/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * Authors: Jeffrey Stedfast <fejj@ximian.com>
 *	     Michael Zucchi <NotZed@Ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 * 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.
 *
 * 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 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

/* POSIX requires <sys/types.h> be included before <regex.h> */
#include <sys/types.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <glib/gi18n-lib.h>

#ifndef G_OS_WIN32
#include <sys/wait.h>
#endif

#include "camel-debug.h"
#include "camel-filter-search.h"
#include "camel-iconv.h"
#include "camel-mime-message.h"
#include "camel-multipart.h"
#include "camel-provider.h"
#include "camel-search-private.h"
#include "camel-session.h"
#include "camel-stream-fs.h"
#include "camel-stream-mem.h"
#include "camel-string-utils.h"
#include "camel-url.h"

#define d(x)

typedef struct {
	CamelSession *session;
	CamelFilterSearchGetMessageFunc get_message;
	gpointer get_message_data;
	CamelMimeMessage *message;
	CamelMessageInfo *info;
	const gchar *source;
	GError **error;
} FilterMessageSearch;

/* CamelSExp callbacks */
static CamelSExpResult *header_contains (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_has_words (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_matches (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_starts_with (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_ends_with (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_exists (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_soundex (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_regex (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_full_regex (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *match_all (struct _CamelSExp *f, gint argc, struct _CamelSExpTerm **argv, FilterMessageSearch *fms);
static CamelSExpResult *body_contains (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *body_regex (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *user_flag (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *user_tag (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *system_flag (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *get_sent_date (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *get_received_date (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *get_current_date (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *get_relative_months (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *header_source (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *get_size (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *pipe_message (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);
static CamelSExpResult *junk_test (struct _CamelSExp *f, gint argc, struct _CamelSExpResult **argv, FilterMessageSearch *fms);

/* builtin functions */
static struct {
	const gchar *name;
	CamelSExpFunc func;
	gint type;		/* set to 1 if a function can perform shortcut evaluation, or
				   doesn't execute everything, 0 otherwise */
} symbols[] = {
	{ "match-all",          (CamelSExpFunc) match_all,          1 },
	{ "body-contains",      (CamelSExpFunc) body_contains,      0 },
	{ "body-regex",         (CamelSExpFunc) body_regex,         0 },
	{ "header-contains",    (CamelSExpFunc) header_contains,    0 },
	{ "header-has-words",   (CamelSExpFunc) header_has_words,   0 },
	{ "header-matches",     (CamelSExpFunc) header_matches,     0 },
	{ "header-starts-with", (CamelSExpFunc) header_starts_with, 0 },
	{ "header-ends-with",   (CamelSExpFunc) header_ends_with,   0 },
	{ "header-exists",      (CamelSExpFunc) header_exists,      0 },
	{ "header-soundex",     (CamelSExpFunc) header_soundex,     0 },
	{ "header-regex",       (CamelSExpFunc) header_regex,       0 },
	{ "header-full-regex",  (CamelSExpFunc) header_full_regex,  0 },
	{ "user-tag",           (CamelSExpFunc) user_tag,           0 },
	{ "user-flag",          (CamelSExpFunc) user_flag,          0 },
	{ "system-flag",        (CamelSExpFunc) system_flag,        0 },
	{ "get-sent-date",      (CamelSExpFunc) get_sent_date,      0 },
	{ "get-received-date",  (CamelSExpFunc) get_received_date,  0 },
	{ "get-current-date",   (CamelSExpFunc) get_current_date,   0 },
	{ "get-relative-months",(CamelSExpFunc) get_relative_months,0 },
	{ "header-source",      (CamelSExpFunc) header_source,      0 },
	{ "get-size",           (CamelSExpFunc) get_size,           0 },
	{ "pipe-message",       (CamelSExpFunc) pipe_message,       0 },
	{ "junk-test",          (CamelSExpFunc) junk_test,          0 },
};

static CamelMimeMessage *
camel_filter_search_get_message (FilterMessageSearch *fms,
                                 struct _CamelSExp *sexp)
{
	if (fms->message)
		return fms->message;

