path: root/calendar/pcs/cal-backend-object-sexp.c

/* -*- 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., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <string.h>
#include <libgnome/gnome-i18n.h>
#include <e-util/e-sexp.h>
#include <gal/widgets/e-unicode.h>
#include <cal-util/timeutil.h>

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

static GObjectClass *parent_class;

typedef struct _SearchContext SearchContext;

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

struct _SearchContext {
    CalComponent *comp;
    CalBackend *backend;
};

static ESExpResult *
func_time_now (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
    ESExpResult *result;

    if (argc != 0) {
        e_sexp_fatal_error (esexp, _("time-now expects 0 arguments"));
        return NULL;
    }

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

    return result;
}

/* (make-time ISODATE)
 *
 * ISODATE - string, ISO 8601 date/time representation
 *
 * Constructs a time_t value for the specified date.
 */
static ESExpResult *
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, _("make-time expects 1 argument"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_STRING) {
        e_sexp_fatal_error (esexp, _("make-time expects argument 1 "
                         "to be a string"));
        return NULL;
    }
    str = argv[0]->value.string;

    t = time_from_isodate (str);
    if (t == -1) {
        e_sexp_fatal_error (esexp, _("make-time argument 1 must be an "
                         "ISO 8601 date/time string"));
        return NULL;
    }

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

    return result;
}

/* (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.
 */
static ESExpResult *
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, _("time-add-day expects 2 arguments"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("time-add-day expects argument 1 "
                         "to be a time_t"));
        return NULL;
    }
    t = argv[0]->value.time;

    if (argv[1]->type != ESEXP_RES_INT) {
        e_sexp_fatal_error (esexp, _("time-add-day expects argument 2 "
                         "to be an integer"));
        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;
}

/* (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.
 */
static ESExpResult *
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, _("time-day-begin expects 1 argument"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("time-day-begin expects argument 1 "
                         "to be a time_t"));
        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;
}

/* (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.
 */
static ESExpResult *
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, _("time-day-end expects 1 argument"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("time-day-end expects argument 1 "
                         "to be a time_t"));
        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;
}

/* (get-vtype)
 *
 * Returns a string indicating the type of component (VEVENT, VTODO, VJOURNAL,
 * VFREEBUSY, VTIMEZONE, UNKNOWN).
 */
static ESExpResult *
func_get_vtype (ESExp *esexp, int argc, ESExpResult **argv, void *data)
{
    SearchContext *ctx = data;
    CalComponentVType vtype;
    char *str;
    ESExpResult *result;

    /* Check argument types */

    if (argc != 0) {
        e_sexp_fatal_error (esexp, _("get-vtype expects 0 arguments"));
        return NULL;
    }

    /* Get the type */

    vtype = cal_component_get_vtype (ctx->comp);

    switch (vtype) {
    case CAL_COMPONENT_EVENT:
        str = g_strdup ("VEVENT");
        break;

    case CAL_COMPONENT_TODO:
        str = g_strdup ("VTODO");
        break;

    case CAL_COMPONENT_JOURNAL:
        str = g_strdup ("VJOURNAL");
        break;

    case CAL_COMPONENT_FREEBUSY:
        str = g_strdup ("VFREEBUSY");
        break;

    case CAL_COMPONENT_TIMEZONE:
        str = g_strdup ("VTIMEZONE");
        break;

    default:
        str = g_strdup ("UNKNOWN");
        break;
    }

    result = e_sexp_result_new (esexp, ESEXP_RES_STRING);
    result->value.string = str;

    return result;
}

/* (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, tt;
    gboolean occurs;
    ESExpResult *result;
    CalComponentDateTime dt;

    /* Check argument types */

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

    if (argv[0]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("occur-in-time-range? expects argument 1 "
                         "to be a time_t"));
        return NULL;
    }
    start = argv[0]->value.time;

    if (argv[1]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("occur-in-time-range? expects argument 2 "
                         "to be a time_t"));
        return NULL;
    }
    end = argv[1]->value.time;

    /* See if the object occurs in the specified time range */
    occurs = FALSE;
    
    cal_component_get_dtstart (ctx->comp, &dt);
    if (dt.value) {
        icaltimezone *zone;

        if (dt.tzid)
            zone = cal_backend_internal_get_timezone (ctx->backend, dt.tzid);
        else
            zone = cal_backend_internal_get_default_timezone (ctx->backend);
        
        tt = icaltime_as_timet_with_zone (*dt.value, zone);
        if (tt >= start && tt <= end)
            occurs = TRUE;
        else {
            cal_component_get_dtend (ctx->comp, &dt);
            if (dt.value) {
                if (dt.tzid)
                    zone = cal_backend_internal_get_timezone (ctx->backend, dt.tzid);
                else
                    zone = cal_backend_internal_get_default_timezone (ctx->backend);

                tt = icaltime_as_timet_with_zone (*dt.value, zone);
                if (tt >= start && tt <= end)
                    occurs = TRUE;
            }
        }
    }

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

    return result;
}

/* Returns whether a list of CalComponentText 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) {
        CalComponentText *text;

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

        if (e_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 (CalComponent *comp, const char *str)
{
    GSList *list;
    gboolean matches;

    cal_component_get_comment_list (comp, &list);
    matches = matches_text_list (list, str);
    cal_component_free_text_list (list);

    return matches;
}

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

    cal_component_get_description_list (comp, &list);
    matches = matches_text_list (list, str);
    cal_component_free_text_list (list);

    return matches;
}

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

    cal_component_get_summary (comp, &text);

    if (!text.value)
        return FALSE;

    return e_utf8_strstrcasedecomp (text.value, str) != NULL;
}

/* Returns whether any text field in a component matches the specified string */
static gboolean
matches_any (CalComponent *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));
}

