path: root/calendar/cal-util/cal-component.c

/* Evolution calendar - iCalendar component object
 *
 * Copyright (C) 2000 Helix Code, Inc.
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Author: Federico Mena-Quintero <federico@ximian.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

#include <config.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "cal-component.h"
#include "timeutil.h"



/* Extension property for alarm components so that we can reference them by UID */
#define EVOLUTION_ALARM_UID_PROPERTY "X-EVOLUTION-ALARM-UID"

/* Private part of the CalComponent structure */
struct _CalComponentPrivate {
    /* The icalcomponent we wrap */
    icalcomponent *icalcomp;

    /* Properties */

    icalproperty *uid;

    icalproperty *status;

    icalproperty *categories;

    icalproperty *classification;

    struct text {
        icalproperty *prop;
        icalparameter *altrep_param;
    };

    GSList *comment_list; /* list of struct text */

    icalproperty *completed;
    icalproperty *created;

    GSList *description_list; /* list of struct text */

    struct datetime {
        icalproperty *prop;
        icalparameter *tzid_param;
    };

    struct datetime dtstart;
    struct datetime dtend;

    icalproperty *dtstamp;

    struct datetime due;

    GSList *exdate_list; /* list of struct datetime */
    GSList *exrule_list; /* list of icalproperty objects */

    icalproperty *geo;
    icalproperty *last_modified;
    icalproperty *percent;
    icalproperty *priority;

    struct period {
        icalproperty *prop;
        icalparameter *value_param;
    };

    GSList *rdate_list; /* list of struct period */

    GSList *rrule_list; /* list of icalproperty objects */

    icalproperty *sequence;

    struct {
        icalproperty *prop;
        icalparameter *altrep_param;
    } summary;

    icalproperty *transparency;
    icalproperty *url;

    /* Subcomponents */

    GHashTable *alarm_uid_hash;

    /* Whether we should increment the sequence number when piping the
     * object over the wire.
     */
    guint need_sequence_inc : 1;
};

/* Private structure for alarms */
struct _CalComponentAlarm {
    /* Our parent component */
    CalComponent *parent;

    /* Alarm icalcomponent we wrap */
    icalcomponent *icalcomp;

    /* Our extension UID property */
    icalproperty *uid;

    /* Properties */

    icalproperty *action;
    icalproperty *trigger;
};



static void cal_component_class_init (CalComponentClass *class);
static void cal_component_init (CalComponent *comp);
static void cal_component_destroy (GtkObject *object);

static GtkObjectClass *parent_class;



/**
 * cal_component_get_type:
 *
 * Registers the #CalComponent class if necessary, and returns the type ID
 * associated to it.
 *
 * Return value: The type ID of the #CalComponent class.
 **/
GtkType
cal_component_get_type (void)
{
    static GtkType cal_component_type = 0;

    if (!cal_component_type) {
        static const GtkTypeInfo cal_component_info = {
            "CalComponent",
            sizeof (CalComponent),
            sizeof (CalComponentClass),
            (GtkClassInitFunc) cal_component_class_init,
            (GtkObjectInitFunc) cal_component_init,
            NULL, /* reserved_1 */
            NULL, /* reserved_2 */
            (GtkClassInitFunc) NULL
        };

        cal_component_type = gtk_type_unique (GTK_TYPE_OBJECT, &cal_component_info);
    }

    return cal_component_type;
}

/* Class initialization function for the calendar component object */
static void
cal_component_class_init (CalComponentClass *class)
{
    GtkObjectClass *object_class;

    object_class = (GtkObjectClass *) class;

    parent_class = gtk_type_class (GTK_TYPE_OBJECT);

    object_class->destroy = cal_component_destroy;
}

/* Object initialization function for the calendar component object */
static void
cal_component_init (CalComponent *comp)
{
    CalComponentPrivate *priv;

    priv = g_new0 (CalComponentPrivate, 1);
    comp->priv = priv;

    priv->alarm_uid_hash = g_hash_table_new (g_str_hash, g_str_equal);
}

/* Does a simple g_free() of the elements of a GSList and then frees the list
 * itself.  Returns NULL.
 */
static GSList *
free_slist (GSList *slist)
{
    GSList *l;

    for (l = slist; l; l = l->next)
        g_free (l->data);

    g_slist_free (slist);
    return NULL;
}

/* Used from g_hash_table_foreach_remove() to free the alarm UIDs hash table.
 * We do not need to do anything to individual elements since we were storing
 * the UID pointers inside the icalproperties themselves.
 */
static gboolean
free_alarm_cb (gpointer key, gpointer value, gpointer data)
{
    return TRUE;
}

/* Frees the internal icalcomponent only if it does not have a parent.  If it
 * does, it means we don't own it and we shouldn't free it.
 */
static void
free_icalcomponent (CalComponent *comp)
{
    CalComponentPrivate *priv;

    priv = comp->priv;

    if (!priv->icalcomp)
        return;

    /* Free the icalcomponent */

    if (icalcomponent_get_parent (priv->icalcomp) == NULL)
        icalcomponent_free (priv->icalcomp);

    priv->icalcomp = NULL;

    /* Free the mappings */

    priv->uid = NULL;

    priv->status = NULL;

    priv->categories = NULL;

    priv->classification = NULL;
    priv->comment_list = NULL;
    priv->completed = NULL;
    priv->created = NULL;

    priv->description_list = free_slist (priv->description_list);

    priv->dtend.prop = NULL;
    priv->dtend.tzid_param = NULL;

    priv->dtstamp = NULL;

    priv->dtstart.prop = NULL;
    priv->dtstart.tzid_param = NULL;

    priv->due.prop = NULL;
    priv->due.tzid_param = NULL;

    priv->exdate_list = free_slist (priv->exdate_list);

    g_slist_free (priv->exrule_list);
    priv->exrule_list = NULL;

    priv->geo = NULL;
    priv->last_modified = NULL;
    priv->percent = NULL;
    priv->priority = NULL;

    priv->rdate_list = free_slist (priv->rdate_list);

    g_slist_free (priv->rrule_list);
    priv->rrule_list = NULL;

    priv->sequence = NULL;

    priv->summary.prop = NULL;
    priv->summary.altrep_param = NULL;

    priv->transparency = NULL;
    priv->url = NULL;

    /* Free the subcomponents */

    g_hash_table_foreach_remove (priv->alarm_uid_hash, free_alarm_cb, NULL);

    /* Clean up */

    priv->need_sequence_inc = FALSE;
}

/* Destroy handler for the calendar component object */
static void
cal_component_destroy (GtkObject *object)
{
    CalComponent *comp;
    CalComponentPrivate *priv;

    g_return_if_fail (object != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (object));

    comp = CAL_COMPONENT (object);
    priv = comp->priv;

    free_icalcomponent (comp);
    g_hash_table_destroy (priv->alarm_uid_hash);
    priv->alarm_uid_hash = NULL;

    g_free (priv);
    comp->priv = NULL;

    if (GTK_OBJECT_CLASS (parent_class)->destroy)
        (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}



/**
 * cal_component_gen_uid:
 *
 * Generates a unique identifier suitable for calendar components.
 *
 * Return value: A unique identifier string.  Every time this function is called
 * a different string is returned.
 **/
char *
cal_component_gen_uid (void)
{
    static char *hostname;
    time_t t = time (NULL);
    static int serial;

    if (!hostname) {
        static char buffer [512];

        if ((gethostname (buffer, sizeof (buffer) - 1) == 0) &&
            (buffer [0] != 0))
            hostname = buffer;
        else
            hostname = "localhost";
    }

    return g_strdup_printf (
        "%s-%d-%d-%d-%d@%s",
        isodate_from_time_t (t),
        getpid (),
        getgid (),
        getppid (),
        serial++,
        hostname);
}

/**
 * cal_component_new:
 *
 * Creates a new empty calendar component object.  You should set it from an
 * #icalcomponent structure by using cal_component_set_icalcomponent() or with a
 * new empty component type by using cal_component_set_new_vtype().
 *
 * Return value: A newly-created calendar component object.
 **/
CalComponent *
cal_component_new (void)
{
    return CAL_COMPONENT (gtk_type_new (CAL_COMPONENT_TYPE));
}

/**
 * cal_component_clone:
 * @comp: A calendar component object.
 *
 * Creates a new calendar component object by copying the information from
 * another one.
 *
 * Return value: A newly-created calendar component with the same values as the
 * original one.
 **/
CalComponent *
cal_component_clone (CalComponent *comp)
{
    CalComponentPrivate *priv;
    CalComponent *new_comp;
    icalcomponent *new_icalcomp;

    g_return_val_if_fail (comp != NULL, NULL);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), NULL);

    priv = comp->priv;
    g_return_val_if_fail (priv->need_sequence_inc == FALSE, NULL);

    new_comp = cal_component_new ();

    if (priv->icalcomp) {
        new_icalcomp = icalcomponent_new_clone (priv->icalcomp);
        cal_component_set_icalcomponent (new_comp, new_icalcomp);
    }

    return new_comp;
}

/* Scans a date/time and timezone pair property */
static void
scan_datetime (CalComponent *comp, struct datetime *datetime, icalproperty *prop)
{
    CalComponentPrivate *priv;

    priv = comp->priv;

    datetime->prop = prop;
    datetime->tzid_param = icalproperty_get_first_parameter (prop, ICAL_TZID_PARAMETER);
}

/* Scans an exception date property */
static void
scan_exdate (CalComponent *comp, icalproperty *prop)
{
    CalComponentPrivate *priv;
    struct datetime *dt;

    priv = comp->priv;

    dt = g_new (struct datetime, 1);
    dt->prop = prop;
    dt->tzid_param = icalproperty_get_first_parameter (prop, ICAL_TZID_PARAMETER);

    priv->exdate_list = g_slist_append (priv->exdate_list, dt);
}

/* Scans an icalperiodtype property */
static void
scan_period (CalComponent *comp, GSList **list, icalproperty *prop)
{
    struct period *period;

    period = g_new (struct period, 1);
    period->prop = prop;
    period->value_param = icalproperty_get_first_parameter (prop, ICAL_VALUE_PARAMETER);

    *list = g_slist_append (*list, period);
}

/* Scans an icalrecurtype property */
static void
scan_recur (CalComponent *comp, GSList **list, icalproperty *prop)
{
    *list = g_slist_append (*list, prop);
}

/* Scans the summary property */
static void
scan_summary (CalComponent *comp, icalproperty *prop)
{
    CalComponentPrivate *priv;

    priv = comp->priv;

    priv->summary.prop = prop;
    priv->summary.altrep_param = icalproperty_get_first_parameter (prop, ICAL_ALTREP_PARAMETER);
}

/* Scans a text (i.e. text + altrep) property */
static void
scan_text (CalComponent *comp, GSList **text_list, icalproperty *prop)
{
    struct text *text;

    text = g_new (struct text, 1);
    text->prop = prop;
    text->altrep_param = icalproperty_get_first_parameter (prop, ICAL_ALTREP_PARAMETER);

