//   A Demonstration of the NCURSES library         S. Murrell 15-11-99
//
//   (ncurses is almost the same as curses)
//   curses and ncurses allow you to control the whole screen and draw
//   on it using normal ascii characters. Editors like pico and jed use
//   curses because it gives you a standard system-independent AND
//   terminal-independent interface.
//
//   Curses is a standard unix library, but it doesn't provide non-blocking
//   input (editors don't need it, but we do here). Ncurses is a special
//   version of curses with a number of extensions. It is almost a standard
//   and is quite widely available.
//
//   This example has been tailored to work properly on rabbit. On other
//   computers you will probably have to play around with the libraries
//   a bit.
//
//   You can download this file, compile and run it directly. Use as much
//   of it as you like. If you want to use any features that I don't
//   illustrate here, try the "man ncurses" command; you may be lucky.
//
//   Assuming you have downloaded this and called the file "curses.cpp"
//   compile with:
//                  CC -c curses.cpp
//   then link with:
//                  CC -lncurses curses.o
//   then run with:
//                  ./a.out
//
//   if your program covers multiple .cpp files, compile each separately
//   with "CC -c", then link them all together like this:
//                  CC -lncurses curses.o otherfile.o wawawa.o woooo.o
//
//   if you are also using the Pthreads library (see the other example)
//   you will still need to use the -pthread switch when linking:
//
//                  CC -c curses.cpp
//                  CC -c other.cpp
//                  CC -pthread -lncurses curses.o other.o
//                  ./a.out
//   Got it?

#include <ncurses.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>

WINDOW *w1, *w2, *w3;
int screenW, screenH, windowW, windowH;

char map[50][100];

char tempstr[100];
int num_moves=0;

int random_in_range(int min, int max)
{ return min+random()%(max+1-min); }

void main(void)
{
  initscr();    // This is required to make curses work
  nonl();       // This stops it from screwing up the output
  raw();                // This stops it from playing with the input
  cbreak();             // this makes it deliver input one character at
                        //    a time, without waiting for you to press
                        //    ENTER
  noecho();             // This stops it from echoing keys you type
  nodelay(stdscr,1);    // This makes it do NON-BLOCKING input. That is,
                        //    if you call getch() but there is no input
                        //    ready yet, it returns ERR immediately.

  getmaxyx(stdscr, screenH, screenW);
  if (screenW>99) windowW=99; else windowW=screenW;
  if (screenH>49) windowH=49; else windowH=screenH-1;

  w1=newwin(windowH,windowW,0,0);  // create the main window (ht,wd,y0,x0)
  w2=newwin(1,windowW,windowH,0);  // create the report window (ht,wd,y0,x0)
  w3=NULL;                         // create 3rd window when needed

                              // we'll fill the map with solid '@'s...
  for (int x=0; x<windowW; x+=1)
    for (int y=0; y<windowH; y+=1)
    { map[y][x]='@';                // keep things in map and on screen
      wmove(w1,y,x);                // move cursor... (note y&x in wrong order)
      waddch(w1,'@'); }             // ...then add character

  srandomdev();               // initialise the random number generator

                              // now use random rectangles to open spaces
  int creatureX, creatureY;
  for (int i=0; i<6; i+=1)
  { int x1=random_in_range(1,windowW-8);
    int y1=random_in_range(1,windowH-8);
    int x2=random_in_range(x1+1,windowW-2);
    int y2=random_in_range(y1+1,windowH-2);
    creatureX=(x1+x2)/2; creatureY=(y1+y2)/2;
    for (int x=x1; x<=x2; x+=1)
      for (int y=y1; y<y2; y+=1)
      { map[y][x]=' ';
        wmove(w1,y,x);
        waddch(w1,' '); } }

  wmove(w1,creatureY,creatureX);   // now display the creature
  waddch(w1,'X');

  wrefresh(w1);        // nothing ever happens until you refresh a window!

                       // use window w2 for status reports...
  wmove(w2,0,0); waddstr(w2,"Started!"); wrefresh(w2);

  int frozen=0;

  while (1)
  { usleep(200000);        // short pause (0.2 seconds)

    int command=getch();   // get single character from user, value is
                           //   ERR if nothing has been typed.
    if (command!=ERR)
    { sprintf(tempstr,"command '%c' = %d", command, command);
      wmove(w2,0,0); 
      wclrtoeol(w2);       // CleaR from cursor position TO End Of Line
      waddstr(w2,tempstr);
      wrefresh(w2);
      if (command=='x')
        break;
      else if (command=='r')     // report on status and freeze simulation
      { if (w3==NULL)
        { w3=newwin(8,44,screenH/2-4,10);   // 8 lines, 44 wide, in middle
          box(w3,'|','-');                  // draw box round window
          wmove(w3,2,2);
          waddstr(w3,"Report of Status");
          sprintf(tempstr,"I have made %d moves",num_moves);
          wmove(w3,4,4);
          waddstr(w3,tempstr);
          sprintf(tempstr,"current coordinates %d,%d",creatureX,creatureY);
          wmove(w3,5,4);
          waddstr(w3,tempstr);
          wrefresh(w3);
          wmove(w2,0,0); 
          wclrtoeol(w2);
          waddstr(w2,"Press 'c' to continue the simulation");
          wrefresh(w2); }
        frozen=1; }
      else if (command=='c')     // continue after 'r'
      { if (w3!=NULL)
        { delwin(w3);       // remove the temporary window
          touchwin(w1);     // unfortunately needed when uncovering
          wrefresh(w1); }   // and refresh the main one
        w3=NULL;
        frozen=0; } }
 
    if (frozen) continue;
    num_moves+=1;
                           // move the creature in a random direction
    int newx=creatureX, newy=creatureY;
    int tryx, tryy;
    tryx=creatureX+random_in_range(-1,+1);
    tryy=creatureY+random_in_range(-1,+1);
    if (map[tryy][tryx]==' ')
    { newx=tryx; newy=tryy; }

                           // update the window
    wmove(w1,creatureY,creatureX);
    waddch(w1,' ');
    wmove(w1,newy,newx);
    waddch(w1,'X');
    creatureX=newx; creatureY=newy;
    wrefresh(w1); }

  endwin();         // needed to return your screen to normal operations
  printf("\n"); }