/* Work-alike for termcap, plus extra features.
   Copyright (C) 1985, 1986, 1993 Free Software Foundation, Inc.
   Copyright (C) 2001 Ben Wing.

This file is part of XEmacs.

XEmacs 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 3 of the License, or (at your
option) any later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Not synched with FSF. */

/* config.h may rename various library functions such as malloc.  */
#ifdef emacs
#include <config.h>
#include "lisp.h" /* For encapsulated open, close, read */
#include "device.h"
#include "device-impl.h" /* For DEVICE_BAUD_RATE */
#include "sysfile.h"
#include "process.h"
#else /* not emacs */

#include <stdlib.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef _POSIX_VERSION
#include <fcntl.h>
#endif

#endif /* not emacs */

/* BUFSIZE is the initial size allocated for the buffer
   for reading the termcap file.
   It is not a limit.
   Make it large normally for speed.
   Make it variable when debugging, so can exercise
   increasing the space dynamically.  */

#ifndef BUFSIZE
#ifdef DEBUG
#define BUFSIZE bufsize

int bufsize = 128;
#else
#define BUFSIZE 2048
#endif
#endif

#ifndef emacs
static void
memory_out ()
{
  retry_write (2, "virtual memory exhausted\n", 25);
  exit (1);
}

static char *
xmalloc (size)
     unsigned int size;
{
  char *tem = malloc (size);

  if (!tem)
    memory_out ();
  return tem;
}

static char *
xrealloc (ptr, size)
     char *ptr;
     unsigned size;
{
  char *tem = realloc (ptr, size);

  if (!tem)
    memory_out ();
  return tem;
}
#endif /* not emacs */

/* Looking up capabilities in the entry already found.  */

/* The pointer to the data made by tgetent is left here
   for tgetnum, tgetflag and tgetstr to find.  */
static char *term_entry;

static const char *tgetst1 (const char *ptr, char **area);

/* Search entry BP for capability CAP.
   Return a pointer to the capability (in BP) if found,
   0 if not found.  */

static const char *
find_capability (bp, cap)
     const char *bp;
     const char *cap;
{
  for (; *bp; bp++)
    if (bp[0] == ':'
	&& bp[1] == cap[0]
	&& bp[2] == cap[1])
      return &bp[4];
  return 0;
}

int
tgetnum (cap)
     const char *cap;
{
  const char *ptr = find_capability (term_entry, cap);
  if (!ptr || ptr[-1] != '#')
    return -1;
  return atoi (ptr);
}

int
tgetflag (cap)
     const char *cap;
{
  const char *ptr = find_capability (term_entry, cap);
  return 0 != ptr && ptr[-1] == ':';
}

/* Look up a string-valued capability CAP.
   If AREA is nonzero, it points to a pointer to a block in which
   to store the string.  That pointer is advanced over the space used.
   If AREA is zero, space is allocated with `malloc'.  */

const char *
tgetstr (cap, area)
     const char *cap;
     char **area;
{
  const char *ptr = find_capability (term_entry, cap);
  if (!ptr || (ptr[-1] != '=' && ptr[-1] != '~'))
    return 0;
  return tgetst1 (ptr, area);
}

/* Table, indexed by a character in range 0100 to 0140 with 0100 subtracted,
   gives meaning of character following \, or a space if no special meaning.
   Eight characters per line within the string.  */

static char esctab[]
  = " \007\010  \033\014 "
"      \012 "
"  \015 \011 \013 "
"        ";

/* PTR points to a string value inside a termcap entry.
   Copy that value, processing \ and ^ abbreviations,
   into the block that *AREA points to,
   or to newly allocated storage if AREA is 0.  */

static const char *
tgetst1 (ptr, area)
     const char *ptr;
     char **area;
{
  const char *p;
  char *r;
  int c;
  int size;
  char *ret;
  int c1;

  if (!ptr)
    return 0;