    *text_list = g_slist_append (*text_list, text);
}

/* Scans an icalproperty and adds its mapping to the component */
static void
scan_property (CalComponent *comp, icalproperty *prop)
{
    CalComponentPrivate *priv;
    icalproperty_kind kind;

    priv = comp->priv;

    kind = icalproperty_isa (prop);

    switch (kind) {
    case ICAL_STATUS_PROPERTY:
        priv->status = prop;
        break;

    case ICAL_CATEGORIES_PROPERTY:
        priv->categories = prop;
        break;

    case ICAL_CLASS_PROPERTY:
        priv->classification = prop;
        break;

    case ICAL_COMMENT_PROPERTY:
        scan_text (comp, &priv->comment_list, prop);
        break;

    case ICAL_COMPLETED_PROPERTY:
        priv->completed = prop;
        break;

    case ICAL_CREATED_PROPERTY:
        priv->created = prop;
        break;

    case ICAL_DESCRIPTION_PROPERTY:
        scan_text (comp, &priv->description_list, prop);
        break;

    case ICAL_DTEND_PROPERTY:
        scan_datetime (comp, &priv->dtend, prop);
        break;

    case ICAL_DTSTAMP_PROPERTY:
        priv->dtstamp = prop;
        break;

    case ICAL_DTSTART_PROPERTY:
        scan_datetime (comp, &priv->dtstart, prop);
        break;

    case ICAL_DUE_PROPERTY:
        scan_datetime (comp, &priv->due, prop);
        break;

    case ICAL_EXDATE_PROPERTY:
        scan_exdate (comp, prop);
        break;

    case ICAL_EXRULE_PROPERTY:
        scan_recur (comp, &priv->exrule_list, prop);
        break;

    case ICAL_GEO_PROPERTY:
        priv->geo = prop;
        break;

    case ICAL_LASTMODIFIED_PROPERTY:
        priv->last_modified = prop;
        break;

    case ICAL_PERCENTCOMPLETE_PROPERTY:
        priv->percent = prop;
        break;

    case ICAL_PRIORITY_PROPERTY:
        priv->priority = prop;
        break;

    case ICAL_RDATE_PROPERTY:
        scan_period (comp, &priv->rdate_list, prop);
        break;

    case ICAL_RRULE_PROPERTY:
        scan_recur (comp, &priv->rrule_list, prop);
        break;

    case ICAL_SEQUENCE_PROPERTY:
        priv->sequence = prop;
        break;

    case ICAL_SUMMARY_PROPERTY:
        scan_summary (comp, prop);
        break;

    case ICAL_TRANSP_PROPERTY:
        priv->transparency = prop;
        break;

    case ICAL_UID_PROPERTY:
        priv->uid = prop;
        break;

    case ICAL_URL_PROPERTY:
        priv->url = prop;
        break;

    default:
        break;
    }
}

/* Gets our alarm UID string from a property that is known to contain it */
static const char *
alarm_uid_from_prop (icalproperty *prop)
{
    const char *xstr;

    g_assert (icalproperty_isa (prop) == ICAL_X_PROPERTY);

    xstr = icalproperty_get_x (prop);
    g_assert (xstr != NULL);

    return xstr;
}

/* Sets our alarm UID extension property on an alarm component.  Returns a
 * pointer to the UID string inside the property itself.
 */
static const char *
set_alarm_uid (icalcomponent *alarm, const char *auid)
{
    icalproperty *prop;
    const char *inprop_auid;

    /* Create the new property */

    prop = icalproperty_new_x ((char *) auid);
    icalproperty_set_x_name (prop, EVOLUTION_ALARM_UID_PROPERTY);

    icalcomponent_add_property (alarm, prop);

    inprop_auid = alarm_uid_from_prop (prop);
    return inprop_auid;
}

/* Removes any alarm UID extension properties from an alarm subcomponent */
static void
remove_alarm_uid (icalcomponent *alarm)
{
    icalproperty *prop;
    GSList *list, *l;

    list = NULL;

    for (prop = icalcomponent_get_first_property (alarm, ICAL_X_PROPERTY);
         prop;
         prop = icalcomponent_get_next_property (alarm, ICAL_X_PROPERTY)) {
        const char *xname;

        xname = icalproperty_get_x_name (prop);
        g_assert (xname != NULL);

        if (strcmp (xname, EVOLUTION_ALARM_UID_PROPERTY) == 0)
            list = g_slist_prepend (list, prop);
    }

    for (l = list; l; l = l->next) {
        prop = l->data;
        icalcomponent_remove_property (alarm, prop);
        icalproperty_free (prop);
    }

    g_slist_free (list);
}

/* Adds an alarm subcomponent to the calendar component's mapping table.  The
 * actual UID with which it gets added may not be the same as the specified one;
 * this function will change it if the table already had an alarm subcomponent
 * with the specified UID.  Returns the actual UID used.
 */
static const char *
add_alarm (CalComponent *comp, icalcomponent *alarm, const char *auid)
{
    CalComponentPrivate *priv;
    icalcomponent *old_alarm;

    priv = comp->priv;

    /* First we see if we already have an alarm with the requested UID.  In
     * that case, we need to change the new UID to something else.  This
     * should never happen, but who knows.
     */

    old_alarm = g_hash_table_lookup (priv->alarm_uid_hash, auid);
    if (old_alarm != NULL) {
        char *new_auid;

        g_message ("add_alarm(): Got alarm with duplicated UID `%s', changing it...", auid);

        remove_alarm_uid (alarm);

        new_auid = cal_component_gen_uid ();
        auid = set_alarm_uid (alarm, new_auid);
        g_free (new_auid);
    }

    g_hash_table_insert (priv->alarm_uid_hash, (char *) auid, alarm);
    return auid;
}

static void
remove_alarm (CalComponent *comp, const char *auid) 
{
    CalComponentPrivate *priv;
    
    priv = comp->priv;
    
    g_hash_table_remove (priv->alarm_uid_hash, auid);
}


/* Scans an alarm subcomponent, adds an UID extension property to it (so that we
 * can reference alarms by unique IDs), and adds its mapping to the component.  */
static void
scan_alarm (CalComponent *comp, icalcomponent *alarm)
{
    CalComponentPrivate *priv;
    icalproperty *prop;
    const char *auid;
    char *new_auid;

    priv = comp->priv;

    for (prop = icalcomponent_get_first_property (alarm, ICAL_X_PROPERTY);
         prop;
         prop = icalcomponent_get_next_property (alarm, ICAL_X_PROPERTY)) {
        const char *xname;

        xname = icalproperty_get_x_name (prop);
        g_assert (xname != NULL);

        if (strcmp (xname, EVOLUTION_ALARM_UID_PROPERTY) == 0) {
            auid = alarm_uid_from_prop (prop);
            add_alarm (comp, alarm, auid);
            return;
        }
    }

    /* The component has no alarm UID property, so we create one. */

    new_auid = cal_component_gen_uid ();
    auid = set_alarm_uid (alarm, new_auid);
    g_free (new_auid);

    add_alarm (comp, alarm, auid);
}

/* Scans an icalcomponent for its properties so that we can provide
 * random-access to them.  It also builds a hash table of the component's alarm
 * subcomponents.
 */
static void
scan_icalcomponent (CalComponent *comp)
{
    CalComponentPrivate *priv;
    icalproperty *prop;
    icalcompiter iter;

    priv = comp->priv;

    g_assert (priv->icalcomp != NULL);

    /* Scan properties */

    for (prop = icalcomponent_get_first_property (priv->icalcomp, ICAL_ANY_PROPERTY);
         prop;
         prop = icalcomponent_get_next_property (priv->icalcomp, ICAL_ANY_PROPERTY))
        scan_property (comp, prop);

    /* Scan subcomponents */

    for (iter = icalcomponent_begin_component (priv->icalcomp, ICAL_VALARM_COMPONENT);
         icalcompiter_deref (&iter) != NULL;
         icalcompiter_next (&iter)) {
        icalcomponent *subcomp;

        subcomp = icalcompiter_deref (&iter);
        scan_alarm (comp, subcomp);
    }
}

/* Ensures that the mandatory calendar component properties (uid, dtstamp) do
 * exist.  If they don't exist, it creates them automatically.
 */
static void
ensure_mandatory_properties (CalComponent *comp)
{
    CalComponentPrivate *priv;

    priv = comp->priv;
    g_assert (priv->icalcomp != NULL);

    if (!priv->uid) {
        char *uid;

        uid = cal_component_gen_uid ();
        priv->uid = icalproperty_new_uid (uid);
        g_free (uid);

        icalcomponent_add_property (priv->icalcomp, priv->uid);
    }

    if (!priv->dtstamp) {
        time_t tim;
        struct icaltimetype t;

        tim = time (NULL);
        t = icaltime_from_timet (tim, FALSE);

        priv->dtstamp = icalproperty_new_dtstamp (t);
        icalcomponent_add_property (priv->icalcomp, priv->dtstamp);
    }
}

/**
 * cal_component_set_new_vtype:
 * @comp: A calendar component object.
 * @type: Type of calendar component to create.
 *
 * Clears any existing component data from a calendar component object and
 * creates a new #icalcomponent of the specified type for it.  The only property
 * that will be set in the new component will be its unique identifier.
 **/
void
cal_component_set_new_vtype (CalComponent *comp, CalComponentVType type)
{
    CalComponentPrivate *priv;
    icalcomponent *icalcomp;
    icalcomponent_kind kind;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;

    free_icalcomponent (comp);

    if (type == CAL_COMPONENT_NO_TYPE)
        return;

    /* Figure out the kind and create the icalcomponent */

    switch (type) {
    case CAL_COMPONENT_EVENT:
        kind = ICAL_VEVENT_COMPONENT;
        break;

    case CAL_COMPONENT_TODO:
        kind = ICAL_VTODO_COMPONENT;
        break;

    case CAL_COMPONENT_JOURNAL:
        kind = ICAL_VJOURNAL_COMPONENT;
        break;

    case CAL_COMPONENT_FREEBUSY:
        kind = ICAL_VFREEBUSY_COMPONENT;
        break;

    case CAL_COMPONENT_TIMEZONE:
        kind = ICAL_VTIMEZONE_COMPONENT;
        break;

    default:
        g_assert_not_reached ();
        kind = ICAL_NO_COMPONENT;
    }

    icalcomp = icalcomponent_new (kind);
    if (!icalcomp) {
        g_message ("cal_component_set_new_vtype(): Could not create the icalcomponent!");
        return;
    }

    /* Scan the component to build our mapping table */

    priv->icalcomp = icalcomp;
    scan_icalcomponent (comp);

