/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* 
 * cal-backend-card-sexp.c
 * Copyright 1999, 2000, 2001, Ximian, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License, version 2, 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; 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 <string.h>
#include <glib/gi18n-lib.h>
#include "libedataserver/e-data-server-util.h"
#include <libecal/e-cal-time-util.h>

#include "e-cal-backend-sexp.h"

static GObjectClass *parent_class;

typedef struct _SearchContext SearchContext;

struct _ECalBackendSExpPrivate {
	ESExp *search_sexp;
	char *text;
	SearchContext *search_context;
};

struct _SearchContext {
	ECalComponent *comp;
	ECalBackend *backend;
	gboolean occurs;
};

static ESExpResult *func_is_completed (ESExp *esexp, int argc, ESExpResult **argv, void *data);

/**
 * e_cal_backend_sexp_func_time_now:
 * @esexp: An #ESExp object.
 * @argc: Number of arguments.
 * @argv: The arguments.
 * @data: Closure data.
 *
 * Processes the (time-now) sexp expression.
 *
 * Return value: The result of the function.
 */
ESExpResult *
e_cal_backend_sexp_func_time_now (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	ESExpResult *result;

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				    "time-now");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_TIME);
	result->value.time = time (NULL);

	return result;
}

/**
 * e_cal_backend_sexp_func_make_time:
 * @esexp: An #ESExp object.
 * @argc: Number of arguments.
 * @argv: The arguments.
 * @data: Closure data.
 *
 * (make-time ISODATE)
 * ISODATE - string, ISO 8601 date/time representation
 *
 * Constructs a time_t value for the specified date.
 *
 * Return value: The result of the function.
 */
ESExpResult *
e_cal_backend_sexp_func_make_time (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	const char *str;
	time_t t;
	ESExpResult *result;

	if (argc != 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects one argument"),
				    "make-time");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_STRING) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a string"),
				    "make-time");
		return NULL;
	}
	str = argv[0]->value.string;
	if (!str || !*str) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a string"),
				    "make-time");
		return NULL;
	}

	t = time_from_isodate (str);
	if (t == -1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be an ISO 8601 "
					     "date/time string"),
				    "make-time");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_TIME);
	result->value.time = t;

	return result;
}

/**
 * e_cal_backend_sexp_func_time_add_day:
 * @esexp: An #ESExp object.
 * @argc: Number of arguments.
 * @argv: The arguments.
 * @data: Closure data.
 *
 * (time-add-day TIME N)
 * TIME - time_t, base time
 * N - int, number of days to add
 *
 * Adds the specified number of days to a time value.
 *
 * FIXME: TIMEZONES - need to use a timezone or daylight saving changes will
 * make the result incorrect.
 *
 * Return value: The result of the function.
 */
ESExpResult *
e_cal_backend_sexp_func_time_add_day (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	ESExpResult *result;
	time_t t;
	int n;

	if (argc != 2) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects two arguments"),
				    "time-add-day");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "time-add-day");
		return NULL;
	}
	t = argv[0]->value.time;

	if (argv[1]->type != ESEXP_RES_INT) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the second "
					     "argument to be an integer"),
				    "time-add-day");
		return NULL;
	}
	n = argv[1]->value.number;
	
	result = e_sexp_result_new (esexp, ESEXP_RES_TIME);
	result->value.time = time_add_day (t, n);

	return result;
}

/**
 * e_cal_backend_sexp_func_time_day_begin:
 * @esexp: An #ESExp object.
 * @argc: Number of arguments.
 * @argv: The arguments.
 * @data: Closure data.
 *
 * (time-day-begin TIME)
 * TIME - time_t, base time
 *
 * Returns the start of the day, according to the local time.
 *
 * FIXME: TIMEZONES - this uses the current Unix timezone.
 *
 * Return value: The result of the function.
 */
ESExpResult *
e_cal_backend_sexp_func_time_day_begin (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	time_t t;
	ESExpResult *result;

	if (argc != 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects one argument"),
				    "time-day-begin");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "time-day-begin");
		return NULL;
	}
	t = argv[0]->value.time;

	result = e_sexp_result_new (esexp, ESEXP_RES_TIME);
	result->value.time = time_day_begin (t);

