/* Convert text in given files from the specified from-set to the to-set.
   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <argp.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <iconv.h>
#include <langinfo.h>
#include <locale.h>
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libintl.h>
#ifdef _POSIX_MAPPED_FILES
# include <sys/mman.h>
#endif
#include <charmap.h>
#include <gconv_int.h>
#include "iconv_prog.h"

/* Get libc version number.  */
#include "../version.h"

#define PACKAGE _libc_intl_domainname


/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

#define OPT_VERBOSE	1000
#define OPT_LIST	'l'

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, N_("Input/Output format specification:") },
  { "from-code", 'f', "NAME", 0, N_("encoding of original text") },
  { "to-code", 't', "NAME", 0, N_("encoding for output") },
  { NULL, 0, NULL, 0, N_("Information:") },
  { "list", 'l', NULL, 0, N_("list all known coded character sets") },
  { NULL, 0, NULL, 0, N_("Output control:") },
  { NULL, 'c', NULL, 0, N_("omit invalid characters from output") },
  { "output", 'o', "FILE", 0, N_("output file") },
  { "silent", 's', NULL, 0, N_("suppress warnings") },
  { "verbose", OPT_VERBOSE, NULL, 0, N_("print progress information") },
  { NULL, 0, NULL, 0, NULL }
};

/* Short description of program.  */
static const char doc[] = N_("\
Convert encoding of given files from one encoding to another.");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("[FILE...]");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Function to print some extra text in the help message.  */
static char *more_help (int key, const char *text, void *input);

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, NULL, more_help
};

/* Code sets to convert from and to respectively.  */
static const char *from_code;
static const char *to_code;

/* File to write output to.  If NULL write to stdout.  */
static const char *output_file;

/* Nonzero if verbose ouput is wanted.  */
int verbose;

/* Nonzero if list of all coded character sets is wanted.  */
static int list;

/* If nonzero omit invalid character from output.  */
int omit_invalid;

/* Prototypes for the functions doing the actual work.  */
static int process_block (iconv_t cd, char *addr, size_t len, FILE *output);
static int process_fd (iconv_t cd, int fd, FILE *output);
static int process_file (iconv_t cd, FILE *input, FILE *output);
static void print_known_names (void) internal_function;


int
main (int argc, char *argv[])
{
  int status = EXIT_SUCCESS;
  int remaining;
  FILE *output;
  iconv_t cd;
  const char *orig_to_code;
  struct charmap_t *from_charmap = NULL;
  struct charmap_t *to_charmap = NULL;

  /* Set locale via LC_ALL.  */
  setlocale (LC_ALL, "");

  /* Set the text message domain.  */
  textdomain (_libc_intl_domainname);

  /* Parse and process arguments.  */
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  /* List all coded character sets if wanted.  */
  if (list)
    {
      print_known_names ();
      exit (EXIT_SUCCESS);
    }
  if (from_code == NULL)
    {
      /* The Unix standard says that in this case the charset of the current
	 locale is used.  */
      from_code = nl_langinfo (CODESET);
      assert (from_code != NULL);
    }
  if (to_code == NULL)
    {
      /* The Unix standard says that in this case the charset of the current
	 locale is used.  */
      to_code = nl_langinfo (CODESET);
      assert (to_code != NULL);
    }

  /* If we have to ignore errors make sure we use the appropriate name for
     the to-character-set.  */
  orig_to_code = to_code;
  if (omit_invalid)
    {
      const char *errhand = strchrnul (to_code, '/');
      int nslash = 2;
      char *newp;
      char *cp;

      if (*errhand == '/')
	{
	  --nslash;
	  errhand = strchrnul (errhand, '/');

	  if (*errhand == '/')
	    {
	      --nslash;
	      ++errhand;
	    }
	}

      newp = (char *) alloca (errhand - to_code + nslash + 6 + 1);
      cp = mempcpy (newp, to_code, errhand - to_code);
      while (nslash-- > 0)
	*cp++ = '/';
      memcpy (cp, "IGNORE", sizeof ("IGNORE"));

      to_code = newp;
    }

  /* POSIX 1003.2b introduces a silly thing: the arguments to -t anf -f
     can be file names of charmaps.  In this case iconv will have to read
     those charmaps and use them to do the conversion.  But there are
     holes in the specification.  There is nothing said that if -f is a
     charmap filename that -t must be, too.  And vice versa.  There is
     also no word about the symbolic names used.  What if they don't
     match?  */
  if (strchr (from_code, '/') != NULL)
    /* The from-name might be a charmap file name.  Try reading the
       file.  */
    from_charmap = charmap_read (from_code, /*0, 1*/1, 0, 0);

  if (strchr (orig_to_code, '/') != NULL)
    /* The to-name might be a charmap file name.  Try reading the
       file.  */
    to_charmap = charmap_read (orig_to_code, /*0, 1,*/1,0, 0);


  /* Determine output file.  */
  if (output_file != NULL && strcmp (output_file, "-") != 0)
    {
      output = fopen (output_file, "w");
      if (output == NULL)
	error (EXIT_FAILURE, errno, _("cannot open output file"));
    }
  else
    output = stdout;

  /* At this point we have to handle two cases.  The first one is
     where a charmap is used for the from- or to-charset, or both.  We
     handle this special since it is very different from the sane way of
     doing things.  The other case allows converting using the iconv()
     function.  */
  if (from_charmap != NULL || to_charmap != NULL)
    /* Construct the conversion table and do the conversion.  */
    status = charmap_conversion (from_code, from_charmap, to_code, to_charmap,
				 argc, remaining, argv, output);
  else
    {
      /* Let's see whether we have these coded character sets.  */
      cd = iconv_open (to_code, from_code);
      if (cd == (iconv_t) -1)
	{
	  if (errno == EINVAL)
	    error (EXIT_FAILURE, 0,
		   _("conversion from `%s' to `%s' not supported"),
		   from_code, orig_to_code);
	  else
	    error (EXIT_FAILURE, errno,
		   _("failed to start conversion processing"));
	}

      /* Now process the remaining files.  Write them to stdout or the file
	 specified with the `-o' parameter.  If we have no file given as
	 the parameter process all from stdin.  */
      if (remaining == argc)
	{
	  if (process_file (cd, stdin, output) != 0)
	    status = EXIT_FAILURE;
	}
      else
	do
	  {
#ifdef _POSIX_MAPPED_FILES
	    struct stat st;
	    char *addr;
#endif
	    int fd;

	    if (verbose)
	      printf ("%s:\n", argv[remaining]);
	    if (strcmp (argv[remaining], "-") == 0)
	      fd = 0;
	    else
	      {
		fd = open (argv[remaining], O_RDONLY);

		if (fd == -1)
		  {
		    error (0, errno, _("cannot open input file `%s'"),
			   argv[remaining]);
		    status = EXIT_FAILURE;
		    continue;
		  }
	      }

#ifdef _POSIX_MAPPED_FILES
	    /* We have possibilities for reading the input file.  First try
	       to mmap() it since this will provide the fastest solution.  */
	    if (fstat (fd, &st) == 0
		&& ((addr = mmap (NULL, st.st_size, PROT_READ, MAP_PRIVATE,
				  fd, 0)) != MAP_FAILED))
	      {
		/* Yes, we can use mmap().  The descriptor is not needed
		   anymore.  */
		if (close (fd) != 0)
		  error (EXIT_FAILURE, errno,
			 _("error while closing input `%s'"),
			 argv[remaining]);

		if (process_block (cd, addr, st.st_size, output) < 0)
		  {
		    /* Something went wrong.  */
		    status = EXIT_FAILURE;

		    /* We don't need the input data anymore.  */
		    munmap ((void *) addr, st.st_size);

		    /* We cannot go on with producing output since it might
		       lead to problem because the last output might leave
		       the output stream in an undefined state.  */
		    break;
		  }

		/* We don't need the input data anymore.  */
		munmap ((void *) addr, st.st_size);
	      }
	    else
#endif	/* _POSIX_MAPPED_FILES */
	      {
		/* Read the file in pieces.  */
		if (process_fd (cd, fd, output) != 0)
		  {
		    /* Something went wrong.  */
		    status = EXIT_FAILURE;

		    /* We don't need the input file anymore.  */
		    close (fd);

		    /* We cannot go on with producing output since it might
		       lead to problem because the last output might leave
		       the output stream in an undefined state.  */
		    break;
		  }

		/* Now close the file.  */
		close (fd);
	      }
	  }
	while (++remaining < argc);
    }

  /* Close the output file now.  */
  if (fclose (output))
    error (EXIT_FAILURE, errno, _("error while closing output file"));

  return status;
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case 'f':
      from_code = arg;
      break;
    case 't':
      to_code = arg;
      break;
    case 'o':
      output_file = arg;
      break;
    case 's':
      /* Nothing, for now at least.  We are not giving out any information
	 about missing character or so.  */
      break;
    case 'c':
      /* Omit invalid characters from output.  */
      omit_invalid = 1;
      break;
    case OPT_VERBOSE:
      verbose = 1;
      break;
    case OPT_LIST:
      list = 1;
      break;
    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}


static char *
more_help (int key, const char *text, void *input)
{
  switch (key)
    {
    case ARGP_KEY_HELP_EXTRA:
      /* We print some extra information.  */
      return strdup (gettext ("\
Report bugs using the `glibcbug' script to <bugs@gnu.org>.\n"));
    default:
      break;
    }
  return (char *) text;
}


/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "iconv (GNU %s) %s\n", PACKAGE, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2001");
  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}


static int
process_block (iconv_t cd, char *addr, size_t len, FILE *output)
{
#define OUTBUF_SIZE	32768
  const char *start = addr;
  char outbuf[OUTBUF_SIZE];
  char *outptr;
  size_t outlen;
  size_t n;

  while (len > 0)
    {
      outptr = outbuf;
      outlen = OUTBUF_SIZE;
      n = iconv (cd, &addr, &len, &outptr, &outlen);

      if (outptr != outbuf)
	{
	  /* We have something to write out.  */
	  int errno_save = errno;

	  if (fwrite (outbuf, 1, outptr - outbuf, output) < outptr - outbuf
	      || ferror (output))
	    {
	      /* Error occurred while printing the result.  */
	      error (0, 0, _("\
conversion stopped due to problem in writing the output"));
	      return -1;
	    }

	  errno = errno_save;
	}

      if (n != (size_t) -1)
	{
	  /* All the input test is processed.  For state-dependent
             character sets we have to flush the state now.  */
	  outptr = outbuf;
	  outlen = OUTBUF_SIZE;
	  (void) iconv (cd, NULL, NULL, &outptr, &outlen);

	  if (outptr != outbuf)
	    {
	      /* We have something to write out.  */
	      int errno_save = errno;

	      if (fwrite (outbuf, 1, outptr - outbuf, output) < outptr - outbuf
		  || ferror (output))
		{
		  /* Error occurred while printing the result.  */
		  error (0, 0, _("\
conversion stopped due to problem in writing the output"));
		  return -1;
		}

	      errno = errno_save;
	    }

	  break;
	}

      if (errno != E2BIG)
	{
	  /* iconv() ran into a problem.  */
	  switch (errno)
	    {
	    case EILSEQ:
	      error (0, 0, _("illegal input sequence at position %ld"),
		     (long) (addr - start));
	      break;
	    case EINVAL:
	      error (0, 0, _("\
incomplete character or shift sequence at end of buffer"));
	      break;
	    case EBADF:
	      error (0, 0, _("internal error (illegal descriptor)"));
	      break;
	    default:
	      error (0, 0, _("unknown iconv() error %d"), errno);
	      break;
	    }

	  return -1;
	}
    }

  return 0;
}


static int
process_fd (iconv_t cd, int fd, FILE *output)
{
  /* we have a problem with reading from a desriptor since we must not
     provide the iconv() function an incomplete character or shift
     sequence at the end of the buffer.  Since we have to deal with
     arbitrary encodings we must read the whole text in a buffer and
     process it in one step.  */
  static char *inbuf = NULL;
  static size_t maxlen = 0;
  char *inptr = NULL;
  size_t actlen = 0;

  while (actlen < maxlen)
    {
      ssize_t n = read (fd, inptr, maxlen - actlen);

      if (n == 0)
	/* No more text to read.  */
	break;

      if (n == -1)
	{
	  /* Error while reading.  */
	  error (0, errno, _("error while reading the input"));
	  return -1;
	}

      inptr += n;
      actlen += n;
    }

  if (actlen == maxlen)
    while (1)
      {
	ssize_t n;