    /* Add missing stuff */

    ensure_mandatory_properties (comp);
}

/**
 * cal_component_set_icalcomponent:
 * @comp: A calendar component object.
 * @icalcomp: An #icalcomponent.
 *
 * Sets the contents of a calendar component object from an #icalcomponent
 * structure.  If the @comp already had an #icalcomponent set into it, it will
 * will be freed automatically if the #icalcomponent does not have a parent
 * component itself.
 *
 * Supported component types are VEVENT, VTODO, VJOURNAL, VFREEBUSY, and VTIMEZONE.
 *
 * Return value: TRUE on success, FALSE if @icalcomp is an unsupported component
 * type.
 **/
gboolean
cal_component_set_icalcomponent (CalComponent *comp, icalcomponent *icalcomp)
{
    CalComponentPrivate *priv;
    icalcomponent_kind kind;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;

    if (priv->icalcomp == icalcomp)
        return TRUE;

    free_icalcomponent (comp);

    if (!icalcomp) {
        priv->icalcomp = NULL;
        return TRUE;
    }

    kind = icalcomponent_isa (icalcomp);

    if (!(kind == ICAL_VEVENT_COMPONENT
          || kind == ICAL_VTODO_COMPONENT
          || kind == ICAL_VJOURNAL_COMPONENT
          || kind == ICAL_VFREEBUSY_COMPONENT
          || kind == ICAL_VTIMEZONE_COMPONENT))
        return FALSE;

    priv->icalcomp = icalcomp;

    scan_icalcomponent (comp);
    ensure_mandatory_properties (comp);

    return TRUE;
}

/**
 * cal_component_get_icalcomponent:
 * @comp: A calendar component object.
 *
 * Queries the #icalcomponent structure that a calendar component object is
 * wrapping.
 *
 * Return value: An #icalcomponent structure, or NULL if the @comp has no
 * #icalcomponent set to it.
 **/
icalcomponent *
cal_component_get_icalcomponent (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, NULL);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), NULL);

    priv = comp->priv;
    g_return_val_if_fail (priv->need_sequence_inc == FALSE, NULL);

    return priv->icalcomp;
}

/**
 * cal_component_get_vtype:
 * @comp: A calendar component object.
 *
 * Queries the type of a calendar component object.
 *
 * Return value: The type of the component, as defined by RFC 2445.
 **/
CalComponentVType
cal_component_get_vtype (CalComponent *comp)
{
    CalComponentPrivate *priv;
    icalcomponent_kind kind;

    g_return_val_if_fail (comp != NULL, CAL_COMPONENT_NO_TYPE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), CAL_COMPONENT_NO_TYPE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, CAL_COMPONENT_NO_TYPE);

    kind = icalcomponent_isa (priv->icalcomp);
    switch (kind) {
    case ICAL_VEVENT_COMPONENT:
        return CAL_COMPONENT_EVENT;

    case ICAL_VTODO_COMPONENT:
        return CAL_COMPONENT_TODO;

    case ICAL_VJOURNAL_COMPONENT:
        return CAL_COMPONENT_JOURNAL;

    case ICAL_VFREEBUSY_COMPONENT:
        return CAL_COMPONENT_FREEBUSY;

    case ICAL_VTIMEZONE_COMPONENT:
        return CAL_COMPONENT_TIMEZONE;

    default:
        /* We should have been loaded with a supported type! */
        g_assert_not_reached ();
        return CAL_COMPONENT_NO_TYPE;
    }
}

/**
 * cal_component_get_as_string:
 * @comp: A calendar component.
 *
 * Gets the iCalendar string representation of a calendar component.  You should
 * call cal_component_commit_sequence() before this function to ensure that the
 * component's sequence number is consistent with the state of the object.
 *
 * Return value: String representation of the calendar component according to
 * RFC 2445.
 **/
char *
cal_component_get_as_string (CalComponent *comp)
{
    CalComponentPrivate *priv;
    char *str, *buf;

    g_return_val_if_fail (comp != NULL, NULL);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), NULL);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, NULL);

    /* Ensure that the user has committed the new SEQUENCE */
    g_return_val_if_fail (priv->need_sequence_inc == FALSE, NULL);

    /* We dup the string; libical owns that memory */

    str = icalcomponent_as_ical_string (priv->icalcomp);

    if (str)
        buf = g_strdup (str);
    else
        buf = NULL;

    return buf;
}

/**
 * cal_component_commit_sequence:
 * @comp:
 *
 * Increments the sequence number property in a calendar component object if it
 * needs it.  This needs to be done when any of a number of properties listed in
 * RFC 2445 change values, such as the start and end dates of a component.
 *
 * This function must be called before calling cal_component_get_as_string() to
 * ensure that the component is fully consistent.
 **/
void
cal_component_commit_sequence (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->need_sequence_inc)
        return;

    if (priv->sequence) {
        int seq;

        seq = icalproperty_get_sequence (priv->sequence);
        icalproperty_set_sequence (priv->sequence, seq + 1);
    } else {
        /* The component had no SEQUENCE property, so assume that the
         * default would have been zero.  Since it needed incrementing
         * anyways, we use a value of 1 here.
         */
        priv->sequence = icalproperty_new_sequence (1);
        icalcomponent_add_property (priv->icalcomp, priv->sequence);
    }

    priv->need_sequence_inc = FALSE;
}

/**
 * cal_component_get_uid:
 * @comp: A calendar component object.
 * @uid: Return value for the UID string.
 *
 * Queries the unique identifier of a calendar component object.
 **/
void
cal_component_get_uid (CalComponent *comp, const char **uid)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (uid != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    /* This MUST exist, since we ensured that it did */
    g_assert (priv->uid != NULL);

    *uid = icalproperty_get_uid (priv->uid);
}

/**
 * cal_component_set_uid:
 * @comp: A calendar component object.
 * @uid: Unique identifier.
 *
 * Sets the unique identifier string of a calendar component object.
 **/
void
cal_component_set_uid (CalComponent *comp, const char *uid)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (uid != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    /* This MUST exist, since we ensured that it did */
    g_assert (priv->uid != NULL);

    icalproperty_set_uid (priv->uid, (char *) uid);
}

/**
 * cal_component_get_categories:
 * @comp: A calendar component object. 
 * @categories: 
 * 
 * 
 **/
void 
cal_component_get_categories (CalComponent *comp, const char **categories)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (categories != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->categories)
        *categories = icalproperty_get_categories (priv->categories);
    else
        *categories = NULL;
}

/**
 * cal_component_set_categories:
 * @comp: A calendar component object.
 * @categories: 
 * 
 * 
 **/
void 
cal_component_set_categories (CalComponent *comp, const char *categories)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!categories || !(*categories)) {
        if (priv->categories) {
            icalcomponent_remove_property (priv->icalcomp, priv->categories);
            icalproperty_free (priv->categories);
            priv->url = NULL;
        }

        return;
    }

    if (priv->categories)
        icalproperty_set_categories (priv->categories, (char *) categories);
    else {
        priv->categories = icalproperty_new_categories ((char *) categories);
        icalcomponent_add_property (priv->icalcomp, priv->categories);
    }
}


/**
 * cal_component_get_categories_list:
 * @comp: A calendar component object.
 * @categ_list: Return value for the list of strings, where each string is a
 * category.  This should be freed using cal_component_free_categories_list().
 *
 * Queries the list of categories of a calendar component object.  Each element
 * in the returned categ_list is a string with the corresponding category.
 **/
void
cal_component_get_categories_list (CalComponent *comp, GSList **categ_list)
{
    CalComponentPrivate *priv;
    const char *categories;
    const char *p;
    const char *cat_start;
    char *str;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (categ_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->categories) {
        *categ_list = NULL;
        return;
    }

    categories = icalproperty_get_categories (priv->categories);
    g_assert (categories != NULL);

    cat_start = categories;
    *categ_list = NULL;

    for (p = categories; *p; p++)
        if (*p == ',') {
            str = g_strndup (cat_start, p - cat_start);
            *categ_list = g_slist_prepend (*categ_list, str);

            cat_start = p + 1;
        }

    str = g_strndup (cat_start, p - cat_start);
    *categ_list = g_slist_prepend (*categ_list, str);

    *categ_list = g_slist_reverse (*categ_list);
}

/* Creates a comma-delimited string of categories */
static char *
stringify_categories (GSList *categ_list)
{
    GString *s;
    GSList *l;
    char *str;

    s = g_string_new (NULL);

    for (l = categ_list; l; l = l->next) {
        g_string_append (s, l->data);

        if (l->next != NULL)
            g_string_append (s, ",");
    }

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

    return str;
}

/**
 * cal_component_set_categories_list:
 * @comp: A calendar component object.
 * @categ_list: List of strings, one for each category.
 *
 * Sets the list of categories of a calendar component object.
 **/
void
cal_component_set_categories_list (CalComponent *comp, GSList *categ_list)
{
    CalComponentPrivate *priv;
    char *categories_str;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!categ_list) {
        if (priv->categories) {
            icalcomponent_remove_property (priv->icalcomp, priv->categories);
            icalproperty_free (priv->categories);
        }
        
        return;
    }

    /* Create a single string of categories */
    categories_str = stringify_categories (categ_list);

    /* Set the categories */
    priv->categories = icalproperty_new_categories (categories_str);
    g_free (categories_str);

    icalcomponent_add_property (priv->icalcomp, priv->categories);
}

/**
 * cal_component_get_classification:
 * @comp: A calendar component object.
 * @classif: Return value for the classification.
 *
 * Queries the classification of a calendar component object.  If the
 * classification property is not set on this component, this function returns
 * #CAL_COMPONENT_CLASS_NONE.
 **/
void
cal_component_get_classification (CalComponent *comp, CalComponentClassification *classif)
{
    CalComponentPrivate *priv;
    const char *class;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (classif != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->classification) {
        *classif = CAL_COMPONENT_CLASS_NONE;
        return;
    }

    class = icalproperty_get_class (priv->classification);

    if (strcasecmp (class, "PUBLIC") == 0)
        *classif = CAL_COMPONENT_CLASS_PUBLIC;
    else if (strcasecmp (class, "PRIVATE") == 0)
        *classif = CAL_COMPONENT_CLASS_PRIVATE;
    else if (strcasecmp (class, "CONFIDENTIAL") == 0)
        *classif = CAL_COMPONENT_CLASS_CONFIDENTIAL;
    else
        *classif = CAL_COMPONENT_CLASS_UNKNOWN;
}

/**
 * cal_component_set_classification:
 * @comp: A calendar component object.
 * @classif: Classification to use.
 *
 * Sets the classification property of a calendar component object.  To unset
 * the property, specify CAL_COMPONENT_CLASS_NONE for @classif.
 **/
void
cal_component_set_classification (CalComponent *comp, CalComponentClassification classif)
{
    CalComponentPrivate *priv;
    char *str;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (classif != CAL_COMPONENT_CLASS_UNKNOWN);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (classif == CAL_COMPONENT_CLASS_NONE) {
        if (priv->classification) {
            icalcomponent_remove_property (priv->icalcomp, priv->classification);
            icalproperty_free (priv->classification);
            priv->classification = NULL;
        }

        return;
    }

    switch (classif) {
    case CAL_COMPONENT_CLASS_PUBLIC:
        str = "PUBLIC";
        break;

    case CAL_COMPONENT_CLASS_PRIVATE:
        str = "PRIVATE";
        break;

    case CAL_COMPONENT_CLASS_CONFIDENTIAL:
        str = "CONFIDENTIAL";
        break;

    default:
        g_assert_not_reached ();
        str = NULL;
    }

    if (priv->classification)
        icalproperty_set_class (priv->classification, str);
    else {
        priv->classification = icalproperty_new_class (str);
        icalcomponent_add_property (priv->icalcomp, priv->classification);
    }
}

/* Gets a text list value */
static void
get_text_list (GSList *text_list,
           const char *(* get_prop_func) (icalproperty *prop),
           GSList **tl)
{
    GSList *l;

    *tl = NULL;

    if (!text_list)
        return;

    for (l = text_list; l; l = l->next) {
        struct text *text;
        CalComponentText *t;

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

        t = g_new (CalComponentText, 1);
        t->value = (* get_prop_func) (text->prop);

        if (text->altrep_param)
            t->altrep = icalparameter_get_altrep (text->altrep_param);
        else
            t->altrep = NULL;

        *tl = g_slist_prepend (*tl, t);
    }

    *tl = g_slist_reverse (*tl);
}

/* Sets a text list value */
static void
set_text_list (CalComponent *comp,
           icalproperty *(* new_prop_func) (const char *value),
           GSList **text_list,
           GSList *tl)
{
    CalComponentPrivate *priv;
    GSList *l;

    priv = comp->priv;

    /* Remove old texts */

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

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

        icalcomponent_remove_property (priv->icalcomp, text->prop);
        icalproperty_free (text->prop);
        g_free (text);
    }

    g_slist_free (*text_list);
    *text_list = NULL;