	return result;
}

/**
 * e_cal_backend_sexp_func_time_day_end:
 * @esexp: An #ESExp object.
 * @argc: Number of arguments.
 * @argv: The arguments.
 * @data: Closure data.
 *
 * (time-day-end TIME)
 * TIME - time_t, base time
 *
 * Returns the end of the day, according to the local time.
 *
 * FIXME: TIMEZONES - this uses the current Unix timezone.
 *
 * Return value: The result of the function.
 */
ESExpResult *
e_cal_backend_sexp_func_time_day_end (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	time_t t;
	ESExpResult *result;

	if (argc != 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects one argument"),
				    "time-day-end");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "time-day-end");
		return NULL;
	}
	t = argv[0]->value.time;

	result = e_sexp_result_new (esexp, ESEXP_RES_TIME);
	result->value.time = time_day_end (t);

	return result;
}

/* (uid? UID)
 *
 * UID - the uid of the component
 *
 * Returns a boolean indicating whether the component has the given UID
 */
static ESExpResult *
func_uid (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	const char *uid = NULL, *arg_uid;
	gboolean equal;
	ESExpResult *result;

	/* Check argument types */

	if (argc != 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects one argument"),
				    "uid");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_STRING) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a string"),
				    "uid");
		return NULL;
	}

	arg_uid = argv[0]->value.string;	
	e_cal_component_get_uid (ctx->comp, &uid);

	if (!arg_uid && !uid)
		equal = TRUE;
	else if ((!arg_uid || !uid) && arg_uid != uid)
		equal = FALSE;
	else if (e_util_utf8_strstrcase (arg_uid, uid) != NULL && strlen (arg_uid) == strlen (uid))
		equal = TRUE;
	else
		equal = FALSE;
	
	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = equal;

	return result;
}

static gboolean
check_instance_time_range_cb (ECalComponent *comp, time_t instance_start, time_t instance_end, gpointer data)
{
	SearchContext *ctx = data;

	/* if we get called, the event has an occurrence in the given time range */
	ctx->occurs = TRUE;

	return FALSE;
}

static icaltimezone *
resolve_tzid (const char *tzid, gpointer user_data)
{
	SearchContext *ctx = user_data;
                                                                                
        if (!tzid || !tzid[0])
                return NULL;
        else if (!strcmp (tzid, "UTC"))
                return icaltimezone_get_utc_timezone ();
                                                                                
        return e_cal_backend_internal_get_timezone (ctx->backend, tzid);
}

/* (occur-in-time-range? START END)
 *
 * START - time_t, start of the time range
 * END - time_t, end of the time range
 *
 * Returns a boolean indicating whether the component has any occurrences in the
 * specified time range.
 */
static ESExpResult *
func_occur_in_time_range (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	time_t start, end;
	ESExpResult *result;
	icaltimezone *default_zone;

	/* Check argument types */

	if (argc != 2) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects two arguments"),
				    "occur-in-time-range");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "occur-in-time-range");
		return NULL;
	}
	start = argv[0]->value.time;

	if (argv[1]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the second "
					     "argument to be a time_t"),
				    "occur-in-time-range");
		return NULL;
	}
	end = argv[1]->value.time;

	/* See if the object occurs in the specified time range */
	default_zone = e_cal_backend_internal_get_default_timezone (ctx->backend);
	if (!default_zone)
		default_zone = icaltimezone_get_utc_timezone ();

	ctx->occurs = FALSE;
	e_cal_recur_generate_instances (ctx->comp, start, end,
					(ECalRecurInstanceFn) check_instance_time_range_cb,
					ctx, resolve_tzid, ctx,
					default_zone);

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = ctx->occurs;

	return result;
}

static ESExpResult *
func_due_in_time_range (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	time_t start, end;
	ESExpResult *result;
	icaltimezone *zone;
	ECalComponentDateTime dt;
	time_t due_t ;
	gboolean retval;

	/* Check argument types */

	if (argc != 2) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects two arguments"),
				"due-in-time-range");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					"argument to be a time_t"),
				"due-in-time-range");
		return NULL;
	}

	start = argv[0]->value.time;

	if (argv[1]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the second "
					"argument to be a time_t"),
				"due-in-time-range");
		return NULL;
	}

	end = argv[1]->value.time;
	e_cal_component_get_due (ctx->comp, &dt);

	if(dt.value != NULL) {
		zone = resolve_tzid (dt.tzid, ctx);
		result = e_sexp_result_new (esexp, ESEXP_RES_INT);
		if (zone)
			due_t = icaltime_as_timet_with_zone(*dt.value,zone);
		else
			due_t = icaltime_as_timet(*dt.value);
	} 	

	if(dt.value != NULL && (due_t <= end && due_t >= start))
		retval = TRUE;
	else 
		retval = FALSE; 

