#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#include <cstdlib>

using namespace std;

typedef pair<float, float> point;

void Header(ofstream & file, int width, int height);
void Footer(ofstream & file);
void Line(ofstream & file, point a, point b);
void FlakeIt(vector<point> & data, int depth);

int main(int argc, char * argv[]) {
    int width = 1000,
        height = 1000;

    vector<point> data;

    point a,b,c,d;
    ofstream file;
    int depth = 15;

    if (argc > 1) {
       depth = atoi(argv[1]);

    }

    a.first = width*.30;
    a.second = height*.30;
    b.first = width*.70;
    b.second = height *.70;

    c.first = a.first;
    c.second = b.second;
    d.first = b.first;
    d.second = a.second;

    data.push_back(a);
    data.push_back(b);

    FlakeIt(data, depth);
    file.open("dragon.svg");
    Header(file, width, height);

    for(int i = 0; i < data.size()-1;i++) {
       Line(file,data[i],data[i+1]); 
    }

/*
    int i;
    file << "<path d=\"M ";
    for(i =0;i< data.size()-1;i++) {
       file << data[i].first << " " << data[i].second << ", ";
    }
    file << data[i].first << " " << data[i].second ;
    file << "\" style=\"fill:none ;stroke:black;\"/>" << endl;
*/

    Footer(file);
    return 0;
}

void Header(ofstream & file, int width, int height){

   file << "<?xlm version=\"1.0\"?>" << endl;
   file << "<svg " << endl;
   file << "\txmlns=\"http://www.w3.org/2000/svg\"" << endl;
   file << "\twidth=\"" << width << '"' << endl;
   file << "\theight=\"" << height << '"' << endl;
   file << ">" << endl;

   return;
}

void Footer(ofstream & file){
   file << "</svg>" << endl;

   return;
}

void Line(ofstream & file, point a, point b){
   file << "<line ";
   file << "x1=\"" << a.first << "\" ";
   file << "y1=\"" << a.second << "\" ";
   file << "x2=\"" << b.first << "\" ";
   file << "y2=\"" << b.second << "\" ";
   file << "style=\"stroke: black;\"";
   file << "/>" << endl;
}

void FlakeIt(vector<point> & data, int depth){
   int i;
   vector<point> newData;
   point p;
   float vx, vy;
   float length, mx, my;

   if (depth != 0) {
       cout << "Depth = " << depth << endl;
       for(i=0;i<data.size()-1;i++) {
          newData.push_back(data[i]);
          // get the next point;
	  vx = data[i].first-data[i+1].first;
	  vy = data[i].second-data[i+1].second;
          length = sqrt(vx*vx + vy*vy);

          mx = (data[i].first+data[i+1].first)/2.0;
          my = (data[i].second+data[i+1].second)/2.0;

          console.log(i, i%2, !(i%2));
	  if ((i %2)) {
	      console.log('a');
	      p.first =  mx + vy/2.0;
	      p.second = my - vx/2.0;
	  } else {
	      console.log('b');
	      p.first =  mx - vy/2.0;
	      p.second = my + vx/2.0;
	  }

          // flake each line;
	  newData.push_back(p);
       }
       newData.push_back(data[data.size()-1]);

       data = newData;
       newData.erase(newData.begin(),newData.end());

       FlakeIt(data,depth-1);
   }
   return;
}