    /* Add in new texts */

    for (l = tl; l; l = l->next) {
        CalComponentText *t;
        struct text *text;

        t = l->data;
        g_return_if_fail (t->value != NULL);

        text = g_new (struct text, 1);

        text->prop = (* new_prop_func) ((char *) t->value);
        icalcomponent_add_property (priv->icalcomp, text->prop);

        if (t->altrep) {
            text->altrep_param = icalparameter_new_altrep ((char *) t->altrep);
            icalproperty_add_parameter (text->prop, text->altrep_param);
        } else
            text->altrep_param = NULL;

        *text_list = g_slist_prepend (*text_list, text);
    }

    *text_list = g_slist_reverse (*text_list);
}

/**
 * cal_component_get_comment_list:
 * @comp: A calendar component object.
 * @text_list: Return value for the comment properties and their parameters, as
 * a list of #CalComponentText structures.  This should be freed using the
 * cal_component_free_text_list() function.
 *
 * Queries the comment of a calendar component object.  The comment property can
 * appear several times inside a calendar component, and so a list of
 * #CalComponentText is returned.
 **/
void
cal_component_get_comment_list (CalComponent *comp, GSList **text_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (text_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_text_list (priv->comment_list, icalproperty_get_comment, text_list);
}

/**
 * cal_component_set_comment_list:
 * @comp: A calendar component object.
 * @text_list: List of #CalComponentText structures.
 *
 * Sets the comment of a calendar component object.  The comment property can
 * appear several times inside a calendar component, and so a list of
 * #CalComponentText structures is used.
 **/
void
cal_component_set_comment_list (CalComponent *comp, GSList *text_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_text_list (comp, icalproperty_new_comment, &priv->comment_list, text_list);
}

/* Gets a struct icaltimetype value */
static void
get_icaltimetype (icalproperty *prop,
          struct icaltimetype (* get_prop_func) (icalproperty *prop),
          struct icaltimetype **t)
{
    if (!prop) {
        *t = NULL;
        return;
    }

    *t = g_new (struct icaltimetype, 1);
    **t = (* get_prop_func) (prop);
}

/* Sets a struct icaltimetype value */
static void
set_icaltimetype (CalComponent *comp, icalproperty **prop,
          icalproperty *(* prop_new_func) (struct icaltimetype v),
          void (* prop_set_func) (icalproperty *prop, struct icaltimetype v),
          struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    priv = comp->priv;

    if (!t) {
        if (*prop) {
            icalcomponent_remove_property (priv->icalcomp, *prop);
            icalproperty_free (*prop);
            *prop = NULL;
        }

        return;
    }

    if (*prop)
        (* prop_set_func) (*prop, *t);
    else {
        *prop = (* prop_new_func) (*t);
        icalcomponent_add_property (priv->icalcomp, *prop);
    }
}

/**
 * cal_component_get_completed:
 * @comp: A calendar component object.
 * @t: Return value for the completion date.  This should be freed using the
 * cal_component_free_icaltimetype() function.
 *
 * Queries the date at which a calendar compoment object was completed.
 **/
void
cal_component_get_completed (CalComponent *comp, struct icaltimetype **t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (t != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_icaltimetype (priv->completed, icalproperty_get_completed, t);
}

/**
 * cal_component_set_completed:
 * @comp: A calendar component object.
 * @t: Value for the completion date.
 *
 * Sets the date at which a calendar component object was completed.
 **/
void
cal_component_set_completed (CalComponent *comp, struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_icaltimetype (comp, &priv->completed,
              icalproperty_new_completed,
              icalproperty_set_completed,
              t);
}


/**
 * cal_component_get_created:
 * @comp: A calendar component object.
 * @t: Return value for the creation date.  This should be freed using the
 * cal_component_free_icaltimetype() function.
 *
 * Queries the date in which a calendar component object was created in the
 * calendar store.
 **/
void
cal_component_get_created (CalComponent *comp, struct icaltimetype **t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (t != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_icaltimetype (priv->created, icalproperty_get_created, t);
}

/**
 * cal_component_set_created:
 * @comp: A calendar component object.
 * @t: Value for the creation date.
 *
 * Sets the date in which a calendar component object is created in the calendar
 * store.  This should only be used inside a calendar store application, i.e.
 * not by calendar user agents.
 **/
void
cal_component_set_created (CalComponent *comp, struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_icaltimetype (comp, &priv->created,
              icalproperty_new_created,
              icalproperty_set_created,
              t);
}

/**
 * cal_component_get_description_list:
 * @comp: A calendar component object.
 * @text_list: Return value for the description properties and their parameters,
 * as a list of #CalComponentText structures.  This should be freed using the
 * cal_component_free_text_list() function.
 *
 * Queries the description of a calendar component object.  Journal components
 * may have more than one description, and as such this function returns a list
 * of #CalComponentText structures.  All other types of components can have at
 * most one description.
 **/
void
cal_component_get_description_list (CalComponent *comp, GSList **text_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (text_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_text_list (priv->description_list, icalproperty_get_description, text_list);
}

/**
 * cal_component_set_description_list:
 * @comp: A calendar component object.
 * @text_list: List of #CalComponentSummary structures.
 *
 * Sets the description of a calendar component object.  Journal components may
 * have more than one description, and as such this function takes in a list of
 * #CalComponentDescription structures.  All other types of components can have
 * at most one description.
 **/
void
cal_component_set_description_list (CalComponent *comp, GSList *text_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_text_list (comp, icalproperty_new_description, &priv->description_list, text_list);
}

/* Gets a date/time and timezone pair */
static void
get_datetime (struct datetime *datetime,
          struct icaltimetype (* get_prop_func) (icalproperty *prop),
          CalComponentDateTime *dt)
{
    if (datetime->prop) {
        dt->value = g_new (struct icaltimetype, 1);
        *dt->value = (* get_prop_func) (datetime->prop);
    } else
        dt->value = NULL;

    if (datetime->tzid_param)
        dt->tzid = icalparameter_get_tzid (datetime->tzid_param);
    else
        dt->tzid = NULL;
}

/* Sets a date/time and timezone pair */
static void
set_datetime (CalComponent *comp, struct datetime *datetime,
          icalproperty *(* prop_new_func) (struct icaltimetype v),
          void (* prop_set_func) (icalproperty * prop, struct icaltimetype v),
          CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    priv = comp->priv;

    if (!dt) {
        if (datetime->prop) {
            icalcomponent_remove_property (priv->icalcomp, datetime->prop);
            icalproperty_free (datetime->prop);

            datetime->prop = NULL;
            datetime->tzid_param = NULL;
        }

        return;
    }

    g_return_if_fail (dt->value != NULL);

    if (datetime->prop)
        (* prop_set_func) (datetime->prop, *dt->value);
    else {
        datetime->prop = (* prop_new_func) (*dt->value);
        icalcomponent_add_property (priv->icalcomp, datetime->prop);
    }

    if (dt->tzid) {
        g_assert (datetime->prop != NULL);

        if (datetime->tzid_param)
            icalparameter_set_tzid (datetime->tzid_param, (char *) dt->tzid);
        else {
            datetime->tzid_param = icalparameter_new_tzid ((char *) dt->tzid);
            icalproperty_add_parameter (datetime->prop, datetime->tzid_param);
        }
    } else if (datetime->tzid_param) {
        icalproperty_remove_parameter (datetime->prop, ICAL_TZID_PARAMETER);
        icalparameter_free (datetime->tzid_param);
        datetime->tzid_param = NULL;
    }
}

/**
 * cal_component_get_dtend:
 * @comp: A calendar component object.
 * @dt: Return value for the date/time end.  This should be freed with the
 * cal_component_free_datetime() function.
 *
 * Queries the date/time end of a calendar component object.
 **/
void
cal_component_get_dtend (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (dt != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_datetime (&priv->dtend, icalproperty_get_dtend, dt);
}

/**
 * cal_component_set_dtend:
 * @comp: A calendar component object.
 * @dt: End date/time.
 *
 * Sets the date/time end property of a calendar component object.
 **/
void
cal_component_set_dtend (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_datetime (comp, &priv->dtend,
              icalproperty_new_dtend,
              icalproperty_set_dtend,
              dt);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_get_dtstamp:
 * @comp: A calendar component object.
 * @t: Return value for the date/timestamp.
 *
 * Queries the date/timestamp property of a calendar component object, which is
 * the last time at which the object was modified by a calendar user agent.
 **/
void
cal_component_get_dtstamp (CalComponent *comp, struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (t != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    /* This MUST exist, since we ensured that it did */
    g_assert (priv->dtstamp != NULL);

    *t = icalproperty_get_dtstamp (priv->dtstamp);
}

/**
 * cal_component_set_dtstamp:
 * @comp: A calendar component object.
 * @t: Date/timestamp value.
 *
 * Sets the date/timestamp of a calendar component object.  This should be
 * called whenever a calendar user agent makes a change to a component's
 * properties.
 **/
void
cal_component_set_dtstamp (CalComponent *comp, struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (t != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    /* This MUST exist, since we ensured that it did */
    g_assert (priv->dtstamp != NULL);

    icalproperty_set_dtstamp (priv->dtstamp, *t);
}

/**
 * cal_component_get_dtstart:
 * @comp: A calendar component object.
 * @dt: Return value for the date/time start.  This should be freed with the
 * cal_component_free_datetime() function.
 *
 * Queries the date/time start of a calendar component object.
 **/
void
cal_component_get_dtstart (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (dt != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_datetime (&priv->dtstart, icalproperty_get_dtstart, dt);
}

/**
 * cal_component_set_dtstart:
 * @comp: A calendar component object.
 * @dt: Start date/time.
 *
 * Sets the date/time start property of a calendar component object.
 **/
void
cal_component_set_dtstart (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_datetime (comp, &priv->dtstart,
              icalproperty_new_dtstart,
              icalproperty_set_dtstart,
              dt);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_get_due:
 * @comp: A calendar component object.
 * @dt: Return value for the due date/time.  This should be freed with the
 * cal_component_free_datetime() function.
 *
 * Queries the due date/time of a calendar component object.
 **/
void
cal_component_get_due (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (dt != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_datetime (&priv->due, icalproperty_get_due, dt);
}

/**
 * cal_component_set_due:
 * @comp: A calendar component object.
 * @dt: End date/time.
 *
 * Sets the due date/time property of a calendar component object.
 **/
void
cal_component_set_due (CalComponent *comp, CalComponentDateTime *dt)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_datetime (comp, &priv->due,
              icalproperty_new_due,
              icalproperty_set_due,
              dt);

    priv->need_sequence_inc = TRUE;
}

/* Builds a list of CalComponentPeriod structures based on a list of icalproperties */
static void
get_period_list (GSList *period_list,
         struct icaldatetimeperiodtype (* get_prop_func) (icalproperty *prop),
         GSList **list)
{
    GSList *l;

    *list = NULL;

    if (!period_list)
        return;

    for (l = period_list; l; l = l->next) {
        struct period *period;
        CalComponentPeriod *p;
        struct icaldatetimeperiodtype ip;

        period = l->data;
        g_assert (period->prop != NULL);

        p = g_new (CalComponentPeriod, 1);

        /* Get value parameter */

        if (period->value_param) {
            icalparameter_value value_type;

            value_type = icalparameter_get_value (period->value_param);

            if (value_type == ICAL_VALUE_DATE || value_type == ICAL_VALUE_DATETIME)
                p->type = CAL_COMPONENT_PERIOD_DATETIME;
            else if (value_type == ICAL_VALUE_DURATION)
                p->type = CAL_COMPONENT_PERIOD_DURATION;
            else {
                g_message ("get_period_list(): Unknown value for period %d; "
                       "using DATETIME", value_type);
                p->type = CAL_COMPONENT_PERIOD_DATETIME;
            }
        } else
            p->type = CAL_COMPONENT_PERIOD_DATETIME;