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = retval;

	e_cal_component_free_datetime (&dt);
	
	return result;
}

/* Returns whether a list of ECalComponentText items matches the specified string */
static gboolean
matches_text_list (GSList *text_list, const char *str)
{
	GSList *l;
	gboolean matches;

	matches = FALSE;

	for (l = text_list; l; l = l->next) {
		ECalComponentText *text;

		text = l->data;
		g_assert (text->value != NULL);

		if (e_util_utf8_strstrcasedecomp (text->value, str) != NULL) {
			matches = TRUE;
			break;
		}
	}

	return matches;
}

/* Returns whether the comments in a component matches the specified string */
static gboolean
matches_comment (ECalComponent *comp, const char *str)
{
	GSList *list;
	gboolean matches;

	e_cal_component_get_comment_list (comp, &list);
	matches = matches_text_list (list, str);
	e_cal_component_free_text_list (list);

	return matches;
}

/* Returns whether the description in a component matches the specified string */
static gboolean
matches_description (ECalComponent *comp, const char *str)
{
	GSList *list;
	gboolean matches;

	e_cal_component_get_description_list (comp, &list);
	matches = matches_text_list (list, str);
	e_cal_component_free_text_list (list);

	return matches;
}

static gboolean
matches_attendee (ECalComponent *comp, const char *str)
{
	GSList *a_list = NULL, *l;
	gboolean matches = FALSE;

	e_cal_component_get_attendee_list (comp, &a_list);

	for (l = a_list; l; l = l->next) {
		ECalComponentAttendee *att = l->data;

		if ((att->value && e_util_strstrcase (att->value, str)) || (att->cn != NULL &&
					e_util_strstrcase (att->cn, str))) {
			matches = TRUE;
			break;
		}
	}

	e_cal_component_free_attendee_list (a_list);

	return matches;

}

static gboolean
matches_organizer (ECalComponent *comp, const char *str)
{

	ECalComponentOrganizer org;

	e_cal_component_get_organizer (comp, &org);
	if (str && !*str)
		return TRUE;

	if ((org.value && e_util_strstrcase (org.value, str)) || 
			(org.cn && e_util_strstrcase (org.cn, str)))
		return TRUE;

	return FALSE;
}

static gboolean
matches_classification (ECalComponent *comp, const char *str)
{
	ECalComponentClassification classification;
	ECalComponentClassification classification1;

	if (!*str)
		return FALSE;
	
	if(g_str_equal (str, "Public"))
		classification1 = E_CAL_COMPONENT_CLASS_PUBLIC;
	else if(g_str_equal (str, "Private"))
		classification1 = E_CAL_COMPONENT_CLASS_PRIVATE;
	else if(g_str_equal (str, "Confidential"))
		classification1 = E_CAL_COMPONENT_CLASS_CONFIDENTIAL;
	else 	
		classification1 = E_CAL_COMPONENT_CLASS_UNKNOWN;

	e_cal_component_get_classification(comp, &classification);

	return (classification == classification1 ? TRUE : FALSE);
}

/* Returns whether the summary in a component matches the specified string */
static gboolean
matches_summary (ECalComponent *comp, const char *str)
{
	ECalComponentText text;

	e_cal_component_get_summary (comp, &text);

	if (!*str)
		return TRUE;

	if (!text.value)
		return FALSE;

	return e_util_utf8_strstrcasedecomp (text.value, str) != NULL;
}

/* Returns whether the location in a component matches the specified string */
static gboolean
matches_location (ECalComponent *comp, const char *str)
{
	const char *location = NULL;

	e_cal_component_get_location (comp, &location);

	if (!location)
		return FALSE;

	return e_util_utf8_strstrcasedecomp (location, str) != NULL;
}

/* Returns whether any text field in a component matches the specified string */
static gboolean
matches_any (ECalComponent *comp, const char *str)
{
	/* As an optimization, and to make life easier for the individual
	 * predicate functions, see if we are looking for the empty string right
	 * away.
	 */
	if (strlen (str) == 0)
		return TRUE;

	return (matches_comment (comp, str)
		|| matches_description (comp, str)
		|| matches_summary (comp, str)
		|| matches_location (comp, str));
}

static gboolean
matches_priority (ECalComponent *comp ,const char *pr)
{
	int *priority = NULL;

