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

/* Evolution calendar utilities and types
 *
 * Copyright (C) 2000 Ximian, 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 version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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 <stdlib.h>
#include <string.h>
#include <glib.h>
#include <libgnome/gnome-i18n.h>
#include <libgnome/gnome-util.h>
#include "cal-util.h"



/**
 * cal_obj_instance_list_free:
 * @list: List of #CalObjInstance structures.
 *
 * Frees a list of #CalObjInstance structures.
 **/
void
cal_obj_instance_list_free (GList *list)
{
    CalObjInstance *i;
    GList *l;

    for (l = list; l; l = l->next) {
        i = l->data;

        g_assert (i != NULL);
        g_assert (i->uid != NULL);

        g_free (i->uid);
        g_free (i);
    }

    g_list_free (list);
}

/**
 * cal_obj_uid_list_free:
 * @list: List of strings with unique identifiers.
 *
 * Frees a list of unique identifiers for calendar objects.
 **/
void
cal_obj_uid_list_free (GList *list)
{
    GList *l;

    for (l = list; l; l = l->next) {
        char *uid;

        uid = l->data;

        g_assert (uid != NULL);
        g_free (uid);
    }

    g_list_free (list);
}

icalcomponent *
cal_util_new_top_level (void)
{
    icalcomponent *icalcomp;
    icalproperty *prop;

    icalcomp = icalcomponent_new (ICAL_VCALENDAR_COMPONENT);

    /* RFC 2445, section 4.7.1 */
    prop = icalproperty_new_calscale ("GREGORIAN");
    icalcomponent_add_property (icalcomp, prop);

       /* RFC 2445, section 4.7.3 */
    prop = icalproperty_new_prodid ("-//Ximian//NONSGML Evolution Calendar//EN");
    icalcomponent_add_property (icalcomp, prop);

    /* RFC 2445, section 4.7.4.  This is the iCalendar spec version, *NOT*
     * the product version!  Do not change this!
     */
    prop = icalproperty_new_version ("2.0");
    icalcomponent_add_property (icalcomp, prop);

    return icalcomp;
}

static char *
get_line_fn (char *buf, size_t size, void *file)
{
    return fgets (buf, size, file);
}

icalcomponent *
cal_util_parse_ics_file (const char *filename)
{
    icalparser *parser;
    icalcomponent *icalcomp;
    FILE *file;

    file = fopen (filename, "r");
    if (!file)
        return NULL;

    parser = icalparser_new ();
    icalparser_set_gen_data (parser, file);

    icalcomp = icalparser_parse (parser, get_line_fn);
    icalparser_free (parser);
    fclose (file);

    return icalcomp;
}

/* Computes the range of time in which recurrences should be generated for a
 * component in order to compute alarm trigger times.
 */
static void
compute_alarm_range (CalComponent *comp, GList *alarm_uids, time_t start, time_t end,
             time_t *alarm_start, time_t *alarm_end)
{
    GList *l;
    time_t repeat_time;

    *alarm_start = start;
    *alarm_end = end;

    repeat_time = 0;

    for (l = alarm_uids; l; l = l->next) {
        const char *auid;
        CalComponentAlarm *alarm;
        CalAlarmTrigger trigger;
        struct icaldurationtype *dur;
        time_t dur_time;
        CalAlarmRepeat repeat;

        auid = l->data;
        alarm = cal_component_get_alarm (comp, auid);
        g_assert (alarm != NULL);

        cal_component_alarm_get_trigger (alarm, &trigger);
        cal_component_alarm_get_repeat (alarm, &repeat);
        cal_component_alarm_free (alarm);

        switch (trigger.type) {
        case CAL_ALARM_TRIGGER_NONE:
        case CAL_ALARM_TRIGGER_ABSOLUTE:
            break;

        case CAL_ALARM_TRIGGER_RELATIVE_START:
        case CAL_ALARM_TRIGGER_RELATIVE_END:
            dur = &trigger.u.rel_duration;
            dur_time = icaldurationtype_as_int (*dur);

            if (repeat.repetitions != 0) {
                int rdur;

                rdur = repeat.repetitions * icaldurationtype_as_int (repeat.duration);
                repeat_time = MAX (repeat_time, rdur);
            }

            if (dur->is_neg)
                /* If the duration is negative then dur_time
                 * will be negative as well; that is why we
                 * subtract to expand the range.
                 */
                *alarm_end = MAX (*alarm_end, end - dur_time);
            else
                *alarm_start = MIN (*alarm_start, start - dur_time);

            break;

        default:
            g_assert_not_reached ();
        }
    }

    *alarm_start -= repeat_time;

    g_assert (*alarm_start <= *alarm_end);
}

/* Closure data to generate alarm occurrences */
struct alarm_occurrence_data {
    /* These are the info we have */
    GList *alarm_uids;
    time_t start;
    time_t end;
    CalAlarmAction *omit;
    