        /* Get start and end/duration */

        ip = (* get_prop_func) (period->prop);

        p->start = ip.period.start;

        if (p->type == CAL_COMPONENT_PERIOD_DATETIME)
            p->u.end = ip.period.end;
        else if (p->type == CAL_COMPONENT_PERIOD_DURATION)
            p->u.duration = ip.period.duration;
        else
            g_assert_not_reached ();

        /* Put in list */

        *list = g_slist_prepend (*list, p);
    }

    *list = g_slist_reverse (*list);
}

/* Sets a period list value */
static void
set_period_list (CalComponent *comp,
         icalproperty *(* new_prop_func) (struct icaldatetimeperiodtype period),
         GSList **period_list,
         GSList *pl)
{
    CalComponentPrivate *priv;
    GSList *l;

    priv = comp->priv;

    /* Remove old periods */

    for (l = *period_list; l; l = l->next) {
        struct period *period;

        period = l->data;
        g_assert (period->prop != NULL);

        icalcomponent_remove_property (priv->icalcomp, period->prop);
        icalproperty_free (period->prop);
        g_free (period);
    }

    g_slist_free (*period_list);
    *period_list = NULL;

    /* Add in new periods */

    for (l = pl; l; l = l->next) {
        CalComponentPeriod *p;
        struct period *period;
        struct icaldatetimeperiodtype ip;
        icalparameter_value value_type;

        g_assert (l->data != NULL);
        p = l->data;

        /* Create libical value */

        ip.period.start = p->start;

        if (p->type == CAL_COMPONENT_PERIOD_DATETIME) {
            value_type = ICAL_VALUE_DATETIME;
            ip.period.end = p->u.end;
        } else if (p->type == CAL_COMPONENT_PERIOD_DURATION) {
            value_type = ICAL_VALUE_DURATION;
            ip.period.duration = p->u.duration;
        } else {
            g_assert_not_reached ();
            return;
        }

        /* Create property */

        period = g_new (struct period, 1);

        period->prop = (* new_prop_func) (ip);
        period->value_param = icalparameter_new_value (value_type);
        icalproperty_add_parameter (period->prop, period->value_param);

        /* Add to list */

        *period_list = g_slist_prepend (*period_list, period);
    }

    *period_list = g_slist_reverse (*period_list);
}

/**
 * cal_component_get_exdate_list:
 * @comp: A calendar component object.
 * @exdate_list: Return value for the list of exception dates, as a list of
 * #CalComponentDateTime structures.  This should be freed using the
 * cal_component_free_exdate_list() function.
 *
 * Queries the list of exception date properties in a calendar component object.
 **/
void
cal_component_get_exdate_list (CalComponent *comp, GSList **exdate_list)
{
    CalComponentPrivate *priv;
    GSList *l;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (exdate_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    *exdate_list = NULL;

    for (l = priv->exdate_list; l; l = l->next) {
        struct datetime *dt;
        CalComponentDateTime *cdt;

        dt = l->data;

        cdt = g_new (CalComponentDateTime, 1);
        cdt->value = g_new (struct icaltimetype, 1);

        *cdt->value = icalproperty_get_exdate (dt->prop);

        if (dt->tzid_param)
            cdt->tzid = icalparameter_get_tzid (dt->tzid_param);
        else
            cdt->tzid = NULL;

        *exdate_list = g_slist_prepend (*exdate_list, cdt);
    }

    *exdate_list = g_slist_reverse (*exdate_list);
}

/**
 * cal_component_set_exdate_list:
 * @comp: A calendar component object.
 * @exdate_list: List of #CalComponentDateTime structures.
 *
 * Sets the list of exception dates in a calendar component object.
 **/
void
cal_component_set_exdate_list (CalComponent *comp, GSList *exdate_list)
{
    CalComponentPrivate *priv;
    GSList *l;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    /* Remove old exception dates */

    for (l = priv->exdate_list; l; l = l->next) {
        struct datetime *dt;

        dt = l->data;

        icalcomponent_remove_property (priv->icalcomp, dt->prop);
        icalproperty_free (dt->prop);
        g_free (dt);
    }

    g_slist_free (priv->exdate_list);
    priv->exdate_list = NULL;

    /* Add in new exception dates */

    for (l = exdate_list; l; l = l->next) {
        CalComponentDateTime *cdt;
        struct datetime *dt;

        g_assert (l->data != NULL);
        cdt = l->data;

        g_assert (cdt->value != NULL);

        dt = g_new (struct datetime, 1);
        dt->prop = icalproperty_new_exdate (*cdt->value);

        if (cdt->tzid) {
            dt->tzid_param = icalparameter_new_tzid ((char *) cdt->tzid);
            icalproperty_add_parameter (dt->prop, dt->tzid_param);
        } else
            dt->tzid_param = NULL;

        icalcomponent_add_property (priv->icalcomp, dt->prop);
        priv->exdate_list = g_slist_prepend (priv->exdate_list, dt);
    }

    priv->exdate_list = g_slist_reverse (priv->exdate_list);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_has_exdates:
 * @comp: A calendar component object.
 *
 * Queries whether a calendar component object has any exception dates defined
 * for it.
 *
 * Return value: TRUE if the component has exception dates, FALSE otherwise.
 **/
gboolean
cal_component_has_exdates (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, FALSE);

    return (priv->exdate_list != NULL);
}

/* Gets a list of recurrence rules */
static void
get_recur_list (GSList *recur_list,
        struct icalrecurrencetype (* get_prop_func) (icalproperty *prop),
        GSList **list)
{
    GSList *l;

    *list = NULL;

    for (l = recur_list; l; l = l->next) {
        icalproperty *prop;
        struct icalrecurrencetype *r;

        prop = l->data;

        r = g_new (struct icalrecurrencetype, 1);
        *r = (* get_prop_func) (prop);

        *list = g_slist_prepend (*list, r);
    }

    *list = g_slist_reverse (*list);
}

/* Sets a list of recurrence rules */
static void
set_recur_list (CalComponent *comp,
        icalproperty *(* new_prop_func) (struct icalrecurrencetype recur),
        GSList **recur_list,
        GSList *rl)
{
    CalComponentPrivate *priv;
    GSList *l;

    priv = comp->priv;

    /* Remove old recurrences */

    for (l = *recur_list; l; l = l->next) {
        icalproperty *prop;

        prop = l->data;
        icalcomponent_remove_property (priv->icalcomp, prop);
        icalproperty_free (prop);
    }

    g_slist_free (*recur_list);
    *recur_list = NULL;

    /* Add in new recurrences */

    for (l = rl; l; l = l->next) {
        icalproperty *prop;
        struct icalrecurrencetype *recur;

        g_assert (l->data != NULL);
        recur = l->data;

        prop = (* new_prop_func) (*recur);
        icalcomponent_add_property (priv->icalcomp, prop);

        *recur_list = g_slist_prepend (*recur_list, prop);
    }

    *recur_list = g_slist_reverse (*recur_list);
}

/**
 * cal_component_get_exrule_list:
 * @comp: A calendar component object.
 * @recur_list: List of exception rules as struct #icalrecurrencetype
 * structures.  This should be freed using the cal_component_free_recur_list()
 * function.
 *
 * Queries the list of exception rule properties of a calendar component
 * object.
 **/
void
cal_component_get_exrule_list (CalComponent *comp, GSList **recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (recur_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_recur_list (priv->exrule_list, icalproperty_get_exrule, recur_list);
}

/**
 * cal_component_get_exrule_property_list:
 * @comp: A calendar component object.
 * @recur_list: Returns a list of exception rule properties.
 *
 * Queries the list of exception rule properties of a calendar component object.
 **/
void
cal_component_get_exrule_property_list (CalComponent *comp, GSList **recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (recur_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    *recur_list = priv->exrule_list;
}

/**
 * cal_component_set_exrule_list:
 * @comp: A calendar component object.
 * @recur_list: List of struct #icalrecurrencetype structures.
 *
 * Sets the list of exception rules in a calendar component object.
 **/
void
cal_component_set_exrule_list (CalComponent *comp, GSList *recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_recur_list (comp, icalproperty_new_exrule, &priv->exrule_list, recur_list);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_has_exrules:
 * @comp: A calendar component object.
 *
 * Queries whether a calendar component object has any exception rules defined
 * for it.
 *
 * Return value: TRUE if the component has exception rules, FALSE otherwise.
 **/
gboolean
cal_component_has_exrules (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, FALSE);

    return (priv->exrule_list != NULL);
}

/**
 * cal_component_has_exceptions:
 * @comp: A calendar component object
 *
 * Queries whether a calendar component object has any exception dates
 * or exception rules.
 *
 * Return value: TRUE if the component has exceptions, FALSE otherwise.
 **/
gboolean
cal_component_has_exceptions (CalComponent *comp)
{
    return cal_component_has_exdates (comp) || cal_component_has_exrules (comp);
}

/**
 * cal_component_get_geo:
 * @comp: A calendar component object.
 * @geo: Return value for the geographic position property.  This should be
 * freed using the cal_component_free_geo() function.
 *
 * Sets the geographic position property of a calendar component object.
 **/
void
cal_component_get_geo (CalComponent *comp, struct icalgeotype **geo)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (geo != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->geo) {
        *geo = g_new (struct icalgeotype, 1);
        **geo = icalproperty_get_geo (priv->geo);
    } else
        *geo = NULL;
}

/**
 * cal_component_set_geo:
 * @comp: A calendar component object.
 * @geo: Value for the geographic position property.
 *
 * Sets the geographic position property on a calendar component object.
 **/
void
cal_component_set_geo (CalComponent *comp, struct icalgeotype *geo)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!geo) {
        if (priv->geo) {
            icalcomponent_remove_property (priv->icalcomp, priv->geo);
            icalproperty_free (priv->geo);
            priv->geo = NULL;
        }

        return;
    }

    if (priv->geo)
        icalproperty_set_geo (priv->geo, *geo);
    else {
        priv->geo = icalproperty_new_geo (*geo);
        icalcomponent_add_property (priv->icalcomp, priv->geo);
    }
}

/**
 * cal_component_get_last_modified:
 * @comp: A calendar component object.
 * @t: Return value for the last modified time value.
 *
 * Queries the time at which a calendar component object was last modified in
 * the calendar store.
 **/
void
cal_component_get_last_modified (CalComponent *comp, struct icaltimetype **t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (t != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_icaltimetype (priv->last_modified, icalproperty_get_lastmodified, t);
}

/**
 * cal_component_set_last_modified:
 * @comp: A calendar component object.
 * @t: Value for the last time modified.
 *
 * Sets the time at which a calendar component object was last stored in the
 * calendar store.  This should not be called by plain calendar user agents.
 **/
void
cal_component_set_last_modified (CalComponent *comp, struct icaltimetype *t)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_icaltimetype (comp, &priv->last_modified,
              icalproperty_new_lastmodified,
              icalproperty_set_lastmodified,
              t);
}

/**
 * cal_component_get_percent:
 * @comp: A calendar component object.
 * @percent: Return value for the percent-complete property.  This should be
 * freed using the cal_component_free_percent() function.
 *
 * Queries the percent-complete property of a calendar component object.
 **/
void
cal_component_get_percent (CalComponent *comp, int **percent)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (percent != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->percent) {
        *percent = g_new (int, 1);
        **percent = icalproperty_get_percentcomplete (priv->percent);
    } else
        *percent = NULL;
}

