#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <string.h>
#include <ctype.h>

/* texinfo2man.
 * Convert a texinfo document to man format.
 * Author: Carlo Wood <carlo@alinoe.com>.
 * Copyright (c) 1999, 2000 Carlo Wood.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation, advertising
 * materials, and other materials related to such distribution and use
 * acknowledge that the software was developed by Carlo Wood.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
 * OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * HISTORY
 * 2002 Jan 17 Carlo Wood. Fixed handling of @@ within an @email{}.
 */
   
int at_start_of_line = 1;
int at_start_of_line_for_dot = 1;
int to_upper = 0;
int ignore = 0;
int disabled = 0;
int in_section = 0;
int in_item = 0;
int in_table = 0;
int no_break = 0;
int indentation = 0;

int bold = 0;
int underlined = 0;

char *texinfoname;

char *
where (int line_no)
{
  static char b[256];

  sprintf (b, "%s line %-3d", texinfoname, line_no);
  return b;
}

void
start_bold (void)
{
  if (!bold && !underlined)
    {
      if (at_start_of_line)
	{
	  printf (".B ");
	  at_start_of_line_for_dot = 0;
	}
      else
	{
	  printf ("\\fB");
	  at_start_of_line_for_dot = at_start_of_line;
	}
      at_start_of_line = 0;
    }
  ++bold;
}

void
stop_bold (void)
{
  if (--bold == 0 && !underlined)
    {
      printf ("\\fR");
      at_start_of_line_for_dot = at_start_of_line;
      at_start_of_line = 0;
    }
}

void
start_I (void)
{
  if (!underlined)
    {
      if (at_start_of_line)
	{
	  printf (".I ");
	  at_start_of_line_for_dot = 0;
	}
      else
	{
	  printf ("\\fI");
	  at_start_of_line_for_dot = at_start_of_line;
	}
      at_start_of_line = 0;
    }
  ++underlined;
}

void
stop_I (void)
{
  if (--underlined == 0)
    {
      if (bold)
	{
	  if (at_start_of_line)
	    {
	      printf (".B ");
	      at_start_of_line_for_dot = 0;
	    }
	  else
	    {
	      printf ("\\fB");
	      at_start_of_line_for_dot = at_start_of_line;
	    }
	}
      else
	{
	  printf ("\\fR");
	  at_start_of_line_for_dot = at_start_of_line;
	}
    }
  at_start_of_line = 0;
}

void
putone (char c)
{
  if (disabled || (in_item && c == ' '))
    return;
  if (at_start_of_line_for_dot && c == '.')
    {
      if (!at_start_of_line)
	printf (" .");
      else if (underlined)
	printf (".I .\fI");
      else if (bold)
	printf (".B .\fB");
      else
	printf (" .");
      return;
    }
  if (no_break && c == '\n')
    c = ' ';
  if (no_break && c == ' ')
    putchar ('\\');
  if (to_upper)
    c = toupper (c);
  if (c == '\'' || c == '`' || c == '\\')
    putchar ('\\');
  putchar (c);
  at_start_of_line = at_start_of_line_for_dot = (c == '\n');
}

/* Replacement stack */
int nr = 0;
char *vars[256];
char *replacement[256];
int start_line[256];

static char value_updated[64], value_edition[64], value_version[64];

process_texi (FILE * in)
{
  char buf[1024];
  int in_block = 0;
  int line_no = 0;

  while (fgets (buf, sizeof (buf), in))
    {
      ++line_no;
      if (strncmp (buf, "@include ", 9) == 0)
	{
	  FILE *in2;
	  char *p = strchr (buf, '\n');

	  if (p)
	    *p = 0;
	  in2 = fopen (buf + 9, "r");
	  if (p)
	    *p = '\n';
	  if (in2)
	    {
	      process_texi (in2);
	      fclose (in2);
	    }
	}
      else if (strncmp (buf, "@set ", 5) == 0)
	{
	  char *p = strchr (buf, '\n');

	  if (p)
	    *p = 0;
	  if (!strncmp (buf + 5, "UPDATED ", 8))
	    strcpy (value_updated, buf + 13);
	  if (!strncmp (buf + 5, "EDITION ", 8))
	    strcpy (value_edition, buf + 13);
	  if (!strncmp (buf + 5, "VERSION ", 8))
	    strcpy (value_version, buf + 13);
	  if (p)
	    *p = '\n';
	}
      if (strncmp (buf, "@c !BEGIN ", 10) == 0)
	{
	  char *p = buf + 10;
	  size_t len = strlen (p);

	  if (nr == 256)
	    exit (-1);
	  vars[nr] = (char *) malloc (len + 1);
	  replacement[nr] = (char *) malloc (131072);
	  start_line[nr] = line_no + 1;
	  strcpy (vars[nr], p);
	  if ((p = strchr (vars[nr], '\n')))
	    *p = 0;
	  if ((p = strchr (vars[nr], ' ')))
	    *p = 0;
	  in_block = 1;
	}
      else if (strncmp (buf, "@c !END", 7) == 0)
	{
	  size_t len = strlen (replacement[nr]);

	  if (replacement[nr][len - 1] == '\n')
	    {
	      replacement[nr][len - 1] = 0;
	      --len;
	    }
	  in_block = 0;
	  replacement[nr] = (char *) realloc (replacement[nr], len + 1);
	  ++nr;
	}
      else if (in_block)
	{
	  if (in_block == 1)
	    {
	      strcpy (replacement[nr], buf);
	      in_block = 2;
	    }
	  else
	    strcat (replacement[nr], buf);
	}
    }
}

int
main (int argc, char *argv[])
{
    FILE *in;
    char buf[1024];
    int line_no = 0;

    texinfoname = argv[2];

    in = fopen (argv[2], "r");
    process_texi (in);
    fclose (in);

    in = fopen (argv[1], "r");

    while (fgets (buf, sizeof (buf), in))
    {
        char *p;

        for (p = buf; *p; ++p)
	{
            if (*p != '@')
                putchar (*p);
            else
	    {
                int i;

                for (i = 0; i < nr; ++i)
		{
                    size_t len = strlen (vars[i]);

                    if (strncmp (p + 1, vars[i], len) == 0 && p[len + 1] == '@')
		    {
                        int stack[16];
                        int *what = stack;
                        int at_start_of_input_line = 1;
                        char *q;

                        *what = 0;
                        p += strlen (vars[i]) + 1;
                        line_no = start_line[i];
                        for (q = replacement[i]; *q; ++q)
			{
                            if (*q != '@')
			    {
                                int was_at_start_of_input_line = at_start_of_input_line;

                                at_start_of_input_line = (*q == '\n');
                                if (at_start_of_input_line)
                                    ++line_no;
                                if (ignore)
                                    continue;
                                if (in_section && *q == '\n')
				{
                                    in_section = 0;
                                    to_upper = 0;
                                    putone ('"');
				}
                                if (in_item && *q == '\n')
				{
                                    in_item = 0;
                                    stop_bold ();
				}
                                if (in_table && *q == '\n')
                                    continue;
                                if (*what && *q == '}')
				{
                                    switch (*what--)
				    {
                                        case 6:
                                            to_upper = 0;
                                            --no_break;
                                            /* fall through */
                                        case 1:
                                            if (!in_section)
                                                stop_bold ();
                                            break;
                                        case 2:
                                            putone ('"');
                                            break;
                                        case 3:
                                            stop_I ();
                                            break;
                                        case 4:
                                            putone (']');
                                            break;
                                        case 5:	/* Emphasis */
                                            /* putone('*'); */
                                            stop_I ();
                                            break;
                                        case 7:
                                            putone ('\'');
                                            break;
                                        case 8:
                                            --no_break;
                                            break;
                                        case 9:
                                            break;
				    }
				}
                                else
				{
                                    if (in_table && was_at_start_of_input_line && !in_item)
                                        putone ('\n');	/* Kludge :/ */
                                    putone (*q);
				}
			    }
                            else
			    {
                                if (at_start_of_input_line)
				{
                                    if (!strncmp (q, "@end ignore", 11) || !strncmp (q, "@end menu", 9)
                                        || !strncmp (q, "@end iftex", 10) || !strncmp (q, "@end tex", 8)
                                        || !strncmp (q, "@end direntry", 13))
				    {
                                        --ignore;
                                        if (!(q = strchr (q, '\n')))
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@ignore\n", 8) || !strncmp (q, "@menu\n", 6)
                                             || !strncmp (q, "@iftex\n", 7) || !strncmp (q, "@tex\n", 5)
                                             || !strncmp (q, "@direntry\n", 10))
				    {
                                        ++ignore;
                                        if (!(q = strchr (q, '\n')))
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (ignore)
                                        continue;
                                    else if (!strncmp (q, "@author ", 8))
				    {
                                        printf (".br\n");
                                        q += 7;
                                        continue;
				    }
                                    else if (!strncmp (q, "@example\n", 9) || !strncmp (q, "@smallexample\n", 14))
				    {
                                        if (!at_start_of_line)
                                            putchar ('\n');
                                        printf (".in +5\n");
                                        indentation += 5;
                                        printf (".nf\n.na\n");
                                        q = strchr (q, '\n');
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@end example", 12) || !strncmp (q, "@end smallexample", 17))
				    {
                                        if (!at_start_of_line)
                                            putchar ('\n');
                                        printf (".in -5\n");
                                        indentation -= 5;
                                        printf (".ad\n.fi\n");
                                        q = strchr (q, '\n');
                                        if (!q)
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@noindent", 9))
				    {
                                        if (indentation)
					{
                                            if (!at_start_of_line)
                                                putchar ('\n');
                                            printf (".in -%d\n", indentation);
                                            at_start_of_line = at_start_of_line_for_dot = 1;
                                            indentation = 0;
					}
                                        q = strchr (q, '\n');
                                        if (!q)
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@display\n", 9))
				    {
                                        if (!at_start_of_line)
                                            putchar ('\n');
                                        printf (".nf\n.na\n");
                                        q += 8;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@end display", 12))
				    {
                                        if (!at_start_of_line)
                                            putchar ('\n');
                                        printf (".ad\n.fi\n");
                                        q = strchr (q, '\n');
                                        if (!q)
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@section ", 9) || !strncmp (q, "@appendix ", 10)
                                             || !strncmp (q, "@subsection ", 12) || !strncmp (q, "@subheading ", 12))
				    {
                                        if (!at_start_of_line)
                                            putchar ('\n');
                                        printf (".SH \"");
                                        at_start_of_line = at_start_of_line_for_dot = 0;
                                        in_section = 1;
                                        to_upper = 1;
                                        if (q[2] == 'e')
                                            q += 8;
                                        else if (q[2] == 'p')
                                            q += 9;
                                        else
					{
                                            q += 11;
                                            to_upper = 0;
					}
                                        continue;
				    }
                                    else if (!strncmp (q, "@table", 6))
				    {
                                        in_table = 1;
                                        q = strchr (q, '\n');
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@end table", 10))
				    {
                                        disabled = 0;
                                        in_table = 0;
                                        q = strchr (q, '\n');
                                        if (!q)
                                            break;
                                        ++line_no;
                                        continue;
				    }
                                    else if (!strncmp (q, "@item ", 6) || !strncmp (q, "@itemx ", 7))
				    {
                                        disabled = 0;
                                        if (in_table && q[5] == ' ')
					{
                                            if (!at_start_of_line)
                                                putchar ('\n');
                                            if (in_table == 1)
					    {
                                                in_table = 2;
                                                printf (".TP 4\n");
                                                at_start_of_line = at_start_of_line_for_dot = 1;
					    }
                                            else
					    {
                                                printf (".TP\n");
                                                at_start_of_line = at_start_of_line_for_dot = 1;
					    }
					}
                                        if (in_table && q[5] == 'x')
					{
                                            printf (", ");
                                            at_start_of_line = at_start_of_line_for_dot = 0;
					}
                                        in_item = 1;
                                        q = strchr (q, ' ');
                                        start_bold ();
                                        continue;
				    }
				}
                                else if (ignore)
                                    continue;
                                if (!strncmp (q, "@code{", 6) || !strncmp (q, "@env{", 5) || !strncmp (q, "@command{", 9))
				{
                                    if (!in_section)
                                        start_bold ();
                                    *++what = 1;
                                    if (q[1] == 'e')
                                        q += 4;
                                    else if (q[3] == 'd')
                                        q += 5;
                                    else
                                        q += 8;
				}
                                else if (!strncmp (q, "@samp{", 6) || !strncmp (q, "@option{", 8)
                                         || !strncmp (q, "@file{", 6))
				{
                                    putone ('`');
                                    *++what = 7;
                                    if (q[1] == 'o')
                                        q += 7;
                                    else
                                        q += 5;
				}
                                else if (!strncmp (q, "@cite{", 6))
				{
                                    putone ('"');
                                    *++what = 2;
                                    q += 5;
				}
                                else if (!strncmp (q, "@var{", 5) || !strncmp (q, "@dfn{", 5))
				{
                                    start_I ();
                                    *++what = 3;
                                    q += 4;
				}
                                else if (!strncmp (q, "@copyright{}", 12))
				{
                                    printf ("(c)");
                                    q += 11;
				}
                                else if (!strncmp (q, "@value{UPDATED}", 15))
				{
                                    printf ("%s", value_updated);
                                    q += 14;
				}
                                else if (!strncmp (q, "@value{VERSION}", 15))
				{
                                    printf ("%s", value_version);
                                    q += 14;
				}
                                else if (!strncmp (q, "@value{EDITION}", 15))
				{
                                    printf ("%s", value_edition);
                                    q += 14;
				}
                                else if (!strncmp (q, "@refill", 7))
				{
                                    q += 6;
				}
                                else if (!strncmp (q, "@footnote{", 10))
				{
                                    if (!at_start_of_line)
                                        putone (' ');
                                    putone ('[');
                                    *++what = 4;
                                    q += 9;
				}
                                else if (!strncmp (q, "@emph{", 6))
				{
                                    /* putone('*'); */
                                    start_I ();
                                    *++what = 5;
                                    q += 5;
				}
                                else if (!strncmp (q, "@xref{", 6) || !strncmp (q, "@pxref{", 7))
				{
                                    if (!disabled)
				    {
                                        printf ("See ");
                                        at_start_of_line = at_start_of_line_for_dot = 0;
                                        start_bold ();
                                        to_upper = 1;
                                        ++no_break;
                                        *++what = 6;
				    }
                                    if (q[1] == 'p')
                                        q += 6;
                                    else
                                        q += 5;
				}
                                else if (!strncmp (q, "@w{", 3))
				{
                                    ++no_break;
                                    *++what = 8;
                                    q += 2;
				}
                                else if (!strncmp (q, "@email{", 7))
				{
                                    *++what = 9;
                                    q += 6;
				}
                                else if (!strncmp (q, "@{", 2))
				{
                                    putone ('{');
                                    ++q;
				}
                                else if (!strncmp (q, "@}", 2))
				{
                                    putone ('}');
                                    ++q;
				}
                                else if (!strncmp (q, "@*", 2))
				{
                                    if (!at_start_of_line_for_dot)
                                        putchar ('\n');
                                    printf (".br\n");
                                    at_start_of_line = at_start_of_line_for_dot = 1;
                                    ++q;
				}
                                else if (!strncmp (q, "@@", 2))
				{
                                    putone ('@');
                                    ++q;
				}
                                else
				{
                                    char *s = strchr (q, ' ');
                                    char *a = strchr (q, '{');

