/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999-2001, 2003-2004, 2007, 2009-2012, 2014-2017 Free
   Software Foundation, Inc.

   This 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 3 of the License, or (at your option) any later version.

   This 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 this library.  If not, see
   <http://www.gnu.org/licenses/>. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <mailutils/cctype.h>
#include <mailutils/cstr.h>
#include <mailutils/message.h>
#include <mailutils/stream.h>
#include <mailutils/body.h>
#include <mailutils/header.h>
#include <mailutils/errno.h>
#include <mailutils/util.h>
#include <mailutils/assoc.h>
#include <mailutils/io.h>

#include <mailutils/sys/mime.h>
#include <mailutils/sys/message.h>
#include <mailutils/sys/stream.h>

#ifndef TRUE
#define TRUE (1)
#define FALSE (0)
#endif

#define CT_MULTIPART_DIGEST "multipart/digest"
#define CT_MULTIPART_DIGEST_LEN (sizeof (CT_MULTIPART_DIGEST) - 1)

/* TODO:
 *  Need to prevent re-entry into mime lib, but allow non-blocking re-entry
 *  into lib.
 */

static int
_mime_is_multipart_digest (mu_mime_t mime)
{
  if (mime->content_type)
    return mu_c_strncasecmp (CT_MULTIPART_DIGEST, mime->content_type,
			     CT_MULTIPART_DIGEST_LEN) == 0;
  return 0;
}

static int
_mime_append_part (mu_mime_t mime, mu_message_t msg,
		   size_t offset, size_t len, size_t lines)
{
  struct _mime_part *mime_part, **part_arr;
  int ret;
  size_t size;
  mu_header_t hdr;

  if ((mime_part = calloc (1, sizeof (*mime_part))) == NULL)
    return ENOMEM;

  if (mime->nmtp_parts >= mime->tparts)
    {
      if ((part_arr =
	   realloc (mime->mtp_parts,
		    (mime->tparts + 5) * sizeof (mime_part))) == NULL)
	{
	  free (mime_part);
	  return ENOMEM;
	}
      mime->mtp_parts = part_arr;
      mime->tparts += 5;
    }
  mime->mtp_parts[mime->nmtp_parts++] = mime_part;
  if (msg == NULL)
    {
      if ((ret = mu_message_create (&mime_part->msg, mime_part)) == 0)
	{
	  if ((ret =
	       mu_header_create (&hdr, mime->header_buf,
				 mime->header_length)) != 0)
	    {
	      mu_message_destroy (&mime_part->msg, mime_part);
	      free (mime_part);
	      return ret;
	    }
	  mu_message_set_header (mime_part->msg, hdr, mime_part);
	}
      else
	{
	  free (mime_part);
	  return ret;
	}
      mime->header_length = 0;
      if ((ret =
	   mu_header_get_value (hdr, MU_HEADER_CONTENT_TYPE, NULL,
				0, &size)) != 0 || size == 0)
	{
	  if (_mime_is_multipart_digest (mime))
	    mu_header_set_value (hdr,
				 MU_HEADER_CONTENT_TYPE, "message/rfc822", 0);
	  else
	    mu_header_set_value (hdr, MU_HEADER_CONTENT_TYPE, "text/plain",
				 0);
	}
      mime_part->len = len;
      mime_part->lines = lines;
      mime_part->offset = offset;
    }
  else
    {
      mu_message_ref (msg);
      mu_message_size (msg, &mime_part->len);
      mu_message_lines (msg, &mime_part->lines);
      if (mime->stream && mime->nmtp_parts > 1)
	mime_part->offset = mime->mtp_parts[mime->nmtp_parts - 2]->len;
      mime_part->msg = msg;
    }
  mime_part->mime = mime;
  return 0;
}

#define _ISSPECIAL(c) (						 \
    ((c) == '(') || ((c) == ')') || ((c) == '<') || ((c) == '>') \
    || ((c) == '@') || ((c) == ',') || ((c) == ';') || ((c) == ':') \
    || ((c) == '\\') || ((c) == '.') || ((c) == '[') \
    || ((c) == ']') )

static void
_mime_munge_content_header (char *field_body)
{
  char *p, *e, *str = field_body;
  int quoted = 0;

  mu_str_stripws (field_body);

  if ((e = strchr (str, ';')) == NULL)
    return;
  while (*e == ';')
    {
      p = e;
      e++;
      while (*e && mu_isspace (*e)) /* remove space up to param */
	e++;
      memmove (p + 1, e, strlen (e) + 1);
      e = p + 1;

