path: root/calendar/gui/e-cal-model.c

/* Evolution calendar - Data model for ETable
 *
 * Copyright (C) 2000 Ximian, Inc.
 * Copyright (C) 2000 Ximian, Inc.
 *
 * Authors: Rodrigo Moya <rodrigo@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 <string.h>
#include <glib/garray.h>
#include <libgnome/gnome-i18n.h>
#include <gal/util/e-util.h>
#include <e-util/e-config-listener.h>
#include <e-util/e-time-utils.h>
#include <cal-util/timeutil.h>
#include "calendar-config.h"
#include "comp-util.h"
#include "e-cal-model.h"
#include "itip-utils.h"
#include "misc.h"

typedef struct {
    CalClient *client;
    CalQuery *query;
} ECalModelClient;

struct _ECalModelPrivate {
    /* The list of clients we are managing. Each element is of type ECalModelClient */
    GList *clients;

    /* The default client in the list */
    CalClient *default_client;
    
    /* Array for storing the objects. Each element is of type ECalModelComponent */
    GPtrArray *objects;

    icalcomponent_kind kind;
    icaltimezone *zone;

    /* The search regular expression */
    gchar *sexp;

    /* The default category */
    gchar *default_category;

    /* Addresses for determining icons */
    EAccountList *accounts;

    /* Whether we display dates in 24-hour format. */
        gboolean use_24_hour_format;
};

static void e_cal_model_class_init (ECalModelClass *klass);
static void e_cal_model_init (ECalModel *model, ECalModelClass *klass);
static void e_cal_model_finalize (GObject *object);

static int ecm_column_count (ETableModel *etm);
static int ecm_row_count (ETableModel *etm);
static void *ecm_value_at (ETableModel *etm, int col, int row);
static void ecm_set_value_at (ETableModel *etm, int col, int row, const void *value);
static gboolean ecm_is_cell_editable (ETableModel *etm, int col, int row);
static void ecm_append_row (ETableModel *etm, ETableModel *source, int row);
static void *ecm_duplicate_value (ETableModel *etm, int col, const void *value);
static void ecm_free_value (ETableModel *etm, int col, void *value);
static void *ecm_initialize_value (ETableModel *etm, int col);
static gboolean ecm_value_is_empty (ETableModel *etm, int col, const void *value);
static char *ecm_value_to_string (ETableModel *etm, int col, const void *value);

static const char *ecm_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data);

static GObjectClass *parent_class = NULL;

E_MAKE_TYPE (e_cal_model, "ECalModel", ECalModel, e_cal_model_class_init,
         e_cal_model_init, E_TABLE_MODEL_TYPE);

static void
e_cal_model_class_init (ECalModelClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);
    ETableModelClass *etm_class = E_TABLE_MODEL_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    object_class->finalize = e_cal_model_finalize;

    etm_class->column_count = ecm_column_count;
    etm_class->row_count = ecm_row_count;
    etm_class->value_at = ecm_value_at;
    etm_class->set_value_at = ecm_set_value_at;
    etm_class->is_cell_editable = ecm_is_cell_editable;
    etm_class->append_row = ecm_append_row;
    etm_class->duplicate_value = ecm_duplicate_value;
    etm_class->free_value = ecm_free_value;
    etm_class->initialize_value = ecm_initialize_value;
    etm_class->value_is_empty = ecm_value_is_empty;
    etm_class->value_to_string = ecm_value_to_string;

    klass->get_color_for_component = ecm_get_color_for_component;
    klass->fill_component_from_model = NULL;
}

static void
e_cal_model_init (ECalModel *model, ECalModelClass *klass)
{
    ECalModelPrivate *priv;

    priv = g_new0 (ECalModelPrivate, 1);
    model->priv = priv;

    priv->sexp = g_strdup ("#t"); /* match all by default */

    priv->objects = g_ptr_array_new ();
    priv->kind = ICAL_NO_COMPONENT;

