/* sectioning.c -- all related stuff @chapter, @section... @contents
   $Id: sectioning.c,v 1.12 1999/08/17 21:06:50 karl Exp $

   Copyright (C) 1999 Free Software Foundation, Inc.

   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, or (at your option)
   any later version.

   This program 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

   Written by Karl Heinz Marbaise <kama@hippo.fido.de>.  */

#include "system.h"
#include "cmds.h"
#include "macro.h"
#include "makeinfo.h"
#include "node.h"
#include "toc.h"
#include "sectioning.h"

/* See comment in sectioning.h.  */
section_alist_type section_alist[] = {
  { "unnumberedsubsubsec", 5, ENUM_SECT_NO,  TOC_YES },
  { "unnumberedsubsec",    4, ENUM_SECT_NO,  TOC_YES },
  { "unnumberedsec",       3, ENUM_SECT_NO,  TOC_YES },
  { "unnumbered",          2, ENUM_SECT_NO,  TOC_YES },

  { "appendixsubsubsec",   5, ENUM_SECT_APP, TOC_YES },  /* numbered like A.X.X.X */
  { "appendixsubsec",      4, ENUM_SECT_APP, TOC_YES },
  { "appendixsec",         3, ENUM_SECT_APP, TOC_YES },
  { "appendixsection",     3, ENUM_SECT_APP, TOC_YES },
  { "appendix",            2, ENUM_SECT_APP, TOC_YES },

  { "subsubsec",           5, ENUM_SECT_YES, TOC_YES },
  { "subsubsection",       5, ENUM_SECT_YES, TOC_YES },
  { "subsection",          4, ENUM_SECT_YES, TOC_YES },
  { "section",             3, ENUM_SECT_YES, TOC_YES },
  { "chapter",             2, ENUM_SECT_YES, TOC_YES },

  { "subsubheading",       5, ENUM_SECT_NO,  TOC_NO },
  { "subheading",          4, ENUM_SECT_NO,  TOC_NO },
  { "heading",             3, ENUM_SECT_NO,  TOC_NO },
  { "chapheading",         2, ENUM_SECT_NO,  TOC_NO },
  { "majorheading",        2, ENUM_SECT_NO,  TOC_NO },
  
  { "top",                 1, ENUM_SECT_NO,  TOC_YES },
  { NULL,                  0, 0, 0 }
};

/* The argument of @settitle, used for HTML. */
char *title = NULL;


#define APPENDIX_MAGIC   1024
#define UNNUMBERED_MAGIC 2048

/* Number memory for every level @chapter, @section,
   @subsection, @subsubsection. */
static int numbers [] = { 0, 0, 0, 0 };

/* enum_marker == APPENDIX_MAGIC then we are counting appendencies
   enum_marker == UNNUMBERED_MAGIC then we are within unnumbered area.
   Handling situations like this:
   @unnumbered ..
   @section ...   */
static int enum_marker = 0;

/* Organized by level commands.  That is, "*" == chapter, "=" == section. */
static char *scoring_characters = "*=-.";

/* Amount to offset the name of sectioning commands to levels by. */
static int section_alist_offset = 0;


/* num == ENUM_SECT_NO  means unnumbered (should never call this)
   num == ENUM_SECT_YES means numbered
   num == ENUM_SECT_APP means numbered like A.1 and so on */
char *
get_sectioning_number (level, num)
      int level;
      int num;
{
  static char s[100]; /* should ever be enough for 99.99.99.99
                         Appendix A.1 */

  char *p;
  int i;

  s[0] = 0;

  /* create enumeration in front of chapter, section, subsection and so on. */
  for (i = 0; i < level; i++)
    {
      p = s + strlen (s);
      if ((i == 0) && (enum_marker == APPENDIX_MAGIC))
	sprintf (p, "%c.", numbers[i] + 64); /* Should be changed to
                                                be more portable */
      else
	sprintf (p, "%d.", numbers[i]);
    }

  /* the last number is never followed by a dot */
  p = s + strlen (s);
  if ((num == ENUM_SECT_APP)
      && (i == 0)
      && (enum_marker == APPENDIX_MAGIC))
    sprintf (p, _("Appendix %c "), numbers[i] + 64);
  else
    sprintf (p, "%d ", numbers[i]);

  return s;
}


/* Set the level of @top to LEVEL.  Return the old level of @top. */
int
set_top_section_level (level)
     int level;
{
  int i, result = -1;

  for (i = 0; section_alist[i].name; i++)
    if (strcmp (section_alist[i].name, "top") == 0)
      {
        result = section_alist[i].level;
        section_alist[i].level = level;
        break;
      }
  return result;
}


/* return the index of the given sectioning command in section_alist */
int
search_sectioning (text)
     char *text;
{
  int i;
  char *t;