      while (*e && *e != '=')	/* find end of value */
	e++;
      e = p = e + 1;
      while (*e
	     && (quoted
		 || (!_ISSPECIAL (*e) && !mu_isspace (*e))))
	{
	  if (*e == '\\')
	    {			/* escaped */
	      memmove (e, e + 1, strlen (e));
	    }
	  else if (*e == '\"')
	    quoted = ~quoted;
	  e++;
	}
    }
}

static char    *
_mime_get_param (char *field_body, const char *param, int *len)
{
  char *str, *p, *v, *e;
  int quoted = 0, was_quoted;

  if (len == NULL || (str = field_body) == NULL)
    return NULL;

  p = strchr (str, ';');
  while (p)
    {
      p++;
      if ((v = strchr (p, '=')) == NULL)
	break;
      *len = 0;
      v = e = v + 1;
      was_quoted = 0;
      while (*e
	     && (quoted
		 || (!_ISSPECIAL (*e) && !mu_isspace (*e))))
	{			/* skip pass value and calc len */
	  if (*e == '\"')
	    quoted = ~quoted, was_quoted = 1;
	  else
	    (*len)++;
	  e++;
	}
      if (mu_c_strncasecmp (p, param, strlen (param)))
	{			/* no match jump to next */
	  p = strchr (e, ';');
	  continue;
	}
      else
	return was_quoted ? v + 1 : v;	/* return unquoted value */
    }
  return NULL;
}

static int
_mime_setup_buffers (mu_mime_t mime)
{
  if (mime->cur_buf == NULL
      && (mime->cur_buf = malloc (mime->buf_size)) == NULL)
    {
      return ENOMEM;
    }
  if (mime->cur_line == NULL
      && (mime->cur_line = calloc (mime->line_size, 1)) == NULL)
    {
      free (mime->cur_buf);
      return ENOMEM;
    }
  return 0;
}

static void
_mime_append_header_line (mu_mime_t mime)
{
  if (mime->header_length + mime->line_ndx > mime->header_buf_size)
    {
      char *nhb;

      if ((nhb = realloc (mime->header_buf,
			  mime->header_length + mime->line_ndx + 128)) == NULL)
	return;
      mime->header_buf = nhb;
      mime->header_buf_size = mime->header_length + mime->line_ndx + 128;
    }
  memcpy (mime->header_buf + mime->header_length, mime->cur_line,
	  mime->line_ndx);
  mime->header_length += mime->line_ndx;
}

static int
_mime_parse_mpart_message (mu_mime_t mime)
{
  char *cp, *cp2;
  size_t blength, mb_length, mb_offset, mb_lines;
  int ret;
  size_t nbytes;

  if (!(mime->flags & MIME_PARSER_ACTIVE))
    {
      char *boundary;
      int len;

      if ((ret = _mime_setup_buffers (mime)) != 0)
	return ret;
      if ((boundary = _mime_get_param (mime->content_type, "boundary", &len))
	  == NULL)
	return EINVAL;
      if ((mime->boundary = calloc (1, len + 1)) == NULL)
	return ENOMEM;
      strncpy (mime->boundary, boundary, len);

      mime->cur_offset = 0;
      mime->line_ndx = 0;
      mime->parser_state = MIME_STATE_SCAN_BOUNDARY;
      mime->flags |= MIME_PARSER_ACTIVE;
    }
  mb_length = mime->body_length;
  mb_offset = mime->body_offset;
  mb_lines = mime->body_lines;
  blength = strlen (mime->boundary);

  mu_stream_seek (mime->stream, mime->cur_offset, MU_SEEK_SET, NULL);
  while ((ret = mu_stream_read (mime->stream, mime->cur_buf, mime->buf_size,
				&nbytes)) == 0 && nbytes)
    {
      cp = mime->cur_buf;
      while (nbytes)
	{
	  mime->cur_line[mime->line_ndx] = *cp;
	  if (*cp == '\n')
	    {
	      switch (mime->parser_state)
		{
		case MIME_STATE_BEGIN_LINE:
		  mime->cur_line[0] = *cp;
		  mime->line_ndx = 0;
		  mime->parser_state = MIME_STATE_SCAN_BOUNDARY;
		  break;