    priv->accounts = itip_addresses_get ();

    priv->use_24_hour_format = TRUE;
}

static void
free_comp_data (ECalModelComponent *comp_data)
{
    g_return_if_fail (comp_data != NULL);

    comp_data->client = NULL;

    if (comp_data->icalcomp) {
        icalcomponent_free (comp_data->icalcomp);
        comp_data->icalcomp = NULL;
    }

    if (comp_data->dtstart) {
        g_free (comp_data->dtstart);
        comp_data->dtstart = NULL;
    }

    if (comp_data->dtend) {
        g_free (comp_data->dtend);
        comp_data->dtend = NULL;
    }

    if (comp_data->due) {
        g_free (comp_data->due);
        comp_data->due = NULL;
    }

    if (comp_data->completed) {
        g_free (comp_data->completed);
        comp_data->completed = NULL;
    }

    g_free (comp_data);
}

static void
clear_objects_array (ECalModelPrivate *priv)
{
    gint i;

    for (i = 0; i < priv->objects->len; i++) {
        ECalModelComponent *comp_data;

        comp_data = g_ptr_array_index (priv->objects, i);
        g_assert (comp_data != NULL);
        free_comp_data (comp_data);
    }

    
    g_ptr_array_set_size (priv->objects, 0);
}

static void
e_cal_model_finalize (GObject *object)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) object;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    if (priv) {
        if (priv->clients) {
            while (priv->clients != NULL) {
                ECalModelClient *client_data = (ECalModelClient *) priv->clients->data;

                g_signal_handlers_disconnect_matched (client_data->client, G_SIGNAL_MATCH_DATA,
                                      0, 0, NULL, NULL, model);
                g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA,
                                      0, 0, NULL, NULL, model);

                priv->clients = g_list_remove (priv->clients, client_data);
                g_object_unref (client_data->client);
                g_object_unref (client_data->query);
                g_free (client_data);
            }

            priv->clients = NULL;
        }

        if (priv->sexp) {
            g_free (priv->sexp);
            priv->sexp = NULL;
        }

        if (priv->default_category) {
            g_free (priv->default_category);
            priv->default_category = NULL;
        }

        if (priv->objects) {
            clear_objects_array (priv);
            g_ptr_array_free (priv->objects, FALSE);
            priv->objects = NULL;
        }
        
        if (priv->accounts) {
            priv->accounts = NULL;
        }

        g_free (priv);
        model->priv = NULL;
    }

    if (parent_class->finalize)
        parent_class->finalize (object);
}

/* ETableModel methods */

static int
ecm_column_count (ETableModel *etm)
{
    return E_CAL_MODEL_FIELD_LAST;
}

static int
ecm_row_count (ETableModel *etm)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), -1);

    priv = model->priv;

    return priv->objects->len;
}

static char *
get_categories (ECalModelComponent *comp_data)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CATEGORIES_PROPERTY);
    if (prop)
        return (char *) icalproperty_get_categories (prop);

    return "";
}

static char *
get_classification (ECalModelComponent *comp_data)
{
    icalproperty *prop;
    icalproperty_class class;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CLASS_PROPERTY);

    if (!prop)
        return _("Public");

    class = icalproperty_get_class (prop);

    switch (class)
    {
    case ICAL_CLASS_PUBLIC:
        return _("Public");
    case ICAL_CLASS_PRIVATE:
        return _("Private");
    case ICAL_CLASS_CONFIDENTIAL:
        return _("Confidential");
    default:
        return _("Unknown");
    }

    return _("Unknown");
}

static const char *
get_color (ECalModel *model, ECalModelComponent *comp_data)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    return e_cal_model_get_color_for_component (model, comp_data);
}

static char *
get_description (ECalModelComponent *comp_data)
{
    icalproperty *prop;
    static GString *str = NULL;

    if (str)
        g_string_free (str, TRUE);