  /* `ret' gets address of where to store the string.  */
  if (!area)
    {
      /* Compute size of block needed (may overestimate).  */
      p = ptr;
      while ((c = *p++) && c != ':' && c != '\n')
	;
      ret = (char *) xmalloc (p - ptr + 1);
    }
  else
    ret = *area;

  /* Copy the string value, stopping at null or colon.
     Also process ^ and \ abbreviations.  */
  p = ptr;
  r = ret;
  while ((c = *p++) && c != ':' && c != '\n')
    {
      if (c == '^')
	c = *p++ & 037;
      else if (c == '\\')
	{
	  c = *p++;
	  if (c >= '0' && c <= '7')
	    {
	      c -= '0';
	      size = 0;

	      while (++size < 3 && (c1 = *p) >= '0' && c1 <= '7')
		{
		  c *= 8;
		  c += c1 - '0';
		  p++;
		}
	    }
	  else if (c >= 0100 && c < 0200)
	    {
	      c1 = esctab[(c & ~040) - 0100];
	      if (c1 != ' ')
		c = c1;
	    }
	}
      *r++ = c;
    }
  *r = 0;
  /* Update *AREA.  */
  if (area)
    *area = r + 1;
  return ret;
}

/* Outputting a string with padding.  */

#ifdef LINUX
speed_t ospeed;
#else
short ospeed;
#endif
/* If `ospeed' is 0, we use `tputs_baud_rate' as the actual baud rate.  */
int tputs_baud_rate;
char PC;

/* Actual baud rate if positive;
   - baud rate / 100 if negative.  */

static short speeds[] =
  {
    0, 50, 75, 110, 135, 150, -2, -3, -6, -12,
    -18, -24, -48, -96, -192, -288, -384, -576, -1152
  };

void
tputs (string, nlines, outfun)
     const char *string;
     int nlines;
     void (*outfun) (int);
{
  int padcount = 0;
  int speed;

#ifdef emacs
  speed = DEVICE_BAUD_RATE (XDEVICE (Fselected_device (Qnil)));
#else
  if (ospeed == 0)
    speed = tputs_baud_rate;
  else
    speed = speeds[ospeed];
#endif

  if (string == (char *) 0)
    return;

  while (isdigit (* (const unsigned char *) string))
    {
      padcount += *string++ - '0';
      padcount *= 10;
    }
  if (*string == '.')
    {
      string++;
      padcount += *string++ - '0';
    }
  if (*string == '*')
    {
      string++;
      padcount *= nlines;
    }
  while (*string)
    (*outfun) (*string++);

  /* padcount is now in units of tenths of msec.  */
  padcount *= speeds[ospeed];
  padcount += 500;
  padcount /= 1000;
  if (speeds[ospeed] < 0)
    padcount = -padcount;
  else
    {
      padcount += 50;
      padcount /= 100;
    }

  while (padcount-- > 0)
    (*outfun) (PC);
}

/* Finding the termcap entry in the termcap data base.  */

struct buffer
  {
    char *beg;
    int size;
    char *ptr;
    int ateof;
    int full;
  };

/* Forward declarations of static functions.  */

static int scan_file ();
static char *gobble_line ();
static int compare_contin ();
static int name_match ();


/* Find the termcap entry data for terminal type NAME
   and store it in the block that BP points to.
   Record its address for future use.

   If BP is zero, space is dynamically allocated.  */

int
tgetent (bp, name)
     char *bp;
     const char *name;
{
  char *tem;
  int fd;
  struct buffer buf;
  char *bp1;
  char *bp2;
  const char *term;
  int malloc_size = 0;
  int c;
  char *tcenv;			/* TERMCAP value, if it contains :tc=.  */
  const char *indirect = 0;	/* Terminal type in :tc= in TERMCAP value.  */

  tem = egetenv ("TERMCAP");
  if (tem && *tem == 0) tem = 0;


