#include <map>
#include <queue>

#include <GL/glew.h>

#include <ptypes/pasync.h>

#include "nexusmt.h"

using namespace nxs;
using namespace vcg;
using namespace std;

void Stats::Init() {
  ktri = 0;
  kdisk = 0;
  if(count == 25) count = 0;
  if(!count) {
    fps = 25/watch.Time();
    watch.Start();
  }
  count++;
}

NexusMt::NexusMt() {
  preload.mt = this;
  preload.start();
}

NexusMt::~NexusMt() {
  preload.signal();
  preload.waitfor();
}

bool NexusMt::Load(const string &filename) {
  if(!Nexus::Load(filename, true)) return false;
  if(!history.IsQuick() && !history.UpdatesToQuick())
    return false;
  return true;
}

//void NexusMt::Close() {
  //  prefetch.signal();
  //  prefetch.waitfor();
  //  patches.Close();
//}

bool NexusMt::InitGL(bool vbo) {
  use_vbo = vbo;

  GLenum ret = glewInit();
  if(ret != GLEW_OK) return false;
  if(vbo && !GLEW_ARB_vertex_buffer_object) {
    cerr << "No vbo available!" << endl;
    use_vbo = false;
  }
  return true;
}

void NexusMt::Render(DrawContest contest) {
  Extraction extraction;
  extraction.frustum.GetView();
  extraction.metric->GetView();
  extraction.Extract(this);
  Render(extraction, contest);
}

void NexusMt::Render(Extraction &extraction, DrawContest &contest,
		     Stats *stats) {
  if(stats) stats->Init();

  preload.post(extraction.selected);

  glEnableClientState(GL_VERTEX_ARRAY);
  if((signature & NXS_COLORS) && (contest.attrs & DrawContest::COLOR))
    glEnableClientState(GL_COLOR_ARRAY);
  if((signature & NXS_NORMALS_SHORT) && (contest.attrs & DrawContest::NORMAL))
    glEnableClientState(GL_NORMAL_ARRAY);

  vector<unsigned int> skipped;
  
  for(unsigned int i = 0; i < extraction.draw_size; i++) {
    unsigned int patch = extraction.selected[i];
    Entry &entry = operator[](patch);
    vcg::Sphere3f &sphere = entry.sphere;
    if(extraction.frustum.IsOutside(sphere.Center(), sphere.Radius())) 
      continue;

    if(stats) stats->ktri += entry.nface;

    if(!entry.patch) {
      skipped.push_back(patch);
      continue;
    }

    Draw(patch, contest);
  }

  preload.lock.enter();  
  for(vector<unsigned int>::iterator i = skipped.begin(); 
      i != skipped.end(); i++) {
    GetPatch(*i);
    Draw(*i, contest);
  }
  Flush(false); //in case there are no skipped... :P
  preload.lock.leave();

  glDisableClientState(GL_VERTEX_ARRAY);
  glDisableClientState(GL_COLOR_ARRAY);
  glDisableClientState(GL_NORMAL_ARRAY);
}

void NexusMt::Draw(unsigned int cell, DrawContest &contest) {
  Entry &entry = operator[](cell);
  Patch &patch = *(entry.patch);
  char *fstart;
  char *vstart;
  char *cstart;
  char *nstart;
  
  if(use_vbo) {
    if(!entry.vbo_element) 
      LoadVbo(entry);
    
    glBindBufferARB(GL_ARRAY_BUFFER_ARB, entry.vbo_array);
    glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, entry.vbo_element);
    
    fstart = NULL;
    vstart = NULL;
    cstart = (char *)(sizeof(float) * patch.cstart);
    nstart = (char *)(sizeof(float) * patch.nstart);
  } else {
    fstart = (char *)patch.FaceBegin();
    vstart = (char *)patch.VertBegin();
    cstart = (char *)patch.ColorBegin();
    nstart = (char *)patch.Norm16Begin();
  }
  
  glVertexPointer(3, GL_FLOAT, 0, vstart);
  if(contest.attrs & DrawContest::COLOR)
    glColorPointer(4, GL_UNSIGNED_BYTE, 0, cstart);
  if(contest.attrs & DrawContest::NORMAL)
    glNormalPointer(GL_SHORT, 8, nstart);
  