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);
    if (prop) {
        str = g_string_new ("");
        do {
            str = g_string_append (str, icalproperty_get_description (prop));
        } while ((prop = icalcomponent_get_next_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY)));

        return str->str;
    }

    return "";
}

static ECellDateEditValue*
get_dtstart (ECalModel *model, ECalModelComponent *comp_data)
{
    ECalModelPrivate *priv;
        struct icaltimetype tt_start;

    priv = model->priv;

    if (!comp_data->dtstart) {
        icaltimezone *zone;
        icalproperty *prop;

        prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
        if (!prop)
            return NULL;

        tt_start = icalproperty_get_dtstart (prop);
        if (!icaltime_is_valid_time (tt_start))
            return NULL;

        comp_data->dtstart = g_new0 (ECellDateEditValue, 1);
        comp_data->dtstart->tt = tt_start;

        /* FIXME: handle errors */
        cal_client_get_timezone (comp_data->client,
                     icaltime_get_tzid (tt_start),
                     &zone, NULL);
        comp_data->dtstart->zone = zone;
    }

    return comp_data->dtstart;
}

static char *
get_summary (ECalModelComponent *comp_data)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_SUMMARY_PROPERTY);
    if (prop)
        return (char *) icalproperty_get_summary (prop);

    return "";
}

static char *
get_uid (ECalModelComponent *comp_data)
{
    return (char *) icalcomponent_get_uid (comp_data->icalcomp);
}

static void *
ecm_value_at (ETableModel *etm, int col, int row)
{
    ECalModelPrivate *priv;
    ECalModelComponent *comp_data;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);
    g_return_val_if_fail (row >= 0 && row < priv->objects->len, NULL);

    comp_data = g_ptr_array_index (priv->objects, row);
    g_assert (comp_data != NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        return get_categories (comp_data);
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
        return get_classification (comp_data);
    case E_CAL_MODEL_FIELD_COLOR :
        return (void *) get_color (model, comp_data);
    case E_CAL_MODEL_FIELD_COMPONENT :
        return comp_data->icalcomp;
    case E_CAL_MODEL_FIELD_DESCRIPTION :
        return get_description (comp_data);
    case E_CAL_MODEL_FIELD_DTSTART :
        return (void *) get_dtstart (model, comp_data);
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
        return GINT_TO_POINTER ((icalcomponent_get_first_component (comp_data->icalcomp,
                                        ICAL_VALARM_COMPONENT) != NULL));
    case E_CAL_MODEL_FIELD_ICON :
    {
        CalComponent *comp;
        icalcomponent *icalcomp;
        gint retval = 0;

        comp = cal_component_new ();
        icalcomp = icalcomponent_new_clone (comp_data->icalcomp);
        if (cal_component_set_icalcomponent (comp, icalcomp)) {
            if (cal_component_has_recurrences (comp))
                retval = 1;
            else if (itip_organizer_is_user (comp, comp_data->client))
                retval = 3;
            else {
                GSList *attendees = NULL, *sl;

                cal_component_get_attendee_list (comp, &attendees);
                for (sl = attendees; sl != NULL; sl = sl->next) {
                    CalComponentAttendee *ca = sl->data;
                    const char *text;

                    text = itip_strip_mailto (ca->value);
                    if (e_account_list_find (priv->accounts, E_ACCOUNT_FIND_ID_ADDRESS, text) != NULL) {
                        if (ca->delto != NULL)
                            retval = 3;
                        else
                            retval = 2;
                        break;
                    }
                }

                cal_component_free_attendee_list (attendees);
            }
        } else
            icalcomponent_free (icalcomp);

        g_object_unref (comp);

        return GINT_TO_POINTER (retval);
    }
    case E_CAL_MODEL_FIELD_SUMMARY :
        return get_summary (comp_data);
    case E_CAL_MODEL_FIELD_UID :
        return get_uid (comp_data);
    }