		case MIME_STATE_SCAN_BOUNDARY:
		  cp2 = mime->cur_line[0] == '\n'
		        ? mime->cur_line + 1 : mime->cur_line;
		  if (mime->line_ndx >= blength)
		    {
		      if ((!strncmp (cp2, "--", 2)
			   && !mu_c_strncasecmp (cp2 + 2, mime->boundary,
				  	         blength))
			  || !mu_c_strncasecmp (cp2, mime->boundary, blength))
			{
			  mime->parser_state = MIME_STATE_HEADERS;
			  mime->flags &= ~MIME_PARSER_HAVE_CR;
			  mb_length = mime->cur_offset 
			                   - mb_offset
			                   - mime->line_ndx;
			  if (mime->header_length)
			    /* this skips the preamble */
			    {
			      /* RFC 1521 [Page 30]:
				 NOTE: The CRLF preceding the encapsulation
				 line is conceptually attached to the boundary
				 so that it is possible to have a part that
				 does not end with a CRLF (line break). Body
				 parts that must be considered to end with line
				 breaks, therefore, must have two CRLFs
				 preceding the encapsulation line, the first
				 of which is part of the preceding body part,
				 and the second of which is part of the
				 encapsulation boundary. */
			      
			      if (mb_lines)
				/* to prevent negative values in case of a
				   malformed message */
				mb_lines--;
				  
			      _mime_append_part (mime, NULL,
						 mb_offset, mb_length,
						 mb_lines);
			    }

			  if ((&mime->cur_line[mime->line_ndx] - cp2 - 1 >
			       blength
			       && !strncmp (cp2 + blength + 2, "--", 2))
			      || (&mime->cur_line[mime->line_ndx] - cp2 - 1 ==
				  blength
				  && !strncmp (cp2 + blength, "--", 2)))
			    {	/* last boundary */
			      mime->parser_state = MIME_STATE_BEGIN_LINE;
			      mime->header_length = 0;
			    }
			  else
			    mime->line_ndx = -1; /* headers parsing requires
						    empty line */
			  break;
			}
		    }

		  if (mime->header_length)
		    mb_lines++;

		  mime->line_ndx = 0;
		  mime->cur_line[0] = *cp;	/* stay in this state but
						   leave '\n' at begining */
		  break;

		case MIME_STATE_HEADERS:
		  mime->line_ndx++;
		  _mime_append_header_line (mime);
		  if (mime->line_ndx == 1 || mime->cur_line[0] == '\r')
		    {
		      mime->parser_state = MIME_STATE_SCAN_BOUNDARY;
		      mb_offset = mime->cur_offset + 1;
		      mb_lines = 0;
		    }
		  mime->line_ndx = -1;
		  break;
		}
	    }
	  mime->line_ndx++;
	  if (mime->line_ndx >= mime->line_size)
	    {
	      size_t newsize = mime->line_size + MIME_MAX_HDR_LEN;
	      char *p = realloc (mime->cur_line, newsize);
	      if (!p)
		{
		  ret = ENOMEM;
		  break;
		}
	      mime->cur_line = p;
	      mime->line_size = newsize;
	    }
	  mime->cur_offset++;
	  nbytes--;
	  cp++;
	}
    }
  mime->body_lines = mb_lines;
  mime->body_length = mb_length;
  mime->body_offset = mb_offset;
  if (ret != EAGAIN)
    {				/* finished cleanup */
      if (mime->header_length)	/* this skips the preamble */
	_mime_append_part (mime, NULL, mb_offset, mb_length, mb_lines);
      mime->flags &= ~MIME_PARSER_ACTIVE;
      mime->body_offset = mime->body_length =
	mime->header_length = mime->body_lines = 0;
    }
  return ret;
}

/*------ Mime message functions for READING a multipart message -----*/

static int
_mimepart_body_size (mu_body_t body, size_t *psize)
{
  mu_message_t msg = mu_body_get_owner (body);
  struct _mime_part *mime_part = mu_message_get_owner (msg);

  if (mime_part == NULL)
    return EINVAL;
  if (psize)
    *psize = mime_part->len;
  return 0;
}

static int
_mimepart_body_lines (mu_body_t body, size_t *plines)
{
  mu_message_t msg = mu_body_get_owner (body);
  struct _mime_part *mime_part = mu_message_get_owner (msg);

  if (mime_part == NULL)
    return EINVAL;
  if (plines)
    *plines = mime_part->lines;
  return 0;
}

/*------ Mime message/header functions for CREATING multipart message -----*/
static int
retain_charset (char const *name, void *value MU_ARG_UNUSED,
		void *data MU_ARG_UNUSED)
{
  return strcmp (name, "charset") != 0;
}
		 
static int
_mime_set_content_type (mu_mime_t mime)
{
  const char  *content_type;
  mu_header_t hdr = NULL;
  size_t size;
  int ret;

