/*
** Copyright (C) 2008-2011 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** 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 3, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/

#if HAVE_CONFIG_H
#include "config.h"
#endif /*HAVE_CONFIG_H*/

#include <string.h>
#include <unistd.h>

#include "mu-util.h"
#include "mu-msg-priv.h"
#include "mu-msg-part.h"

struct _FindPartData {
		guint			 idx, wanted_idx;
		GMimeObject		*part;
};
typedef struct _FindPartData FindPartData;


static void
find_part_cb (GMimeObject *parent, GMimeObject *part, FindPartData *fpdata)
{
		if (fpdata->part || fpdata->wanted_idx != fpdata->idx++)
				return; /* not yet found */

		fpdata->part = part;
}

static GMimeObject*
find_part (MuMsg* msg, guint partidx)
{
		FindPartData fpdata;

		fpdata.wanted_idx = partidx;
		fpdata.idx = 0;
		fpdata.part = NULL;
		
		g_mime_message_foreach (msg->_mime_msg,
								(GMimeObjectForeachFunc)find_part_cb,
								&fpdata);
		return fpdata.part;
}

struct _PartData {
		MuMsg					*_msg;
		unsigned				_idx;
		MuMsgPartForeachFunc	_func;
		gpointer				_user_data;
};
typedef struct _PartData		PartData;


static void
part_foreach_cb (GMimeObject *parent, GMimeObject *part, PartData *pdata)
{
		GMimeContentType *ct;
		MuMsgPart pi;

		memset (&pi, 0, sizeof pi);
		pi.index       = pdata->_idx++;
		pi.content_id  = (char*)g_mime_object_get_content_id (part);

		ct = g_mime_object_get_content_type (part);

		if (GMIME_IS_CONTENT_TYPE(ct)) {
				pi.type	   = (char*)g_mime_content_type_get_media_type (ct);
				pi.subtype = (char*)g_mime_content_type_get_media_subtype (ct);	
		}

		if (GMIME_IS_PART(part)) {
				pi.disposition = (char*)g_mime_object_get_disposition (part);
				pi.file_name   = (char*)g_mime_part_get_filename (GMIME_PART(part));
		}
	
		pdata->_func(pdata->_msg, &pi, pdata->_user_data);	
}

void
mu_msg_part_foreach (MuMsg *msg, MuMsgPartForeachFunc func,
					 gpointer user_data)
{
		PartData pdata;
	
		g_return_if_fail (msg);
		g_return_if_fail (GMIME_IS_OBJECT(msg->_mime_msg));

		pdata._msg       = msg;
		pdata._idx       = 0;
		pdata._func		 = func;
		pdata._user_data = user_data;
	
		g_mime_message_foreach (msg->_mime_msg,
								(GMimeObjectForeachFunc)part_foreach_cb,
								&pdata);
}


static gboolean
write_to_stream (GMimeObject *part, int fd)
{
		GMimeStream *stream;
		GMimeDataWrapper *wrapper;
		gboolean rv;
		
		stream = g_mime_stream_fs_new (fd);
		if (!GMIME_IS_STREAM(stream)) {
				g_critical ("%s: failed to create stream",__FUNCTION__);
				return FALSE;
		}
		g_mime_stream_fs_set_owner (GMIME_STREAM_FS(stream), FALSE);
		
		wrapper = g_mime_part_get_content_object (GMIME_PART(part));
		if (!GMIME_IS_DATA_WRAPPER(wrapper)) {
				g_critical ("%s: failed to create wrapper", __FUNCTION__);
				g_object_unref (stream);
				return FALSE;
		}
		g_object_ref (part); /* FIXME: otherwise, the unrefs below
							  * give errors...*/
		
		rv = g_mime_data_wrapper_write_to_stream (wrapper, stream);
		if (!rv)
				g_critical ("%s: failed to write to stream", __FUNCTION__);
		
		g_object_unref (wrapper);
		g_object_unref (stream);
		
		return rv;
}


gboolean
save_part (GMimeObject *part, const char *fullpath,
		   gboolean overwrite, gboolean use_existing)
{
		int fd;
		gboolean rv;
		
		/* don't try to overwrite when we already have it; useful when
		 * you're sure it's not a different file with the same name */
		if (use_existing && access (fullpath, F_OK) == 0)
				return TRUE;
		