    return "";
}

static void
set_categories (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CATEGORIES_PROPERTY);
    if (!value || !(*value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
        if (!prop) {
            prop = icalproperty_new_categories (value);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        } else
            icalproperty_set_categories (prop, value);
    }
}

static void
set_classification (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_CLASS_PROPERTY);
    if (!value || !(*value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
      icalproperty_class ical_class;

      if (!strcasecmp (value, "PUBLIC"))
        ical_class = ICAL_CLASS_PUBLIC;
      else if (!strcasecmp (value, "PRIVATE"))
        ical_class = ICAL_CLASS_PRIVATE;
      else if (!strcasecmp (value, "CONFIDENTIAL"))
        ical_class = ICAL_CLASS_CONFIDENTIAL;
      else
        ical_class = ICAL_CLASS_NONE;

        if (!prop) {
            prop = icalproperty_new_class (ical_class);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        } else
            icalproperty_set_class (prop, ical_class);
    }
}

static void
set_description (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    /* remove old description(s) */
    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);
    while (prop) {
        icalproperty *next;

        next = icalcomponent_get_next_property (comp_data->icalcomp, ICAL_DESCRIPTION_PROPERTY);

        icalcomponent_remove_property (comp_data->icalcomp, prop);
        icalproperty_free (prop);

        prop = next;
    }

    /* now add the new description */
    if (!value || !(*value))
        return;

    prop = icalproperty_new_description (value);
    icalcomponent_add_property (comp_data->icalcomp, prop);
}

static void
set_dtstart (ECalModel *model, ECalModelComponent *comp_data, const void *value)
{
    icalproperty *prop;
    ECellDateEditValue *dv = (ECellDateEditValue *) value;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_DTSTART_PROPERTY);
    if (!dv) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else
        icalcomponent_set_dtstart (comp_data->icalcomp, dv->tt);
}

static void
set_summary (ECalModelComponent *comp_data, const char *value)
{
    icalproperty *prop;

    prop = icalcomponent_get_first_property (comp_data->icalcomp, ICAL_SUMMARY_PROPERTY);

    if (string_is_empty (value)) {
        if (prop) {
            icalcomponent_remove_property (comp_data->icalcomp, prop);
            icalproperty_free (prop);
        }
    } else {
        if (prop)
            icalproperty_set_summary (prop, value);
        else {
            prop = icalproperty_new_summary (value);
            icalcomponent_add_property (comp_data->icalcomp, prop);
        }
    }
}

static void
ecm_set_value_at (ETableModel *etm, int col, int row, const void *value)
{
    ECalModelPrivate *priv;
    ECalModelComponent *comp_data;
    ECalModel *model = (ECalModel *) etm;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;

    g_return_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST);
    g_return_if_fail (row >= 0 && row < priv->objects->len);

    comp_data = g_ptr_array_index (priv->objects, row);
    g_assert (comp_data != NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        set_categories (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
        set_classification (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_DESCRIPTION :
        set_description (comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_DTSTART :
        set_dtstart (model, comp_data, value);
        break;
    case E_CAL_MODEL_FIELD_SUMMARY :
        set_summary (comp_data, value);
        break;
    }

    /* FIXME ask about mod type */
    if (!cal_client_modify_object (comp_data->client, comp_data->icalcomp, CALOBJ_MOD_ALL, NULL)) {
        g_warning (G_STRLOC ": Could not modify the object!");
        
        /* FIXME Show error dialog */
    }
}

static gboolean
ecm_is_cell_editable (ETableModel *etm, int col, int row)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), FALSE);

    priv = model->priv;

    g_return_val_if_fail (col >= 0 && col <= E_CAL_MODEL_FIELD_LAST, FALSE);

    /* FIXME: We can't check this as 'click-to-add' passes row 0. */
    /*g_return_val_if_fail (row >= 0 && row < priv->objects->len, FALSE);*/

