {
  //  		cerr << "**************************************************" << endl;
  //  		cerr << "Sound turned off in init function. Sound must be" << endl;
  //  		cerr << "turned on and the game must be restarted to enable" << endl;
  //  		cerr << "playback." << endl;
  //  		cerr << "**************************************************" << endl;
  // 	}

  srand((unsigned int)time((time_t *)NULL));
	p_Engine = this;
}

Engine::~Engine() {
	p_Engine = NULL;
  this->stopEngine();
}

void Engine::stopEngine() {
#if EM_USE_SDL
  SoundUtil::getInstance()->stopSound();
  TextureUtil::getInstance()->stopGrx();
#endif

#if EM_DEBUG
  extern float em_groups_m, em_shapes_m, em_bounds_m, em_polygons_m;

  cerr << "Collision profile ********************" << endl;
  cerr << "Group-group detections " << em_groups_m << endl;
  cerr << "Shape-shape detections " << em_shapes_m << endl;
  cerr << "Bound-bound detections " << em_bounds_m << endl;
  cerr << "Poly-poly detections " << em_polygons_m << endl;
  Profiler::getInstance()->printProfile();
  //	cerr << "Seconds " << ((float)g_iSeconds/FPS) <<" " << ((float)g_iLoops*FPS/g_iSeconds) 
  //			 << " fps" << endl;
  // cerr << "Fps " << (float)(g_iLoops)*1000 / (SDL_GetTicks()-g_iStartTime) << endl;
#endif
}

void Engine::clear() {
  SignalSender::getInstance()->clear();
  AmbientLightVisitor::getInstance()->clear();
  //PointLightVisitor::getInstance()->clear();
  this->freeObjects();
}

void Engine::addLight(Light* l) {
  //PointLightVisitor::getInstance()->add(l);
  AmbientLightVisitor::getInstance()->add(l);
}

void Engine::setClearColor(float r, float g, float b, float a) {
  TextureUtil::getInstance()->setClearColor(r, g, b, a);
}

void Engine::clearScreen() {
  StartProfile(SWAP);
#if EM_USE_SDL
  glDepthMask(GL_TRUE);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glColor3f(1, 1, 1);
  glLoadIdentity();
  //gluLookAt(0,0,0, 0,0,-1, 0,1,0);
#endif

#if EM_USE_ALLEGRO
  clear_zbuffer(zbuffer, 0);
  clear_bitmap(backbuffer);
#endif
  StopProfile();
}

void Engine::setLightning(float diffuse, float ambient) {
  AmbientLightVisitor::getInstance()->setLightning(diffuse, ambient);
  // light model
}

void Engine::drawSplash(EmTexture * tex) {
	if (tex == NULL) return;
#if EM_USE_SDL
	int filter = Config::getInstance()->getGLFilter();
	if (filter == -1) return;
	glDisable(GL_DEPTH_TEST);
  glDepthMask(GL_FALSE);
	glDisable(GL_ALPHA_TEST);
  glDisable(GL_BLEND);
	glDepthMask(GL_FALSE);
  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, *(tex));
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

	glBegin(GL_QUADS);
	glTexCoord2f(0, 0);
	glVertex3f(-EM_RIGHT, EM_UP, -1); 
	glTexCoord2f(1, 0);
	glVertex3f(EM_RIGHT, EM_UP, -1); 
	glTexCoord2f(1, 1);
	glVertex3f(EM_RIGHT, -EM_UP, -1);
	glTexCoord2f(0, 1);
	glVertex3f(-EM_RIGHT, -EM_UP, -1);
	glEnd();
#endif
	// allegro todo
#if EM_USE_ALLEGRO
	// TODO fix static 256x256 image size
	stretch_blit(tex, backbuffer, 0, 0, 256, 256, 0, 0, 
							 Config::getInstance()->getWidth(), Config::getInstance()->getHeight());
#endif	
}

void Engine::setEngineCamera(Group* g) {
  AlignVisitor::getInstance()->setCamera(g);
  TransformVisitor::getInstance()->setCamera(g);
}