	fms->message = fms->get_message (fms->get_message_data, fms->error);

	if (fms->message == NULL)
		camel_sexp_fatal_error (sexp, _("Failed to retrieve message"));

	return fms->message;
}

static gboolean
check_header_in_message_info (CamelMessageInfo *info,
                              gint argc,
                              struct _CamelSExpResult **argv,
                              camel_search_match_t how,
                              gboolean *matched)
{
	struct _KnownHeaders {
		const gchar *header_name;
		guint info_key;
	} known_headers[] = {
		{ "Subject", CAMEL_MESSAGE_INFO_SUBJECT },
		{ "From", CAMEL_MESSAGE_INFO_FROM },
		{ "To", CAMEL_MESSAGE_INFO_TO },
		{ "Cc", CAMEL_MESSAGE_INFO_CC }
	};
	camel_search_t type = CAMEL_SEARCH_TYPE_ENCODED;
	const gchar *name, *value;
	gboolean found = FALSE;
	gint ii;

	g_return_val_if_fail (argc > 1, FALSE);
	g_return_val_if_fail (argv != NULL, FALSE);
	g_return_val_if_fail (matched != NULL, FALSE);

	if (!info)
		return FALSE;

	name = argv[0]->value.string;
	g_return_val_if_fail (name != NULL, FALSE);

	/* test against any header */
	if (!*name) {
		gint jj;

		for (jj = 0; jj < G_N_ELEMENTS (known_headers); jj++) {
			value = camel_message_info_ptr (info, known_headers[jj].info_key);
			if (!value)
				continue;

			if (known_headers[jj].info_key == CAMEL_MESSAGE_INFO_SUBJECT)
				type = CAMEL_SEARCH_TYPE_ENCODED;
			else
				type = CAMEL_SEARCH_TYPE_ADDRESS_ENCODED;

			for (ii = 1; ii < argc && !*matched; ii++) {
				if (argv[ii]->type == CAMEL_SEXP_RES_STRING)
					*matched = camel_search_header_match (value, argv[ii]->value.string, how, type, NULL);
			}

			if (*matched)
				return TRUE;
		}

		return FALSE;
	}

	value = NULL;

	for (ii = 0; ii < G_N_ELEMENTS (known_headers); ii++) {
		found = g_ascii_strcasecmp (name, known_headers[ii].header_name) == 0;
		if (found) {
			value = camel_message_info_ptr (info, known_headers[ii].info_key);
			if (known_headers[ii].info_key != CAMEL_MESSAGE_INFO_SUBJECT)
				type = CAMEL_SEARCH_TYPE_ADDRESS_ENCODED;
			break;
		}
	}

	if (!found || !value)
		return FALSE;

	for (ii = 1; ii < argc && !*matched; ii++) {
		if (argv[ii]->type == CAMEL_SEXP_RES_STRING)
			*matched = camel_search_header_match (value, argv[ii]->value.string, how, type, NULL);
	}

	return TRUE;
}

static CamelSExpResult *
check_header (struct _CamelSExp *f,
              gint argc,
              struct _CamelSExpResult **argv,
              FilterMessageSearch *fms,
              camel_search_match_t how)
{
	gboolean matched = FALSE;
	CamelSExpResult *r;
	gint i;

	if (argc > 1 && argv[0]->type == CAMEL_SEXP_RES_STRING) {
		gchar *name = argv[0]->value.string;

		/* shortcut: a match for "" against any header always matches */
		for (i = 1; i < argc && !matched; i++)
			matched = argv[i]->type == CAMEL_SEXP_RES_STRING && argv[i]->value.string[0] == 0;

		if (g_ascii_strcasecmp (name, "x-camel-mlist") == 0) {
			const gchar *list = camel_message_info_mlist (fms->info);

			if (list) {
				for (i = 1; i < argc && !matched; i++) {
					if (argv[i]->type == CAMEL_SEXP_RES_STRING)
						matched = camel_search_header_match (list, argv[i]->value.string, how, CAMEL_SEARCH_TYPE_MLIST, NULL);
				}
			}
		} else if (fms->message || !check_header_in_message_info (fms->info, argc, argv, how, &matched)) {
			CamelMimeMessage *message;
			CamelMimePart *mime_part;
			struct _camel_header_raw *header;
			const gchar *charset = NULL;
			camel_search_t type = CAMEL_SEARCH_TYPE_ENCODED;
			CamelContentType *ct;

			message = camel_filter_search_get_message (fms, f);
			mime_part = CAMEL_MIME_PART (message);