                                    if (!s || !a || s < a)
				    {
                                        char *q2 = strchr (q, '\n');

                                        if (strncmp (q, "@ifinfo", 7) && strncmp (q, "@end ifinfo", 11)
                                            && strncmp (q, "@cindex", 7) && strncmp (q, "@kindex", 7)
                                            && strncmp (q, "@refill", 7) && strncmp (q, "@include", 8)
                                            && strncmp (q, "@set", 4) && strncmp (q, "@group", 6)
                                            && strncmp (q, "@end group", 10) && strncmp (q, "@node", 5)
                                            && strncmp (q, "@comment", 8) && strncmp (q, "@c\n", 3)
                                            && strncmp (q, "@c ", 3) && strncmp (q, "@need", 5)
                                            && strncmp (q, "@dircategory", 12))
					{
                                            if (a)
                                                *a = 0;
                                            if (q2)
                                                *q2 = 0;
                                            fprintf (stderr, "%s: Unknown texinfo command %s\n", where (line_no), q);
                                            if (a)
                                                *a = '{';
					}
                                        q = q2;
                                        ++line_no;
                                        if (!q)
                                            break;
                                        continue;
				    }
				}
			    }
			}
                        break;
		    }
		}
                if (i == nr)
                    putone ('@');
	    }
	}
    }
    return 0;
}