  /* Delayed the creation of the header 'til they create the final message via
     mu_mime_get_message()  */
  if (mime->hdrs == NULL)
    return 0;
  if (mime->nmtp_parts > 1)
    {
      char *cstr;
      
      if (mime->flags & MIME_ADDED_MULTIPART_CT)
	return 0;
      if (mime->flags & MU_MIME_MULTIPART_MIXED)
	content_type = "multipart/mixed; boundary=";
      else
	{
	  size_t i;

	  /* Make sure content disposition is not set for alternative
	     parts */
	  for (i = 0; i < mime->nmtp_parts; i++)
	    {
	      mu_header_t hdr;
	      char *val;
	      int rc;
	      
	      mu_message_get_header (mime->mtp_parts[i]->msg, &hdr);
	      mu_header_remove (hdr, MU_HEADER_CONTENT_DISPOSITION, 1);

	      rc = mu_header_aget_value_unfold (hdr, MU_HEADER_CONTENT_TYPE,
						&val);
	      if (rc == 0)
		{
		  mu_content_type_t ct;
		  rc = mu_content_type_parse (val, NULL, &ct);
		  if (rc == 0)
		    {
		      char *type;
		      
		      mu_assoc_mark (ct->param, retain_charset, NULL);
		      mu_assoc_sweep (ct->param);

		      rc = mu_asprintf (&type, "%s/%s", ct->type, ct->subtype);
		      if (rc == 0)
			{
			  mu_mime_header_set (hdr,
					      MU_HEADER_CONTENT_TYPE, type,
					      ct->param);
			  free (type);
			}
		      mu_content_type_destroy (&ct);
		    }
		}
	    }
	  
	  content_type = "multipart/alternative; boundary=";
	}
      if (mime->boundary == NULL)
	{
	  char boundary[128];
	  
	  snprintf (boundary, sizeof boundary, "%ld-%ld=:%ld",
		    (long) random (), (long) time (0), (long) getpid ());
	  if ((mime->boundary = strdup (boundary)) == NULL)
	    return ENOMEM;
	}
      size = strlen (content_type) + 2 + strlen (mime->boundary) + 1;
      cstr = malloc (size);
      if (!cstr)
	return ENOMEM;
      strcpy (cstr, content_type);
      strcat (cstr, "\"");
      strcat (cstr, mime->boundary);
      strcat (cstr, "\"");
      mime->flags |= MIME_ADDED_MULTIPART_CT;

      ret = mu_header_set_value (mime->hdrs, MU_HEADER_CONTENT_TYPE, cstr, 1);
      free (cstr);
    }
  else
    {
      if ((mime->flags & (MIME_ADDED_CT | MIME_ADDED_MULTIPART_CT))
	  == MIME_ADDED_CT)
	return 0;
      mime->flags &= ~MIME_ADDED_MULTIPART_CT;
      if (mime->nmtp_parts)
	mu_message_get_header (mime->mtp_parts[0]->msg, &hdr);

      if (hdr == NULL
	  || mu_header_sget_value (hdr, MU_HEADER_CONTENT_TYPE,
				   &content_type))
	content_type = "text/plain; charset=us-ascii";

      ret = mu_header_set_value (mime->hdrs, MU_HEADER_CONTENT_TYPE,
				 content_type, 1);
      if (ret)
	return ret;

      if (hdr)
	{
	  const char *content_te;
	  
	  /* if the only part contains a transfer-encoding
	     field, set it on the message header too */
	  if (mu_header_sget_value (hdr,
				MU_HEADER_CONTENT_TRANSFER_ENCODING,
				&content_te) == 0)
	    ret = mu_header_set_value (mime->hdrs,
				       MU_HEADER_CONTENT_TRANSFER_ENCODING,
				       content_te, 1);

	  if (ret == 0
	      && mu_header_sget_value (hdr,
				       MU_HEADER_CONTENT_DESCRIPTION,
				       &content_te) == 0)
	    ret = mu_header_set_value (mime->hdrs,
				       MU_HEADER_CONTENT_DESCRIPTION,
				       content_te, 1);