		/* ok, try to create the file */
		fd = mu_util_create_writeable_fd (fullpath, 0600, overwrite);
		if (fd == -1)
				return FALSE;
				
		rv = write_to_stream (part, fd);
		if (close (fd) != 0)
				g_warning ("%s: failed to close %s: %s", __FUNCTION__,
						   fullpath, strerror(errno));
		
		return TRUE;
}


gchar*
mu_msg_part_filepath (MuMsg *msg, const char* targetdir, guint partidx)
{
		char *fname, *filepath;
		GMimeObject* part;

		part = find_part (msg, partidx);
		if (!part) {
				g_warning ("%s: cannot find part %u", __FUNCTION__, partidx);
				return NULL;
		}
		
		/* the easy case: the part has a filename */
		fname = (gchar*)g_mime_part_get_filename (GMIME_PART(part));
		if (fname) /* security: don't include any directory components... */
				fname = g_path_get_basename (fname);
		else
				fname =  g_strdup_printf ("%x-part-%u",
										  g_str_hash (mu_msg_get_path (msg)),
										  partidx);

		filepath = g_build_path (G_DIR_SEPARATOR_S, targetdir ? targetdir : "",
								 fname, NULL);
		g_free (fname);

		return filepath;
}



gchar*
mu_msg_part_filepath_cache (MuMsg *msg, guint partid)
{
		char *dirname, *filepath;
		const char* path;
		
		g_return_val_if_fail (msg, NULL);
		
		path = mu_msg_get_path (msg);
		if (!path)
				return NULL;

		/* g_compute_checksum_for_string may be better, but requires
		 * rel. new glib (2.16) */
        dirname = g_strdup_printf ("%s%c%x%c%u",
								   mu_util_cache_dir(), G_DIR_SEPARATOR,
								   g_str_hash (path), G_DIR_SEPARATOR,
								   partid);
		
		if (!mu_util_create_dir_maybe (dirname, 0700)) {
				g_free (dirname);
				return NULL;
		}

		filepath = mu_msg_part_filepath (msg, dirname, partid);
		g_free (dirname);
		if (!filepath) 
				g_warning ("%s: could not get filename", __FUNCTION__);
	
		return filepath;
}


gboolean
mu_msg_part_save (MuMsg *msg, const char *fullpath, guint partidx,
				  gboolean overwrite, gboolean use_cached)
{
		GMimeObject *part;
		
		g_return_val_if_fail (msg, FALSE);
		g_return_val_if_fail (fullpath, FALSE);
		g_return_val_if_fail (!overwrite||!use_cached, FALSE);
		
		part = find_part (msg, partidx);
		if (!GMIME_IS_PART(part)) {
				g_warning ("%s: cannot find part %u", __FUNCTION__, partidx);
				return FALSE;
		}
				
		if (!save_part (part, fullpath, overwrite, use_cached)) {
				g_warning ("%s: failed to save '%s'", __FUNCTION__, fullpath);
				return FALSE;
		}

		return TRUE;
}




typedef gboolean (*MatchFunc) (GMimeObject *part, gpointer data);

struct _MatchData {
	MatchFunc _matcher;
	gpointer  _user_data;
	gint      _idx, _found_idx;
};
typedef struct _MatchData MatchData;

static void
part_match_foreach_cb (GMimeObject *parent, GMimeObject *part, MatchData *mdata)
{
	if (mdata->_found_idx >= 0)
		if (mdata->_matcher (part, mdata->_user_data))
			mdata->_found_idx = mdata->_idx;
	
	++mdata->_idx;
}

static int
msg_part_find_idx (GMimeMessage *msg, MatchFunc func, gpointer user_data)
{
	MatchData mdata;
	
	g_return_val_if_fail (msg, -1);
	g_return_val_if_fail (GMIME_IS_MESSAGE(msg), -1);
	
	mdata._idx       = 0;
	mdata._found_idx = -1;
	mdata._matcher   = func;
	mdata._user_data = user_data;
	
	g_mime_message_foreach (msg,
							(GMimeObjectForeachFunc)part_match_foreach_cb,
							&mdata);

	return mdata._found_idx;
}


static gboolean
match_content_id (GMimeObject *part, const char *sought_cid)
{
		return g_strcmp0 (g_mime_object_get_content_id (part),
						  sought_cid) == 0;
}

int
mu_msg_part_find_cid (MuMsg *msg, const char* content_id)
{
	g_return_val_if_fail (msg, -1L);
	g_return_val_if_fail (content_id, -1);

	return msg_part_find_idx (msg->_mime_msg, (MatchFunc)match_content_id,
							  (gpointer)content_id);
}