	e_cal_component_get_priority (comp, &priority);

	if (!priority || !*priority)
		return FALSE;

	if (g_str_equal (pr, "HIGH") && *priority <= 4) 
		return TRUE;
	else if (g_str_equal (pr, "NORMAL") && *priority == 5)
		return TRUE;
	else if (g_str_equal (pr, "LOW") && *priority > 5)
		return TRUE;
	else if (g_str_equal (pr, "UNDEFINED") && (!priority || !*priority))
		return TRUE ;

	return FALSE;
}

static gboolean
matches_status (ECalComponent *comp ,const char *str)
{
	icalproperty_status status ;

	if (!*str)
		return FALSE;

	e_cal_component_get_status (comp, &status);

	if (g_str_equal (str, "NOT STARTED") && status == ICAL_STATUS_NONE)
			return TRUE;
	else if (g_str_equal (str, "COMPLETED") && status == ICAL_STATUS_COMPLETED) 
			return TRUE;
	else if(g_str_equal (str, "CANCELLED") && status == ICAL_STATUS_CANCELLED)  
			return TRUE;
	else if(g_str_equal (str, "IN PROGRESS")  && status == ICAL_STATUS_INPROCESS)
			return TRUE;

	return FALSE;
}

static ESExpResult *
func_has_attachment (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result;

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				"has-attachments?");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = e_cal_component_has_attachments (ctx->comp);

	return result;
}

static ESExpResult *
func_percent_complete (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result = NULL;
	int *percent;

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				"percent-completed");
		return NULL;
	}

	e_cal_component_get_percent (ctx->comp, &percent);

	if (percent && *percent) {	
		result = e_sexp_result_new (esexp, ESEXP_RES_INT);
		result->value.number = *percent;

	}  

	return result;
}

/* (contains? FIELD STR)
 *
 * FIELD - string, name of field to match (any, comment, description, summary, location)
 * STR - string, match string
 *
 * Returns a boolean indicating whether the specified field contains the
 * specified string.
 */
static ESExpResult *
func_contains (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	const char *field;
	const char *str;
	gboolean matches;
	ESExpResult *result;

	/* Check argument types */

	if (argc != 2) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects two arguments"),
				    "contains");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_STRING) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a string"),
				    "contains");
		return NULL;
	}
	field = argv[0]->value.string;

	if (argv[1]->type != ESEXP_RES_STRING) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the second "
					     "argument to be a string"),
				    "contains");
		return NULL;
	}
	str = argv[1]->value.string;

	/* See if it matches */

	if (strcmp (field, "any") == 0)
		matches = matches_any (ctx->comp, str);
	else if (strcmp (field, "comment") == 0)
		matches = matches_comment (ctx->comp, str);
	else if (strcmp (field, "description") == 0)
		matches = matches_description (ctx->comp, str);
	else if (strcmp (field, "summary") == 0)
		matches = matches_summary (ctx->comp, str);
	else if (strcmp (field, "location") == 0)
		matches = matches_location (ctx->comp, str);
	else if (strcmp (field, "attendee") == 0)
		matches = matches_attendee (ctx->comp, str);
	else if (strcmp (field, "organizer") == 0)
		matches = matches_organizer (ctx->comp, str);
	else if(strcmp (field, "classification") == 0)
		matches = matches_classification (ctx->comp, str);
	else if(strcmp (field, "status") == 0)
		matches = matches_status (ctx->comp, str);
	else if(strcmp (field, "priority") == 0)
		matches = matches_priority (ctx->comp, str);
	else {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be either \"any\", "
					"\"summary\", or \"description\", or \"location\", or \"attendee\", or \"organizer\", or \"classification\""),
				    "contains");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = matches;

	return result;
}

/* (has-alarms?)
 *
 * A boolean value for components that have/dont have alarms.
 *
 * Returns: a boolean indicating whether the component has alarms or not.
 */
static ESExpResult *
func_has_alarms (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result;

	/* Check argument types */

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				    "has-alarms");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = e_cal_component_has_alarms (ctx->comp);

	return result;
}

/* (has-alarms-in-range? START END)
 *
 * START - time_t, start of the time range
 * END - time_t, end of the time range
 *
 * Returns: a boolean indicating whether the component has alarms in the given
 * time range or not.
 */
static ESExpResult *
func_has_alarms_in_range (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	time_t start, end;
	ESExpResult *result;
	icaltimezone *default_zone;
	ECalComponentAlarms *alarms;
	ECalComponentAlarmAction omit[] = {-1};
	SearchContext *ctx = data;

