/*
 * Copyright (C) 1996  Ben Fowler
 * Copyright (C) 2003  Pekka Enberg <penberg@cs.helsinki.fi>
 *
 * Contents of this file originated from Linux sources sometime late
 * 1995.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 */

#include "ansi-esc.h"

/*
 * Global variables used by the ANSI escape code translator. The list
 * is long; please feel free to send patches to Walt ;-).
 */
static int fore;
static int back;
static int need_wrap;
static int def_color;
static int par[8];
static int intensity;
static int underline;
static int blink;
static int reverse;
static int saved_x;
static int saved_y;
static int s_intensity;
static int s_underline;
static int s_blink;
static int s_reverse;
static int s_color;
static int npar;
static int y;
static int x;
static int color;
static int pos;
static int vc_state;
static int ques;
static int attr;
static int tab_stop[5];


void
default_attr ()
{
  intensity = 1;
  underline = 0;
  reverse = 0;
  blink = 0;
  color = 7;
  fore = 7;
  back = 0;
}


void
update_attr ()
{
  attr = color;

  if (blink)
    attr ^= 0x80;

  if (intensity == 2)
    attr ^= 0x08;
}


void
csi_m ()
{
  int i;

  for (i = 0; i <= npar; i++)
    switch (par[i])
      {
      case 0:			/* all attributes off */
	default_attr ();
	break;
      case 1:
	intensity = 2;
	break;
      case 2:
	intensity = 0;
	break;
      case 4:
	underline = 1;
	break;
      case 5:
	blink = 1;
	break;
      case 7:
	reverse = 1;
	break;
      case 10:			/* ANSI X3.64-1979 (SCO-ish?)
				 * Select primary font, don't display
				 * control chars if defined, don't set
				 * bit 8 on output.
				 */
	break;
      case 11:			/* ANSI X3.64-1979 (SCO-ish?)
				 * Select first alternate font, let's
				 * chars < 32 be displayed as ROM chars.
				 */
	break;
      case 12:			/* ANSI X3.64-1979 (SCO-ish?)
				 * Select second alternate font, toggle
				 * high bit before displaying as ROM char.
				 */
	break;
      case 21:
      case 22:
	intensity = 1;
	break;
      case 24:
	underline = 0;
	break;
      case 25:
	blink = 0;
	break;
      case 27:
	reverse = 0;
	break;
      case 38:			/* ANSI X3.64-1979 (SCO-ish?)
				 * Enables underscore, white foreground
				 * with white underscore (Linux - use
				 * default foreground).
				 */
	color = (def_color & 0x0f) | back;
	underline = 1;
	break;
      case 39:			/* ANSI X3.64-1979 (SCO-ish?)
				 * Disable underline option.
				 * Reset colour to default? It did this
				 * before...
				 */
	color = (def_color & 0x0f) | back;
	underline = 0;
	break;
      case 49:
	color = (def_color & 0xf0) | fore;
	break;
      default:
	if (par[i] >= 30 && par[i] <= 37)
	  {
	    fore  = (par[i] - 30) & 0x07;
	    color = (back << 4) | fore;
	  }
	else if (par[i] >= 40 && par[i] <= 47)
	  {
	    back  = (par[i] - 40) & 0x07;
	    color = (back << 4) | fore;
	  }
	break;
      }
  update_attr ();
}


void
gotoxy (int new_x, int new_y, unsigned long width, unsigned long height)
{
  if (new_x < 0)
    x = 0;
  else if (new_x >= width)
    x = width - 1;
  else
    x = new_x;
  
  if (new_y < 0)
    y = 0;
  else if (new_y >= height)
    y = height - 1;
  else
    y = new_y;
  
  pos = (y * width) + x;
  need_wrap = 0;
}


void
save_cur ()
{
  saved_x = x;
  saved_y = y;
  s_intensity = intensity;
  s_underline = underline;
  s_blink = blink;
  s_reverse = reverse;
  s_color = color;
}