    /* This is what we compute */
    GSList *triggers;
    int n_triggers;
};

static void
add_trigger (struct alarm_occurrence_data *aod, const char *auid, time_t trigger,
         time_t occur_start, time_t occur_end)
{
    CalAlarmInstance *instance;

    instance = g_new (CalAlarmInstance, 1);
    instance->auid = auid;
    instance->trigger = trigger;
    instance->occur_start = occur_start;
    instance->occur_end = occur_end;

    aod->triggers = g_slist_prepend (aod->triggers, instance);
    aod->n_triggers++;
}

/* Callback used from cal_recur_generate_instances(); generates triggers for all
 * of a component's RELATIVE alarms.
 */
static gboolean
add_alarm_occurrences_cb (CalComponent *comp, time_t start, time_t end, gpointer data)
{
    struct alarm_occurrence_data *aod;
    GList *l;

    aod = data;

    for (l = aod->alarm_uids; l; l = l->next) {
        const char *auid;
        CalComponentAlarm *alarm;
        CalAlarmAction action;
        CalAlarmTrigger trigger;
        CalAlarmRepeat repeat;
        struct icaldurationtype *dur;
        time_t dur_time;
        time_t occur_time, trigger_time;
        int i;
        
        auid = l->data;
        alarm = cal_component_get_alarm (comp, auid);
        g_assert (alarm != NULL);

        cal_component_alarm_get_action (alarm, &action);
        cal_component_alarm_get_trigger (alarm, &trigger);
        cal_component_alarm_get_repeat (alarm, &repeat);
        cal_component_alarm_free (alarm);

        for (i = 0; aod->omit[i] != -1; i++) {
            if (aod->omit[i] == action)
                break;
        }
        if (aod->omit[i] != -1)
            continue;
        
        if (trigger.type != CAL_ALARM_TRIGGER_RELATIVE_START
            && trigger.type != CAL_ALARM_TRIGGER_RELATIVE_END)
            continue;

        dur = &trigger.u.rel_duration;
        dur_time = icaldurationtype_as_int (*dur);

        if (trigger.type == CAL_ALARM_TRIGGER_RELATIVE_START)
            occur_time = start;
        else
            occur_time = end;

        /* If dur->is_neg is true then dur_time will already be
         * negative.  So we do not need to test for dur->is_neg here; we
         * can simply add the dur_time value to the occur_time and get
         * the correct result.
         */

        trigger_time = occur_time + dur_time;

        /* Add repeating alarms */

        if (repeat.repetitions != 0) {
            int i;
            time_t repeat_time;

            repeat_time = icaldurationtype_as_int (repeat.duration);

            for (i = 0; i < repeat.repetitions; i++) {
                time_t t;

                t = trigger_time + (i + 1) * repeat_time;

                if (t >= aod->start && t < aod->end)
                    add_trigger (aod, auid, t, start, end);
            }
        }

        /* Add the trigger itself */

        if (trigger_time >= aod->start && trigger_time < aod->end)
            add_trigger (aod, auid, trigger_time, start, end);
    }

    return TRUE;
}

/* Generates the absolute triggers for a component */
static void
generate_absolute_triggers (CalComponent *comp, struct alarm_occurrence_data *aod,
                CalRecurResolveTimezoneFn resolve_tzid,
                gpointer user_data,
                icaltimezone *default_timezone)
{
    GList *l;
    CalComponentDateTime dt_start, dt_end;

    cal_component_get_dtstart (comp, &dt_start);
    cal_component_get_dtend (comp, &dt_end);

    for (l = aod->alarm_uids; l; l = l->next) {
        const char *auid;
        CalComponentAlarm *alarm;
        CalAlarmAction action;
        CalAlarmRepeat repeat;
        CalAlarmTrigger trigger;
        time_t abs_time;
        time_t occur_start, occur_end;
        icaltimezone *zone;
        int i;
        
        auid = l->data;
        alarm = cal_component_get_alarm (comp, auid);
        g_assert (alarm != NULL);

        cal_component_alarm_get_action (alarm, &action);
        cal_component_alarm_get_trigger (alarm, &trigger);
        cal_component_alarm_get_repeat (alarm, &repeat);
        cal_component_alarm_free (alarm);

        for (i = 0; aod->omit[i] != -1; i++) {
            if (aod->omit[i] == action)
                break;
        }
        if (aod->omit[i] != -1)
            continue;

        if (trigger.type != CAL_ALARM_TRIGGER_ABSOLUTE)
            continue;