	/* Check argument types */

	if (argc != 2) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects two arguments"),
				    "has-alarms-in-range");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "has-alarms-in-range");
		return NULL;
	}
	start = argv[0]->value.time;

	if (argv[1]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the second "
					     "argument to be a time_t"),
				    "has-alarms-in-range");
		return NULL;
	}
	end = argv[1]->value.time;

	/* See if the object has alarms in the given time range */
	default_zone = e_cal_backend_internal_get_default_timezone (ctx->backend);
	if (!default_zone)
		default_zone = icaltimezone_get_utc_timezone ();

	alarms = e_cal_util_generate_alarms_for_comp (ctx->comp, start, end,
						      omit, resolve_tzid,
						      ctx, default_zone);

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	if (alarms) {
		result->value.bool = TRUE;
		e_cal_component_alarms_free (alarms);
	} else
		result->value.bool = FALSE;

	return result;
}

/* (has-categories? STR+)
 * (has-categories? #f)
 *
 * STR - At least one string specifying a category
 * Or you can specify a single #f (boolean false) value for components
 * that have no categories assigned to them ("unfiled").
 *
 * Returns a boolean indicating whether the component has all the specified
 * categories.
 */
static ESExpResult *
func_has_categories (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	gboolean unfiled;
	int i;
	GSList *categories;
	gboolean matches;
	ESExpResult *result;

	/* Check argument types */

	if (argc < 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects at least one "
					     "argument"),
				    "has-categories");
		return NULL;
	}

	if (argc == 1 && argv[0]->type == ESEXP_RES_BOOL)
		unfiled = TRUE;
	else
		unfiled = FALSE;

	if (!unfiled)
		for (i = 0; i < argc; i++)
			if (argv[i]->type != ESEXP_RES_STRING) {
				e_sexp_fatal_error (esexp, _("\"%s\" expects "
							     "all arguments to "
							     "be strings or "
							     "one and only one "
							     "argument to be a "
							     "boolean false "
							     "(#f)"),
						    "has-categories");
				return NULL;
			}

	/* Search categories.  First, if there are no categories we return
	 * whether unfiled components are supposed to match.
	 */

	e_cal_component_get_categories_list (ctx->comp, &categories);
	if (!categories) {
		result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
		result->value.bool = unfiled;

		return result;
	}

	/* Otherwise, we *do* have categories but unfiled components were
	 * requested, so this component does not match.
	 */
	if (unfiled) {
		result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
		result->value.bool = FALSE;

		return result;
	}

	matches = TRUE;

	for (i = 0; i < argc; i++) {
		const char *sought;
		GSList *l;
		gboolean has_category;

		sought = argv[i]->value.string;

		has_category = FALSE;

		for (l = categories; l; l = l->next) {
			const char *category;

			category = l->data;

			if (strcmp (category, sought) == 0) {
				has_category = TRUE;
				break;
			}
		}

		if (!has_category) {
			matches = FALSE;
			break;
		}
	}

	e_cal_component_free_categories_list (categories);

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = matches;

	return result;
}

/* (has-recurrences?)
 *
 * A boolean value for components that have/dont have recurrences.
 *
 * Returns: a boolean indicating whether the component has recurrences or not.
 */
static ESExpResult *
func_has_recurrences (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result;

	/* Check argument types */

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				    "has-recurrences");
		return NULL;
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = (e_cal_component_has_recurrences (ctx->comp) || e_cal_component_is_instance (ctx->comp));

	return result;
}

/* (is-completed?)
 *
 * Returns a boolean indicating whether the component is completed (i.e. has
 * a COMPLETED property. This is really only useful for TODO components.
 */
static ESExpResult *
func_is_completed (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result;
	struct icaltimetype *t;
	gboolean complete = FALSE;

	/* Check argument types */

	if (argc != 0) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects no arguments"),
				    "is-completed");
		return NULL;
	}

	e_cal_component_get_completed (ctx->comp, &t);
	if (t) {
		complete = TRUE;
		e_cal_component_free_icaltimetype (t);
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = complete;

	return result;
}

/* (completed-before? TIME)
 *
 * TIME - time_t
 *
 * Returns a boolean indicating whether the component was completed on or
 * before the given time (i.e. it checks the COMPLETED property).
 * This is really only useful for TODO components.
 */
static ESExpResult *
func_completed_before (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
	SearchContext *ctx = data;
	ESExpResult *result;
	struct icaltimetype *tt;
	icaltimezone *zone;
	gboolean retval = FALSE;
	time_t before_time, completed_time;