			/* FIXME: what about Resent-To, Resent-Cc and Resent-From? */
			if (g_ascii_strcasecmp ("to", name) == 0 || g_ascii_strcasecmp ("cc", name) == 0 || g_ascii_strcasecmp ("from", name) == 0)
				type = CAMEL_SEARCH_TYPE_ADDRESS_ENCODED;
			else if (message) {
				ct = camel_mime_part_get_content_type (mime_part);
				if (ct) {
					charset = camel_content_type_param (ct, "charset");
					charset = camel_iconv_charset_name (charset);
				}
			}

			for (header = mime_part->headers; header && !matched; header = header->next) {
				/* empty name means any header */
				if (!name || !*name || !g_ascii_strcasecmp (header->name, name)) {
					for (i = 1; i < argc && !matched; i++) {
						if (argv[i]->type == CAMEL_SEXP_RES_STRING)
							matched = camel_search_header_match (header->value, argv[i]->value.string, how, type, charset);
					}
				}
			}
		}
	}

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = matched;

	return r;
}

static CamelSExpResult *
header_contains (struct _CamelSExp *f,
                 gint argc,
                 struct _CamelSExpResult **argv,
                 FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_CONTAINS);
}

static CamelSExpResult *
header_has_words (struct _CamelSExp *f,
                  gint argc,
                  struct _CamelSExpResult **argv,
                  FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_WORD);
}

static CamelSExpResult *
header_matches (struct _CamelSExp *f,
                gint argc,
                struct _CamelSExpResult **argv,
                FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_EXACT);
}

static CamelSExpResult *
header_starts_with (struct _CamelSExp *f,
                    gint argc,
                    struct _CamelSExpResult **argv,
                    FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_STARTS);
}

static CamelSExpResult *
header_ends_with (struct _CamelSExp *f,
                  gint argc,
                  struct _CamelSExpResult **argv,
                  FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_ENDS);
}

static CamelSExpResult *
header_soundex (struct _CamelSExp *f,
                gint argc,
                struct _CamelSExpResult **argv,
                FilterMessageSearch *fms)
{
	return check_header (f, argc, argv, fms, CAMEL_SEARCH_MATCH_SOUNDEX);
}

static CamelSExpResult *
header_exists (struct _CamelSExp *f,
               gint argc,
               struct _CamelSExpResult **argv,
               FilterMessageSearch *fms)
{
	CamelMimeMessage *message;
	gboolean matched = FALSE;
	CamelSExpResult *r;
	gint i;

	message = camel_filter_search_get_message (fms, f);

	for (i = 0; i < argc && !matched; i++) {
		if (argv[i]->type == CAMEL_SEXP_RES_STRING)
			matched = camel_medium_get_header (CAMEL_MEDIUM (message), argv[i]->value.string) != NULL;
	}

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = matched;

	return r;
}

static CamelSExpResult *
header_regex (struct _CamelSExp *f,
              gint argc,
              struct _CamelSExpResult **argv,
              FilterMessageSearch *fms)
{
	CamelSExpResult *r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	CamelMimeMessage *message;
	regex_t pattern;
	const gchar *contents;

	message = camel_filter_search_get_message (fms, f);

	if (argc > 1 && argv[0]->type == CAMEL_SEXP_RES_STRING
	    && (contents = camel_medium_get_header (CAMEL_MEDIUM (message), argv[0]->value.string))
	    && camel_search_build_match_regex (&pattern, CAMEL_SEARCH_MATCH_REGEX | CAMEL_SEARCH_MATCH_ICASE, argc - 1, argv + 1, fms->error) == 0) {
		r->value.boolean = regexec (&pattern, contents, 0, NULL, 0) == 0;
		regfree (&pattern);
	} else
		r->value.boolean = FALSE;