	}
    }
  mime->flags |= MIME_ADDED_CT;
  return ret;
}


static int
_mime_part_size (mu_mime_t mime, size_t *psize)
{
  size_t total;
  int ret;

  if (mime->nmtp_parts == 0)
    {
      *psize = 0;
      return 0;
    }
  
  if ((ret = _mime_set_content_type (mime)) != 0)
    return ret;
  if (mime->nmtp_parts == 1)
    {
      ret = mu_message_size (mime->mtp_parts[0]->msg, &total);
    }
  else
    {
      size_t i, size, boundary_len;

      boundary_len = strlen (mime->boundary);
      total = boundary_len + 3;

      for (i = 0; i < mime->nmtp_parts; i++)
	{
	  ret = mu_message_size (mime->mtp_parts[i]->msg, &size);
	  if (ret)
	    break;
	  total += size + boundary_len + 4;
	}
      total += 2; /* ending boundary line */
    }
  *psize = total;
  return ret;
}


struct _mime_body_stream
{
  struct _mu_stream stream;
  mu_mime_t mime;
};

static int
_mime_body_stream_size (mu_stream_t stream, mu_off_t *psize)
{
  struct _mime_body_stream *mstr = (struct _mime_body_stream *)stream;
  mu_mime_t mime = mstr->mime;
  size_t sz;
  int rc = _mime_part_size (mime, &sz);
  if (rc == 0)
    *psize = sz;
  return rc;
}

static void
mime_reset_state (mu_mime_t mime)
{				/* reset message */
  mime->cur_offset = 0;
  mime->cur_part = 0;
  mime->part_offset = 0;
  
  if (mime->nmtp_parts > 1)
    mime->flags |= MIME_INSERT_BOUNDARY;
}

/* FIXME: The seek method is defective */
static int
_mime_body_stream_seek (mu_stream_t stream, mu_off_t off, mu_off_t *presult)
{
  struct _mime_body_stream *mstr = (struct _mime_body_stream *)stream;
  mu_mime_t mime = mstr->mime;

  if (off == 0)
    mime_reset_state (mime);

  if (off != mime->cur_offset)
    {
      int rc;
      mu_stream_t nullstr;

      if (mime->flags & MIME_SEEK_ACTIVE)
	return ESPIPE;
      mime->flags |= MIME_SEEK_ACTIVE;
      
      rc = mu_nullstream_create (&nullstr, MU_STREAM_WRITE);
      if (rc == 0)
	{
	  mu_off_t total;
	  rc = mu_stream_copy (nullstr, stream, off, &total);
	  mu_stream_destroy (&nullstr);
	  if (rc == 0 && total != off)
	    rc = ESPIPE;
	}
      mime->flags &= ~MIME_SEEK_ACTIVE;
      if (rc)
	return rc;
    }
  *presult = off;
  return 0;
}

#define ADD_CHAR(buf, c, offset, buflen, total, nbytes)	\
  do							\
    {							\
      *(buf)++ = c;					\
      (offset)++;					\
      (total)++;				        \
      if (--(buflen) == 0)			        \
	{						\
	  *(nbytes) = total;				\
	  return 0;					\
	}						\
    }							\
  while (0)

static int
_mime_body_stream_read (mu_stream_t stream, char *buf, size_t buflen,
			size_t *nbytes)
{
  struct _mime_body_stream *mstr = (struct _mime_body_stream *)stream;
  mu_mime_t mime = mstr->mime;
  int ret = 0;
  size_t total = 0;
  
  if (mime->nmtp_parts == 0)
    {
      *nbytes = 0;
      return 0;
    }
  
  if ((ret = _mime_set_content_type (mime)) == 0)
    {
      do
	{
	  size_t part_nbytes = 0;

	  if (buflen == 0)
	    break;
	  if (mime->nmtp_parts > 1)
	    {
	      size_t len;
	      
	      if (mime->flags & MIME_INSERT_BOUNDARY)
		{
		  if ((mime->flags & MIME_ADDING_BOUNDARY) == 0)
		    {
		      mime->boundary_len = strlen (mime->boundary);
		      mime->preamble = 2;
		      if (mime->cur_part == mime->nmtp_parts)
			mime->postamble = 2;
		      mime->flags |= MIME_ADDING_BOUNDARY;
		    }
		  while (mime->preamble)
		    {
		      mime->preamble--;
		      ADD_CHAR (buf, '-', mime->cur_offset, buflen,
				total, nbytes);
		    }
		  len = strlen (mime->boundary) - mime->boundary_len;
		  while (mime->boundary_len)
		    {
		      mime->boundary_len--;
		      ADD_CHAR (buf,
				mime->boundary[len++],
				mime->cur_offset, buflen,
				total, nbytes);
		    }
		  while (mime->postamble)
		    {
		      mime->postamble--;
		      ADD_CHAR (buf, '-', mime->cur_offset, buflen,
				total, nbytes);
		    }
		  mime->flags &=
		    ~(MIME_INSERT_BOUNDARY | MIME_ADDING_BOUNDARY);
		  mime->part_offset = 0;
		  ADD_CHAR (buf, '\n', mime->cur_offset, buflen,
			    total, nbytes);
		}