	/* Check argument types */

	if (argc != 1) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects one argument"),
				    "completed-before");
		return NULL;
	}

	if (argv[0]->type != ESEXP_RES_TIME) {
		e_sexp_fatal_error (esexp, _("\"%s\" expects the first "
					     "argument to be a time_t"),
				    "completed-before");
		return NULL;
	}
	before_time = argv[0]->value.time;

	e_cal_component_get_completed (ctx->comp, &tt);
	if (tt) {
		/* COMPLETED must be in UTC. */
		zone = icaltimezone_get_utc_timezone ();
		completed_time = icaltime_as_timet_with_zone (*tt, zone);

#if 0
		g_print ("Query Time    : %s", ctime (&before_time));
		g_print ("Completed Time: %s", ctime (&completed_time));
#endif

		/* We want to return TRUE if before_time is after
		   completed_time. */
		if (difftime (before_time, completed_time) > 0) {
#if 0
			g_print ("  Returning TRUE\n");
#endif
			retval = TRUE;
		}

		e_cal_component_free_icaltimetype (tt);
	}

	result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);
	result->value.bool = retval;

	return result;
}

#if 0
static struct prop_info {
	ECardSimpleField field_id;
	const char *query_prop;
	const char *ecard_prop;
#define PROP_TYPE_NORMAL   0x01
#define PROP_TYPE_LIST     0x02
#define PROP_TYPE_LISTITEM 0x03
#define PROP_TYPE_ID 0x04
	int prop_type;
	gboolean (*list_compare)(ECardSimple *ecard, const char *str,
				 char *(*compare)(const char*, const char*));

} prop_info_table[] = {
#define NORMAL_PROP(f,q,e) {f, q, e, PROP_TYPE_NORMAL, NULL}
#define ID_PROP {0, "id", NULL, PROP_TYPE_ID, NULL}
#define LIST_PROP(q,e,c) {0, q, e, PROP_TYPE_LIST, c}

	/* query prop,  ecard prop,   type,              list compare function */
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_FILE_AS, "file_as", "file_as" ),
	LIST_PROP ( "full_name", "full_name", compare_name), /* not really a list, but we need to compare both full and surname */
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_URL, "url", "url" ),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_MAILER, "mailer", "mailer"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_ORG, "org", "org"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_ORG_UNIT, "org_unit", "org_unit"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_OFFICE, "office", "office"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_TITLE, "title", "title"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_ROLE, "role", "role"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_MANAGER, "manager", "manager"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_ASSISTANT, "assistant", "assistant"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_NICKNAME, "nickname", "nickname"),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_SPOUSE, "spouse", "spouse" ),
	NORMAL_PROP ( E_CARD_SIMPLE_FIELD_NOTE, "note", "note"),
	ID_PROP,
	LIST_PROP ( "email", "email", compare_email ),
	LIST_PROP ( "phone", "phone", compare_phone ),
	LIST_PROP ( "address", "address", compare_address ),
	LIST_PROP ( "category", "category", compare_category ),
	LIST_PROP ( "arbitrary", "arbitrary", compare_arbitrary )
};
static int num_prop_infos = sizeof(prop_info_table) / sizeof(prop_info_table[0]);

static ESExpResult *
entry_compare(SearchContext *ctx, struct _ESExp *f,
	      int argc, struct _ESExpResult **argv,
	      char *(*compare)(const char*, const char*))
{
	ESExpResult *r;
	int truth = FALSE;

	if (argc == 2
	    && argv[0]->type == ESEXP_RES_STRING
	    && argv[1]->type == ESEXP_RES_STRING) {
		char *propname;
		struct prop_info *info = NULL;
		int i;
		gboolean any_field;

		propname = argv[0]->value.string;

		any_field = !strcmp(propname, "x-evolution-any-field");
		for (i = 0; i < num_prop_infos; i ++) {
			if (any_field
			    || !strcmp (prop_info_table[i].query_prop, propname)) {
				info = &prop_info_table[i];
				
				if (info->prop_type == PROP_TYPE_NORMAL) {
					char *prop = NULL;
					/* searches where the query's property
					   maps directly to an ecard property */
					
