/*
 *****************************************************************************
 *
 *	$RCSfile: getmessage.c,v $
 *	$Date: 1998/07/29 13:02:50 $
 *	$Source: /home/richard/Xml/RCS/getmessage.c,v $
 *	$Revision: 1.10 $
 *	$Author: richard $
 *
 *****************************************************************************
 *
 *  Copyright 1998, Brown University and Richard Goerwitz
 *
 *****************************************************************************
 *
 *  Routines for retrieving strings by number from an external file.
 *  The main entry point is:
 *
 *    getmessage (message_catalog *mc, char *key)
 *
 *  This routine is used heavily by the routines in errabort.c.  The
 *  message catalog, mc, is normally taken from the global xmlparse_env
 *  structure.  For example:
 *
 *    getmessage (xmlparse_env.messages, "10")
 *
 *  This would return string number 10 in xmlparse_env.messages catalog.
 *  The xmlparse_env.messages catalog is initialized in readcfg.c after
 *  compiled-in defaults, command-line arguments, and the configuration
 *  file have all been processed.
 *
 *  The routine that does the initialization is create_message_catalog(),
 *  which takes a single argument - the name of a file containing the
 *  message catalog.  The compiled-in default filename is "messages".
 *  Normally create_message_catalog() looks for this file in the default
 *  libdir (xmlparse_env.libdir).  If it doesn't find it there, it looks
 *  in the current directory.
 *
 *****************************************************************************
 *
 *  This file is best viewed with a fixed-width font, on at least a
 *  100-column display window.
 *
 *****************************************************************************
 *
 *  Error numbers from 130-139.
 *
 *****************************************************************************
 */

#include "getmessage.h"
#include "errabort.h"
#include "fileutil.h"
#include "hashutil.h"
#include "lockutil.h"
#include "strutil.h"

static void parse_line_add_to_htable (message_catalog *, char *, int);

/*
 * create_message_catalog
 *
 *   Allocates and fill out entries in the message catalog.  Returns 0
 *   if it can't open fname (sole argument).  Otherwise uses errabort()
 *   and errwarn() to signal problems.
 */
message_catalog *
create_message_catalog (char *fname)
{

  int lineno;
  FILE *message_file;
  message_catalog *mc;
  char *line, pathbuf[MAXPATHLEN];

  /* What are we doing? */
  xwrap (errdebug (7, "reading message catalog file\n"));

  /* Keep track of where we were */
  xwrap (errdebug (5, "saving current dir\n"));
  if (getcwd (pathbuf, MAXPATHLEN) == NULL)
    errabort (136, "can't determine current working directory\n");

  /* Try to cd into libdir */
  xwrap (errdebug (5, "moving into libdir, %s\n", xmlparse_env.libdir));
  if (xmlparse_env.libdir)
    if (chdir (xmlparse_env.libdir) < 0)
      {
	errwarn (72, "can't cd to %s; using cwd\n", xmlparse_env.libdir);
	free (xmlparse_env.libdir);
	xmlparse_env.libdir = strdup (".");
      }

  if ((mc = malloc (sizeof (message_catalog))) == NULL)
    errabort (40, "malloc error in %s\n", "init_message_catalog()");
  memset (mc, 0, sizeof (message_catalog));

  if ((mc->message_filename = strdup (fname)) == NULL)
    errabort (40, "malloc error in %s\n", "init_message_catalog()");

  /* open message file */
  if ((message_file = fopen_and_readlock (fname)) == NULL)
    /* error message gets emitted by caller */
    { mc = NULL; goto restore_dir; }

  /* create hash table */
  if ((mc->htable = rg_create_htable (200)) == NULL)
    errabort (40, "malloc error in %s\n", "fill_out_message_catalog()");

  /* Here's the meat of the message-catalog-reading routine */
  lineno = 0;
  while ((line = getline (message_file, fname, &lineno)))
    /* parse line into key-data and insert key-data into htable */
    parse_line_add_to_htable (mc, line, lineno);
  fclose_and_unlock (message_file);

  /* Leave libdir; return to previous working dir */
 restore_dir:
  xwrap (errdebug (5, "restoring current dir\n"));
  if (chdir (pathbuf) < 0)
    errabort (73, "can't cd to %s\n", pathbuf);

  xwrap (errdebug (5, "created in-memory message catalog\n"));
  return mc;

}


/*
 * free_message_catalog
 *
 *   free() up space used by message catalog mc (this includes the
 *   message_filename string, the hash table, and the message_catalog
 *   structure itself).
 */
void
free_message_catalog (message_catalog *mc)
{

  struct rg_htable_item *item;

  if (mc != NULL)
    {
      if (mc->message_filename != NULL)
	free (mc->message_filename);
      if (mc->htable != NULL)
	{
	  /* free up the strings pointed to by mc->htable items */
	  item = rg_get_htable_items (mc->htable);
	  while (item != NULL)
	    {
	      free (item->key);
	      free (item->data);
	      item = rg_get_htable_items (NULL);
	    }
	  /* now, free up the skeleton and items themselves */
	  rg_free_htable (mc->htable);
	}
      free (mc);
    }

  return;

}


char *
getmessage (message_catalog *mc, char *key)
{

  char *p;
  size_t len;
  static char *msg = NULL;
  static size_t msg_buflen;
  struct rg_htable_item item, *result;

  if (mc == NULL)
    return NULL;
  if (mc->htable == NULL)
    return NULL;

  if (msg == NULL)
    if ((msg = malloc (msg_buflen = 128)) == NULL)
      errabort (40, "malloc error in %s\n", "getmessage()");

  item.key = key; item.uni_key = NULL; item.data = NULL;
  p = "(key not found in message catalog)\n";
  if ((result = rg_find_item (mc->htable, item)) != NULL)
    {
      p = (char *)result->data;
      if ((len = strlen (p) + 1) > msg_buflen)
	if ((msg = realloc (msg, msg_buflen = len)) == NULL)
	  errabort (41, "realloc error in %s\n", "getmessage()");
    }
  strcpy (msg, p);

  return msg;

}


static void
parse_line_add_to_htable (message_catalog *mc, char *line, int lineno)
{

  char *p;
  struct rg_htable_item item;

  /* What are we doing? */
  xwrap (errdebug (7, "Parsing message catalog file, line %d\n", lineno));

  /* Take out trailing #comments */
  xwrap (errdebug (7, "stripping out trailing comments: %s\n", line));
  trimhash_no_quotes_or_backslash (line);
  trim (line, " \r\n\t\f");

  if (*line == '\0')
    xwrap (errdebug (7, "blank or commented-out line; skipping\n"));
  else
    {
      /* Look for the first space; that's then end of our key */
      for (p = line; ! isspace (*p) && *p != '\0'; p++);
      if (*p == '\0')
	errabort (132, "missing message value, line %d\n", lineno);
      *p = '\0';
      item.uni_key = NULL;
      if ((item.key = get_string (line)) == NULL)
	errabort (133, "invalid message key, line %d\n", lineno);
      /* if line contains something of interest */
      if ((item.data = get_string (p + 1)) == NULL)
	errabort (134, "invalid message value, line %d\n", lineno);
      if (rg_add_item (mc->htable, item) != NULL)
	errabort (135, "duplicate key, message catalog, line %d\n", lineno);

      /* What did we just do? */
      xwrap (errdebug (5, "added %s::%s to message hash table\n", item.key, item.data));
    }

  return;

}