  /* ignore the optional command prefix */
  if (text[0] == COMMAND_PREFIX)
    text++;
  
  for (i = 0; (t = section_alist[i].name); i++)
    {
      if (strcmp (t, text) == 0)
        {
          return i;
        }
    }
  return -1;
}
    
/* Return an integer which identifies the type section present in TEXT. */
int
what_section (text)
     char *text;
{
  int index, j;
  char *temp;
  int return_val;

 find_section_command:
  for (j = 0; text[j] && cr_or_whitespace (text[j]); j++);
  if (text[j] != COMMAND_PREFIX)
    return -1;

  text = text + j + 1;

  /* We skip @c, @comment, and @?index commands. */
  if ((strncmp (text, "comment", strlen ("comment")) == 0) ||
      (text[0] == 'c' && cr_or_whitespace (text[1])) ||
      (strcmp (text + 1, "index") == 0))
    {
      while (*text++ != '\n');
      goto find_section_command;
    }

  /* Handle italicized sectioning commands. */
  if (*text == 'i')
    text++;

  for (j = 0; text[j] && !cr_or_whitespace (text[j]); j++);

  temp = xmalloc (1 + j);
  strncpy (temp, text, j);
  temp[j] = 0;

  index = search_sectioning (temp);
  free (temp);
  if (index >= 0)
    {
      return_val = section_alist[index].level + section_alist_offset;
      if (return_val < 0)
	return_val = 0;
      else if (return_val > 5)
          return_val = 5;
      return return_val;
    }
  return -1;
}


void
sectioning_underscore (cmd)
     char *cmd;
{
  char character;
  char *temp;
  int level;

  temp = xmalloc (2 + strlen (cmd));
  temp[0] = COMMAND_PREFIX;
  strcpy (&temp[1], cmd);
  level = what_section (temp);
  free (temp);
  level -= 2;

  if (level < 0)
    level = 0;

  if (html)
    sectioning_html (level, cmd);
  else
    {
      character = scoring_characters[level];
      insert_and_underscore (level, character, cmd);
    }
}

/* insert_and_underscore and sectioning_html are the
   only functions which call this.
   I have created this, because it was exactly the same
   code in both functions. */
static char *
handle_enum_increment (level, index)
     int level;
     int index;
{
  /* special for unnumbered */
  if (number_sections && section_alist[index].num == ENUM_SECT_NO)
    {
      if (level == 0
	  && enum_marker != UNNUMBERED_MAGIC)
	enum_marker = UNNUMBERED_MAGIC;
    }
  /* enumerate only things which are allowed */
  if (number_sections && section_alist[index].num)
    {
      /* reset the marker if we get into enumerated areas */
      if (section_alist[index].num == ENUM_SECT_YES
	  && level == 0
	  && enum_marker == UNNUMBERED_MAGIC)
	enum_marker = 0;
      /* This is special for appendix; if we got the first
         time an appendix command then we are entering appendix.
         Thats the point we have to start countint with A, B and so on. */
      if (section_alist[index].num == ENUM_SECT_APP
	  && level == 0
	  && enum_marker != APPENDIX_MAGIC)
	{
	  enum_marker = APPENDIX_MAGIC;
	  numbers [0] = 0; /* this means we start with Appendix A */
	}
  
      /* only increment counters if we are not in unnumbered
         area. This handles situations like this:
         @unnumbered ....   This sets enum_marker to UNNUMBERED_MAGIC
         @section ....   */
      if (enum_marker != UNNUMBERED_MAGIC)
	{
	  int i;

	  /* reset all counters which are one level deeper */
	  for (i = level; i < 3; i++)
	    numbers [i + 1] = 0;
  
	  numbers[level]++;
	  return xstrdup
	    (get_sectioning_number (level, section_alist[index].num));
	}
    } /* if (number_sections)... */

  return xstrdup ("");
}


/* Insert the text following input_text_offset up to the end of the line
   in a new, separate paragraph.  Directly underneath it, insert a
   line of WITH_CHAR, the same length of the inserted text. */
void
insert_and_underscore (level, with_char, cmd)
     int level;
     int with_char;
     char *cmd;
{
  int i, len;
  int index;
  int old_no_indent;
  unsigned char *starting_pos, *ending_pos;
  char *temp;

  close_paragraph ();
  filling_enabled =  indented_fill = 0;
  old_no_indent = no_indent;
  no_indent = 1;

  if (macro_expansion_output_stream && !executing_string)
    append_to_expansion_output (input_text_offset + 1);

  get_rest_of_line (0, &temp);
  starting_pos = output_paragraph + output_paragraph_offset;

  index = search_sectioning (cmd);
  if (index < 0)
    {
      /* should never happen, but a poor guy, named Murphy ... */
      warning (_("Internal error (search_sectioning) \"%s\"!"), cmd);
      return;
    }

