/* GNU mailutils - a suite of utilities for electronic mail
   Copyright (C) 1999, 2000, 2001 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "mail.h"

/*
  FIXME:
 decode, this is temporary, until the API on how to present
 mime/attachements etc is less confusing.
 */

static int print_stream __P ((stream_t, FILE *));
static int display_message __P ((message_t, FILE *, int));
static int mailcap_lookup __P ((const char *));
static int get_hdr_value __P ((header_t hdr, const char *name, char **value));
static int get_content_encoding __P ((header_t hdr, char **value));
static int get_content_type __P ((header_t hdr, char **value));

int
mail_decode (int argc, char **argv)
{
  if (argc > 1)
    return util_msglist_command (mail_print, argc, argv, 1);
  else
    {
      message_t mesg;
      int lines = 0;
      FILE *out = ofile;
      attribute_t attr;

      if (mailbox_get_message (mbox, cursor, &mesg) != 0)
	return 1;

      if (util_isdeleted (cursor))
        return 1;

      message_lines (mesg, &lines);

      if ((util_find_env("crt"))->set && lines > util_getlines ())
	    out = popen (getenv("PAGER"), "w");

      display_message (mesg, out, islower (argv[0][0]));

      message_get_attribute (mesg, &attr);
      attribute_set_read (attr);

      if (out != ofile)
	pclose (out);

      return 0;
    }
  return 1;
}

static int
display_message (message_t mesg, FILE *out, int select_hdr)
{
  size_t nparts = 0;
  header_t hdr = NULL;
  size_t j;

  /* Print the selected headers only.  */
  if (select_hdr)
    {
      size_t num = 0;
      size_t i = 0;
      char buffer[512];

      hdr = NULL;
      message_get_header (mesg, &hdr);
      header_get_field_count (hdr, &num);
      for (i = 1; i <= num; i++)
	{
	  buffer[0] = '\0';
	  header_get_field_name (hdr, i, buffer, sizeof(buffer), NULL);
	  if (mail_header_is_visible (buffer))
	    {
	      fprintf (out, "%s: ", buffer);
	      header_get_field_value (hdr, i, buffer, sizeof(buffer), NULL);
	      fprintf (out, "%s\n", buffer);
	    }
	}
      fprintf (out, "\n");
    }
  else /* Print displays all headers.  */
    {
      stream_t stream = NULL;
      if (message_get_header (mesg, &hdr) == 0
	  && header_get_stream (hdr, &stream) == 0)
	print_stream (stream, out);
    }

  message_get_num_parts (mesg, &nparts);
  for (j = 1; j <= nparts; j++)
    {
      message_t message = NULL;
      if (message_get_part (mesg, j, &message) == 0)
	{
	  char *type = NULL;
	  char *encoding = NULL;
	  int ismime = 0;

	  message_is_multipart (message, &ismime);
	  if (ismime)
	    {
	      display_message (message, out, 0);
	      continue;
	    }

	  message_get_header (message, &hdr);

	  get_content_type (hdr, &type);
	  get_content_encoding (hdr, &encoding);

	  if (strncasecmp (type, "message/rfc822", strlen (type)) == 0)
	    {
	      message_t submsg = NULL;
	      if (message_unencapsulate (message, &submsg, NULL) == 0)
		display_message (submsg, out, select_hdr);
	    }
	  else if (mailcap_lookup (type))
	    {
	      /* FIXME: lookup .mailcap and do the appropriate action when
		 an match engry is find.  */
	      /* Do something, spawn a process etc ....  */
	    }
	  else if (strncasecmp (type, "text/plain", strlen ("text/plain")) == 0
		   || strncasecmp (type, "text/html", strlen ("text/html")) == 0)
	    {
	      body_t body = NULL;
	      stream_t b_stream = NULL;

	      if (message_get_body (message, &body) == 0 &&
		  body_get_stream (body, &b_stream) == 0)
		{
		  stream_t d_stream = NULL;
		  stream_t stream = NULL;

		  /* Can we decode.  */
		  if (filter_create(&d_stream, b_stream, encoding,
				    MU_FILTER_DECODE, MU_STREAM_READ) == 0)
		    stream = d_stream;
		  else
		    stream = b_stream;

		  print_stream (stream, out);
		  if (d_stream)
		    stream_destroy (&d_stream, NULL);
		}
	    }
	  else
	    {
	      int size = util_screen_columns () - 3;
	      int i;
	      fputc ('+', out);
	      for (i = 0; i <= size; i++)
		fputc ('-', out);
	      fputc ('+', out); fputc ('\n', out);
	      fprintf (out, "| Message=%d[%d]\n", cursor, j);
	      fprintf (out, "| Type=%s\n", type);
	      fprintf (out, "| encoding=%s\n", encoding);
	      fputc ('+', out);
	      for (i = 0; i <= size; i++)
		fputc ('-', out);
	      fputc ('+', out); fputc ('\n', out);
	    }
	  free (type);
	  free (encoding);
	}
    }
  return 0;
}

static int
print_stream (stream_t stream, FILE *out)
{
  char buffer[512];
  off_t off = 0;
  size_t n = 0;

  while (stream_read (stream, buffer, sizeof (buffer) - 1, off, &n) == 0
	 && n != 0)
    {
      if (ml_got_interrupt())
	{
	  util_error("\nInterrupt");
	  break;
	}
      buffer[n] = '\0';
      fprintf (out, "%s", buffer);
      off += n;
    }
  return 0;
}

static int
get_content_type (header_t hdr, char **value)
{
  char *type = NULL;
  get_hdr_value (hdr, MU_HEADER_CONTENT_TYPE, &type);
  if (type == NULL || *type == '\0')
    {
      if (type)
	free (type);
      type = strdup ("text/plain"); /* Default.  */
    }
  *value = type;
  return 0;
}

static int
get_content_encoding (header_t hdr, char **value)
{
  char *encoding = NULL;
  get_hdr_value (hdr, MU_HEADER_CONTENT_TRANSFER_ENCODING, &encoding);
  if (encoding == NULL || *encoding == '\0')
    {
      if (encoding)
	free (encoding);
      encoding = strdup ("7bit"); /* Default.  */
    }
  *value = encoding;
  return 0;
}

static int
get_hdr_value (header_t hdr, const char *name, char **value)
{
  int status = header_aget_value (hdr, name, value);
  if (status == 0)
    {
      /* Remove the newlines.  */
      char *nl;
      while ((nl = strchr (*value, '\n')) != NULL)
	{
	  *nl = ' ';
	}
    }
  return status;
}

static int
mailcap_lookup (const char *type)
{
  (void)type;
  return 0;
}