	      if (!mime->part_stream)
		{
		  if (mime->cur_part >= mime->nmtp_parts)
		    {
		      *nbytes = total;
		      return 0;
		    }
		  ret = mu_message_get_streamref (mime->mtp_parts[mime->cur_part]->msg,
						  &mime->part_stream);
		}
	    }
	  else if (!mime->part_stream)
	    {
	      mu_body_t part_body;

	      if (mime->cur_part >= mime->nmtp_parts)
		{
		  *nbytes = total;
		  return 0;
		}
	      mu_message_get_body (mime->mtp_parts[mime->cur_part]->msg,
				   &part_body);
	      ret = mu_body_get_streamref (part_body, &mime->part_stream);
	    }
	  if (ret)
	    break;
	  ret = mu_stream_seek (mime->part_stream, mime->part_offset,
				MU_SEEK_SET, NULL);
	  if (ret)
	    {
	      mu_stream_destroy (&mime->part_stream);
	      break;
	    }
	  while (buflen > 0 &&
		 (ret = mu_stream_read (mime->part_stream, buf, buflen,
					&part_nbytes)) == 0)
	    {
	      if (part_nbytes)
		{
		  mime->part_offset += part_nbytes;
		  mime->cur_offset += part_nbytes;
		  total += part_nbytes;
		  buflen -= part_nbytes;
		  buf += part_nbytes;
		}
	      else 
		{
		  mu_stream_destroy (&mime->part_stream);
		  mime->flags |= MIME_INSERT_BOUNDARY;
		  mime->cur_part++;
		  ADD_CHAR (buf, '\n', mime->cur_offset, buflen,
			    total, nbytes);
		  break;
		}
	    }
	}
      while (ret == 0 && mime->cur_part <= mime->nmtp_parts);
    }
  if (ret)
    mu_stream_destroy (&mime->part_stream);
  
  *nbytes = total;
  return ret;
}

static int
_mime_body_stream_ioctl (mu_stream_t stream, int code, int opcode, void *arg)
{
  struct _mime_body_stream *mstr = (struct _mime_body_stream *)stream;
  mu_mime_t mime = mstr->mime;
  mu_stream_t msg_stream;
  int rc;
  
  switch (code)
    {
    case MU_IOCTL_TRANSPORT:
      if (!arg)
	return EINVAL;
      switch (opcode)
        {
        case MU_IOCTL_OP_GET:
          if (mime->nmtp_parts == 0 || mime->cur_offset == 0)
	    return EINVAL;
          rc = mu_message_get_streamref (mime->mtp_parts[mime->cur_part]->msg,
				         &msg_stream);
          if (rc)
	    break;
          rc = mu_stream_ioctl (msg_stream, code, opcode, arg);
          mu_stream_destroy (&msg_stream);
          break;
	  
	case MU_IOCTL_OP_SET:
	  return ENOSYS;
	  
	default:
	  return EINVAL;
	}
      break;

    default:
      rc = ENOSYS;
    }
  return rc;
}

static int
create_mime_body_stream (mu_stream_t *pstr, mu_mime_t mime)
{
  struct _mime_body_stream *sp =
    (struct _mime_body_stream *)_mu_stream_create (sizeof (*sp),
						   MU_STREAM_READ | MU_STREAM_SEEK);
  if (!sp)
    return ENOMEM;
  sp->stream.read = _mime_body_stream_read;
  sp->stream.seek = _mime_body_stream_seek;
  sp->stream.ctl = _mime_body_stream_ioctl;
  sp->stream.size = _mime_body_stream_size;
  sp->mime = mime;
  mime_reset_state (mime);
  *pstr = (mu_stream_t) sp;
  return 0;
}


static int
_mime_body_size (mu_body_t body, size_t *psize)
{
  mu_message_t msg = mu_body_get_owner (body);
  mu_mime_t mime = mu_message_get_owner (msg);
  return _mime_part_size (mime, psize);
}

static int
_mime_body_lines (mu_body_t body, size_t *plines)
{
  mu_message_t msg = mu_body_get_owner (body);
  mu_mime_t mime = mu_message_get_owner (msg);
  int i, ret;
  size_t total = 0;

  if (mime->nmtp_parts == 0)
    {
      *plines = 0;
      return 0;
    }
  
  if ((ret = _mime_set_content_type (mime)) != 0)
    return ret;
  for (i = 0; i < mime->nmtp_parts; i++)
    {
      size_t lines;
      
      mu_message_lines (mime->mtp_parts[i]->msg, &lines);
      total += lines;
      if (mime->nmtp_parts > 1)	/* boundary line */
	total++;
    }
  *plines = total;
  return 0;
}