	return r;
}

static gchar *
get_full_header (CamelMimeMessage *message)
{
	CamelMimePart *mime_part;
	GString *str = g_string_new ("");
	gchar   *ret;
	struct _camel_header_raw *h;

	mime_part = CAMEL_MIME_PART (message);

	for (h = mime_part->headers; h; h = h->next) {
		if (h->value != NULL) {
			g_string_append (str, h->name);
			if (isspace (h->value[0]))
				g_string_append (str, ":");
			else
				g_string_append (str, ": ");
			g_string_append (str, h->value);
			g_string_append_c (str, '\n');
		}
	}

	ret = str->str;
	g_string_free (str, FALSE);

	return ret;
}

static CamelSExpResult *
header_full_regex (struct _CamelSExp *f,
                   gint argc,
                   struct _CamelSExpResult **argv,
                   FilterMessageSearch *fms)
{
	CamelSExpResult *r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	CamelMimeMessage *message;
	regex_t pattern;
	gchar *contents;

	if (camel_search_build_match_regex (&pattern, CAMEL_SEARCH_MATCH_REGEX | CAMEL_SEARCH_MATCH_ICASE | CAMEL_SEARCH_MATCH_NEWLINE,
					   argc, argv, fms->error) == 0) {
		message = camel_filter_search_get_message (fms, f);
		contents = get_full_header (message);
		r->value.boolean = regexec (&pattern, contents, 0, NULL, 0) == 0;
		g_free (contents);
		regfree (&pattern);
	} else
		r->value.boolean = FALSE;

	return r;
}

static CamelSExpResult *
match_all (struct _CamelSExp *f,
           gint argc,
           struct _CamelSExpTerm **argv,
           FilterMessageSearch *fms)
{
	/* match-all: when dealing with single messages is a no-op */
	CamelSExpResult *r;

	if (argc > 0)
		return camel_sexp_term_eval (f, argv[0]);

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = TRUE;

	return r;
}

static CamelSExpResult *
body_contains (struct _CamelSExp *f,
               gint argc,
               struct _CamelSExpResult **argv,
               FilterMessageSearch *fms)
{
	CamelSExpResult *r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	CamelMimeMessage *message;
	regex_t pattern;

	if (camel_search_build_match_regex (&pattern, CAMEL_SEARCH_MATCH_ICASE, argc, argv, fms->error) == 0) {
		message = camel_filter_search_get_message (fms, f);
		r->value.boolean = camel_search_message_body_contains ((CamelDataWrapper *) message, &pattern);
		regfree (&pattern);
	} else
		r->value.boolean = FALSE;

	return r;
}

static CamelSExpResult *
body_regex (struct _CamelSExp *f,
            gint argc,
            struct _CamelSExpResult **argv,
            FilterMessageSearch *fms)
{
	CamelSExpResult *r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	CamelMimeMessage *message;
	regex_t pattern;

	if (camel_search_build_match_regex (&pattern, CAMEL_SEARCH_MATCH_ICASE | CAMEL_SEARCH_MATCH_REGEX | CAMEL_SEARCH_MATCH_NEWLINE,
					   argc, argv, fms->error) == 0) {
		message = camel_filter_search_get_message (fms, f);
		r->value.boolean = camel_search_message_body_contains ((CamelDataWrapper *) message, &pattern);
		regfree (&pattern);
	} else
		r->value.boolean = FALSE;

	return r;
}

static CamelSExpResult *
user_flag (struct _CamelSExp *f,
           gint argc,
           struct _CamelSExpResult **argv,
           FilterMessageSearch *fms)
{
	CamelSExpResult *r;
	gboolean truth = FALSE;
	gint i;

