/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
   Written by James Clark (jjc@jclark.com)

   This file is part of groff.

   groff 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.

   groff 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <assert.h>

#include "driver.h"

/* If we are sending output to an onscreen pager (as is the normal case
   when reading man pages), then we may get an error state on the output
   stream, if the user does not read all the way to the end.

   We normally expect to catch this, and clean up the error context,
   when the pager exits, because we should get, and handle, a SIGPIPE.

   However ...
*/

#if (defined(_MSC_VER) || defined(_WIN32)) \
    && !defined(__CYGWIN__) && !defined(_UWIN)

  /* Native MS-Windows doesn't know about SIGPIPE, so we cannot detect
     the early exit from the pager, and therefore, cannot clean up the
     error context; thus we use the following static function to
     identify this particular error context, and so suppress unwanted
     diagnostics.
  */

  static int
  check_for_output_error (FILE* stream)
  {
    /* First, clean up any prior error context on the output stream */
    if (ferror (stream))
      clearerr (stream);
    /* Clear errno, in case clearerr() and fflush() don't */
    errno = 0;
    /* Flush the output stream, so we can capture any error context,
       other than the specific case we wish to suppress.

       Microsoft doesn't document it, but the error code for the
       specific context we are trying to suppress seems to be EINVAL --
       a strange choice, since it is not normally associated with
       fflush(); of course, it *should* be EPIPE, but this *definitely*
       is not used, and *is* so documented.
    */
    return ((fflush(stream) < 0) && (errno != EINVAL));
  }

#else

  /* For other systems, we simply assume that *any* output error context
     is to be reported.
  */
# define check_for_output_error(stream) ferror(stream) || fflush(stream) < 0

#endif


font_pointer_list::font_pointer_list(font *f, font_pointer_list *fp)
: p(f), next(fp)
{
}

printer::printer()
: font_list(0), font_table(0), nfonts(0)
{
}

printer::~printer()
{
  delete[] font_table;
  while (font_list) {
    font_pointer_list *tem = font_list;
    font_list = font_list->next;
    delete tem->p;
    delete tem;
  }
  if (check_for_output_error(stdout))
    fatal("output error");
}

void printer::load_font(int n, const char *nm)
{
  assert(n >= 0);
  if (n >= nfonts) {
    if (nfonts == 0) {
      nfonts = 10;
      if (nfonts <= n)
	nfonts = n + 1;
      font_table = new font *[nfonts];
      for (int i = 0; i < nfonts; i++)
	font_table[i] = 0;
    }
    else {
      font **old_font_table = font_table;
      int old_nfonts = nfonts;
      nfonts *= 2;
      if (n >= nfonts)
	nfonts = n + 1;
      font_table = new font *[nfonts];
      int i;
      for (i = 0; i < old_nfonts; i++)
	font_table[i] = old_font_table[i];
      for (i = old_nfonts; i < nfonts; i++)
	font_table[i] = 0;
      delete[] old_font_table;
    }
  }
  font *f = find_font(nm);
  font_table[n] = f;
}

font *printer::find_font(const char *nm)
{
  for (font_pointer_list *p = font_list; p; p = p->next)
    if (strcmp(p->p->get_name(), nm) == 0)
      return p->p;
  font *f = make_font(nm);
  if (0 /* nullptr */ == f)
    fatal("cannot find font '%1'", nm);
  font_list = new font_pointer_list(f, font_list);
  return f;
}

font *printer::make_font(const char *nm)
{
  return font::load_font(nm);
}

void printer::end_of_line()
{
}

void printer::special(char *, const environment *, char)
{
}

void printer::devtag(char *, const environment *, char)
{
}

void printer::draw(int, int *, int, const environment *)
{
}

void printer::change_color(const environment * const)
{
}

void printer::change_fill_color(const environment * const)
{
}

void printer::set_ascii_char(unsigned char c, const environment *env, 
			     int *widthp)
{
  char  buf[2];
  int   w;
  font *f;

  buf[0] = c;
  buf[1] = '\0';

  glyph *g = set_char_and_width(buf, env, &w, &f);

  if (g != UNDEFINED_GLYPH) {
    set_char(g, f, env, w, 0);
    if (widthp)
      *widthp = w;
  }
}

void printer::set_special_char(const char *nm, const environment *env,
			       int *widthp)
{
  font *f;
  int w;
  glyph *g = set_char_and_width(nm, env, &w, &f);
  if (g != UNDEFINED_GLYPH) {
    set_char(g, f, env, w, nm);
    if (widthp)
      *widthp = w;
  }
}

glyph *printer::set_char_and_width(const char *nm,
				   const environment *env, int *widthp,
				   font **f)
{
  glyph *g = name_to_glyph(nm);
  int fn = env->fontno;
  if (fn < 0 || fn >= nfonts) {
    error("invalid font position '%1'", fn);
    return UNDEFINED_GLYPH;
  }
  *f = font_table[fn];
  if (*f == 0) {
    error("no font mounted at position %1", fn);
    return UNDEFINED_GLYPH;
  }
  if (!(*f)->contains(g)) {
    if (nm[0] != '\0' && nm[1] == '\0')
      error("font '%1' does not contain ordinary character '%2'",
	    (*f)->get_name(), nm[0]);
    else
      error("font '%1' does not contain special character '%2'",
	    (*f)->get_name(), nm);
    return UNDEFINED_GLYPH;
  }
  int w = (*f)->get_width(g, env->size);
  if (widthp)
    *widthp = w;
  return g;
}

void printer::set_numbered_char(int num, const environment *env, int
				*widthp)
{
  glyph *g = number_to_glyph(num);
  int fn = env->fontno;
  if (fn < 0 || fn >= nfonts) {
    error("invalid font position '%1'", fn);
    return;
  }
  font *f = font_table[fn];
  if (f == 0) {
    error("no font mounted at position %1", fn);
    return;
  }
  if (!f->contains(g)) {
    error("font '%1' does not contain numbered character %2",
	  f->get_name(), num);
    return;
  }
  int w = f->get_width(g, env->size);
  if (widthp)
    *widthp = w;
  set_char(g, f, env, w, 0);
}

font *printer::get_font_from_index(int fontno)
{
  if ((fontno >= 0) && (fontno < nfonts))
    return font_table[fontno];
  else
    return 0;
}

// Local Variables:
// fill-column: 72
// mode: C++
// End:
// vim: set cindent noexpandtab shiftwidth=2 textwidth=72:
