/* info.c -- Display nodes of Info files in multiple windows. */

/* This file is part of GNU Info, a program for reading online documentation
   stored in Info format.

   Copyright (C) 1993 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 Brian Fox (bfox@ai.mit.edu). */

#include "info.h"
#include "dribble.h"
#include "getopt.h"
#if defined (HANDLE_MAN_PAGES)
#  include "man.h"
#endif /* HANDLE_MAN_PAGES */

/* The version numbers of this version of Info. */
int info_major_version = 2;
int info_minor_version = 14;
int info_patch_level = 0;

/* Non-zero means search all indices for APROPOS_SEARCH_STRING. */
static int apropos_p = 0;

/* Variable containing the string to search for when apropos_p is non-zero. */
static char *apropos_search_string = (char *)NULL;

/* Non-zero means print version info only. */
static int print_version_p = 0;

/* Non-zero means print a short description of the options. */
static int print_help_p = 0;

/* Array of the names of nodes that the user specified with "--node" on the
   command line. */
static char **user_nodenames = (char **)NULL;
static int user_nodenames_index = 0;
static int user_nodenames_slots = 0;

/* String specifying the first file to load.  This string can only be set
   by the user specifying "--file" on the command line. */
static char *user_filename = (char *)NULL;

/* String specifying the name of the file to dump nodes to.  This value is
   filled if the user speficies "--output" on the command line. */
static char *user_output_filename = (char *)NULL;

/* Non-zero indicates that when "--output" is specified, all of the menu
   items of the specified nodes (and their subnodes as well) should be
   dumped in the order encountered.  This basically can print a book. */
int dump_subnodes = 0;

/* Structure describing the options that Info accepts.  We pass this structure
   to getopt_long ().  If you add or otherwise change this structure, you must
   also change the string which follows it. */
#define APROPOS_OPTION 1
#define DRIBBLE_OPTION 2
#define RESTORE_OPTION 3
static struct option long_options[] = {
  { "apropos", 1, 0, APROPOS_OPTION },
  { "directory", 1, 0, 'd' },
  { "node", 1, 0, 'n' },
  { "file", 1, 0, 'f' },
  { "subnodes", 0, &dump_subnodes, 1 },
  { "output", 1, 0, 'o' },
  { "help", 0, &print_help_p, 1 },
  { "version", 0, &print_version_p, 1 },
  { "dribble", 1, 0, DRIBBLE_OPTION },
  { "restore", 1, 0, RESTORE_OPTION },
  {NULL, 0, NULL, 0}
};

/* String describing the shorthand versions of the long options found above. */
static char *short_options = "d:n:f:o:s";

/* When non-zero, the Info window system has been initialized. */
int info_windows_initialized_p = 0;

/* Some "forward" declarations. */
static void usage (), info_short_help (), remember_info_program_name ();


/* **************************************************************** */
/*								    */
/*		  Main Entry Point to the Info Program		    */
/*								    */
/* **************************************************************** */

int
main (argc, argv)
     int argc;
     char **argv;
{
  int getopt_long_index;	/* Index returned by getopt_long (). */
  NODE *initial_node;		/* First node loaded by Info. */

  remember_info_program_name (argv[0]);

  while (1)
    {
      int option_character;

      option_character = getopt_long
	(argc, argv, short_options, long_options, &getopt_long_index);

      /* getopt_long () returns EOF when there are no more long options. */
      if (option_character == EOF)
	break;

      /* If this is a long option, then get the short version of it. */
      if (option_character == 0 && long_options[getopt_long_index].flag == 0)
	option_character = long_options[getopt_long_index].val;

      /* Case on the option that we have received. */
      switch (option_character)
	{
	case 0:
	  break;

	  /* User wants to add a directory. */
	case 'd':
	  info_add_path (optarg, INFOPATH_PREPEND);
	  break;

	  /* User is specifying a particular node. */
	case 'n':
	  add_pointer_to_array (optarg, user_nodenames_index, user_nodenames,
				user_nodenames_slots, 10, char *);
	  break;

	  /* User is specifying a particular Info file. */
	case 'f':
	  if (user_filename)
	    free (user_filename);

	  user_filename = strdup (optarg);
	  break;

	  /* User is specifying the name of a file to output to. */
	case 'o':
	  if (user_output_filename)
	    free (user_output_filename);
	  user_output_filename = strdup (optarg);
	  break;

	  /* User is specifying that she wishes to dump the subnodes of
	     the node that she is dumping. */
	case 's':
	  dump_subnodes = 1;
	  break;

	  /* User has specified a string to search all indices for. */
	case APROPOS_OPTION:
	  apropos_p = 1;
	  maybe_free (apropos_search_string);
	  apropos_search_string = strdup (optarg);
	  break;

	  /* User has specified a dribble file to receive keystrokes. */
	case DRIBBLE_OPTION:
	  close_dribble_file ();
	  open_dribble_file (optarg);
	  break;

	  /* User has specified an alternate input stream. */
	case RESTORE_OPTION:
	  info_set_input_from_file (optarg);
	  break;

	default:
	  usage ();
	}
    }

  /* If the output device is not a terminal, and no output filename has been
     specified, make user_output_filename be "-", so that the info is written
     to stdout, and turn on the dumping of subnodes. */
  if ((!isatty (fileno (stdout))) && (user_output_filename == (char *)NULL))
    {
      user_output_filename = strdup ("-");
      dump_subnodes = 1;
    }

  /* If the user specified --version, then show the version and exit. */
  if (print_version_p)
    {
      printf ("GNU Info, Version %s.\n", version_string ());
      exit (0);
    }

  /* If the `--help' option was present, show the help and exit. */
  if (print_help_p)
    {
      info_short_help ();
      exit (0);
    }
  
  /* If the user hasn't specified a path for Info files, default that path
     now. */
  if (!infopath)
    {
      char *path_from_env, *getenv ();

      path_from_env = getenv ("INFOPATH");

      if (path_from_env)
	info_add_path (path_from_env, INFOPATH_PREPEND);
      else
	info_add_path (DEFAULT_INFOPATH, INFOPATH_PREPEND);
    }

  /* If the user specified a particular filename, add the path of that
     file to the contents of INFOPATH. */
  if (user_filename)
    {
      char *directory_name, *temp;

      directory_name = strdup (user_filename);
      temp = filename_non_directory (directory_name);

      if (temp != directory_name)
	{
	  *temp = 0;
	  info_add_path (directory_name, INFOPATH_PREPEND);
	}

      free (directory_name);
    }

  /* If the user wants to search every known index for a given string,
     do that now, and report the results. */
  if (apropos_p)
    {
      info_apropos (apropos_search_string);
      exit (0);
    }

  /* Get the initial Info node.  It is either "(dir)Top", or what the user
     specifed with values in user_filename and user_nodenames. */
  if (user_nodenames)
    initial_node = info_get_node (user_filename, user_nodenames[0]);
  else
    initial_node = info_get_node (user_filename, (char *)NULL);

  /* If we couldn't get the initial node, this user is in trouble. */
  if (!initial_node)
    {
      if (info_recent_file_error)
	info_error (info_recent_file_error);
      else
	info_error
	  (CANT_FIND_NODE, user_nodenames ? user_nodenames[0] : "Top");
      exit (1);
    }

  /* Special cases for when the user specifies multiple nodes.  If we are
     dumping to an output file, dump all of the nodes specified.  Otherwise,
     attempt to create enough windows to handle the nodes that this user wants
     displayed. */
  if (user_nodenames_index > 1)
    {
      free (initial_node);

      if (user_output_filename)
	dump_nodes_to_file
	  (user_filename, user_nodenames, user_output_filename, dump_subnodes);
      else
	begin_multiple_window_info_session (user_filename, user_nodenames);

      exit (0);
    }

  /* If there are arguments remaining, they are the names of menu items
     in sequential info files starting from the first one loaded.  That
     file name is either "dir", or the contents of user_filename if one
     was specified. */
  while (optind != argc)
    {
      REFERENCE **menu;
      REFERENCE *entry;
      NODE *node;
      char *arg;
      static char *first_arg = (char *)NULL;

      /* Remember the name of the menu entry we want. */
      arg = argv[optind++];

      if (first_arg == (char *)NULL)
	first_arg = arg;

      /* Build and return a list of the menu items in this node. */
      menu = info_menu_of_node (initial_node);

      /* If there wasn't a menu item in this node, stop here, but let
	 the user continue to use Info.  Perhaps they wanted this node
	 and didn't realize it. */
      if (!menu)
	{
#if defined (HANDLE_MAN_PAGES)
	  if (first_arg == arg)
	    {
	      node = make_manpage_node (first_arg);
	      if (node)
		goto maybe_got_node;
	    }
#endif /* HANDLE_MAN_PAGES */
	  begin_info_session_with_error
	    (initial_node, "There is no menu in this node.");
	  exit (0);
	}

      /* Find the specified menu item. */
      entry = info_get_labeled_reference (arg, menu);

      /* If the item wasn't found, search the list sloppily.  Perhaps this
	 user typed "buffer" when they really meant "Buffers". */
      if (!entry)
	{
	  register int i;

	  for (i = 0; entry = menu[i]; i++)
	    if (strncasecmp (entry->label, arg, strlen (arg)) == 0)
	      break;
	}

      /* If we failed to find the reference, start Info with the current
	 node anyway.  It is probably a misspelling. */
      if (!entry)
	{
	  char *error_message = "There is no menu item \"%s\" in this node.";

#if defined (HANDLE_MAN_PAGES)
	  if (first_arg == arg)
	    {
	      node = make_manpage_node (first_arg);
	      if (node)
		goto maybe_got_node;
	    }
#endif /* HANDLE_MAN_PAGES */

	  info_free_references (menu);

	  /* If we were supposed to dump this node, complain. */
	  if (user_output_filename)
	    info_error (error_message, arg);
	  else
	    begin_info_session_with_error (initial_node, error_message, arg);

	  exit (0);
	}

      /* We have found the reference that the user specified.  Clean it
	 up a little bit. */
      if (!entry->filename)
	{
	  if (initial_node->parent)
	    entry->filename = strdup (initial_node->parent);
	  else
	    entry->filename = strdup (initial_node->filename);
	}

      /* Find this node.  If we can find it, then turn the initial_node
	 into this one.  If we cannot find it, try using the label of the
	 entry as a file (i.e., "(LABEL)Top").  Otherwise the Info file is
	 malformed in some way, and we will just use the current value of
	 initial node. */
      node = info_get_node (entry->filename, entry->nodename);

#if defined (HANDLE_MAN_PAGES)
	  if ((first_arg == arg) && !node)
	    {
	      node = make_manpage_node (first_arg);
	      if (node)
		goto maybe_got_node;
	    }
#endif /* HANDLE_MAN_PAGES */

      if (!node && entry->nodename &&
	  (strcmp (entry->label, entry->nodename) == 0))
	node = info_get_node (entry->label, "Top");

    maybe_got_node:
      if (node)
	{
	  free (initial_node);
	  initial_node = node;
	  info_free_references (menu);
	}
      else
	{
	  char *temp = strdup (entry->label);
	  char *error_message;

	  error_message = "Unable to find the node referenced by \"%s\".";

	  info_free_references (menu);

	  /* If we were trying to dump the node, then give up.  Otherwise,
	     start the session with an error message. */
	  if (user_output_filename)
	    info_error (error_message, temp);
	  else
	    begin_info_session_with_error (initial_node, error_message, temp);

	  exit (0);
	}
    }

  /* If the user specified that this node should be output, then do that
     now.  Otherwise, start the Info session with this node. */
  if (user_output_filename)
    dump_node_to_file (initial_node, user_output_filename, dump_subnodes);
  else
    begin_info_session (initial_node);

  exit (0);
}

/* Return a string describing the current version of Info. */
char *
version_string ()
{
  static char *vstring = (char *)NULL;

  if (!vstring)
    {
      vstring = (char *)xmalloc (50);
      sprintf (vstring, "%d.%d", info_major_version, info_minor_version);
      if (info_patch_level)
	sprintf (vstring + strlen (vstring), "-p%d", info_patch_level);
    }
  return (vstring);
}

/* **************************************************************** */
/*								    */
/*		   Error Handling for Info			    */
/*								    */
/* **************************************************************** */

static char *program_name = (char *)NULL;

static void
remember_info_program_name (fullpath)
     char *fullpath;
{
  char *filename;

  filename = filename_non_directory (fullpath);
  program_name = strdup (filename);
}

/* Non-zero if an error has been signalled. */
int info_error_was_printed = 0;

/* Non-zero means ring terminal bell on errors. */
int info_error_rings_bell_p = 1;

/* Print FORMAT with ARG1 and ARG2.  If the window system was initialized,
   then the message is printed in the echo area.  Otherwise, a message is
   output to stderr. */
void
info_error (format, arg1, arg2)
     char *format;
     void *arg1, *arg2;
{
  info_error_was_printed = 1;

  if (!info_windows_initialized_p || display_inhibited)
    {
      fprintf (stderr, "%s: ", program_name);
      fprintf (stderr, format, arg1, arg2);
      fprintf (stderr, "\n");
      fflush (stderr);
    }
  else
    {
      if (!echo_area_is_active)
	{
	  if (info_error_rings_bell_p)
	    terminal_ring_bell ();
	  window_message_in_echo_area (format, arg1, arg2);
	}
      else
	{
	  NODE *temp;

	  temp = build_message_node (format, arg1, arg2);
	  if (info_error_rings_bell_p)
	    terminal_ring_bell ();
	  inform_in_echo_area (temp->contents);
	  free (temp->contents);
	  free (temp);
	}
    }
}

/* Produce a very brief descripton of the available options and exit with
   an error. */
static void
usage ()
{
  fprintf (stderr,"%s\n%s\n%s\n%s\n%s\n",
"Usage: info [-d dir-path] [-f info-file] [-o output-file] [-n node-name]...",
"            [--directory dir-path] [--file info-file] [--node node-name]...",
"            [--help] [--output output-file] [--subnodes] [--version]",
"            [--dribble dribble-file] [--restore from-file]",
"            [menu-selection ...]");
  exit (1);
}

/* Produce a scaled down description of the available options to Info. */
static void
info_short_help ()
{
  printf ("%s", "\
Here is a quick description of Info's options.  For a more complete\n\
description of how to use Info, type `info info options'.\n\
\n\
   --directory DIR		Add DIR to INFOPATH.\n\
   --file FILENAME		Specify Info file to visit.\n\
   --node NODENAME		Specify nodes in first visited Info file.\n\
   --output FILENAME		Output selected nodes to FILENAME.\n\
   --dribble FILENAME		Remember user keystrokes in FILENAME.\n\
   --restore FILENAME		Read initial keystrokes from FILENAME.\n\
   --subnodes			Recursively output menu items.\n\
   --help			Get this help message.\n\
   --version			Display Info's version information.\n\
\n\
Remaining arguments to Info are treated as the names of menu\n\
items in the initial node visited.  You can easily move to the\n\
node of your choice by specifying the menu names which describe\n\
the path to that node.  For example, `info emacs buffers'.\n");

  exit (0);
}