  /* This is a bit tricky: we must produce "X.Y SECTION-NAME" in the
     Info output and in TOC, but only SECTION-NAME in the macro-expanded
     output.  */

  /* Step 1: produce "X.Y" and add it to Info output.  */
  add_word (handle_enum_increment (level, index));

  /* Step 2: add "SECTION-NAME" to both Info and macro-expanded output.  */
  if (macro_expansion_output_stream && !executing_string)
    {
      char *temp1 = xmalloc (2 + strlen (temp));
      sprintf (temp1, "%s\n", temp);
      remember_itext (input_text, input_text_offset);
      me_execute_string (temp1);
      free (temp1);
    }
  else
    execute_string ("%s\n", temp);

  /* Step 3: pluck "X.Y SECTION-NAME" from the output buffer and
     insert it into the TOC.  */
  ending_pos = output_paragraph + output_paragraph_offset;
  if (section_alist[index].toc == TOC_YES)
    toc_add_entry (substring (starting_pos, ending_pos - 1),
                   level, current_node, NULL);

  free (temp);

  len = (ending_pos - starting_pos) - 1;
  for (i = 0; i < len; i++)
    add_char (with_char);
  insert ('\n');
  close_paragraph ();
  filling_enabled = 1;
  no_indent = old_no_indent;
}

/* Insert the text following input_text_offset up to the end of the
   line as an HTML heading element of the appropriate `level' and
   tagged as an anchor for the current node.. */
void
sectioning_html (level, cmd)
     int level;
     char *cmd;
{
  static int toc_ref_count = 0;
  int index;
  int old_no_indent;
  unsigned char *starting_pos, *ending_pos;
  char *temp, *toc_anchor = NULL;

  close_paragraph ();
  filling_enabled =  indented_fill = 0;
  old_no_indent = no_indent;
  no_indent = 1;

  add_word_args ("<h%d>", level + 1); /* level 0 is <h1> */

  /* If we are outside of any node, produce an anchor that
     the TOC could refer to.  */
  if (!current_node || !*current_node)
    {
      starting_pos = output_paragraph + output_paragraph_offset;
      add_word_args ("<a name=\"TOC%d\">", toc_ref_count++);
      toc_anchor = substring (starting_pos + 9,
                              output_paragraph + output_paragraph_offset);
    }
  starting_pos = output_paragraph + output_paragraph_offset;

  if (macro_expansion_output_stream && !executing_string)
    append_to_expansion_output (input_text_offset + 1);

  get_rest_of_line (0, &temp);

  index = search_sectioning (cmd);
  if (index < 0)
    {
      /* should never happen, but a poor guy, named Murphy ... */
      warning (_("Internal error (search_sectioning) \"%s\"!"), cmd);
      return;
    }

  /* Produce "X.Y" and add it to HTML output.  */
  add_word (handle_enum_increment (level, index));

  /* add the section name to both HTML and macro-expanded output.  */
  if (macro_expansion_output_stream && !executing_string)
    {
      remember_itext (input_text, input_text_offset);
      me_execute_string (temp);
      write_region_to_macro_output ("\n", 0, 1);
    }
  else
    execute_string ("%s", temp);

  ending_pos = output_paragraph + output_paragraph_offset;

  /* Pluck ``X.Y SECTION-NAME'' from the output buffer and insert it
     into the TOC.  */
  if (section_alist[index].toc == TOC_YES)
    toc_add_entry (substring (starting_pos, ending_pos),
                   level, current_node, toc_anchor);
  
  free (temp);

  if (outstanding_node)
    outstanding_node = 0;

  add_word_args ("</h%d>", level+1);
  close_paragraph();
  filling_enabled = 1;
  no_indent = old_no_indent;
}


/* Shift the meaning of @section to @chapter. */
void
cm_raisesections ()
{
  discard_until ("\n");
  section_alist_offset--;
}

/* Shift the meaning of @chapter to @section. */
void
cm_lowersections ()
{
  discard_until ("\n");
  section_alist_offset++;
}

/* The command still works, but prints a warning message in addition. */
void
cm_ideprecated (arg, start, end)
     int arg, start, end;
{
  warning (_("%c%s is obsolete; use %c%s instead"),
           COMMAND_PREFIX, command, COMMAND_PREFIX, command + 1);
  sectioning_underscore (command + 1);
}