  /* If tem is non-null and starts with / (in the un*x case, that is),
     it is a file name to use instead of /etc/termcap.
     If it is non-null and does not start with /,
     it is the entry itself, but only if
     the name the caller requested matches the TERM variable.  */

  if (tem && !IS_DIRECTORY_SEP (*tem) && !strcmp (name, egetenv ("TERM")))
    {
      indirect = tgetst1 (find_capability (tem, "tc"), 0);
      if (!indirect)
	{
	  if (!bp)
	    bp = tem;
	  else
	    strcpy (bp, tem);
	  goto ret;
	}
      else
	{			/* We will need to read /etc/termcap.  */
	  tcenv = tem;
 	  tem = 0;
	}
    }
  else
    indirect = (char *) 0;

  if (!tem)
    tem = "/etc/termcap";

  /* Here we know we must search a file and tem has its name.  */

  fd = qxe_open ((Ibyte *) tem, 0, 0);
  if (fd < 0)
    return -1;

  buf.size = BUFSIZE;
  /* Add 1 to size to ensure room for terminating null.  */
  buf.beg = (char *) xmalloc (buf.size + 1);
  term = indirect ? indirect : name;

  if (!bp)
    {
      malloc_size = indirect ? strlen (tcenv) + 1 : buf.size;
      bp = (char *) xmalloc (malloc_size);
    }
  bp1 = bp;

  if (indirect)
    /* Copy the data from the environment variable.  */
    {
      strcpy (bp, tcenv);
      bp1 += strlen (tcenv);
    }

  while (term)
    {
      /* Scan the file, reading it via buf, till find start of main entry.  */
      if (scan_file (term, fd, &buf) == 0)
	return 0;

      /* Free old `term' if appropriate.  */
      if (term != name)
	xfree (term);

      /* If BP is malloc'd by us, make sure it is big enough.  */
      if (malloc_size)
	{
	  malloc_size = bp1 - bp + buf.size;
	  tem = (char *) xrealloc (bp, malloc_size);
	  bp1 += tem - bp;
	  bp = tem;
	}

      bp2 = bp1;

      /* Copy the line of the entry from buf into bp.  */
      tem = buf.ptr;
      while ((*bp1++ = c = *tem++) && c != '\n')
	/* Drop out any \ newline sequence.  */
	if (c == '\\' && *tem == '\n')
	  {
	    bp1--;
	    tem++;
	  }
      *bp1 = 0;

      /* Does this entry refer to another terminal type's entry?
	 If something is found, copy it into heap and null-terminate it.  */
      term = tgetst1 (find_capability (bp2, "tc"), 0);
    }

  retry_close (fd);
  xfree (buf.beg);

  if (malloc_size)
    {
      bp = (char *) xrealloc (bp, bp1 - bp + 1);
    }

 ret:
  term_entry = bp;
  if (malloc_size)
    /* #### yuck, why the hell are we casting a pointer to an int? */
    return (int) (long) bp;
  return 1;
}

/* Given file open on FD and buffer BUFP,
   scan the file from the beginning until a line is found
   that starts the entry for terminal type STRING.
   Returns 1 if successful, with that line in BUFP,
   or returns 0 if no entry found in the file.  */

static int
scan_file (string, fd, bufp)
     char *string;
     int fd;
     struct buffer *bufp;
{
  char *end;

  bufp->ptr = bufp->beg;
  bufp->full = 0;
  bufp->ateof = 0;
  *bufp->ptr = 0;

  lseek (fd, 0L, 0);

  while (!bufp->ateof)
    {
      /* Read a line into the buffer.  */
      end = 0;
      do
	{
	  /* if it is continued, append another line to it,
	     until a non-continued line ends.  */
	  end = gobble_line (fd, bufp, end);
	}
      while (!bufp->ateof && end[-2] == '\\');

      if (*bufp->ptr != '#'
	  && name_match (bufp->ptr, string))
	return 1;

      /* Discard the line just processed.  */
      bufp->ptr = end;
    }
  return 0;
}

