#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <algorithm>
#include <string>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#ifdef HAVE_GL_GL_H
#  include <GL/gl.h>
#elif HAVE_OPENGL_GL_H
#  include <OpenGL/gl.h>
#endif
#ifdef HAVE_GL_GLU_H
#  include <GL/glu.h>
#elif HAVE_OPENGL_GLU_H
#  include <OpenGL/glu.h>
#endif
#include <SDL.h>
#include "anugavis.hh"
#include "height_quantity.hh"
#include "sww_file.hh"

using boost::bind;
using boost::shared_ptr;
using std::for_each;
using std::string;

AnugaVis::AnugaVis(const string &file_name, int width, int height):
  frame(0), paused(false), screen(NULL), sww_file(new SWWFile(file_name)){
  init_camera();
  init_SDL(width, height);
  init_OpenGL(width, height);
}

AnugaVis::~AnugaVis(void){
  if(this->screen != NULL) SDL_Quit();
}

void AnugaVis::add_HeightQuantity(shared_ptr<HeightQuantity> &height){
  height->set_SWWFile(this->sww_file);
  this->heights.push_back(height);
}

void AnugaVis::run(void){
  while(this->step());
}

void AnugaVis::init_camera(void){
  this->eye = Vector(this->sww_file->minX, this->sww_file->minY, 0);
  this->focus = Vector(this->sww_file->minX +
		       (this->sww_file->maxX - this->sww_file->minX) / 2,
		       this->sww_file->minY + 
		       (this->sww_file->maxY - this->sww_file->minY) / 2,
		       0);
  this->eye.z = (eye - focus).magnitude();
}

void AnugaVis::init_SDL(int width, int height){
  if((SDL_Init(SDL_INIT_VIDEO) == -1) ||
     (SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5) == -1) ||
     (SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5) == -1) ||
     (SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5) == -1) ||
     (SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16) == -1) ||
     (SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1) == -1) ||
     ((this->screen = 
       SDL_SetVideoMode(width, height, 16, SDL_OPENGL)) == NULL))
    throw SDL_GetError();
  SDL_WM_SetCaption("ANUGA Visualiser", "ANUGA Visualiser");
}

void AnugaVis::init_OpenGL(int width, int height){
  GLfloat lightAmbient[] = {0.0, 0.0, 0.0, 1.0};
  GLfloat lightDiffuse[] = {1.0, 1.0, 1.0, 1.0};
  glEnable(GL_DEPTH_TEST);
  glShadeModel(GL_FLAT);
  glEnable(GL_NORMALIZE);
  glMatrixMode(GL_PROJECTION);
  gluPerspective(45.0, ((GLdouble)width)/((GLdouble)height), 0.1, 1000);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
  glEnable(GL_COLOR_MATERIAL);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);
}

static const Uint32 TARGET_TICK_RATE = 50;
bool AnugaVis::step(void){
  static Uint32 ticks = 0;
  static Uint32 lastframe;
  bool more = true;
  float light[4];

  if(ticks == 0) lastframe = ticks = SDL_GetTicks();
  else ticks = SDL_GetTicks();
  if(ticks - lastframe < TARGET_TICK_RATE) return more;
  
  lastframe = ticks;
  if(this->frame < this->sww_file->number_of_timesteps - 1){
    if(!this->paused) this->frame++;
  }else
    this->paused = 1;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  gluLookAt(this->eye  .x, this->eye  .y, this->eye  .z,
	    this->focus.x, this->focus.y, this->focus.z,
	                0,             0,             1);
  light[0] = this->eye.x;
  light[1] = this->eye.y;
  light[2] = this->eye.z;
  light[3] = 1.0;
  glLightfv(GL_LIGHT0, GL_POSITION, light);
  for_each(this->heights.begin(),
	   this->heights.end  (),
	   bind(&HeightQuantity::draw, _1, this->frame));
  return false;
}