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_DTSTART :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return TRUE;
    }

    return FALSE;
}

static void
ecm_append_row (ETableModel *etm, ETableModel *source, int row)
{
    ECalModelClass *model_class;
    ECalModelComponent comp_data;
    ECalModel *source_model = (ECalModel *) source;
    ECalModel *model = (ECalModel *) etm;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (E_IS_CAL_MODEL (source_model));

    memset (&comp_data, 0, sizeof (comp_data));
    comp_data.client = e_cal_model_get_default_client (model);

    /* guard against saving before the calendar is open */
    if (!(comp_data.client && cal_client_get_load_state (comp_data.client) == CAL_CLIENT_LOAD_LOADED))
        return;

    comp_data.icalcomp = e_cal_model_create_component_with_defaults (model);

    /* set values for our fields */
    set_categories (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_CATEGORIES, row));
    set_classification (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_CLASSIFICATION, row));
    set_description (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_DESCRIPTION, row));
    set_dtstart (model, &comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_DTSTART, row));
    set_summary (&comp_data, e_table_model_value_at (source, E_CAL_MODEL_FIELD_SUMMARY, row));

    /* call the class' method for filling the component */
    model_class = (ECalModelClass *) G_OBJECT_GET_CLASS (model);
    if (model_class->fill_component_from_model != NULL) {
        model_class->fill_component_from_model (model, &comp_data, source_model, row);
    }


    if (!cal_client_create_object (comp_data.client, comp_data.icalcomp, NULL, NULL)) {
        g_warning (G_STRLOC ": Could not create the object!");

        /* FIXME: show error dialog */
    }

    icalcomponent_free (comp_data.icalcomp);
}

static void *
ecm_duplicate_value (ETableModel *etm, int col, const void *value)
{
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup (value);
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
        return (void *) value;
    case E_CAL_MODEL_FIELD_COMPONENT :
        return icalcomponent_new_clone ((icalcomponent *) value);
    case E_CAL_MODEL_FIELD_DTSTART :
        if (value) {
            ECellDateEditValue *dv, *orig_dv;

            orig_dv = (ECellDateEditValue *) value;
            dv = g_new0 (ECellDateEditValue, 1);
            *dv = *orig_dv;

            return dv;
        }
        break;
    }

    return NULL;
}

static void
ecm_free_value (ETableModel *etm, int col, void *value)
{
    g_return_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        if (value)
            g_free (value);
        break;
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
        break;
    case E_CAL_MODEL_FIELD_DTSTART :
        if (value)
            g_free (value);
        break;
    case E_CAL_MODEL_FIELD_COMPONENT :
        if (value)
            icalcomponent_free ((icalcomponent *) value);
        break;
    }
}

static void *
ecm_initialize_value (ETableModel *etm, int col)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);

    priv = model->priv;

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        return g_strdup (priv->default_category);
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup ("");
    case E_CAL_MODEL_FIELD_DTSTART :
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return NULL;
    }

    return NULL;
}

static gboolean
ecm_value_is_empty (ETableModel *etm, int col, const void *value)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) etm;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), TRUE);
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, TRUE);

    priv = model->priv;

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
        /* This could be a hack or not.  If the categories field only
         * contains the default category, then it possibly means that
         * the user has not entered anything at all in the click-to-add;
         * the category is in the value because we put it there in
         * ecm_initialize_value().
         */
        if (priv->default_category && value && strcmp (priv->default_category, value) == 0)
            return TRUE;
        else
            return string_is_empty (value);
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return string_is_empty (value);
    case E_CAL_MODEL_FIELD_DTSTART :
        return value ? FALSE : TRUE;
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
    case E_CAL_MODEL_FIELD_ICON :
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return TRUE;
    }

    return TRUE;
}

static char *
ecm_value_to_string (ETableModel *etm, int col, const void *value)
{
    g_return_val_if_fail (col >= 0 && col < E_CAL_MODEL_FIELD_LAST, NULL);