void Engine::render() {
  EM_COUT("Engine::render()", 0);
  if (GET_TIME - g_iLastRender != 0.0f) {
    m_fFps = m_fFps*0.9f + 0.1f*1000.0f/(GET_TIME - g_iLastRender);
  }
  g_iLastRender = GET_TIME;
  // Put some overall light.
  StartProfile(GLIGHT);
  AmbientLightVisitor::getInstance()->empty();
  this->accept(AmbientLightVisitor::getInstance());
  StopProfile();
  // Put some light from light sources.
  EM_COUT("Engine::render() lights", 0);
  StartProfile(PLIGHT);
  //PointLightVisitor::getInstance()->empty();
  //this->accept(PointLightVisitor::getInstance());
  StopProfile();
  // Align vertices to view space.
  EM_COUT("Engine::render() align", 0);
  StartProfile(ALIGN);
  AlignVisitor::getInstance()->empty();
  this->accept(AlignVisitor::getInstance());
  StopProfile();
  // Adjust sounds.
  StartProfile(SOUND);
  //	p_SoundVisitor->empty();
  //	this->accept(p_SoundVisitor);
  StopProfile();
  this->clearScreen();
  // Draw screenr
  EM_COUT("Engine::render() render", 0);
  StartProfile(RENDER);
#if EM_USE_SDL
  OpenGLVisitor::getInstance()->setMode(EM_GL_GCOL_TEX);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());
  OpenGLVisitor::getInstance()->setMode(EM_GL_GCOL_TEX_TRANS);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());
  OpenGLVisitor::getInstance()->setMode(EM_GL_CLEAN);
  OpenGLVisitor::getInstance()->empty();
#endif

#if EM_USE_ALLEGRO
  AllegroVisitor::getInstance()->setMode(EM_ALLEGRO_GCOL_TEX);
  AllegroVisitor::getInstance()->empty();
  this->accept(AllegroVisitor::getInstance());
  AllegroVisitor::getInstance()->setMode(EM_ALLEGRO_GCOL_TEX_TRANS);
  AllegroVisitor::getInstance()->empty();
  this->accept(AllegroVisitor::getInstance());
  AllegroVisitor::getInstance()->setMode(EM_GL_CLEAN);
  AllegroVisitor::getInstance()->empty();
#endif
  StopProfile();
}

void Engine::swap() {
  StartProfile(SWAP);
  EM_COUT("Engine::swap()", 0);
  g_iLoops++;
  // Draw to screen.
#if EM_USE_SDL
  SDL_GL_SwapBuffers();
  EM_GLERROR(" In Engine::swap ");
#endif

#if EM_USE_ALLEGRO
  blit(backbuffer, screen, 0, 0, 0, 0, Config::getInstance()->getWidth(), Config::getInstance()->getHeight());
#endif
  StopProfile();
}

void Engine::tick() {
  EM_COUT("Engine::tick() key", 0);
  if (!Config::getInstance()->useExternGL()) {
    StartProfile(KEY);
    // Check keyboard.
    Keyboard::poll();
    StopProfile();
  }
  // Perform behaviors. Behaviors must be done before transformation and collision.
  EM_COUT("Engine::tick() beh", 0);
  StartProfile(BEH);
  BehaviorVisitor::getInstance()->empty();
  this->accept(BehaviorVisitor::getInstance());
  StopProfile();
  // Calculate positions
  EM_COUT("Engine::tick() trans", 0);
  StartProfile(TRANS);
  TransformVisitor::getInstance()->empty();
  this->accept(TransformVisitor::getInstance());
  StopProfile();
  // Detect collision.
  EM_COUT("Engine::tick() coll", 0);
  StartProfile(COLLISION);
  CollisionVisitor::getInstance()->empty();
  this->accept(CollisionVisitor::getInstance());
  StopProfile();
  // Perform signals. Signals must be done last.
  StartProfile(SIG);
  SignalSender::getInstance()->tick();
  StopProfile();
}

void Engine::delay(int ms) {
#if EM_USE_SDL
  SDL_Delay(ms);
#endif
#if EM_USE_ALLEGRO
  rest(ms);
#endif
}

bool Engine::nextTickFPS(int fps) {
  // default 100 FPS
  int delay = 10;
  if (fps > 0) {
    delay = 1000/fps;
  }
  if ((g_iStartTime + delay) <= GET_TIME) {
    g_iStartTime += delay;
    return true;
  }
  return false;
}

void Engine::resetTick() {
  g_iStartTime = GET_TIME;
}

#undef GET_TIME

#if EM_THREADS

volatile bool g_bThread = true;;
SDL_mutex* g_Mutex = NULL;
SDL_Thread* g_Thread = NULL;

void Engine::renderThreadSafe() {
  this->pauseTickThread();

