#include "OffObject.h"
#include <cmath>
#include "vgl.h"
#include <vector>
#include <fstream>
#include <algorithm>
#include <iostream>
using namespace std;

OffObject::OffObject(string name) {
   SetName(name);
   SetType(GL_TRIANGLES);
}

void OffObject::SetName(string name) {
    if (name == "" ) {
        fileName = "offs/teapot.off"; 
    } else {
        fileName = name;
    }
}

void OffObject::Init() {
    LoadFile(fileName);
    return;
}

void EatComment(ifstream & inFile) {
    bool comment = true;
    char peek;
    string junk;

    while (comment and inFile) {
        inFile.get(peek);
        if (peek =='#') {
           getline(inFile, junk);
        } else {
           inFile.unget();
           comment = false;
        }
    }
    return;
}
      
void FindExtreme(vec3 & min,vec3 &  max, vec3 point){
    int i;
    for(i=0;i<3;i++) {
        min[i] = std::min(min[i],point[i]);
	max[i] = std::max(max[i], point[i]);
    }
    return;
}

void OffObject::LoadFile(string name){
    Vertex v;
    int vertices, polys;
    int i,j;
    ifstream file;
    string junk;
    vec3 min, max;
    GLushort a,b,c;
    int pts;

    file.open(fileName.c_str());
    if (!file) {
        cerr << " Unable to open " << fileName << endl;
	return;
    }
  
    // read in the header, should be OFF, 
    getline(file, junk);
    EatComment(file);

    file  >> vertices >> polys ;
    getline(file, junk);

    // set everything to be red.
    v.color = color;

    for(i=0;i<vertices;i++) {
       EatComment(file);
       file >> v.position;
       points.push_back(v);

       if (i == 0) {
           min = v.position;
	   max = v.position;
       } else {
           FindExtreme(min, max, v.position);
       }
       // for now ignore anything else.
       getline(file, junk);
    }
  
    // normalize the object between -.5 and .5 in all dimensions.
    max  -= min;
    GLfloat norm  = std::max(max.x, max.y);
    norm = std::max(norm, max.z);

    vec3 move = vec3(-0.5);

    for(i=0;i<points.size();i++) {
        points[i].position = (points[i].position - min) * 1.0/ norm  + move ;
    }

    for(i=0; i<polys ; i++){
       EatComment(file);
       file >> pts; 
       file >> a >> b >> c;
       if (file) {
           index.push_back(a);
           index.push_back(b);
           index.push_back(c);
           for(j=4; j<= pts; j++){
              b = c;
	      file >> c;
	      if (file) {
                  index.push_back(a);
                  index.push_back(b);
                  index.push_back(c);
	      } else {
                  cout << "Attempt to read past end of file " << endl;
	      }
           }
       } else {
          cout << "Attempt to read past end of file " << endl;
       }

       getline(file,junk);
    }

    file.close();
    return;
}

void OffObject::DisplaySetup() {
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
      return;
}