					prop = e_card_simple_get (ctx->card, info->field_id);

					if (prop && compare(prop, argv[1]->value.string)) {
						truth = TRUE;
					}
					if ((!prop) && compare("", argv[1]->value.string)) {
						truth = TRUE;
					}
					g_free (prop);
				} else if (info->prop_type == PROP_TYPE_LIST) {
				/* the special searches that match any of the list elements */
					truth = info->list_compare (ctx->card, argv[1]->value.string, compare);
				} else if (info->prop_type == PROP_TYPE_ID) {
					const char *prop = NULL;
					/* searches where the query's property
					   maps directly to an ecard property */
					
					prop = e_card_get_id (ctx->card->card);

					if (prop && compare(prop, argv[1]->value.string)) {
						truth = TRUE;
					}
					if ((!prop) && compare("", argv[1]->value.string)) {
						truth = TRUE;
					}
				}

				/* if we're looking at all fields and find a match,
				   or if we're just looking at this one field,
				   break. */
				if ((any_field && truth)
				    || !any_field)
					break;
			}
		}
		
	}
	r = e_sexp_result_new(f, ESEXP_RES_BOOL);
	r->value.bool = truth;

	return r;
}
#endif

/* 'builtin' functions */
static struct {
	char *name;
	ESExpFunc *func;
	int type;		/* set to 1 if a function can perform shortcut evaluation, or
				   doesn't execute everything, 0 otherwise */
} symbols[] = {
	/* Time-related functions */
	{ "time-now", e_cal_backend_sexp_func_time_now, 0 },
	{ "make-time", e_cal_backend_sexp_func_make_time, 0 },
	{ "time-add-day", e_cal_backend_sexp_func_time_add_day, 0 },
	{ "time-day-begin", e_cal_backend_sexp_func_time_day_begin, 0 },
	{ "time-day-end", e_cal_backend_sexp_func_time_day_end, 0 },
	/* Component-related functions */
	{ "uid?", func_uid, 0 },
	{ "occur-in-time-range?", func_occur_in_time_range, 0 },
	{ "due-in-time-range?", func_due_in_time_range, 0 },
	{ "contains?", func_contains, 0 },
	{ "has-alarms?", func_has_alarms, 0 },
	{ "has-alarms-in-range?", func_has_alarms_in_range, 0 },
	{ "has-recurrences?", func_has_recurrences, 0 },
	{ "has-categories?", func_has_categories, 0 },
	{ "is-completed?", func_is_completed, 0 },
	{ "completed-before?", func_completed_before, 0 },
	{ "has-attachments?", func_has_attachment, 0 },
	{ "percent-complete?", func_percent_complete, 0 }
};

/**
 * e_cal_backend_sexp_match_comp:
 * @sexp: An #ESExp object.
 * @comp: Component to match against the expression.
 * @backend: Backend.
 *
 * Matches the given ECalComponent against the expression.
 *
 * Return value: TRUE if the component matched the expression, FALSE if not.
 */
gboolean
e_cal_backend_sexp_match_comp (ECalBackendSExp *sexp, ECalComponent *comp, ECalBackend *backend)
{
	ESExpResult *r;
	gboolean retval;

	g_return_val_if_fail (E_IS_CAL_BACKEND_SEXP (sexp), FALSE);
	g_return_val_if_fail (E_IS_CAL_COMPONENT (comp), FALSE);
	g_return_val_if_fail (E_IS_CAL_BACKEND (backend), FALSE);

	sexp->priv->search_context->comp = g_object_ref (comp);
	sexp->priv->search_context->backend = g_object_ref (backend);

	/* if it's not a valid vcard why is it in our db? :) */
	if (!sexp->priv->search_context->comp)  {
		g_object_unref (sexp->priv->search_context->backend);
		return FALSE;
	}
	r = e_sexp_eval(sexp->priv->search_sexp);

	retval = (r && r->type == ESEXP_RES_BOOL && r->value.bool);

	g_object_unref (sexp->priv->search_context->comp);
	g_object_unref (sexp->priv->search_context->backend);

	e_sexp_result_free(sexp->priv->search_sexp, r);

	return retval;
}

/**
 * e_cal_backend_sexp_match_object:
 * @sexp: An #ESExp object.
 * @object: An iCalendar string.
 * @backend: A backend.
 *
 * Match an iCalendar expression against the expression.
 *
 * Return value: TRUE if the object matches the expression, FALSE if not.
 */
gboolean
e_cal_backend_sexp_match_object (ECalBackendSExp *sexp, const char *object, ECalBackend *backend)
{
	ECalComponent *comp;
	icalcomponent *icalcomp;
	gboolean retval;