  EM_COUT("Engine::render()", 0);
  // Put some overall light.
  EM_COUT("Engine::render() glight", 0);
  AmbientLightVisitor::getInstance()->empty();
  this->accept(AmbientLightVisitor::getInstance());

  // Put some light from light sources.
//   EM_COUT("Engine::render() plight", 0);
//   PointLightVisitor::getInstance()->empty();
//   this->accept(PointLightVisitor::getInstance());

  // Align vertices to view space.
  EM_COUT("Engine::render() align", 0);
  AlignVisitor::getInstance()->empty();
  this->accept(AlignVisitor::getInstance());

  // Adjust sounds.
  EM_COUT("Engine::render() sound", 0);
  //	p_SoundVisitor->empty();
  //	this->accept(p_SoundVisitor);

  this->resumeTickThread();
  this->pauseTickThread();
  // Draw screen
  EM_COUT("Engine::render() opengl", 0);
  this->clearScreen();
  OpenGLVisitor::getInstance()->setMode(EM_GL_GCOL);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());
  OpenGLVisitor::getInstance()->setMode(EM_GL_TEX);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());

  this->resumeTickThread();
  this->pauseTickThread();

  OpenGLVisitor::getInstance()->setMode(EM_GL_GCOL_TRANS);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());
  OpenGLVisitor::getInstance()->setMode(EM_GL_TEX_TRANS);
  OpenGLVisitor::getInstance()->empty();
  this->accept(OpenGLVisitor::getInstance());
  OpenGLVisitor::getInstance()->setMode(EM_GL_CLEAN);
  OpenGLVisitor::getInstance()->empty();
	

  EM_COUT("Engine::render() opengltrans", 0);
  //OpenGLTransVisitor::getInstance()->empty();
  //this->accept(OpenGLTransVisitor::getInstance());

  // The keyboard is polled here cause it is not allowed get polled from fctThread
  Keyboard::poll();

  this->resumeTickThread();
}

/* This function is not allowed to call render or event functions.
 * that's why the poll is moved to 'renderThreadSafe()' */
int fctThread(void * data) {
  Engine* engine = (Engine*) data;
  while (g_bThread) {
    //cerr << "tick" << endl;
    if (SDL_mutexP(g_Mutex) == -1) 	cerr << "Error locking mutex" << endl;

    EM_COUT("Engine::tick()", 0);
		
    // Perform signals.
    EM_COUT("Engine::tick() signal", 0);
    SignalSender::getInstance()->tick();
	
    // Perform behaviors.
    EM_COUT("Engine::tick() behavior", 0);
    BehaviorVisitor::getInstance()->empty();
    engine->accept(BehaviorVisitor::getInstance());
		
    // Calculate positions
    EM_COUT("Engine::tick() trans", 0);
    TransformVisitor::getInstance()->empty();
    engine->accept(TransformVisitor::getInstance());
		
    // Detect collision.
    EM_COUT("Engine::tick() collision", 0);
    CollisionVisitor::getInstance()->empty();
    engine->accept(CollisionVisitor::getInstance());
		
    if (SDL_mutexV(g_Mutex) == -1) 	cerr << "Error unlocking mutex" << endl;
    engine->limitFPS(100);
  }
  return 0;
}

void Engine::startTickThread() {
  g_bThread = true;
  if (g_Mutex == NULL) {
    g_Mutex = SDL_CreateMutex();
  } else {
    cerr << "Mutex already created" << endl;
  }
  if (g_Thread == NULL) {
    g_Thread = SDL_CreateThread(fctThread, this);
  } else {
    cerr << "Thread already created" << endl;
  }
}

void Engine::endTickThread() {
  int status;
  g_bThread = false;
  SDL_WaitThread(g_Thread, &status);
  SDL_DestroyMutex(g_Mutex);
  g_Thread = NULL;
  g_Mutex = NULL;
}

void Engine::pauseTickThread() {
  if (g_Mutex != NULL) {
    if (SDL_mutexP(g_Mutex) == -1) 	cerr << "Error unlocking mutex" << endl;
  }
}

void Engine::resumeTickThread() {
  if (g_Mutex != NULL) {
    if (SDL_mutexV(g_Mutex) == -1) 	cerr << "Error unlocking mutex" << endl;
  }
  sched_yield();
}
#endif