#define MIME_MULTIPART_FLAGS \
  (MU_MIME_MULTIPART_MIXED|MU_MIME_MULTIPART_ALT)

int
mu_mime_create (mu_mime_t *pmime, mu_message_t msg, int flags)
{
  mu_mime_t mime = NULL;
  int ret = 0;
  size_t size;
  mu_body_t body;
  
  if (pmime == NULL)
    return EINVAL;
  
  switch (flags & MIME_MULTIPART_FLAGS)
    {
    case MIME_MULTIPART_FLAGS:
      return EINVAL;

    case 0:
      flags |= MU_MIME_MULTIPART_MIXED;
    }
  
  *pmime = NULL;
  if ((mime = calloc (1, sizeof (*mime))) == NULL)
    return ENOMEM;
  if (msg)
    {
      if ((ret = mu_message_get_header (msg, &mime->hdrs)) == 0)
	{
	  if ((ret = mu_header_get_value (mime->hdrs,
					  MU_HEADER_CONTENT_TYPE,
					  NULL, 0, &size)) == 0 && size)
	    {
	      if ((mime->content_type = malloc (size + 1)) == NULL)
		ret = ENOMEM;
	      else if ((ret = mu_header_get_value (mime->hdrs,
						   MU_HEADER_CONTENT_TYPE,
						   mime->content_type,
						   size + 1, 0)) == 0)
		_mime_munge_content_header (mime->content_type);
	    }
	  else
	    {
	      if (ret == MU_ERR_NOENT)
		{
		  ret = 0;
		  if ((mime->content_type =
		       strdup ("text/plain; charset=us-ascii")) == NULL)
		    /* default as per spec. */
		    ret = ENOMEM;
		}
	    }
	  if (ret == 0)
	    {
	      mime->msg = msg;
	      mime->buf_size = MIME_DFLT_BUF_SIZE;
	      mime->line_size = MIME_MAX_HDR_LEN;
	      mu_message_get_body (msg, &body);
	      mu_body_get_streamref (body, &mime->stream);
	    }
	}
    }
  else
    {
      mime->flags |= MIME_NEW_MESSAGE;
    }
  if (ret != 0)
    {
      if (mime->content_type)
	free (mime->content_type);
      free (mime);
    }
  else
    {
      mime->flags |= (flags & MIME_FLAG_MASK);
      mime->ref_count = 1;
      *pmime = mime;
    }
  return ret;
}

void
mu_mime_ref (mu_mime_t mime)
{
  mime->ref_count++;
}

static void
_mu_mime_free (mu_mime_t mime)
{
  struct _mime_part *mime_part;
  int i;

  if (mime->mtp_parts)
    {
      for (i = 0; i < mime->nmtp_parts; i++)
	{
	  mime_part = mime->mtp_parts[i];
	  mu_message_unref (mime_part->msg);
	  free (mime_part);
	}
      free (mime->mtp_parts);
    }
  mu_stream_destroy (&mime->stream);
  mu_stream_destroy (&mime->part_stream);
  if (mime->msg && mime->flags & MIME_NEW_MESSAGE)
    mu_message_destroy (&mime->msg, mime);
  if (mime->content_type)
    free (mime->content_type);
  if (mime->cur_buf)
    free (mime->cur_buf);
  if (mime->cur_line)
    free (mime->cur_line);
  if (mime->boundary)
    free (mime->boundary);
  if (mime->header_buf)
    free (mime->header_buf);
  free (mime);
}

void
mu_mime_unref (mu_mime_t mime)
{
  if (--mime->ref_count == 0)
    _mu_mime_free (mime);
}

void
mu_mime_destroy (mu_mime_t *pmime)
{
  if (pmime && *pmime)
    {
      mu_mime_unref (*pmime);
      *pmime = NULL;
    }
}

int
mu_mime_get_part (mu_mime_t mime, size_t part, mu_message_t *msg)
{
  size_t          nmtp_parts;
  int             ret = 0, flags = 0;
  mu_stream_t        stream;
  mu_body_t          body;
  struct _mime_part *mime_part;