void
restore_cur (unsigned long width, unsigned long height)
{

  gotoxy (saved_x, saved_y, width, height);
  intensity = s_intensity;
  underline = s_underline;
  blink = s_blink;
  reverse = s_reverse;
  color = s_color;
  update_attr ();
  need_wrap = 0;
}


static void
lf (unsigned long width, unsigned long height)
{
  if (y < height - 1)
    {
      y++;
      pos += width;
    }
  need_wrap = 0;
}


void
cr ()
{
  pos -= x;
  need_wrap = 0;
  x = 0;
}


/* DOS end-of-file character.  */
#define DOS_EOF 26

unsigned long
ansi_esc_translate (FILE * fp, unsigned int * editbuffer,
		    unsigned long width, unsigned long height)
{
  int c, ok;

  /*
   * Some of these initial values might not be needed but right now
   * it's better to be safe than sorry. -Pekka, 2003-01-11
   */
  y = 0;
  x = 0;
  intensity = 1;
  underline = 0;
  blink = 0;
  reverse = 0;
  saved_x = 0;
  saved_y = 0;
  s_intensity = 0;
  s_underline = 0;
  s_blink = 0;
  s_reverse = 0;
  s_color = 0;
  color = 0;
  npar = 0;
  need_wrap = 0;
  def_color = 0x07;
  pos = 0;
  fore = 7;
  back = 0;
  vc_state = ESnormal;
  ques = 0;
  attr = 7;

  tab_stop[0] = 0x01010100;
  tab_stop[1] = 0x01010101;
  tab_stop[2] = 0x01010101;
  tab_stop[3] = 0x01010101;
  tab_stop[4] = 0x01010101;

  /* Read file, translate escape codes to color codes, and store them
     into an array.  */
  while (((c = getc (fp)) != -1) && (c != DOS_EOF) && (pos < width * height))
    {
      ok = (c >= 32);	/* less than ' ' ignored */

      if ((vc_state == ESnormal) && ok)
	{
	  if (need_wrap)
	    {
	      cr ();
	      lf (width, height);
	    }
	  editbuffer[pos] = ((attr << 8) + c);
	  if (x == width - 1)
	    need_wrap = 1;	/* decawm; */
	  else
	    {
	      x++;
	      pos++;
	    }
	  continue;
	}
      switch (c)
	{
	case 7:
	  continue;
	case 8:
	  continue;
	case 9:
	  pos -= x;
	  while (x < width - 1)
	    {
	      x++;
	      if (tab_stop[x >> 5] & (1 << (x & 31)))
		break;
	    }
	  pos += x;
	  continue;
	case 10:
	case 11:
	case 12:
	  cr ();
	  lf (width, height);
	  continue;
	case 13:
	  continue;
	case 14:
	  continue;
	case 15:
	  continue;
	case 24:
	case 26:
	  vc_state = ESnormal;
	  continue;
	case 27:
	  vc_state = ESesc;
	  continue;
	case 127:
	  continue;
	case 128 + 27:
	  vc_state = ESsquare;
	  continue;
	}