/**
 * cal_component_set_percent:
 * @comp: A calendar component object.
 * @percent: Value for the percent-complete property.
 *
 * Sets the percent-complete property of a calendar component object.
 **/
void
cal_component_set_percent (CalComponent *comp, int *percent)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!percent) {
        if (priv->percent) {
            icalcomponent_remove_property (priv->icalcomp, priv->percent);
            icalproperty_free (priv->percent);
            priv->percent = NULL;
        }

        return;
    }

    g_return_if_fail (*percent >= 0 && *percent <= 100);

    if (priv->percent)
        icalproperty_set_percentcomplete (priv->percent, *percent);
    else {
        priv->percent = icalproperty_new_percentcomplete (*percent);
        icalcomponent_add_property (priv->icalcomp, priv->percent);
    }
}

/**
 * cal_component_get_priority:
 * @comp: A calendar component object.
 * @priority: Return value for the priority property.  This should be freed using
 * the cal_component_free_priority() function.
 *
 * Queries the priority property of a calendar component object.
 **/
void
cal_component_get_priority (CalComponent *comp, int **priority)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (priority != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->priority) {
        *priority = g_new (int, 1);
        **priority = icalproperty_get_priority (priv->priority);
    } else
        *priority = NULL;
}

/**
 * cal_component_set_priority:
 * @comp: A calendar component object.
 * @priority: Value for the priority property.
 *
 * Sets the priority property of a calendar component object.
 **/
void
cal_component_set_priority (CalComponent *comp, int *priority)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priority) {
        if (priv->priority) {
            icalcomponent_remove_property (priv->icalcomp, priv->priority);
            icalproperty_free (priv->priority);
            priv->priority = NULL;
        }

        return;
    }

    g_return_if_fail (*priority >= 0 && *priority <= 9);

    if (priv->priority)
        icalproperty_set_priority (priv->priority, *priority);
    else {
        priv->priority = icalproperty_new_priority (*priority);
        icalcomponent_add_property (priv->icalcomp, priv->priority);
    }
}

/**
 * cal_component_get_rdate_list:
 * @comp: A calendar component object.
 * @period_list: Return value for the list of recurrence dates, as a list of
 * #CalComponentPeriod structures.  This should be freed using the
 * cal_component_free_period_list() function.
 *
 * Queries the list of recurrence date properties in a calendar component
 * object.
 **/
void
cal_component_get_rdate_list (CalComponent *comp, GSList **period_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (period_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_period_list (priv->rdate_list, icalproperty_get_rdate, period_list);
}

/**
 * cal_component_set_rdate_list:
 * @comp: A calendar component object.
 * @period_list: List of #CalComponentPeriod structures.
 *
 * Sets the list of recurrence dates in a calendar component object.
 **/
void
cal_component_set_rdate_list (CalComponent *comp, GSList *period_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_period_list (comp, icalproperty_new_rdate, &priv->rdate_list, period_list);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_has_rdates:
 * @comp: A calendar component object.
 *
 * Queries whether a calendar component object has any recurrence dates defined
 * for it.
 *
 * Return value: TRUE if the component has recurrence dates, FALSE otherwise.
 **/
gboolean
cal_component_has_rdates (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, FALSE);

    return (priv->rdate_list != NULL);
}

/**
 * cal_component_get_rrule_list:
 * @comp: A calendar component object.
 * @recur_list: List of recurrence rules as struct #icalrecurrencetype
 * structures.  This should be freed using the cal_component_free_recur_list()
 * function.
 *
 * Queries the list of recurrence rule properties of a calendar component
 * object.
 **/
void
cal_component_get_rrule_list (CalComponent *comp, GSList **recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (recur_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    get_recur_list (priv->rrule_list, icalproperty_get_rrule, recur_list);
}

/**
 * cal_component_get_rrule_property_list:
 * @comp: A calendar component object.
 * @recur_list: Returns a list of recurrence rule properties.
 *
 * Queries a list of recurrence rule properties of a calendar component object.
 **/
void
cal_component_get_rrule_property_list (CalComponent *comp, GSList **recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (recur_list != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    *recur_list = priv->rrule_list;
}

/**
 * cal_component_set_rrule_list:
 * @comp: A calendar component object.
 * @recur_list: List of struct #icalrecurrencetype structures.
 *
 * Sets the list of recurrence rules in a calendar component object.
 **/
void
cal_component_set_rrule_list (CalComponent *comp, GSList *recur_list)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    set_recur_list (comp, icalproperty_new_rrule, &priv->rrule_list, recur_list);

    priv->need_sequence_inc = TRUE;
}

/**
 * cal_component_has_rrules:
 * @comp: A calendar component object.
 *
 * Queries whether a calendar component object has any recurrence rules defined
 * for it.
 *
 * Return value: TRUE if the component has recurrence rules, FALSE otherwise.
 **/
gboolean
cal_component_has_rrules (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, FALSE);

    return (priv->rrule_list != NULL);
}

/**
 * cal_component_has_recurrences:
 * @comp: A calendar component object
 *
 * Queries whether a calendar component object has any recurrence dates or
 * recurrence rules.
 *
 * Return value: TRUE if the component has recurrences, FALSE otherwise.
 **/
gboolean
cal_component_has_recurrences (CalComponent *comp)
{
    return cal_component_has_rdates (comp) || cal_component_has_rrules (comp);
}

/**
 * cal_component_get_sequence:
 * @comp: A calendar component object.
 * @sequence: Return value for the sequence number.  This should be freed using
 * cal_component_free_sequence().
 *
 * Queries the sequence number of a calendar component object.
 **/
void
cal_component_get_sequence (CalComponent *comp, int **sequence)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (sequence != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->sequence) {
        *sequence = NULL;
        return;
    }

    *sequence = g_new (int, 1);
    **sequence = icalproperty_get_sequence (priv->sequence);
}

/**
 * cal_component_set_sequence:
 * @comp: A calendar component object.
 * @sequence: Sequence number value.
 *
 * Sets the sequence number of a calendar component object.  Normally this
 * function should not be called, since the sequence number is incremented
 * automatically at the proper times.
 **/
void
cal_component_set_sequence (CalComponent *comp, int *sequence)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    priv->need_sequence_inc = FALSE;

    if (!sequence) {
        if (priv->sequence) {
            icalcomponent_remove_property (priv->icalcomp, priv->sequence);
            icalproperty_free (priv->sequence);
            priv->sequence = NULL;
        }

        return;
    }

    if (priv->sequence)
        icalproperty_set_sequence (priv->sequence, *sequence);
    else {
        priv->sequence = icalproperty_new_sequence (*sequence);
        icalcomponent_add_property (priv->icalcomp, priv->sequence);
    }
}

/**
 * cal_component_get_status:
 * @comp: A calendar component object.
 * @status: Return value for the status value.  It is set to #ICAL_STATUS_NONE
 * if the component has no status property.
 *
 * Queries the status property of a calendar component object.
 **/
void
cal_component_get_status (CalComponent *comp, icalproperty_status *status)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (status != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->status) {
        *status = ICAL_STATUS_NONE;
        return;
    }

    *status = icalproperty_get_status (priv->status);
}

/**
 * cal_component_set_status:
 * @comp: A calendar component object.
 * @status: Status value.  You should use #ICAL_STATUS_NONE if you want to unset
 * this property.
 *
 * Sets the status property of a calendar component object.
 **/
void
cal_component_set_status (CalComponent *comp, icalproperty_status status)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    priv->need_sequence_inc = TRUE;

    if (status == ICAL_STATUS_NONE) {
        if (priv->status) {
            icalcomponent_remove_property (priv->icalcomp, priv->status);
            icalproperty_free (priv->status);
            priv->status = NULL;
        }

        return;
    }

    if (priv->status) {
        icalproperty_set_status (priv->status, status);
    } else {
        priv->status = icalproperty_new_status (status);
        icalcomponent_add_property (priv->icalcomp, priv->status);
    }
}

/**
 * cal_component_get_summary:
 * @comp: A calendar component object.
 * @summary: Return value for the summary property and its parameters.
 *
 * Queries the summary of a calendar component object.
 **/
void
cal_component_get_summary (CalComponent *comp, CalComponentText *summary)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (summary != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->summary.prop)
        summary->value = icalproperty_get_summary (priv->summary.prop);
    else
        summary->value = NULL;

    if (priv->summary.altrep_param)
        summary->altrep = icalparameter_get_altrep (priv->summary.altrep_param);
    else
        summary->altrep = NULL;
}

/**
 * cal_component_set_summary:
 * @comp: A calendar component object.
 * @summary: Summary property and its parameters.
 *
 * Sets the summary of a calendar component object.
 **/
void
cal_component_set_summary (CalComponent *comp, CalComponentText *summary)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!summary) {
        if (priv->summary.prop) {
            icalcomponent_remove_property (priv->icalcomp, priv->summary.prop);
            icalproperty_free (priv->summary.prop);

            priv->summary.prop = NULL;
            priv->summary.altrep_param = NULL;
        }

        return;
    }

    g_return_if_fail (summary->value != NULL);

    if (priv->summary.prop)
        icalproperty_set_summary (priv->summary.prop, (char *) summary->value);
    else {
        priv->summary.prop = icalproperty_new_summary ((char *) summary->value);
        icalcomponent_add_property (priv->icalcomp, priv->summary.prop);
    }

    if (summary->altrep) {
        g_assert (priv->summary.prop != NULL);

        if (priv->summary.altrep_param)
            icalparameter_set_altrep (priv->summary.altrep_param,
                          (char *) summary->altrep);
        else {
            priv->summary.altrep_param = icalparameter_new_altrep (
                (char *) summary->altrep);
            icalproperty_add_parameter (priv->summary.prop,
                            priv->summary.altrep_param);
        }
    } else if (priv->summary.altrep_param) {
        icalproperty_remove_parameter (priv->summary.prop, ICAL_ALTREP_PARAMETER);
        icalparameter_free (priv->summary.altrep_param);
        priv->summary.altrep_param = NULL;
    }
}

/**
 * cal_component_get_transparency:
 * @comp: A calendar component object.
 * @transp: Return value for the time transparency.
 *
 * Queries the time transparency of a calendar component object.
 **/
void
cal_component_get_transparency (CalComponent *comp, CalComponentTransparency *transp)
{
    CalComponentPrivate *priv;
    const char *val;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (transp != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!priv->transparency) {
        *transp = CAL_COMPONENT_TRANSP_NONE;
        return;
    }

    val = icalproperty_get_transp (priv->transparency);

    if (strcasecmp (val, "TRANSPARENT"))
        *transp = CAL_COMPONENT_TRANSP_TRANSPARENT;
    else if (strcasecmp (val, "OPAQUE"))
        *transp = CAL_COMPONENT_TRANSP_OPAQUE;
    else
        *transp = CAL_COMPONENT_TRANSP_UNKNOWN;
}

/**
 * cal_component_set_transparency:
 * @comp: A calendar component object.
 * @transp: Time transparency value.
 *
 * Sets the time transparency of a calendar component object.
 **/
void
cal_component_set_transparency (CalComponent *comp, CalComponentTransparency transp)
{
    CalComponentPrivate *priv;
    char *str;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (transp != CAL_COMPONENT_TRANSP_UNKNOWN);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);


    if (transp == CAL_COMPONENT_TRANSP_NONE) {
        if (priv->transparency) {
            icalcomponent_remove_property (priv->icalcomp, priv->transparency);
            icalproperty_free (priv->transparency);
            priv->transparency = NULL;
        }

        return;
    }

    switch (transp) {
    case CAL_COMPONENT_TRANSP_TRANSPARENT:
        str = "TRANSPARENT";
        break;

    case CAL_COMPONENT_TRANSP_OPAQUE:
        str = "OPAQUE";
        break;

    default:
        g_assert_not_reached ();
        str = NULL;
    }

    if (priv->transparency)
        icalproperty_set_transp (priv->transparency, str);
    else {
        priv->transparency = icalproperty_new_transp (str);
        icalcomponent_add_property (priv->icalcomp, priv->transparency);
    }
}