	/* performs an OR of all words */
	for (i = 0; i < argc && !truth; i++) {
		if (argv[i]->type == CAMEL_SEXP_RES_STRING
		    && camel_message_info_user_flag (fms->info, argv[i]->value.string)) {
			truth = TRUE;
			break;
		}
	}

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = truth;

	return r;
}

static CamelSExpResult *
system_flag (struct _CamelSExp *f,
             gint argc,
             struct _CamelSExpResult **argv,
             FilterMessageSearch *fms)
{
	CamelSExpResult *r;

	if (argc != 1 || argv[0]->type != CAMEL_SEXP_RES_STRING)
		camel_sexp_fatal_error (f, _("Invalid arguments to (system-flag)"));

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = camel_system_flag_get (camel_message_info_flags (fms->info), argv[0]->value.string);

	return r;
}

static CamelSExpResult *
user_tag (struct _CamelSExp *f,
          gint argc,
          struct _CamelSExpResult **argv,
          FilterMessageSearch *fms)
{
	CamelSExpResult *r;
	const gchar *tag;

	if (argc != 1 || argv[0]->type != CAMEL_SEXP_RES_STRING)
		camel_sexp_fatal_error (f, _("Invalid arguments to (user-tag)"));

	tag = camel_message_info_user_tag (fms->info, argv[0]->value.string);

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_STRING);
	r->value.string = g_strdup (tag ? tag : "");

	return r;
}

static CamelSExpResult *
get_sent_date (struct _CamelSExp *f,
               gint argc,
               struct _CamelSExpResult **argv,
               FilterMessageSearch *fms)
{
	CamelMimeMessage *message;
	CamelSExpResult *r;

	message = camel_filter_search_get_message (fms, f);
	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
	r->value.number = camel_mime_message_get_date (message, NULL);

	return r;
}

static CamelSExpResult *
get_received_date (struct _CamelSExp *f,
                   gint argc,
                   struct _CamelSExpResult **argv,
                   FilterMessageSearch *fms)
{
	CamelMimeMessage *message;
	CamelSExpResult *r;

	message = camel_filter_search_get_message (fms, f);
	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
	r->value.number = camel_mime_message_get_date_received (message, NULL);

	return r;
}

static CamelSExpResult *
get_current_date (struct _CamelSExp *f,
                  gint argc,
                  struct _CamelSExpResult **argv,
                  FilterMessageSearch *fms)
{
	CamelSExpResult *r;

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
	r->value.number = time (NULL);

	return r;
}

static CamelSExpResult *
get_relative_months (struct _CamelSExp *f,
                     gint argc,
                     struct _CamelSExpResult **argv,
                     FilterMessageSearch *fms)
{
	CamelSExpResult *r;

	if (argc != 1 || argv[0]->type != CAMEL_SEXP_RES_INT) {
		r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
		r->value.boolean = FALSE;

		g_debug ("%s: Expecting 1 argument, an integer, but got %d arguments", G_STRFUNC, argc);
	} else {
		r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
		r->value.number = camel_folder_search_util_add_months (time (NULL), argv[0]->value.number);
	}

	return r;
}

static CamelService *
ref_service_for_source (CamelSession *session,
                        const gchar *src)
{
	CamelService *service = NULL;

	/* Source strings are now CamelService UIDs. */
	if (src != NULL)
		service = camel_session_ref_service (session, src);

	/* For backward-compability, also handle CamelService URLs. */
	if (service == NULL && src != NULL) {
		CamelURL *url;

		url = camel_url_new (src, NULL);

		if (service == NULL && url != NULL)
			service = camel_session_ref_service_by_url (
				session, url, CAMEL_PROVIDER_STORE);

		if (service == NULL && url != NULL)
			service = camel_session_ref_service_by_url (
				session, url, CAMEL_PROVIDER_TRANSPORT);

		if (url != NULL)
			camel_url_free (url);
	}

	return service;
}

static CamelSExpResult *
header_source (struct _CamelSExp *f,
               gint argc,
               struct _CamelSExpResult **argv,
               FilterMessageSearch *fms)
{
	CamelMimeMessage *message;
	CamelSExpResult *r;
	const gchar *src;
	CamelService *msg_source = NULL;
	gboolean truth = FALSE;