	/* Increase the buffer.  */
	maxlen += 32768;
	inbuf = realloc (inbuf, maxlen);
	if (inbuf == NULL)
	  error (0, errno, _("unable to allocate buffer for input"));
	inptr = inbuf + actlen;

	do
	  {
	    n = read (fd, inptr, maxlen - actlen);

	    if (n == 0)
	      /* No more text to read.  */
	      break;

	    if (n == -1)
	      {
		/* Error while reading.  */
		error (0, errno, _("error while reading the input"));
		return -1;
	      }

	    inptr += n;
	    actlen += n;
	  }
	while (actlen < maxlen);

	if (n == 0)
	  /* Break again so we leave both loops.  */
	  break;
      }

  /* Now we have all the input in the buffer.  Process it in one run.  */
  return process_block (cd, inbuf, actlen, output);
}


static int
process_file (iconv_t cd, FILE *input, FILE *output)
{
  /* This should be safe since we use this function only for `stdin' and
     we haven't read anything so far.  */
  return process_fd (cd, fileno (input), output);
}


/* Print all known character sets/encodings.  */
static void *printlist;
static size_t column;
static int not_first;

static void
insert_print_list (const void *nodep, VISIT value, int level)
{
  if (value == leaf || value == postorder)
    {
      const struct gconv_alias *s = *(const struct gconv_alias **) nodep;
      tsearch (s->fromname, &printlist, (__compar_fn_t) strverscmp);
    }
}

static void
do_print_human  (const void *nodep, VISIT value, int level)
{
  if (value == leaf || value == postorder)
    {
      const char *s = *(const char **) nodep;
      size_t len = strlen (s);
      size_t cnt;

      while (len > 0 && s[len - 1] == '/')
	--len;

      for (cnt = 0; cnt < len; ++cnt)
	if (isalnum (s[cnt]))
	  break;
      if (cnt == len)
	return;

      if (not_first)
	{
	  putchar (',');
	  ++column;

	  if (column > 2 && column + len > 77)
	    {
	      fputs ("\n  ", stdout);
	      column = 2;
	    }
	  else
	    {
	      putchar (' ');
	      ++column;
	    }
	}
      else
	not_first = 1;

      fwrite (s, len, 1, stdout);
      column += len;
    }
}

static void
do_print  (const void *nodep, VISIT value, int level)
{
  if (value == leaf || value == postorder)
    {
      const char *s = *(const char **) nodep;

      puts (s);
    }
}

static void
internal_function
add_known_names (struct gconv_module *node)
{
  if (node->left != NULL)
    add_known_names (node->left);
  if (node->right != NULL)
    add_known_names (node->right);
  do
    {
      if (strcmp (node->from_string, "INTERNAL"))
	tsearch (node->from_string, &printlist,
		 (__compar_fn_t) strverscmp);
      if (strcmp (node->to_string, "INTERNAL"))
	tsearch (node->to_string, &printlist, (__compar_fn_t) strverscmp);

      node = node->same;
    }
  while (node != NULL);
}

static void
internal_function
print_known_names (void)
{
  iconv_t h;

  /* We must initialize the internal databases first.  */
  h = iconv_open ("L1", "L1");
  iconv_close (h);

  /* First add the aliases.  */
  twalk (__gconv_alias_db, insert_print_list);

  /* Add the from- and to-names from the known modules.  */
  add_known_names (__gconv_modules_db);

  fputs (_("\
The following list contain all the coded character sets known.  This does\n\
not necessarily mean that all combinations of these names can be used for\n\
the FROM and TO command line parameters.  One coded character set can be\n\
listed with several different names (aliases).\n\n  "), stdout);

  /* Now print the collected names.  */
  column = 2;
  if (isatty (fileno (stdout)))
    {
      twalk (printlist, do_print_human);

      if (column != 0)
	puts ("");
    }
  else
    twalk (printlist, do_print);
}