/**
 * cal_component_get_url:
 * @comp: A calendar component object.
 * @url: Return value for the URL.
 *
 * Queries the uniform resource locator property of a calendar component object.
 **/
void
cal_component_get_url (CalComponent *comp, const char **url)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (url != NULL);

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (priv->url)
        *url = icalproperty_get_url (priv->url);
    else
        *url = NULL;
}

/**
 * cal_component_set_url:
 * @comp: A calendar component object.
 * @url: URL value.
 *
 * Sets the uniform resource locator property of a calendar component object.
 **/
void
cal_component_set_url (CalComponent *comp, const char *url)
{
    CalComponentPrivate *priv;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));

    priv = comp->priv;
    g_return_if_fail (priv->icalcomp != NULL);

    if (!url) {
        if (priv->url) {
            icalcomponent_remove_property (priv->icalcomp, priv->url);
            icalproperty_free (priv->url);
            priv->url = NULL;
        }

        return;
    }

    if (priv->url)
        icalproperty_set_url (priv->url, (char *) url);
    else {
        priv->url = icalproperty_new_url ((char *) url);
        icalcomponent_add_property (priv->icalcomp, priv->url);
    }
}



/**
 * cal_component_free_categories_list:
 * @categ_list: List of category strings.
 *
 * Frees a list of category strings.
 **/
void
cal_component_free_categories_list (GSList *categ_list)
{
    GSList *l;

    for (l = categ_list; l; l = l->next)
        g_free (l->data);

    g_slist_free (categ_list);
}

/**
 * cal_component_free_datetime:
 * @dt: A date/time structure.
 *
 * Frees a date/time structure.
 **/
void
cal_component_free_datetime (CalComponentDateTime *dt)
{
    g_return_if_fail (dt != NULL);

    if (dt->value)
        g_free (dt->value);
}

/**
 * cal_component_free_exdate_list:
 * @exdate_list: List of #CalComponentDateTime structures.
 *
 * Frees a list of #CalComponentDateTime structures as returned by the
 * cal_component_get_exdate_list() function.
 **/
void
cal_component_free_exdate_list (GSList *exdate_list)
{
    GSList *l;

    for (l = exdate_list; l; l = l->next) {
        CalComponentDateTime *cdt;

        g_assert (l->data != NULL);
        cdt = l->data;

        g_assert (cdt->value != NULL);
        g_free (cdt->value);

        g_free (cdt);
    }

    g_slist_free (exdate_list);
}

/**
 * cal_component_free_geo:
 * @geo: An #icalgeotype structure.
 *
 * Frees a struct #icalgeotype structure as returned by the calendar component
 * functions.
 **/
void
cal_component_free_geo (struct icalgeotype *geo)
{
    g_return_if_fail (geo != NULL);

    g_free (geo);
}

/**
 * cal_component_free_icaltimetype:
 * @t: An #icaltimetype structure.
 *
 * Frees a struct #icaltimetype value as returned by the calendar component
 * functions.
 **/
void
cal_component_free_icaltimetype (struct icaltimetype *t)
{
    g_return_if_fail (t != NULL);

    g_free (t);
}

/**
 * cal_component_free_percent:
 * @percent: Percent value.
 *
 * Frees a percent value as returned by the cal_component_get_percent()
 * function.
 **/
void
cal_component_free_percent (int *percent)
{
    g_return_if_fail (percent != NULL);

    g_free (percent);
}

/**
 * cal_component_free_priority:
 * @priority: Priority value.
 *
 * Frees a priority value as returned by the cal_component_get_priority()
 * function.
 **/
void
cal_component_free_priority (int *priority)
{
    g_return_if_fail (priority != NULL);

    g_free (priority);
}

/**
 * cal_component_free_period_list:
 * @period_list: List of #CalComponentPeriod structures.
 *
 * Frees a list of #CalComponentPeriod structures.
 **/
void
cal_component_free_period_list (GSList *period_list)
{
    GSList *l;

    for (l = period_list; l; l = l->next) {
        CalComponentPeriod *period;

        g_assert (l->data != NULL);

        period = l->data;
        g_free (period);
    }

    g_slist_free (period_list);
}

/**
 * cal_component_free_recur_list:
 * @recur_list: List of struct #icalrecurrencetype structures.
 *
 * Frees a list of struct #icalrecurrencetype structures.
 **/
void
cal_component_free_recur_list (GSList *recur_list)
{
    GSList *l;

    for (l = recur_list; l; l = l->next) {
        struct icalrecurrencetype *r;

        g_assert (l->data != NULL);
        r = l->data;

        g_free (r);
    }

    g_slist_free (recur_list);
}

/**
 * cal_component_free_sequence:
 * @sequence: Sequence number value.
 *
 * Frees a sequence number value.
 **/
void
cal_component_free_sequence (int *sequence)
{
    g_return_if_fail (sequence != NULL);

    g_free (sequence);
}

/**
 * cal_component_free_text_list:
 * @text_list: List of #CalComponentText structures.
 *
 * Frees a list of #CalComponentText structures.  This function should only be
 * used to free lists of text values as returned by the other getter functions
 * of #CalComponent.
 **/
void
cal_component_free_text_list (GSList *text_list)
{
    GSList *l;

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

        g_assert (l->data != NULL);

        text = l->data;
        g_return_if_fail (text != NULL);
        g_free (text);
    }

    g_slist_free (text_list);
}



/**
 * cal_component_has_alarms:
 * @comp: A calendar component object.
 *
 * Checks whether the component has any alarms.
 *
 * Return value: TRUE if the component has any alarms.
 **/
gboolean
cal_component_has_alarms (CalComponent *comp)
{
    CalComponentPrivate *priv;

    g_return_val_if_fail (comp != NULL, FALSE);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), FALSE);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, FALSE);

    return g_hash_table_size (priv->alarm_uid_hash) != 0;
}

void 
cal_component_add_alarm (CalComponent *comp, CalComponentAlarm *alarm)
{
    CalComponentPrivate *priv;
    
    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (alarm != NULL);
    
    priv = comp->priv;
    
    alarm->parent = comp;
    add_alarm (comp, alarm->icalcomp, icalproperty_get_x (alarm->uid));
    icalcomponent_add_component (priv->icalcomp, alarm->icalcomp);
}

void 
cal_component_remove_alarm (CalComponent *comp, const char *auid)
{
    CalComponentPrivate *priv;
    icalcompiter iter;

    g_return_if_fail (comp != NULL);
    g_return_if_fail (IS_CAL_COMPONENT (comp));
    g_return_if_fail (auid != NULL);

    priv = comp->priv;

    for (iter = icalcomponent_begin_component (priv->icalcomp, ICAL_VALARM_COMPONENT);
         icalcompiter_deref (&iter) != NULL;
         icalcompiter_next (&iter)) {
        icalproperty *prop;
        icalcomponent *subcomp;

        subcomp = icalcompiter_deref (&iter);
        for (prop = icalcomponent_get_first_property (subcomp, ICAL_X_PROPERTY);
             prop;
             prop = icalcomponent_get_next_property (subcomp, ICAL_X_PROPERTY)) {
            const char *xname;
            const char *alarm_uid;
            
            xname = icalproperty_get_x_name (prop);
            g_assert (xname != NULL);

            if (strcmp (xname, EVOLUTION_ALARM_UID_PROPERTY) == 0) {
                alarm_uid = alarm_uid_from_prop (prop);
                if (strcmp (alarm_uid, auid) == 0) {
                    remove_alarm (comp, auid);
                    icalcomponent_remove_component (priv->icalcomp, subcomp);
                    icalcomponent_free (subcomp);
                    break;
                }
                
                return;
            }
        }
    }
}


/* Scans an icalproperty from a calendar component and adds its mapping to our
 * own alarm structure.
 */
static void
scan_alarm_property (CalComponentAlarm *alarm, icalproperty *prop)
{
    icalproperty_kind kind;
    const char *xname;

    kind = icalproperty_isa (prop);

    switch (kind) {
    case ICAL_ACTION_PROPERTY:
        alarm->action = prop;
        break;

    case ICAL_TRIGGER_PROPERTY:
        alarm->trigger = prop;
        break;

    case ICAL_X_PROPERTY:
        xname = icalproperty_get_x_name (prop);
        g_assert (xname != NULL);

        if (strcmp (xname, EVOLUTION_ALARM_UID_PROPERTY) == 0)
            alarm->uid = prop;

        break;

    default:
        break;
    }
}

/* Creates a CalComponentAlarm from a libical alarm subcomponent */
static CalComponentAlarm *
make_alarm (CalComponent *comp, icalcomponent *subcomp)
{
    CalComponentAlarm *alarm;
    icalproperty *prop;

    alarm = g_new (CalComponentAlarm, 1);

    alarm->parent = comp;
    alarm->icalcomp = subcomp;
    alarm->uid = NULL;

    for (prop = icalcomponent_get_first_property (subcomp, ICAL_ANY_PROPERTY);
         prop;
         prop = icalcomponent_get_next_property (subcomp, ICAL_ANY_PROPERTY))
        scan_alarm_property (alarm, prop);

    g_assert (alarm->uid != NULL);

    return alarm;
}

/* Used from g_hash_table_foreach(); adds an alarm UID to a list */
static void
add_alarm_uid (gpointer key, gpointer value, gpointer data)
{
    const char *auid;
    GList **l;

    auid = key;
    l = data;

    *l = g_list_prepend (*l, g_strdup (auid));
}

/**
 * cal_component_get_alarm_uids:
 * @comp: A calendar component.
 * 
 * Builds a list of the unique identifiers of the alarm subcomponents inside a
 * calendar component.
 * 
 * Return value: List of unique identifiers for alarms.  This should be freed
 * using cal_obj_uid_list_free().
 **/
GList *
cal_component_get_alarm_uids (CalComponent *comp)
{
    CalComponentPrivate *priv;
    GList *l;

    g_return_val_if_fail (comp != NULL, NULL);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), NULL);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, NULL);

    l = NULL;
    g_hash_table_foreach (priv->alarm_uid_hash, add_alarm_uid, &l);

    return l;
}

/**
 * cal_component_get_alarm:
 * @comp: A calendar component.
 * @auid: Unique identifier for the sought alarm subcomponent.
 * 
 * Queries a particular alarm subcomponent of a calendar component.
 * 
 * Return value: The alarm subcomponent that corresponds to the specified @auid,
 * or #NULL if no alarm exists with that UID.  This should be freed using
 * cal_component_alarm_free().
 **/
CalComponentAlarm *
cal_component_get_alarm (CalComponent *comp, const char *auid)
{
    CalComponentPrivate *priv;
    icalcomponent *alarm;

    g_return_val_if_fail (comp != NULL, NULL);
    g_return_val_if_fail (IS_CAL_COMPONENT (comp), NULL);

    priv = comp->priv;
    g_return_val_if_fail (priv->icalcomp != NULL, NULL);

    g_return_val_if_fail (auid != NULL, NULL);

    alarm = g_hash_table_lookup (priv->alarm_uid_hash, auid);

    if (alarm)
        return make_alarm (comp, alarm);
    else
        return NULL;
}

void 
cal_component_free_alarm_uids (GList *alarm_uids)
{
    g_list_foreach (alarm_uids, (GFunc)g_free, NULL);
}