	if (fms->source) {
		src = fms->source;
	} else {
		message = camel_filter_search_get_message (fms, f);
		src = camel_mime_message_get_source (message);
	}

	if (src)
		msg_source = ref_service_for_source (fms->session, src);

	if (msg_source != NULL) {
		gint ii;

		for (ii = 0; ii < argc && !truth; ii++) {
			if (argv[ii]->type == CAMEL_SEXP_RES_STRING) {
				CamelService *candidate;

				candidate = ref_service_for_source (
					fms->session,
					argv[ii]->value.string);
				if (candidate != NULL) {
					truth = (msg_source == candidate);
					g_object_unref (candidate);
				}
			}
		}

		g_object_unref (msg_source);
	}

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.boolean = truth;

	return r;
}

/* remember, the size comparisons are done at Kbytes */
static CamelSExpResult *
get_size (struct _CamelSExp *f,
          gint argc,
          struct _CamelSExpResult **argv,
          FilterMessageSearch *fms)
{
	CamelSExpResult *r;

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
	r->value.number = camel_message_info_size (fms->info) / 1024;

	return r;
}

#ifndef G_OS_WIN32
static void
child_setup_func (gpointer user_data)
{
	setsid ();
}
#else
#define child_setup_func NULL
#endif

typedef struct {
	gint child_status;
	GMainLoop *loop;
} child_watch_data_t;

static void
child_watch (GPid pid,
             gint status,
             gpointer data)
{
	child_watch_data_t *child_watch_data = data;

	g_spawn_close_pid (pid);

	child_watch_data->child_status = status;
	g_main_loop_quit (child_watch_data->loop);
}

static gint
run_command (struct _CamelSExp *f,
             gint argc,
             struct _CamelSExpResult **argv,
             FilterMessageSearch *fms)
{
	CamelMimeMessage *message;
	CamelStream *stream;
	gint i;
	gint pipe_to_child;
	GPid child_pid;
	GError *error = NULL;
	GPtrArray *args;
	child_watch_data_t child_watch_data;
	GSource *source;
	GMainContext *context;

	if (argc < 1 || argv[0]->value.string[0] == '\0')
		return 0;

	args = g_ptr_array_new ();
	for (i = 0; i < argc; i++)
		g_ptr_array_add (args, argv[i]->value.string);
	g_ptr_array_add (args, NULL);

	if (!g_spawn_async_with_pipes (NULL,
				       (gchar **) args->pdata,
				       NULL,
				       G_SPAWN_DO_NOT_REAP_CHILD |
				       G_SPAWN_SEARCH_PATH |
				       G_SPAWN_STDOUT_TO_DEV_NULL |
				       G_SPAWN_STDERR_TO_DEV_NULL,
				       child_setup_func,
				       NULL,
				       &child_pid,
				       &pipe_to_child,
				       NULL,
				       NULL,
				       &error)) {
		g_ptr_array_free (args, TRUE);

		g_set_error (
			fms->error, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
			_("Failed to create child process '%s': %s"),
			argv[0]->value.string, error->message);
		g_error_free (error);
		return -1;
	}

	g_ptr_array_free (args, TRUE);

	message = camel_filter_search_get_message (fms, f);

	stream = camel_stream_fs_new_with_fd (pipe_to_child);
	camel_data_wrapper_write_to_stream_sync (
		CAMEL_DATA_WRAPPER (message), stream, NULL, NULL);
	camel_stream_flush (stream, NULL, NULL);
	g_object_unref (stream);

	context = g_main_context_new ();
	child_watch_data.loop = g_main_loop_new (context, FALSE);
	g_main_context_unref (context);

	source = g_child_watch_source_new (child_pid);
	g_source_set_callback (source, (GSourceFunc) child_watch, &child_watch_data, NULL);
	g_source_attach (source, g_main_loop_get_context (child_watch_data.loop));
	g_source_unref (source);

	g_main_loop_run (child_watch_data.loop);
	g_main_loop_unref (child_watch_data.loop);