        /* Absolute triggers are always in UTC; see RFC 2445 section 4.8.6.3 */
        zone = icaltimezone_get_utc_timezone ();

        abs_time = icaltime_as_timet_with_zone (trigger.u.abs_time, zone);

        /* No particular occurrence, so just use the times from the component */

        if (dt_start.value) {
            if (dt_start.tzid && !dt_start.value->is_date)
                zone = (* resolve_tzid) (dt_start.tzid, user_data);
            else
                zone = default_timezone;

            occur_start = icaltime_as_timet_with_zone (*dt_start.value, zone);
        } else
            occur_start = -1;

        if (dt_end.value) {
            if (dt_end.tzid && !dt_end.value->is_date)
                zone = (* resolve_tzid) (dt_end.tzid, user_data);
            else
                zone = default_timezone;

            occur_end = icaltime_as_timet_with_zone (*dt_end.value, zone);
        } else
            occur_end = -1;

        /* Add repeating alarms */

        if (repeat.repetitions != 0) {
            int i;
            time_t repeat_time;

            repeat_time = icaldurationtype_as_int (repeat.duration);

            for (i = 0; i < repeat.repetitions; i++) {
                time_t t;

                t = abs_time + (i + 1) * repeat_time;

                if (t >= aod->start && t < aod->end)
                    add_trigger (aod, auid, t, occur_start, occur_end);
            }
        }

        /* Add the trigger itself */

        if (abs_time >= aod->start && abs_time < aod->end)
            add_trigger (aod, auid, abs_time, occur_start, occur_end);
    }

    cal_component_free_datetime (&dt_start);
    cal_component_free_datetime (&dt_end);
}

/* Compares two alarm instances; called from g_slist_sort() */
static gint
compare_alarm_instance (gconstpointer a, gconstpointer b)
{
    const CalAlarmInstance *aia, *aib;

    aia = a;
    aib = b;

    if (aia->trigger < aib->trigger)
        return -1;
    else if (aia->trigger > aib->trigger)
        return 1;
    else
        return 0;
}

/**
 * cal_util_generate_alarms_for_comp
 * @comp: the CalComponent to generate alarms from
 * @start: start time
 * @end: end time
 * @resolve_tzid: callback for resolving timezones
 * @user_data: data to be passed to the resolve_tzid callback
 * @default_timezone: the timezone used to resolve DATE and floating DATE-TIME
 * values.
 *
 * Generates alarm instances for a calendar component.  Returns the instances
 * structure, or NULL if no alarm instances occurred in the specified time
 * range.
 */
CalComponentAlarms *
cal_util_generate_alarms_for_comp (CalComponent *comp,
                   time_t start,
                   time_t end,
                   CalAlarmAction *omit,
                   CalRecurResolveTimezoneFn resolve_tzid,
                   gpointer user_data,
                   icaltimezone *default_timezone)
{
    GList *alarm_uids;
    time_t alarm_start, alarm_end;
    struct alarm_occurrence_data aod;
    CalComponentAlarms *alarms;

    if (!cal_component_has_alarms (comp))
        return NULL;

    alarm_uids = cal_component_get_alarm_uids (comp);
    compute_alarm_range (comp, alarm_uids, start, end, &alarm_start, &alarm_end);

    aod.alarm_uids = alarm_uids;
    aod.start = start;
    aod.end = end;
    aod.omit = omit;
    aod.triggers = NULL;
    aod.n_triggers = 0;

    cal_recur_generate_instances (comp, alarm_start, alarm_end,
                      add_alarm_occurrences_cb, &aod,
                      resolve_tzid, user_data,
                      default_timezone);

    /* We add the ABSOLUTE triggers separately */
    generate_absolute_triggers (comp, &aod, resolve_tzid, user_data, default_timezone);

    if (aod.n_triggers == 0)
        return NULL;