      switch (vc_state)
	{
	case ESesc:
	  vc_state = ESnormal;
	  switch (c)
	    {
	    case '[':
	      vc_state = ESsquare;
	      continue;
	    case ']':
	      vc_state = ESnonstd;
	      continue;
	    case '%':
	      vc_state = ESpercent;
	      continue;
	    case 'E':
	      cr ();
	      lf (width, height);
	      continue;
	    case 'M':
	      /* nothing */
	      continue;
	    case 'D':
	      lf (width, height);
	      continue;
	    case 'H':
	      continue;
	    case 'Z':
	      continue;
	    case '7':
	      save_cur ();
	      continue;
	    case '8':
	      restore_cur (width, height);
	      continue;
	    case '(':
	      vc_state = ESsetG0;
	      continue;
	    case ')':
	      vc_state = ESsetG1;
	      continue;
	    case '#':
	      vc_state = EShash;
	      continue;
	    case 'c':
	      continue;
	    case '>':	/* Numeric keypad */
	      continue;
	    case '=':	/* Appl. keypad */
	      continue;
	    }
	  continue;
	case ESnonstd:
	  if (c == 'P')
	    {		/* palette escape sequence */
	      for (npar = 0; npar < 7; npar++)
		par[npar] = 0;
	      npar = 0;
	      vc_state = ESpalette;
	      continue;
	    }
	  else if (c == 'R')
	    {		/* reset palette */
	      vc_state = ESnormal;
	    }
	  else
	    vc_state = ESnormal;
	  continue;
	case ESpalette:
	  if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
	      || (c >= 'a' && c <= 'f'))
	    {
	      par[npar++] = (c > '9' ? (c & 0xDF) - 'A' + 10 : c - '0');
	    }
	  else
	    vc_state = ESnormal;
	  continue;
	case ESsquare:
	  for (npar = 0; npar < 7; npar++)
	    par[npar] = 0;
	  npar = 0;
	  vc_state = ESgetpars;
	  if (c == '[')
	    {		/* Function key */
	      vc_state = ESfunckey;
	      continue;
	    }
	  ques = (c == '?');
	  if (ques)
	    continue;
	case ESgetpars:
	  if (c == ';' && npar < 6)
	    {
	      npar++;
	      continue;
	    }
	  else if (c >= '0' && c <= '9')
	    {
	      par[npar] *= 10;
	      par[npar] += c - '0';
	      continue;
	    }
	  else
	    vc_state = ESgotpars;
	case ESgotpars:
	  vc_state = ESnormal;
	  switch (c)
	    {
	    case 'h':
	      continue;
	    case 'l':
	      continue;
	    case 'n':
	      continue;
	    }
	  if (ques)
	    {
	      ques = 0;
	      continue;
	    }
	  switch (c)
	    {
	    case 'G':
	    case '`':
	      if (par[0])
		par[0]--;
	      gotoxy (par[0], y, width, height);
	      continue;
	    case 'A':
	      if (!par[0])
		par[0]++;
	      gotoxy (x, y - par[0], width, height);
	      continue;
	    case 'B':
	    case 'e':
	      if (!par[0])
		par[0]++;
	      gotoxy (x, y + par[0], width, height);
	      continue;
	    case 'C':
	    case 'a':
	      if (!par[0])
		par[0]++;
	      gotoxy (x + par[0], y, width, height);
	      continue;
	    case 'D':
	      if (!par[0])
		par[0]++;
	      gotoxy (x - par[0], y, width, height);
	      continue;
	    case 'E':
	      if (!par[0])
		par[0]++;
	      gotoxy (0, y + par[0], width, height);
	      continue;
	    case 'F':
	      if (!par[0])
		par[0]++;
	      gotoxy (0, y - par[0], width, height);
	      continue;
	    case 'd':
	      if (par[0])
		par[0]--;
	      gotoxy (x, par[0], width, height);
	      continue;
	    case 'H':
	    case 'f':
	      if (par[0])
		par[0]--;
	      if (par[1])
		par[1]--;
	      gotoxy (par[1], par[0], width, height);
	      continue;
	    case 'J':
	      continue;
	    case 'K':
	      continue;
	    case 'L':
	      continue;
	    case 'M':
	      continue;
	    case 'P':
	      continue;
	    case 'c':
	      continue;
	    case 'g':
	      continue;
	    case 'm':
	      csi_m ();
	      continue;
	    case 'q':	/* DECLL - but only 3 leds */
	      continue;
	    case 'r':
	      continue;
	    case 's':
	      save_cur ();
	      continue;
	    case 'u':
	      restore_cur (width, height);
	      continue;
	    case 'X':
	      continue;
	    case '@':
	      continue;
	    case ']':	/* setterm functions */
	      continue;
	    }
	  continue;
	case ESpercent:
	  vc_state = ESnormal;
	  continue;
	case ESfunckey:
	  vc_state = ESnormal;
	  continue;
	case EShash:
	  vc_state = ESnormal;
	  continue;
	case ESsetG0:
	  vc_state = ESnormal;
	  continue;
	case ESsetG1:
	  vc_state = ESnormal;
	  continue;
	default:
	  vc_state = ESnormal;
	}
    }
  return pos; /* return number of bytes stored in buffer.  */
}