/* Treat this just like @unnumbered.  The only difference is
   in node defaulting. */
void
cm_top ()
{
  /* It is an error to have more than one @top. */
  if (top_node_seen && strcmp (current_node, "Top") != 0)
    {
      TAG_ENTRY *tag = tag_table;

      line_error (_("Node with %ctop as a section already exists"),
                  COMMAND_PREFIX);

      while (tag)
        {
          if (tag->flags & TAG_FLAG_IS_TOP)
            {
              int old_line_number = line_number;
              char *old_input_filename = input_filename;

              line_number = tag->line_no;
              input_filename = tag->filename;
              line_error (_("Here is the %ctop node"), COMMAND_PREFIX);
              input_filename = old_input_filename;
              line_number = old_line_number;
              return;
            }
          tag = tag->next_ent;
        }
    }
  else
    {
      TAG_ENTRY *top_node = find_node ("Top");
      top_node_seen = 1;

      /* It is an error to use @top before you have used @node. */
      if (!tag_table)
        {
          char *top_name;

          get_rest_of_line (0, &top_name);
          line_error (_("%ctop used before %cnode, defaulting to %s"),
                      COMMAND_PREFIX, COMMAND_PREFIX, top_name);
          execute_string ("@node Top, , (dir), (dir)\n@top %s\n", top_name);
          free (top_name);
          return;
        }
      else if (html && splitting)
        {
          char *next = top_node ? top_node->next : NULL;

          add_word ("<p>");
          if (next)
            {
              add_word (_("Next:"));
              add_word ("<a rel=next href=\"");
              add_anchor_name (next, 1);
              add_word ("\">");
              execute_string (next);
              add_word ("</a>\n");
            }
        }

      cm_unnumbered ();

      /* The most recently defined node is the top node. */
      tag_table->flags |= TAG_FLAG_IS_TOP;

      /* Now set the logical hierarchical level of the Top node. */
      {
        int orig_offset = input_text_offset;

        input_text_offset = search_forward (node_search_string, orig_offset);

        if (input_text_offset > 0)
          {
            int this_section;

            /* We have encountered a non-top node, so mark that one exists. */
            non_top_node_seen = 1;

            /* Move to the end of this line, and find out what the
               sectioning command is here. */
            while (input_text[input_text_offset] != '\n')
              input_text_offset++;

            if (input_text_offset < input_text_length)
              input_text_offset++;

            this_section = what_section (input_text + input_text_offset);

            /* If we found a sectioning command, then give the top section
               a level of this section - 1. */
            if (this_section != -1)
              set_top_section_level (this_section - 1);
          }
        input_text_offset = orig_offset;
      }
    }
}

/* The remainder of the text on this line is a chapter heading. */
void
cm_chapter ()
{
  sectioning_underscore ("chapter");
}

/* The remainder of the text on this line is a section heading. */
void
cm_section ()
{
  sectioning_underscore ("section");
}

/* The remainder of the text on this line is a subsection heading. */
void
cm_subsection ()
{
  sectioning_underscore ("subsection");
}

/* The remainder of the text on this line is a subsubsection heading. */
void
cm_subsubsection ()
{
  sectioning_underscore ("subsubsection");
}

/* The remainder of the text on this line is an unnumbered heading. */
void
cm_unnumbered ()
{
  sectioning_underscore ("unnumbered");
}

/* The remainder of the text on this line is an unnumbered section heading. */
void
cm_unnumberedsec ()
{
  sectioning_underscore ("unnumberedsec");
}

/* The remainder of the text on this line is an unnumbered
   subsection heading. */
void
cm_unnumberedsubsec ()
{
  sectioning_underscore ("unnumberedsubsec");
}

/* The remainder of the text on this line is an unnumbered
   subsubsection heading. */
void
cm_unnumberedsubsubsec ()
{
  sectioning_underscore ("unnumberedsubsubsec");
}

/* The remainder of the text on this line is an appendix heading. */
void
cm_appendix ()
{
  sectioning_underscore ("appendix");
}

/* The remainder of the text on this line is an appendix section heading. */
void
cm_appendixsec ()
{
  sectioning_underscore ("appendixsec");
}

/* The remainder of the text on this line is an appendix subsection heading. */
void
cm_appendixsubsec ()
{
  sectioning_underscore ("appendixsubsec");
}

/* The remainder of the text on this line is an appendix
   subsubsection heading. */
void
cm_appendixsubsubsec ()
{
  sectioning_underscore ("appendixsubsubsec");
}

/* Compatibility functions substitute for chapter, section, etc. */
void
cm_majorheading ()
{
  sectioning_underscore ("majorheading");
}

void
cm_chapheading ()
{
  sectioning_underscore ("chapheading");
}

void
cm_heading ()
{
  sectioning_underscore ("heading");
}

void
cm_subheading ()
{
  sectioning_underscore ("subheading");
}

void
cm_subsubheading ()
{
  sectioning_underscore ("subsubheading");
}
