#include <curses.h>
#include <caml/mlvalues.h>


#define max(a,b) ((a>b)?a:b)
#define min(a,b) ((a<b)?a:b)

#define MAXCOLOR 8


/* environnement */

WINDOW *pad=NULL; /* pad */
WINDOW *scr=NULL; /* ecran */

WINDOW *win=NULL; /* fenêtre courante */

int yheader;     /* nombre  de lignes de l'entête */
int xpad;        /* taille  du pad */
int ypad;


int ylast=1;
int ycur=0;     /* curseur pour les menus déroulant */

/* fin --------- */ 
int isnew = TRUE; 
int keyspace = FALSE;

value cur_initscr (value size , value nlines ) 
{
  static int COLOR[MAXCOLOR]=
  {COLOR_BLACK,COLOR_YELLOW,COLOR_CYAN,COLOR_RED,COLOR_GREEN,
   COLOR_MAGENTA,COLOR_BLUE,COLOR_WHITE};
  
  int x,y;  
  getmaxyx(scr,y,x);
  if (!scr)  
    {
      scr = initscr();
 
    }
  else
    {
      wresize(scr,y,x);
    }


      if (has_colors())
	{
	  int i,j;
	  int num = 0;
      
	  start_color();      
	  /* color assignment */
	  for (j= 1;j<MAXCOLOR;j=j++)
	    {
	      num++;
	      init_pair(num,COLOR[j],COLOR[0]);
	    }

	  for (i=1; i<MAXCOLOR;i++)
	    for (j=(i+1)%MAXCOLOR;j!=i;j=(j+1)%MAXCOLOR)
	      {
		if (j != 0) 
		  {
		    num++;
		    init_pair(num,COLOR[i],COLOR[j]);
		  }
		
	      }
	  
	}

  (void)  cbreak();       /* don't wait for NL */
  (void)  noecho();       /* disable echoing while reading char */
  (void)  keypad(scr,TRUE);
  (void)  nodelay(scr,TRUE); 


  /* pad allocation */
  {

    int xold,yold;

    getmaxyx(pad,yold,xold);
    
    ypad = Int_val(nlines);
    xpad = x;

    yheader = Int_val(size);

    
    if (ypad+y != yold || xold != xpad)
      {
	delwin(pad);
	pad = newpad(ypad+y,xpad); 
	ycur = 0;
	ylast= 1;
      }
    win = pad; 
  }
     /* initialize the curses library */
  isnew = FALSE;
  prefresh(pad,ycur,0,yheader,0,y,x);
  doupdate();

  return Val_unit;    
}


value cur_endscr(value unit)  
{ 
  isnew=TRUE;
  if (scr) endwin();
  return Val_unit;
}
  

static short delay = FALSE;

value cur_isnew(value unit) {return (Val_bool(isnew));}

value cur_iswait(value unit) {return (Val_bool(delay));}

value cur_init_color (value i,value r,value g, value b) 
{ if (has_colors()) init_color(Int_val(i),Int_val(r),Int_val(g),Int_val(b));return Val_unit;}

value cur_init_pair (value i,value fg,value bg) 
{ if (has_colors()) init_pair(Int_val(i),Int_val(fg),Int_val(bg));return Val_unit;}



/* commutation entre le header et la fenêtre */
value cur_getx (value unit) { int x,y ; getmaxyx(scr,y,x);  return Val_int(x); }

value cur_win(value unit) { win = pad ; return Val_unit ;}

value cur_head(value unit)  { win = scr ; return Val_unit ;}

value cur_addch(value c)  { waddch(win,Int_val(c)); return Val_unit; }

value cur_addstr(value s) { waddstr (win,String_val(s)); return Val_unit; }

value cur_addnstr(value s, value n) {waddnstr (win,String_val(s), Int_val(n)); return Val_unit; }



#define KEY_SPACE 32
#define KEY_RET 10
value cur_refresh(value unit) 
{
  int key;
  int xscr,yscr;
  int ypage ;
  
  if (delay)  keyspace = TRUE;
  do
    {
      key=getch();
      
      getmaxyx(scr,yscr,xscr);
      
      ypage = yscr-yheader;
      
      switch(key) 
	{
	case   KEY_DOWN  : ycur=min(ycur+1,ypad);break;
	case   KEY_UP    : ycur=max(ycur-1,0) ;break; 
	case   KEY_PPAGE : ycur=max(ycur-(ypage-1),0);break;
	case   KEY_NPAGE : ycur=min(ycur+(ypage-1),ypad-ypage+1);break;
	case   KEY_HOME  : ycur=0;break;
	case   KEY_END   : ycur=ypad-ypage;break;
	case   KEY_IC    : ycur=max(ylast-(ypage/3),1);break;

	  
	case  KEY_RESIZE : 
	  {
	    int x,y;
	    while (getch()==KEY_RESIZE); 
	    getmaxyx(scr,yscr,xscr);
	    getmaxyx(pad,y,x);	  
	    wresize(pad,y,xscr);
	    wresize(scr,yscr,xscr);
	    isnew=TRUE;
	    break;
	  }
	case KEY_DC    : delay = !delay;
	case KEY_RET   :
	case KEY_SPACE : keyspace = FALSE;break;
	  
	}
      
      
      prefresh(pad,ycur,0,yheader,0,yscr,xscr);
      
      doupdate();
    }while(keyspace);
  
  return Val_unit;
	 
  
}

value cur_screenon (value unit) 
{
  int key;
  int xscr,yscr;
  int ypage ;
  
  short modif = FALSE;
  {
    key=getch();
 
    getmaxyx(scr,yscr,xscr);
    
    ypage = yscr-yheader;
    
    switch(key) 
      {
      case   KEY_DOWN  : ycur=min(ycur+1,ypad);modif=TRUE;break;
      case   KEY_UP    : ycur=max(ycur-1,0);modif=TRUE ;break; 
      case   KEY_PPAGE : ycur=max(ycur-(ypage-1),0);;modif=TRUE;break;
      case   KEY_NPAGE : ycur=min(ycur+(ypage-1),ypad-ypage+1);modif=TRUE;break;
      case   KEY_HOME  : ycur=0;modif=TRUE;break;
      case   KEY_END   : ycur=ypad-ypage;modif=TRUE;break;
      case   KEY_IC    : ycur=max(ylast-(ypage/3),1);modif=TRUE;break; 
      case   KEY_DC    : delay = !delay;break;
	
      case  KEY_RESIZE : 
	     {
	       int x,y;
	       while (getch()==KEY_RESIZE); 
	       getmaxyx(scr,yscr,xscr);
	       getmaxyx(pad,y,x);	  
	       wresize(pad,y,xscr);
	       wresize(scr,yscr,xscr);
	       isnew=TRUE;modif=TRUE;
	       break;
	     }
      }
    
    if (modif)
      {
	prefresh(pad,ycur,0,yheader,0,yscr,xscr);
	
	doupdate();
      }

    return Val_unit;
	 
    
  }
}


value cur_keyspace(value unit) {keyspace = TRUE; return (Val_unit) ;}


value cur_keepy(value y) { if (win==pad) ylast = Int_val(y);  return Val_unit;}

value cur_clear (value unit) {wclear(win) ;ylast = 0;ycur = 0; return Val_unit;}

value cur_move(value x,value y) {wmove(win,Int_val(x),Int_val(y)); return Val_unit;}


value cur_normal(value unit)  {wattrset(win,A_NORMAL ) ;return Val_unit;}

value cur_standout (value unit) {wattron(win,A_STANDOUT ) ; return Val_unit;}

value cur_color (value i)     { wcolor_set(win,Int_val(i),NULL);return Val_unit;}

value cur_bold (value unit)  {wattron(win,A_BOLD) ; return Val_unit;}

value cur_halfbold (value unit)  {wattron(win,A_DIM) ; return Val_unit;}

value cur_blink (value unit)  {wattron(win,A_BLINK);return Val_unit;}

value cur_reverse (value unit) {wattron(win,A_REVERSE);return Val_unit;}

value cur_delch (value unit) { wdelch(win) ;  return Val_unit; }

value cur_delln (value unit) { wdeleteln (win) ;  return Val_unit; }

value cur_insertln (value unit) {winsertln(win) ;  return Val_unit; }

value cur_flash (value unit) { flash() ;  return Val_unit; }