    switch (col) {
    case E_CAL_MODEL_FIELD_CATEGORIES :
    case E_CAL_MODEL_FIELD_CLASSIFICATION :
    case E_CAL_MODEL_FIELD_DESCRIPTION :
    case E_CAL_MODEL_FIELD_SUMMARY :
        return g_strdup (value);
    case E_CAL_MODEL_FIELD_DTSTART :
        return e_cal_model_date_value_to_string (E_CAL_MODEL (etm), value);
    case E_CAL_MODEL_FIELD_ICON :
        if (GPOINTER_TO_INT (value) == 0)
            return _("Normal");
        else if (GPOINTER_TO_INT (value) == 1)
            return _("Recurring");
        else
            return _("Assigned");
    case E_CAL_MODEL_FIELD_HAS_ALARMS :
        return value ? _("Yes") : _("No");
    case E_CAL_MODEL_FIELD_COLOR :
    case E_CAL_MODEL_FIELD_COMPONENT :
        return NULL;
    }

    return NULL;
}

/* ECalModel class methods */

typedef struct {
    const gchar *color;
    GList *uris;
} AssignedColorData;

static const char *
ecm_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data)
{
    ECalModelPrivate *priv;
    gint i, first_empty = 0;
    static AssignedColorData assigned_colors[] = {
        { "#BECEDD", NULL }, /* 190 206 221     Blue */
        { "#E2F0EF", NULL }, /* 226 240 239     Light Blue */
        { "#C6E2B7", NULL }, /* 198 226 183     Green */
        { "#E2F0D3", NULL }, /* 226 240 211     Light Green */
        { "#E2D4B7", NULL }, /* 226 212 183     Khaki */
        { "#EAEAC1", NULL }, /* 234 234 193     Light Khaki */
        { "#F0B8B7", NULL }, /* 240 184 183     Pink */
        { "#FED4D3", NULL }, /* 254 212 211     Light Pink */
        { "#E2C6E1", NULL }, /* 226 198 225     Purple */
        { "#F0E2EF", NULL }  /* 240 226 239     Light Purple */
    };

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;
                                                                                
    for (i = 0; i < G_N_ELEMENTS (assigned_colors); i++) {
        GList *l;

        if (assigned_colors[i].uris == NULL) {
            first_empty = i;
            continue;
        }

        for (l = assigned_colors[i].uris; l != NULL; l = l->next) {
            if (!strcmp ((const char *) l->data,
                     cal_client_get_uri (comp_data->client)))
            {
                return assigned_colors[i].color;
            }
        }
    }

    /* return the first unused color */
    assigned_colors[first_empty].uris = g_list_append (assigned_colors[first_empty].uris,
                               g_strdup (cal_client_get_uri (comp_data->client)));

    return assigned_colors[first_empty].color;
}

/**
 * e_cal_model_get_component_kind
 */
icalcomponent_kind
e_cal_model_get_component_kind (ECalModel *model)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), ICAL_NO_COMPONENT);

    priv = model->priv;
    return priv->kind;
}

/**
 * e_cal_model_set_component_kind
 */
void
e_cal_model_set_component_kind (ECalModel *model, icalcomponent_kind kind)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    priv->kind = kind;
}

/**
 * e_cal_model_get_timezone
 */
icaltimezone *
e_cal_model_get_timezone (ECalModel *model)
{
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    return model->priv->zone;
}

/**
 * e_cal_model_set_timezone
 */
void
e_cal_model_set_timezone (ECalModel *model, icaltimezone *zone)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    if (priv->zone != zone) {
        e_table_model_pre_change (E_TABLE_MODEL (model));
        priv->zone = zone;

        /* the timezone affects the times shown for date fields,
           so we need to redisplay everything */
        e_table_model_changed (E_TABLE_MODEL (model));
    }
}