    /* Create the component alarm instances structure */

    alarms = g_new (CalComponentAlarms, 1);
    alarms->comp = comp;
    g_object_ref (G_OBJECT (alarms->comp));
    alarms->alarms = g_slist_sort (aod.triggers, compare_alarm_instance);

    return alarms;
}

/**
 * cal_util_generate_alarms_for_list
 * @comps: list of CalComponent's
 * @start: start time
 * @end: end time
 * @comp_alarms: list to be returned
 * @resolve_tzid: callback for resolving timezones
 * @user_data: data to be passed to the resolve_tzid callback
 * @default_timezone: the timezone used to resolve DATE and floating DATE-TIME
 * values.
 *
 * Iterates through all the components in the comps list and generates alarm
 * instances for them; putting them in the comp_alarms list.
 *
 * Returns: the number of elements it added to that list.
 */
int
cal_util_generate_alarms_for_list (GList *comps,
                   time_t start,
                   time_t end,
                   CalAlarmAction *omit,
                   GSList **comp_alarms,
                   CalRecurResolveTimezoneFn resolve_tzid,
                   gpointer user_data,
                   icaltimezone *default_timezone)
{
    GList *l;
    int n;

    n = 0;

    for (l = comps; l; l = l->next) {
        CalComponent *comp;
        CalComponentAlarms *alarms;

        comp = CAL_COMPONENT (l->data);
        alarms = cal_util_generate_alarms_for_comp (comp, start, end, omit, resolve_tzid, user_data, default_timezone);

        if (alarms) {
            *comp_alarms = g_slist_prepend (*comp_alarms, alarms);
            n++;
        }
    }

    return n;
}


/* Converts an iCalendar PRIORITY value to a translated string. Any unknown
   priority value (i.e. not 0-9) will be returned as "" (undefined). */
char *
cal_util_priority_to_string (int priority)
{
    char *retval;

    if (priority <= 0)
        retval = "";
    else if (priority <= 4)
        retval = _("High");
    else if (priority == 5)
        retval = _("Normal");
    else if (priority <= 9)
        retval = _("Low");
    else
        retval = "";

    return retval;
}


/* Converts a translated priority string to an iCalendar priority value.
   Returns -1 if the priority string is not valid. */
int
cal_util_priority_from_string (const char *string)
{
    int priority;

    /* An empty string is the same as 'None'. */
    if (!string || !string[0] || !g_strcasecmp (string, _("Undefined")))
        priority = 0;
    else if (!g_strcasecmp (string, _("High")))
        priority = 3;
    else if (!g_strcasecmp (string, _("Normal")))
        priority = 5;
    else if (!g_strcasecmp (string, _("Low")))
        priority = 7;
    else
        priority = -1;

    return priority;
}

char *
cal_util_expand_uri (char *uri, gboolean tasks)
{
    char *file_uri, *file_name;

    if (!strncmp (uri, "file://", 7)) {
        file_uri = uri + 7;
        if (strlen (file_uri) > 4
            && !strcmp (file_uri + strlen (file_uri) - 4, ".ics")) {
            
            /* it's a .ics file */
            return g_strdup (uri);
        }

        /* we assume it's a dir and glom <type>.ics onto the end. */
        if (tasks)
            file_name = g_concat_dir_and_file (file_uri, "tasks.ics");
        else
            file_name = g_concat_dir_and_file (file_uri, "calendar.ics");
        file_uri = g_strdup_printf("file://%s", file_name);
        g_free(file_name);
    } else {
        file_uri = g_strdup (uri);
    }

    return file_uri;
}

/* callback for icalcomponent_foreach_tzid */
typedef struct {
    icalcomponent *vcal_comp;
    CalComponent *comp;
} ForeachTzidData;

static void
add_timezone_cb (icalparameter *param, void *data)
{
    icaltimezone *tz;
    const char *tzid;
    icalcomponent *vtz_comp;
    ForeachTzidData *f_data = (ForeachTzidData *) data;

    tzid = icalparameter_get_tzid (param);
    if (!tzid)
        return;

    tz = icalcomponent_get_timezone (f_data->vcal_comp, tzid);
    if (tz)
        return;

    tz = icalcomponent_get_timezone (cal_component_get_icalcomponent (f_data->comp),
                     tzid);
    if (!tz) {
        tz = icaltimezone_get_builtin_timezone_from_tzid (tzid);
        if (!tz)
            return;
    }

    vtz_comp = icaltimezone_get_component (tz);
    if (!vtz_comp)
        return;

    icalcomponent_add_component (f_data->vcal_comp,
                     icalcomponent_new_clone (vtz_comp));
}

/* Adds VTIMEZONE components to a VCALENDAR for all tzid's
 * in the given CalComponent. */
void
cal_util_add_timezones_from_component (icalcomponent *vcal_comp,
                       CalComponent *comp)
{
    ForeachTzidData f_data;

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

    f_data.vcal_comp = vcal_comp;
    f_data.comp = comp;
    icalcomponent_foreach_tzid (cal_component_get_icalcomponent (comp),
                    add_timezone_cb, &f_data);
}