/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2001-2004 Ximian, Inc. (www.ximian.com)
 *
 *  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 of the License, 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.
 *
 */


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

#include <stdio.h>
#include <string.h>

#include "em-stripsig-filter.h"


static void em_stripsig_filter_class_init (EMStripSigFilterClass *klass);
static void em_stripsig_filter_init (EMStripSigFilter *filter, EMStripSigFilterClass *klass);

static void filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
			   char **out, size_t *outlen, size_t *outprespace);
static void filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
			     char **out, size_t *outlen, size_t *outprespace);
static void filter_reset (CamelMimeFilter *filter);


static CamelMimeFilterClass *parent_class = NULL;


CamelType
em_stripsig_filter_get_type (void)
{
	static CamelType type = CAMEL_INVALID_TYPE;
	
	if (type == CAMEL_INVALID_TYPE) {
		type = camel_type_register (camel_mime_filter_get_type (),
					    "EMStripSigFilter",
					    sizeof (EMStripSigFilter),
					    sizeof (EMStripSigFilterClass),
					    (CamelObjectClassInitFunc) em_stripsig_filter_class_init,
					    NULL,
					    (CamelObjectInitFunc) em_stripsig_filter_init,
					    NULL);
	}
	
	return type;
}


static void
em_stripsig_filter_class_init (EMStripSigFilterClass *klass)
{
	CamelMimeFilterClass *filter_class = (CamelMimeFilterClass *) klass;
	
	parent_class = CAMEL_MIME_FILTER_CLASS (camel_type_get_global_classfuncs (camel_mime_filter_get_type ()));
	
	filter_class->reset = filter_reset;
	filter_class->filter = filter_filter;
	filter_class->complete = filter_complete;
}

static void
em_stripsig_filter_init (EMStripSigFilter *filter, EMStripSigFilterClass *klass)
{
	filter->midline = FALSE;
}

static void
strip_signature (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
		 char **out, size_t *outlen, size_t *outprespace, int flush)
{
	EMStripSigFilter *stripsig = (EMStripSigFilter *) filter;
	register const char *inptr = in;
	const char *inend = in + len;
	const char *start = NULL;
	
	if (stripsig->midline) {
		while (inptr < inend && *inptr != '\n')
			inptr++;
		
		if (inptr < inend) {
			stripsig->midline = FALSE;
			inptr++;
		}
	}
	
	while (inptr < inend) {
		if ((inend - inptr) >= 4 && !strncmp (inptr, "-- \n", 4)) {
			start = inptr;
			inptr += 4;
		} else {
			while (inptr < inend && *inptr != '\n')
				inptr++;
			
			if (inptr == inend) {
				stripsig->midline = TRUE;
				break;
			}
			
			inptr++;
		}
	}
	
	if (start != NULL)
		inptr = start;
	
	if (!flush && inend > inptr)
		camel_mime_filter_backup (filter, inptr, inend - inptr);
	else if (!start)
		inptr = inend;
	
	*out = in;
	*outlen = inptr - in;
	*outprespace = prespace;
}

static void
filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
	       char **out, size_t *outlen, size_t *outprespace)
{
	strip_signature (filter, in, len, prespace, out, outlen, outprespace, FALSE);
}

static void
filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
		 char **out, size_t *outlen, size_t *outprespace)
{
	strip_signature (filter, in, len, prespace, out, outlen, outprespace, TRUE);
}

/* should this 'flush' outstanding state/data bytes? */
static void
filter_reset (CamelMimeFilter *filter)
{
	EMStripSigFilter *stripsig = (EMStripSigFilter *) filter;
	
	stripsig->midline = FALSE;
}


/**
 * em_stripsig_filter_new:
 *
 * Creates a new stripsig filter.
 *
 * Returns a new stripsig filter.
 **/
CamelMimeFilter *
em_stripsig_filter_new (void)
{
	return (CamelMimeFilter *) camel_object_new (EM_TYPE_STRIPSIG_FILTER);
}