  switch(contest.mode) {
  case DrawContest::POINTS:
    glDrawArrays(GL_POINTS, 0, patch.nv); break;
  case DrawContest::PATCHES:
    glColor3ub((cell * 27)%255, (cell * 37)%255, (cell * 87)%255);
  case DrawContest::SMOOTH:
    if(signature & NXS_FACES)
      glDrawElements(GL_TRIANGLES, patch.nf * 3, 
		     GL_UNSIGNED_SHORT, fstart);
    else if(signature & NXS_STRIP)
      glDrawElements(GL_TRIANGLE_STRIP, patch.nf, 
		     GL_UNSIGNED_SHORT, fstart);
    break;
  case DrawContest::FLAT:
    if(signature & NXS_FACES) {
      glBegin(GL_TRIANGLES);
      for(int i = 0; i < patch.nf; i++) {
	unsigned short *f = patch.Face(i);
	Point3f &p0 = patch.Vert(f[0]);
	Point3f &p1 = patch.Vert(f[1]);
	Point3f &p2 = patch.Vert(f[2]);
	Point3f n = ((p1 - p0) ^ (p2 - p0));
	glNormal3f(n[0], n[1], n[2]);
	glVertex3f(p0[0], p0[1], p0[2]);
	glVertex3f(p1[0], p1[1], p1[2]);
	glVertex3f(p2[0], p2[1], p2[2]);
      }
      glEnd();
    } else if(signature & NXS_STRIP) {
      cerr << "Unsupported rendering mode sorry\n";
      exit(0);
    }
    break;
  default: 
    cerr << "Unsupported rendering mode sorry\n";
    exit(0);
    break;
  }
}

void NexusMt::FlushPatch(unsigned int id) {
  Entry &entry = operator[](id);
  if(entry.vbo_element)
    FlushVbo(entry);

  if(entry.patch->start)
    delete [](entry.patch->start);
  delete entry.patch;  
  entry.patch = NULL;    
  ram_used -= entry.ram_size;      
}

void NexusMt::LoadVbo(Entry &entry) { 
  if(entry.vbo_element) return;
  glGenBuffersARB(1, &entry.vbo_element);
  assert(entry.vbo_element);
  glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, entry.vbo_element);

  Patch &patch  = *entry.patch;    
  unsigned int size = patch.nf * sizeof(unsigned short);
  if((signature & NXS_FACES) != 0) size *= 3;
  
  glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, size, patch.FaceBegin(),
		  GL_STATIC_DRAW_ARB);
  vbo_used += size;
  
  //TODO fix this when we allow data :p
  size = sizeof(float) * patch.dstart;
    
  glGenBuffersARB(1, &entry.vbo_array);
  assert(entry.vbo_array);
  glBindBufferARB(GL_ARRAY_BUFFER_ARB, entry.vbo_array);
    
  glBufferDataARB(GL_ARRAY_BUFFER_ARB, size, patch.VertBegin(), 
		  GL_STATIC_DRAW_ARB);
    
  vbo_used += size;
  delete [](entry.patch->start);
  entry.patch->start = NULL;
}

void NexusMt::FlushVbo(Entry &entry) {
  if(!entry.vbo_element) return;
  glDeleteBuffersARB(1, &entry.vbo_element);
  glDeleteBuffersARB(1, &entry.vbo_array);
  entry.vbo_element = 0;
  entry.vbo_array = 0;

  Patch &patch  = *entry.patch; 
  vbo_used -= patch.nf * sizeof(unsigned short);
  vbo_used -= sizeof(float) * patch.dstart;
}

//Kept for historical reasons.
/*void NexusMt::ExtractFixed(vector<unsigned int>  &selected, float error) {
  std::vector<Node>::iterator n;
  for(n = nodes.begin(); n != nodes.end(); n++)
    (*n).visited = false;
    
  std::queue<Node *> qnodo;
  qnodo.push(&nodes[0]);
  nodes[0].visited = true;
    
  for( ; !qnodo.empty(); qnodo.pop()) {
    Node &node = *qnodo.front();
      
    std::vector<Frag>::iterator fragment;
    std::vector<Node *>::iterator on;
    for(on = node.out.begin(), fragment = node.frags.begin(); 
	    on != node.out.end(); ++on, ++fragment) {

      if((*on)->visited) continue;
	
      if(error < (*on)->error) { //need to expand this node.
	      qnodo.push(*on);
	      (*on)->visited = 1;
      } else {
	      vector<unsigned int>::iterator cell;
	      for(cell=(*fragment).begin(); cell != (*fragment).end(); ++cell) 	        selected.push_back(*cell);                   
      }
    }
  }  
} */