#include "library.h"

void read_parameters(double & fieldw, double & fieldl,
                     double & boyx, double & boyy,
                     double & bullx, double & bully,
                     double & treex, double & treey,
                     double & boys, double & bulls,
                     double & speedscale)
{ ifstream fin("boyandbull.txt");
  while (true)
  { string s;
    fin >> s;
    if (fin.fail())
      break;
    if (s=="field")
      fin >> fieldw >> fieldl;
    else if (s=="boy")
      fin >> boyx >> boyy >> boys;
    else if (s=="bull")
      fin >> bullx >> bully >> bulls;
    else if (s=="tree")
      fin >> treex >> treey;
    else if (s=="speed")
      fin >> speedscale;
    else
      cout << "File is bad!\n"; }
  cout << "field dims w,l " << fieldw << ", " << fieldl << "\n"; }

void run_simulation(double & fieldw, double & fieldl,
                    double & boyx, double & boyy,
                    double & bullx, double & bully,
                    double & treex, double & treey,
                    double & boys, double & bulls,
                    double & speedscale)
{ const double dirboy = direction_from_to_in_radians(boyx, boyy, treex, treey);
  const double boynewx = boyx + speedscale*boys * sin(dirboy);
  const double boynewy = boyy - speedscale*boys * cos(dirboy);
  set_pen_color(color::blue);
  move_to(boyx, boyy);
  draw_to(boynewx, boynewy);
  boyx = boynewx;
  boyy = boynewy;
 
  const double dirbull = direction_from_to_in_radians(bullx, bully, boyx, boyy);
  const double bullnewx = bullx + speedscale*bulls * sin(dirbull);
  const double bullnewy = bully - speedscale*bulls * cos(dirbull);
  set_pen_color(color::red);
  move_to(bullx, bully);
  draw_to(bullnewx, bullnewy);
  bullx = bullnewx;
  bully = bullnewy; }

double distance(const double x1, const double y1,
                const double x2, const double y2)
{ return sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1)); }

void main()
{ double fieldw, fieldl, boyx, boyy, bullx, bully, treex, treey, boys, bulls, speedscale;
  read_parameters(fieldw, fieldl, boyx, boyy, bullx, bully, treex, treey, boys, bulls, speedscale);
  make_window(fieldw, fieldl);
  set_pen_width(5);
  set_pen_color(color::green);
  draw_point(treex, treey);
  set_pen_color(color::blue);
  set_font_size(36);
  while (true)
  { if (distance(boyx, boyy, treex, treey)<1)
    { move_to(treex, treey);
      write_string("Boy Safe");
      break; }
    if (distance(bullx, bully, boyx, boyy)<0.5)
    { move_to(boyx, boyy);
      write_string("Boy Eaten");
      break; }
    run_simulation(fieldw, fieldl, boyx, boyy, bullx, bully, treex, treey, boys, bulls, speedscale);
    wait(0.01); } }