#ifndef G_OS_WIN32
	if (WIFEXITED (child_watch_data.child_status))
		return WEXITSTATUS (child_watch_data.child_status);
	else
		return -1;
#else
	return child_watch_data.child_status;
#endif
}

static CamelSExpResult *
pipe_message (struct _CamelSExp *f,
              gint argc,
              struct _CamelSExpResult **argv,
              FilterMessageSearch *fms)
{
	CamelSExpResult *r;
	gint retval, i;

	/* make sure all args are strings */
	for (i = 0; i < argc; i++) {
		if (argv[i]->type != CAMEL_SEXP_RES_STRING) {
			retval = -1;
			goto done;
		}
	}

	retval = run_command (f, argc, argv, fms);

 done:
	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_INT);
	r->value.number = retval;

	return r;
}

static CamelSExpResult *
junk_test (struct _CamelSExp *f,
           gint argc,
           struct _CamelSExpResult **argv,
           FilterMessageSearch *fms)
{
	CamelSExpResult *r;
	CamelMessageInfo *info = fms->info;
	CamelJunkFilter *junk_filter;
	CamelMessageFlags flags;
	CamelMimeMessage *message;
	CamelJunkStatus status;
	const GHashTable *ht;
	const struct _camel_header_param *node;
	gboolean sender_is_known;
	gboolean message_is_junk = FALSE;
	GError *error = NULL;

	/* Check if the message is already classified. */

	flags = camel_message_info_flags (info);

	if (flags & CAMEL_MESSAGE_JUNK) {
		message_is_junk = TRUE;
		if (camel_debug ("junk"))
			printf (
				"Message has a Junk flag set already, "
				"skipping junk test...\n");
		goto done;
	}

	if (flags & CAMEL_MESSAGE_NOTJUNK) {
		if (camel_debug ("junk"))
			printf (
				"Message has a NotJunk flag set already, "
				"skipping junk test...\n");
		goto done;
	}

	/* If the sender is known, the message is not junk.
	   Do this before header test, to be able to override server-side set headers. */

	sender_is_known = camel_session_lookup_addressbook (
		fms->session, camel_message_info_from (info));
	if (camel_debug ("junk"))
		printf (
			"Sender '%s' in book? %d\n",
			camel_message_info_from (info),
			sender_is_known);
	if (sender_is_known)
		goto done;

	/* Check the headers for a junk designation. */

	ht = camel_session_get_junk_headers (fms->session);
	node = camel_message_info_headers (info);

	while (node != NULL) {
		const gchar *value = NULL;

		if (node->name != NULL)
			value = g_hash_table_lookup (
				(GHashTable *) ht, node->name);

		message_is_junk =
			(value != NULL) &&
			(camel_strstrcase (node->value, value) != NULL);

		if (message_is_junk) {
			if (camel_debug ("junk"))
				printf (
					"Message contains \"%s: %s\"",
					node->name, value);
			goto done;
		}

		node = node->next;
	}

	/* Not every message info has headers available, thus try headers of the message itself */
	message = camel_filter_search_get_message (fms, f);
	if (message) {
		struct _camel_header_raw *h;

		for (h = CAMEL_MIME_PART (message)->headers; h; h = h->next) {
			const gchar *value;

			if (!h->name)
				continue;

			value = g_hash_table_lookup ((GHashTable *) ht, h->name);
			if (!value)
				continue;

			message_is_junk = camel_strstrcase (h->value, value) != NULL;

			if (message_is_junk) {
				if (camel_debug ("junk"))
					printf (
						"Message contains \"%s: %s\"",
						h->name, value);
				goto done;
			}
		}
	} else {
		goto done;
	}