	icalcomp = icalcomponent_new_from_string ((char *) object);
	if (!icalcomp)
		return FALSE;

	comp = e_cal_component_new ();
	e_cal_component_set_icalcomponent (comp, icalcomp);
	
	retval = e_cal_backend_sexp_match_comp (sexp, comp, backend);

	g_object_unref (comp);

	return retval;
}



/**
 * e_cal_backend_card_sexp_new:
 * @text: The expression to use.
 *
 * Creates a new #EXCalBackendSExp object.
 *
 * Return value: The newly created ECalBackendSExp object.
 */
ECalBackendSExp *
e_cal_backend_sexp_new (const char *text)
{
	ECalBackendSExp *sexp = g_object_new (E_TYPE_CAL_BACKEND_SEXP, NULL);
	int esexp_error;
	int i;

	sexp->priv->search_sexp = e_sexp_new();
	sexp->priv->text = g_strdup (text);

	for (i = 0; i < G_N_ELEMENTS (symbols); i++) {
		if (symbols[i].type == 1) {
			e_sexp_add_ifunction(sexp->priv->search_sexp, 0, symbols[i].name,
					     (ESExpIFunc *)symbols[i].func, sexp->priv->search_context);
		} else {
			e_sexp_add_function(sexp->priv->search_sexp, 0, symbols[i].name,
					    symbols[i].func, sexp->priv->search_context);
		}
	}

	e_sexp_input_text(sexp->priv->search_sexp, text, strlen(text));
	esexp_error = e_sexp_parse(sexp->priv->search_sexp);

	if (esexp_error == -1) {
		g_object_unref (sexp);
		sexp = NULL;
	}

	return sexp;
}

/**
 * e_cal_backend_sexp_text:
 * @sexp: An #ECalBackendSExp object.
 *
 * Retrieve the text expression for the given ECalBackendSExp object.
 *
 * Return value: The text expression.
 */
const char *
e_cal_backend_sexp_text (ECalBackendSExp *sexp)
{
	ECalBackendSExpPrivate *priv;
	
	g_return_val_if_fail (sexp != NULL, NULL);
	g_return_val_if_fail (E_IS_CAL_BACKEND_SEXP (sexp), NULL);

	priv = sexp->priv;

	return priv->text;
}

static void
e_cal_backend_sexp_dispose (GObject *object)
{
	ECalBackendSExp *sexp = E_CAL_BACKEND_SEXP (object);

	if (sexp->priv) {
		e_sexp_unref(sexp->priv->search_sexp);

		g_free (sexp->priv->text);

		g_free (sexp->priv->search_context);
		g_free (sexp->priv);
		sexp->priv = NULL;
	}

	if (G_OBJECT_CLASS (parent_class)->dispose)
		G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
e_cal_backend_sexp_class_init (ECalBackendSExpClass *klass)
{
	GObjectClass  *object_class = G_OBJECT_CLASS (klass);

	parent_class = g_type_class_peek_parent (klass);

	/* Set the virtual methods. */

	object_class->dispose = e_cal_backend_sexp_dispose;
}

static void
e_cal_backend_sexp_init (ECalBackendSExp *sexp)
{
	ECalBackendSExpPrivate *priv;

	priv = g_new0 (ECalBackendSExpPrivate, 1);

	sexp->priv = priv;
	priv->search_context = g_new (SearchContext, 1);
}

/**
 * e_cal_backend_sexp_get_type:
 *
 * Registers the #ECalBackendSExp class if needed.
 *
 * Return value: The unique identifier of the class.
 */
GType
e_cal_backend_sexp_get_type (void)
{
	static GType type = 0;

	if (! type) {
		GTypeInfo info = {
			sizeof (ECalBackendSExpClass),
			NULL, /* base_class_init */
			NULL, /* base_class_finalize */
			(GClassInitFunc)  e_cal_backend_sexp_class_init,
			NULL, /* class_finalize */
			NULL, /* class_data */
			sizeof (ECalBackendSExp),
			0,    /* n_preallocs */
			(GInstanceInitFunc) e_cal_backend_sexp_init
		};

		type = g_type_register_static (G_TYPE_OBJECT, "ECalBackendSExp", &info, 0);
	}

	return type;
}