/**
 * cal_component_alarms_free:
 * @alarms: Component alarms structure.
 * 
 * Frees a #CalComponentAlarms structure.
 **/
void
cal_component_alarms_free (CalComponentAlarms *alarms)
{
    GSList *l;

    g_return_if_fail (alarms != NULL);

    g_assert (alarms->comp != NULL);
    gtk_object_unref (GTK_OBJECT (alarms->comp));

    for (l = alarms->alarms; l; l = l->next) {
        CalAlarmInstance *instance;

        instance = l->data;
        g_assert (instance != NULL);
        g_free (instance);
    }

    g_slist_free (alarms->alarms);
    g_free (alarms);
}

/**
 * cal_component_alarm_new:
  * 
 * 
 * 
 * Return value: a new alarm component
 **/
CalComponentAlarm *
cal_component_alarm_new (void)
{
    CalComponentAlarm *alarm = g_new0 (CalComponentAlarm, 1);
    char *new_auid ;

    alarm->icalcomp = icalcomponent_new (ICAL_VALARM_COMPONENT);

    new_auid = cal_component_gen_uid ();
    alarm->uid = icalproperty_new_x (new_auid);
    icalproperty_set_x_name (alarm->uid, EVOLUTION_ALARM_UID_PROPERTY);
    icalcomponent_add_property (alarm->icalcomp, alarm->uid);
    g_free (new_auid);
    
    return alarm;
}

/**
 * cal_component_alarm_get_uid:
 * @alarm: An alarm subcomponent.
 * 
 * Queries the unique identifier of an alarm subcomponent.
 * 
 * Return value: UID of the alarm.
 **/
const char *
cal_component_alarm_get_uid (CalComponentAlarm *alarm)
{
    g_return_val_if_fail (alarm != NULL, NULL);

    return alarm_uid_from_prop (alarm->uid);
}

/**
 * cal_component_alarm_get_action:
 * @alarm: An alarm.
 * @action: Return value for the alarm's action type.
 *
 * Queries the action type of an alarm.
 **/
void
cal_component_alarm_get_action (CalComponentAlarm *alarm, CalAlarmAction *action)
{
    const char *str;

    g_return_if_fail (alarm != NULL);
    g_return_if_fail (action != NULL);

    g_assert (alarm->icalcomp != NULL);

    if (!alarm->action) {
        *action = CAL_ALARM_NONE;
        return;
    }

    str = icalproperty_get_action (alarm->action);

    if (strcasecmp (str, "AUDIO") == 0)
        *action = CAL_ALARM_AUDIO;
    else if (strcasecmp (str, "DISPLAY") == 0)
        *action = CAL_ALARM_DISPLAY;
    else if (strcasecmp (str, "EMAIL") == 0)
        *action = CAL_ALARM_EMAIL;
    else if (strcasecmp (str, "PROCEDURE") == 0)
        *action = CAL_ALARM_PROCEDURE;
    else
        *action = CAL_ALARM_UNKNOWN;
}

/**
 * cal_component_alarm_set_action:
 * @alarm: An alarm.
 * @action: Action type.
 *
 * Sets the action type for an alarm.
 **/
void
cal_component_alarm_set_action (CalComponentAlarm *alarm, CalAlarmAction action)
{
    char *str;

    g_return_if_fail (alarm != NULL);
    g_return_if_fail (action != CAL_ALARM_NONE);
    g_return_if_fail (action != CAL_ALARM_UNKNOWN);

    g_assert (alarm->icalcomp != NULL);

    switch (action) {
    case CAL_ALARM_AUDIO:
        str = "AUDIO";
        break;

    case CAL_ALARM_DISPLAY:
        str = "DISPLAY";
        break;

    case CAL_ALARM_EMAIL:
        str = "EMAIL";
        break;

    case CAL_ALARM_PROCEDURE:
        str = "PROCEDURE";
        break;

    default:
        g_assert_not_reached ();
        str = NULL;
    }

    if (alarm->action)
        icalproperty_set_action (alarm->action, str);
    else {
        alarm->action = icalproperty_new_action (str);
        icalcomponent_add_property (alarm->icalcomp, alarm->action);
    }
}

/**
 * cal_component_alarm_get_trigger:
 * @alarm: An alarm.
 * @trigger: Return value for the trigger time.
 *
 * Queries the trigger time for an alarm.
 **/
void
cal_component_alarm_get_trigger (CalComponentAlarm *alarm, CalAlarmTrigger *trigger)
{
    icalparameter *param;
    struct icaltriggertype t;
    gboolean relative;

    g_return_if_fail (alarm != NULL);
    g_return_if_fail (trigger != NULL);

    g_assert (alarm->icalcomp != NULL);

    if (!alarm->trigger) {
        trigger->type = CAL_ALARM_TRIGGER_NONE;
        return;
    }

    /* Get trigger type */

    param = icalproperty_get_first_parameter (alarm->trigger, ICAL_VALUE_PARAMETER);
    if (param) {
        icalparameter_value value;

        value = icalparameter_get_value (param);

        switch (value) {
        case ICAL_VALUE_DURATION:
            relative = TRUE;
            break;

        case ICAL_VALUE_DATETIME:
            relative = FALSE;
            break;

        default:
            g_message ("cal_component_alarm_get_trigger(): Unknown value for trigger "
                   "value %d; using RELATIVE", value);

            relative = TRUE;
            break;
        }
    } else
        relative = TRUE;

    /* Get trigger value and the RELATED parameter */

    t = icalproperty_get_trigger (alarm->trigger);

    if (relative) {
        trigger->u.rel_duration = t.duration;

        param = icalproperty_get_first_parameter (alarm->trigger, ICAL_RELATED_PARAMETER);
        if (param) {
            icalparameter_related rel;

            rel = icalparameter_get_related (param);

            switch (rel) {
            case ICAL_RELATED_START:
                trigger->type = CAL_ALARM_TRIGGER_RELATIVE_START;
                break;

            case ICAL_RELATED_END:
                trigger->type = CAL_ALARM_TRIGGER_RELATIVE_END;
                break;

            default:
                g_assert_not_reached ();
            }
        } else
            trigger->type = CAL_ALARM_TRIGGER_RELATIVE_START;
    } else {
        trigger->u.abs_time = t.time;
        trigger->type = CAL_ALARM_TRIGGER_ABSOLUTE;
    }
}

/**
 * cal_component_alarm_set_trigger:
 * @alarm: An alarm.
 * @trigger: Trigger time structure.
 *
 * Sets the trigger time of an alarm.
 **/
void
cal_component_alarm_set_trigger (CalComponentAlarm *alarm, CalAlarmTrigger trigger)
{
    struct icaltriggertype t;
    icalparameter *param;
    icalparameter_value value_type;
    icalparameter_related related;

    g_return_if_fail (alarm != NULL);
    g_return_if_fail (trigger.type != CAL_ALARM_TRIGGER_NONE);

    g_assert (alarm->icalcomp != NULL);

    /* Delete old trigger */

    if (alarm->trigger) {
        icalcomponent_remove_property (alarm->icalcomp, alarm->trigger);
        icalproperty_free (alarm->trigger);
        alarm->trigger = NULL;
    }

    /* Set the value */

    related = ICAL_RELATED_START; /* Keep GCC happy */

    t.time = icaltime_null_time ();
    t.duration = icaldurationtype_null_duration ();
    switch (trigger.type) {
    case CAL_ALARM_TRIGGER_RELATIVE_START:
        t.duration = trigger.u.rel_duration;
        t.time.is_date = -1;
        value_type = ICAL_DURATION_VALUE;
        related = ICAL_RELATED_START;
        break;

    case CAL_ALARM_TRIGGER_RELATIVE_END:
        t.duration = trigger.u.rel_duration;
        t.time.is_date = -1;
        value_type = ICAL_DURATION_VALUE;
        related = ICAL_RELATED_END;
        break;

    case CAL_ALARM_TRIGGER_ABSOLUTE:
        t.time = trigger.u.abs_time;
        value_type = ICAL_DATETIME_VALUE;
        break;

    default:
        g_assert_not_reached ();
        return;
    }

    alarm->trigger = icalproperty_new_trigger (t);
    icalcomponent_add_property (alarm->icalcomp, alarm->trigger);

    /* Value parameters */

    param = icalproperty_get_first_parameter (alarm->trigger, ICAL_VALUE_PARAMETER);
    if (param)
        icalparameter_set_value (param, value_type);
    else {
        param = icalparameter_new_value (value_type);
        icalproperty_add_parameter (alarm->trigger, param);
    }

    /* Related parameter */

    if (trigger.type != CAL_ALARM_TRIGGER_ABSOLUTE) {
        param = icalproperty_get_first_parameter (alarm->trigger, ICAL_RELATED_PARAMETER);

        if (param)
            icalparameter_set_related (param, related);
        else {
            param = icalparameter_new_related (related);
            icalproperty_add_parameter (alarm->trigger, param);
        }
    }
}

/**
 * cal_component_alarm_free:
 * @alarm: A calendar alarm.
 *
 * Frees an alarm structure.
 **/
void
cal_component_alarm_free (CalComponentAlarm *alarm)
{
    g_return_if_fail (alarm != NULL);

    g_assert (alarm->icalcomp != NULL);

    if (icalcomponent_get_parent (alarm->icalcomp) != NULL)
        icalcomponent_free (alarm->icalcomp);

    alarm->icalcomp = NULL;

    alarm->parent = NULL;
    alarm->action = NULL;

    g_free (alarm);
}


/* Returns TRUE if both strings match, i.e. they are both NULL or the
   strings are equal. */
static gboolean
cal_component_strings_match (const gchar    *string1,
                 const gchar    *string2)
{
    if (string1 == NULL || string2 == NULL)
        return (string1 == string2) ? TRUE : FALSE;

    if (!strcmp (string1, string2))
        return TRUE;

    return FALSE;
}


/**
 * cal_component_event_dates_match:
 * @comp1: A calendar component object.
 * @comp2: A calendar component object.
 *
 * Checks if the DTSTART and DTEND properties of the 2 components match.
 * Note that the events may have different recurrence properties which are not
 * taken into account here.
 *
 * Returns: TRUE if the DTSTART and DTEND properties of the 2 components match.
 **/
gboolean
cal_component_event_dates_match (CalComponent *comp1,
                 CalComponent *comp2)
{
    CalComponentDateTime comp1_dtstart, comp1_dtend;
    CalComponentDateTime comp2_dtstart, comp2_dtend;

    cal_component_get_dtstart (comp1, &comp1_dtstart);
    cal_component_get_dtend   (comp1, &comp1_dtend);
    cal_component_get_dtstart (comp2, &comp2_dtstart);
    cal_component_get_dtend   (comp2, &comp2_dtend);

    /* If either value is NULL they must both be NULL to match. */
    if (comp1_dtstart.value == NULL || comp2_dtstart.value == NULL) {
        if (comp1_dtstart.value != comp2_dtstart.value)
            return FALSE;
    } else {
        if (icaltime_compare (*comp1_dtstart.value,
                      *comp2_dtstart.value))
            return FALSE;
    }

    if (comp1_dtend.value == NULL || comp2_dtend.value == NULL) {
        if (comp1_dtend.value != comp2_dtend.value)
            return FALSE;
    } else {
        if (icaltime_compare (*comp1_dtend.value,
                      *comp2_dtend.value))
            return FALSE;
    }

    /* Now check the timezones. */
    if (!cal_component_strings_match (comp1_dtstart.tzid,
                      comp2_dtstart.tzid))
        return FALSE;

    if (!cal_component_strings_match (comp1_dtend.tzid,
                      comp2_dtend.tzid))
        return FALSE;

    return TRUE;
}