  if ((ret = mu_mime_get_num_parts (mime, &nmtp_parts)) == 0)
    {
      if (part < 1 || part > nmtp_parts)
	return MU_ERR_NOENT;
      if (nmtp_parts == 1 && mime->mtp_parts == NULL)
	*msg = mime->msg;
      else
	{
	  mime_part = mime->mtp_parts[part - 1];
	  if (mime->stream &&
	      !mime_part->body_created &&
	      (ret = mu_body_create (&body, mime_part->msg)) == 0)
	    {
	      mu_body_set_size (body, _mimepart_body_size, mime_part->msg);
	      mu_body_set_lines (body, _mimepart_body_lines, mime_part->msg);
	      mu_stream_get_flags (mime->stream, &flags);
	      ret = mu_streamref_create_abridged (&stream, mime->stream,
						  mime_part->offset,
						  mime_part->offset +
						    mime_part->len - 1);
	      if (ret == 0)
		{
		  mu_stream_set_flags (stream,
				       MU_STREAM_READ
				       | (flags &
					  (MU_STREAM_SEEK
					   | MU_STREAM_NONBLOCK)));
		  mu_body_set_stream (body, stream, mime_part->msg);
		  mu_message_set_body (mime_part->msg, body, mime_part);
		  mime_part->body_created = 1;
		}
	    }
	  *msg = mime_part->msg;
	}
    }
  return ret;
}

int
mu_mime_get_num_parts (mu_mime_t mime, size_t *nmtp_parts)
{
  int             ret = 0;

  if ((mime->nmtp_parts == 0 && !mime->boundary)
      || mime->flags & MIME_PARSER_ACTIVE)
    {
      if (mu_mime_is_multipart (mime))
	{
	  if ((ret = _mime_parse_mpart_message (mime)) != 0)
	    return (ret);
	}
      else
	{
	  *nmtp_parts = 1;
	  return 0;
	}
    }
  *nmtp_parts = mime->nmtp_parts;
  return (ret);
}

int
mu_mime_add_part (mu_mime_t mime, mu_message_t msg)
{
  int ret;
  
  if (mime == NULL || msg == NULL || (mime->flags & MIME_NEW_MESSAGE) == 0)
    return EINVAL;
  if ((ret = _mime_append_part (mime, msg, 0, 0, 0)) == 0)
    ret = _mime_set_content_type (mime);
  return ret;
}

int
mu_mime_get_message (mu_mime_t mime, mu_message_t *msg)
{
  mu_stream_t body_stream;
  mu_body_t body;
  int ret = 0;

  if (mime == NULL || msg == NULL)
    return EINVAL;
  if (mime->msg == NULL)
    {
      if ((mime->flags & MIME_NEW_MESSAGE) == 0)
	return EINVAL;
      if ((ret = mu_message_create (&mime->msg, mime)) == 0)
	{
	  if ((ret = mu_header_create (&mime->hdrs, NULL, 0)) == 0)
	    {
	      mu_message_set_header (mime->msg, mime->hdrs, mime);
	      mu_header_set_value (mime->hdrs, MU_HEADER_MIME_VERSION, "1.0",
				   1);
	      if ((ret = _mime_set_content_type (mime)) == 0)
		{
		  if ((ret = mu_body_create (&body, mime->msg)) == 0)
		    {
		      mu_message_set_body (mime->msg, body, mime);
		      mu_body_set_size (body, _mime_body_size, mime->msg);
		      mu_body_set_lines (body, _mime_body_lines, mime->msg);
		      ret = create_mime_body_stream (&body_stream, mime);
		      if (ret == 0)
			{
			  mu_body_set_stream (body, body_stream, mime->msg);
			  mime->msg->mime = mime;
			  mu_message_ref (mime->msg);
			  *msg = mime->msg;
			  return 0;
			}
		    }
		}
	    }
	  mu_message_destroy (&mime->msg, mime);
	  mime->msg = NULL;
	}
    }
  if (ret == 0)
    {
      mu_message_ref (mime->msg);
      *msg = mime->msg;
    }
  return ret;
}


int
mu_mime_to_message (mu_mime_t mime, mu_message_t *pmsg)
{
  mu_message_t msg;
  int rc = mu_mime_get_message (mime, &msg);
  if (rc == 0)
    {
      mu_message_unref (msg);
      mime->msg = NULL;
      mu_mime_ref (mime);
      *pmsg = msg;
    }
  return rc;
}

int
mu_mime_is_multipart (mu_mime_t mime)
{
  if (mime->content_type)
    return (mu_c_strncasecmp ("multipart", mime->content_type,
			      strlen ("multipart")) ? 0 : 1);
  return 0;
}