/* Return nonzero if NAME is one of the names specified
   by termcap entry LINE.  */

static int
name_match (line, name)
     char *line, *name;
{
  char *tem;

  if (!compare_contin (line, name))
    return 1;
  /* This line starts an entry.  Is it the right one?  */
  for (tem = line; *tem && *tem != '\n' && *tem != ':'; tem++)
    if (*tem == '|' && !compare_contin (tem + 1, name))
      return 1;

  return 0;
}

static int
compare_contin (str1, str2)
     char *str1, *str2;
{
  int c1, c2;
  while (1)
    {
      c1 = *str1++;
      c2 = *str2++;
      while (c1 == '\\' && *str1 == '\n')
	{
	  str1++;
	  while ((c1 = *str1++) == ' ' || c1 == '\t');
	}
      if (c2 == '\0')
	{
	  /* End of type being looked up.  */
	  if (c1 == '|' || c1 == ':')
	    /* If end of name in data base, we win.  */
	    return 0;
	  else
	    return 1;
        }
      else if (c1 != c2)
	return 1;
    }
}

/* Make sure that the buffer <- BUFP contains a full line
   of the file open on FD, starting at the place BUFP->ptr
   points to.  Can read more of the file, discard stuff before
   BUFP->ptr, or make the buffer bigger.

   Returns the pointer to after the newline ending the line,
   or to the end of the file, if there is no newline to end it.

   Can also merge on continuation lines.  If APPEND_END is
   nonzero, it points past the newline of a line that is
   continued; we add another line onto it and regard the whole
   thing as one line.  The caller decides when a line is continued.  */

static char *
gobble_line (fd, bufp, append_end)
     int fd;
     struct buffer *bufp;
     char *append_end;
{
  char *end;
  int nread;
  char *buf = bufp->beg;
  char *tem;

  if (append_end == 0)
    append_end = bufp->ptr;

  while (1)
    {
      end = append_end;
      while (*end && *end != '\n') end++;
      if (*end)
        break;
      if (bufp->ateof)
	return buf + bufp->full;
      if (bufp->ptr == buf)
	{
	  if (bufp->full == bufp->size)
	    {
	      bufp->size *= 2;
	      /* Add 1 to size to ensure room for terminating null.  */
	      tem = (char *) xrealloc (buf, bufp->size + 1);
	      bufp->ptr = (bufp->ptr - buf) + tem;
	      append_end = (append_end - buf) + tem;
	      bufp->beg = buf = tem;
	    }
	}
      else
	{
	  append_end -= bufp->ptr - buf;
	  memcpy (buf, bufp->ptr, bufp->full -= bufp->ptr - buf);
	  bufp->ptr = buf;
	}
      if (!(nread = retry_read (fd, buf + bufp->full, bufp->size - bufp->full)))
	bufp->ateof = 1;
      bufp->full += nread;
      buf[bufp->full] = 0;
    }
  return end + 1;
}

#ifdef TEST

#include <stdio.h>

main (argc, argv)
     int argc;
     char **argv;
{
  char *term;
  char *buf;

  term = argv[1];
  printf ("TERM: %s\n", term);

  buf = (char *) tgetent (0, term);
  if ((int) buf <= 0)
    {
      printf ("No entry.\n");
      return 0;
    }

  printf ("Entry: %s\n", buf);

  tprint ("cm");
  tprint ("AL");

  printf ("co: %d\n", tgetnum ("co"));
  printf ("am: %d\n", tgetflag ("am"));
}

tprint (cap)
     const char *cap;
{
  char *x = tgetstr (cap, 0);
  char *y;

  printf ("%s: ", cap);
  if (x)
    {
      for (y = x; *y; y++)
	if (*y <= ' ' || *y == 0177)
	  printf ("\\%0o", *y);
	else
	  putchar (*y);
      xfree (x);
    }
  else
    printf ("none");
  putchar ('\n');
}

#endif /* TEST */