	/* Consult 3rd party junk filtering software. */

	junk_filter = camel_session_get_junk_filter (fms->session);
	if (junk_filter == NULL)
		goto done;

	status = camel_junk_filter_classify (
		junk_filter, message, NULL, &error);

	if (error == NULL) {
		const gchar *status_desc;

		switch (status) {
			case CAMEL_JUNK_STATUS_INCONCLUSIVE:
				status_desc = "inconclusive";
				message_is_junk = FALSE;
				break;
			case CAMEL_JUNK_STATUS_MESSAGE_IS_JUNK:
				status_desc = "junk";
				message_is_junk = TRUE;
				break;
			case CAMEL_JUNK_STATUS_MESSAGE_IS_NOT_JUNK:
				status_desc = "not junk";
				message_is_junk = FALSE;
				break;
			default:
				g_warn_if_reached ();
				status_desc = "invalid";
				message_is_junk = FALSE;
				break;
		}

		if (camel_debug ("junk"))
			printf (
				"Junk filter classification: %s\n",
				status_desc);
	} else {
		g_warn_if_fail (status == CAMEL_JUNK_STATUS_ERROR);
		g_warning ("%s: %s", G_STRFUNC, error->message);
		g_error_free (error);
		message_is_junk = FALSE;
	}

 done:
	if (camel_debug ("junk"))
		printf (
			"Message is determined to be %s\n",
			message_is_junk ? "*JUNK*" : "clean");

	r = camel_sexp_result_new (f, CAMEL_SEXP_RES_BOOL);
	r->value.number = message_is_junk;

	return r;
}

/**
 * camel_filter_search_match:
 * @session:
 * @get_message: function to retrieve the message if necessary
 * @data: data for above
 * @info:
 * @source:
 * @expression:
 * @error: return location for a #GError, or %NULL
 *
 * Returns: one of CAMEL_SEARCH_MATCHED, CAMEL_SEARCH_NOMATCH, or
 * CAMEL_SEARCH_ERROR.
 **/
gint
camel_filter_search_match (CamelSession *session,
                           CamelFilterSearchGetMessageFunc get_message,
                           gpointer data,
                           CamelMessageInfo *info,
                           const gchar *source,
                           const gchar *expression,
                           GError **error)
{
	FilterMessageSearch fms;
	CamelSExp *sexp;
	CamelSExpResult *result;
	gboolean retval;
	GError *local_error = NULL;
	gint i;

	fms.session = session;
	fms.get_message = get_message;
	fms.get_message_data = data;
	fms.message = NULL;
	fms.info = info;
	fms.source = source;
	fms.error = &local_error;

	sexp = camel_sexp_new ();

	for (i = 0; i < G_N_ELEMENTS (symbols); i++) {
		if (symbols[i].type == 1)
			camel_sexp_add_ifunction (sexp, 0, symbols[i].name, (CamelSExpIFunc) symbols[i].func, &fms);
		else
			camel_sexp_add_function (sexp, 0, symbols[i].name, symbols[i].func, &fms);
	}

	camel_sexp_input_text (sexp, expression, strlen (expression));
	if (camel_sexp_parse (sexp) == -1) {
		if (!local_error) {
			/* A filter search is a search through your filters,
			 * ie. your filters is the corpus being searched thru. */
			g_set_error (
				&local_error, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
				_("Error executing filter search: %s: %s"),
				camel_sexp_error (sexp), expression);
		}
		goto error;
	}

	result = camel_sexp_eval (sexp);
	if (result == NULL) {
		if (!local_error)
			g_set_error (
				&local_error, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
				_("Error executing filter search: %s: %s"),
				camel_sexp_error (sexp), expression);
		goto error;
	}

	if (local_error) {
		camel_sexp_result_free (sexp, result);
		goto error;
	}

	if (result->type == CAMEL_SEXP_RES_BOOL)
		retval = result->value.boolean ? CAMEL_SEARCH_MATCHED : CAMEL_SEARCH_NOMATCH;
	else
		retval = CAMEL_SEARCH_NOMATCH;

	camel_sexp_result_free (sexp, result);
	g_object_unref (sexp);

	if (fms.message)
		g_object_unref (fms.message);

	return retval;

 error:
	if (fms.message)
		g_object_unref (fms.message);

	g_object_unref (sexp);

	if (local_error)
		g_propagate_error (error, local_error);

	return CAMEL_SEARCH_ERROR;
}