/* (contains? FIELD STR)
 *
 * FIELD - string, name of field to match (any, comment, description, summary)
 * 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, _("contains? expects 2 arguments"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_STRING) {
        e_sexp_fatal_error (esexp, _("contains? expects argument 1 "
                         "to be a string"));
        return NULL;
    }
    field = argv[0]->value.string;

    if (argv[1]->type != ESEXP_RES_STRING) {
        e_sexp_fatal_error (esexp, _("contains? expects argument 2 "
                         "to be a string"));
        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 {
        e_sexp_fatal_error (esexp, _("contains? expects argument 1 to "
                         "be one of \"any\", \"summary\", \"description\""));
        return NULL;
    }

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

    return result;
}

/* (has-alarms? #f|#t)
 *
 * 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;
    gboolean has_to_have_alarms;

    /* Check argument types */

    if (argc != 1) {
        e_sexp_fatal_error (esexp, _("has-alarms? expects at least 1 argument"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_BOOL) {
        e_sexp_fatal_error (esexp, _("has-alarms? excepts argument to be a boolean"));
        return NULL;
    }

    has_to_have_alarms = argv[0]->value.bool;
    result = e_sexp_result_new (esexp, ESEXP_RES_BOOL);

    if (has_to_have_alarms && cal_component_has_alarms (ctx->comp))
        result->value.bool = TRUE;
    else if (!has_to_have_alarms && !cal_component_has_alarms (ctx->comp))
        result->value.bool = TRUE;
    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, _("has-categories? expects at least 1 argument"));
        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, _("has-categories? expects all arguments "
                                 "to be strings or one and only one "
                                 "argument to be a boolean false (#f)"));
                return NULL;
            }

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

    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;
        }
    }

    cal_component_free_categories_list (categories);

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

    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, _("is-completed? expects 0 arguments"));
        return NULL;
    }

    cal_component_get_completed (ctx->comp, &t);
    if (t) {
        complete = TRUE;
        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, _("completed-before? expects 1 argument"));
        return NULL;
    }

    if (argv[0]->type != ESEXP_RES_TIME) {
        e_sexp_fatal_error (esexp, _("completed-before? expects argument 1 "
                         "to be a time_t"));
        return NULL;
    }
    before_time = argv[0]->value.time;

    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;
        }

        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", func_time_now, 0 },
    { "make-time", func_make_time, 0 },
    { "time-add-day", func_time_add_day, 0 },
    { "time-day-begin", func_time_day_begin, 0 },
    { "time-day-end", func_time_day_end, 0 },

    /* Component-related functions */
    { "get-vtype", func_get_vtype, 0 },
    { "occur-in-time-range?", func_occur_in_time_range, 0 },
    { "contains?", func_contains, 0 },
    { "has-alarms?", func_has_alarms, 0 },
    { "has-categories?", func_has_categories, 0 },
    { "is-completed?", func_is_completed, 0 },
    { "completed-before?", func_completed_before, 0 }
};

gboolean
cal_backend_object_sexp_match_comp (CalBackendObjectSExp *sexp, CalComponent *comp, CalBackend *backend)
{
    ESExpResult *r;
    gboolean retval;

    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)
        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;
}

gboolean
cal_backend_object_sexp_match_object (CalBackendObjectSExp *sexp, const char *object, CalBackend *backend)
{
    CalComponent *comp;
    icalcomponent *icalcomp;
    gboolean retval;

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

    comp = cal_component_new ();
    cal_component_set_icalcomponent (comp, icalcomp);
    
    retval = cal_backend_object_sexp_match_comp (sexp, comp, backend);

    g_object_unref (comp);

    return retval;
}



/**
 * cal_backend_card_sexp_new:
 */
CalBackendObjectSExp *
cal_backend_object_sexp_new (const char *text)
{
    CalBackendObjectSExp *sexp = g_object_new (CAL_TYPE_BACKEND_OBJECT_SEXP, NULL);
    int esexp_error;
    int i;

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

    for(i=0;i<sizeof(symbols)/sizeof(symbols[0]);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;
}

const char *
cal_backend_object_sexp_text (CalBackendObjectSExp *sexp)
{
    CalBackendObjectSExpPrivate *priv;
    
    g_return_val_if_fail (sexp != NULL, NULL);
    g_return_val_if_fail (CAL_IS_BACKEND_OBJECT_SEXP (sexp), NULL);

    priv = sexp->priv;

    return priv->text;
}

static void
cal_backend_object_sexp_dispose (GObject *object)
{
    CalBackendObjectSExp *sexp = CAL_BACKEND_OBJECT_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
cal_backend_object_sexp_class_init (CalBackendObjectSExpClass *klass)
{
    GObjectClass  *object_class = G_OBJECT_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    /* Set the virtual methods. */

    object_class->dispose = cal_backend_object_sexp_dispose;
}

static void
cal_backend_object_sexp_init (CalBackendObjectSExp *sexp)
{
    CalBackendObjectSExpPrivate *priv;

    priv = g_new0 (CalBackendObjectSExpPrivate, 1);

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

/**
 * cal_backend_object_sexp_get_type:
 */
GType
cal_backend_object_sexp_get_type (void)
{
    static GType type = 0;

    if (! type) {
        GTypeInfo info = {
            sizeof (CalBackendObjectSExpClass),
            NULL, /* base_class_init */
            NULL, /* base_class_finalize */
            (GClassInitFunc)  cal_backend_object_sexp_class_init,
            NULL, /* class_finalize */
            NULL, /* class_data */
            sizeof (CalBackendObjectSExp),
            0,    /* n_preallocs */
            (GInstanceInitFunc) cal_backend_object_sexp_init
        };

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

    return type;
}