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

/* Evolution calendar - iCalendar component object
 *
 * Copyright (C) 2000 Helix Code, Inc.
 *
 * Author: Federico Mena-Quintero <federico@helixcode.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 <unistd.h>
#include "cal-component.h"
#include "timeutil.h"



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

    /* Properties */

    icalproperty *uid_prop;

    struct categories {
        icalproperty *prop;
    };
    GSList *categories_list;

    icalproperty *classification;

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

    GSList *comment_list;

    GSList *description_list;

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

    struct datetime dtstart;
    struct datetime dtend;
    struct datetime due;

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



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:
 * @void: 
 * 
 * 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->uid_prop = cal_component_gen_uid ();
}

/* 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;
}

/* 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_prop = NULL;

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

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

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

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

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

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

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

/* 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_free (priv);
    comp->priv = NULL;

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



/**
 * cal_component_gen_uid:
 * @void: 
 * 
 * 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:
 * @void:
 * 
 * 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));
}

/* Scans the categories property */
static void
scan_categories (CalComponent *comp, icalproperty *prop)
{
    CalComponentPrivate *priv;
    struct categories *categ;

    priv = comp->priv;

    categ = g_new (struct categories, 1);
    categ->prop = prop;

    priv->categories_list = g_slist_append (priv->categories_list, categ);
}

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

    priv = comp->priv;

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

    for (param = icalproperty_get_first_parameter (prop, ICAL_ANY_PARAMETER);
         param;
         param = icalproperty_get_next_parameter (prop, ICAL_ANY_PARAMETER)) {
        icalparameter_kind kind;

        kind = icalparameter_isa (param);

        switch (kind) {
        case ICAL_ALTREP_PARAMETER:
            text->altrep_param = param;
            break;

        default:
            break;
        }
    }

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

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

    priv = comp->priv;

    datetime->prop = prop;

    for (param = icalproperty_get_first_parameter (prop, ICAL_ANY_PARAMETER);
         param;
         param = icalproperty_get_next_parameter (prop, ICAL_ANY_PARAMETER)) {
        icalparameter_kind kind;

        kind = icalparameter_isa (param);

        switch (kind) {
        case ICAL_TZID_PARAMETER:
            datetime->tzid_param = param;
            break;

        default:
            break;
        }
    }
}

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

    priv = comp->priv;

    priv->summary.prop = prop;

    for (param = icalproperty_get_first_parameter (prop, ICAL_ANY_PARAMETER);
         param;
         param = icalproperty_get_next_parameter (prop, ICAL_ANY_PARAMETER)) {
        icalparameter_kind kind;
        
        kind = icalparameter_isa (param);
        
        switch (kind) {
        case ICAL_ALTREP_PARAMETER:
            priv->summary.altrep_param = param;
            break;

        default:
            break;
        }
    }
}

/* 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_CATEGORIES_PROPERTY:
        scan_categories (comp, prop);
        break;

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

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

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

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

    default:
        break;
    }
}

/* Scans an icalcomponent for its properties so that we can provide
 * random-access to them.
 */
static void
scan_icalcomponent (CalComponent *comp)
{
    CalComponentPrivate *priv;
    icalproperty *prop;

    priv = comp->priv;

    g_assert (priv->icalcomp != NULL);

    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);

    /* FIXME: parse ALARM subcomponents */
}

/**
 * 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;
    char *uid;
    icalproperty *prop;

    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 */

    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;
    }

    /* Create an UID */

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

    uid = cal_component_gen_uid ();
    prop = icalproperty_new_uid (uid);
    g_free (uid);

    if (!prop) {
        icalcomponent_free (icalcomp);
        g_message ("cal_component_set_new_vtype(): Could not create the UID property!");
        return;
    }

    icalcomponent_add_property (icalcomp, prop);

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

    priv->icalcomp = icalcomp;
    scan_icalcomponent (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.
 **/
void
cal_component_set_icalcomponent (CalComponent *comp, icalcomponent *icalcomp)
{
    CalComponentPrivate *priv;

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

    priv = comp->priv;

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

    free_icalcomponent (comp);

    priv->icalcomp = icalcomp;

    if (priv->icalcomp)
        scan_icalcomponent (comp);
}

/**
 * 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;
    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_uid:
 * @comp: A calendar component object.
 * 
 * Queries the unique identifier of a calendar component object.
 * 
 * Return value: The unique identifier string.
 **/
const char *
cal_component_get_uid (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->icalcomp != NULL, NULL);

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

    return icalproperty_get_uid (priv->uid_prop);
}

/**
 * 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_prop != NULL);

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

/**
 * 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_list) {
        *categ_list = NULL;
        return;
    }

    categories = icalproperty_get_categories (priv->categories_list);
    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;
    struct categories *cat;
    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);

    /* Free the old list */

    if (!categ_list) {
        if (priv->categories_list) {
            GSList *l;

            for (l = priv->categories_list; l; l = l->next) {
                struct categories *c;

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

                g_free (c);
            }

            g_slist_free (priv->categories_list);
            priv->categories_list = NULL;
        }

        return;
    }

    /* Create a single string of categories */

    categories_str = stringify_categories (categ_list);

    /* Set the categories */

    cat = g_new (struct categories, 1);
    cat->prop = icalproperty_new_categories (categories_str);
    g_free (categories_str);

    icalcomponent_add_property (priv->icalcomp, cat->prop);
}

/**
 * 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_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);
    }
}

/**
 * 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;

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

    g_slist_free (text_list);
}

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

    if (!text_list) {
        *tl = NULL;
        return;
    }

    *tl = NULL;

    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) (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);
        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);
}

/**
 * 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);
}

/**
 * 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);
}

/* 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;
}

/**
 * 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);
}

/* 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) {
#if 0
        /* FIXME: this fucking routine will assert(0) since it is not implemented */
        icalproperty_remove_parameter (datetime->prop, ICAL_TZID_PARAMETER);
        icalparameter_free (datetime->tzid_param);
#endif
        datetime->tzid_param = NULL;
    }
}

/**
 * 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);
}

/**
 * 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);
}

/**
 * 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);
}

/**
 * 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) {
#if 0
        /* FIXME: this fucking routine will assert(0) since it is not implemented */
        icalproperty_remove_parameter (priv->summary.prop, ICAL_ALTREP_PARAMETER);
        icalparameter_free (priv->summary.altrep_param);
#endif
        priv->summary.altrep_param = NULL;
    }
}