/**
 * e_cal_model_set_default_category
 */
void
e_cal_model_set_default_category (ECalModel *model, const gchar *default_cat)
{
    g_return_if_fail (E_IS_CAL_MODEL (model));

    if (model->priv->default_category)
        g_free (model->priv->default_category);

    model->priv->default_category = g_strdup (default_cat);
}

/**
 * e_cal_model_set_use_24_hour_format
 */
void
e_cal_model_set_use_24_hour_format (ECalModel *model, gboolean use24)
{
    g_return_if_fail (E_IS_CAL_MODEL (model));

    if (model->priv->use_24_hour_format != use24) {
                e_table_model_pre_change (E_TABLE_MODEL (model));
                model->priv->use_24_hour_format = use24;
                /* Get the views to redraw themselves. */
                e_table_model_changed (E_TABLE_MODEL (model));
        }
}

/**
 * e_cal_model_get_default_client
 */
CalClient *
e_cal_model_get_default_client (ECalModel *model)
{
    ECalModelPrivate *priv;
    ECalModelClient *client_data;

    g_return_val_if_fail (model != NULL, NULL);
    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    
    priv = model->priv;

    /* we always return a valid CalClient, since we rely on it in many places */
    if (priv->default_client)
        return priv->default_client;

    if (!priv->clients)
        return NULL;

    client_data = (ECalModelClient *) priv->clients->data;

    return client_data ? client_data->client : NULL;
}

void
e_cal_model_set_default_client (ECalModel *model, CalClient *client)
{
    ECalModelPrivate *priv;
    GList *l;
    gboolean found = FALSE;
    
    g_return_if_fail (model != NULL);
    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (client != NULL);
    g_return_if_fail (IS_CAL_CLIENT (client));

    priv = model->priv;

    /* See if we already know about the client */
    for (l = priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = l->data;

        if (client == client_data->client)
            found = TRUE;
    }

    /* If its not found, add it */
    if (!found)
        e_cal_model_add_client (model, client);
    
    /* Store the default client */
    priv->default_client = client;
}

/**
 * e_cal_model_get_client_list
 */
GList *
e_cal_model_get_client_list (ECalModel *model)
{
    GList *list = NULL, *l;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    for (l = model->priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        list = g_list_append (list, client_data->client);
    }

    return list;
}

/**
 * e_cal_model_get_client_for_uri
 * @model: A calendar model.
 * @uri: Uri for the client to get.
 */
CalClient *
e_cal_model_get_client_for_uri (ECalModel *model, const char *uri)
{
    GList *l;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (uri != NULL, NULL);

    for (l = model->priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        if (!strcmp (uri, cal_client_get_uri (client_data->client)))
            return client_data->client;
    }

    return NULL;
}

static ECalModelComponent *
search_by_uid_and_client (ECalModelPrivate *priv, CalClient *client, const char *uid)
{
    gint i;

    for (i = 0; i < priv->objects->len; i++) {
        ECalModelComponent *comp_data = g_ptr_array_index (priv->objects, i);

        if (comp_data) {
            const char *tmp_uid;

            tmp_uid = icalcomponent_get_uid (comp_data->icalcomp);
            if (tmp_uid && *tmp_uid) {
                if (comp_data->client == client && !strcmp (uid, tmp_uid))
                    return comp_data;
            }
        }
    }

    return NULL;
}

static gint
get_position_in_array (GPtrArray *objects, gpointer item)
{
    gint i;

    for (i = 0; i < objects->len; i++) {
        if (g_ptr_array_index (objects, i) == item)
            return i;
    }

    return -1;
}

static void
query_objects_added_cb (CalQuery *query, GList *objects, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;
    ECalModelPrivate *priv;
    GList *l;
    int start_row;
    
    priv = model->priv;

    e_table_model_pre_change (E_TABLE_MODEL (model));

    start_row = priv->objects->len ? priv->objects->len - 1 : 0;
    
    for (l = objects; l; l = l->next) {
        ECalModelComponent *comp_data;

        comp_data = g_new0 (ECalModelComponent, 1);
        comp_data->client = cal_query_get_client (query);
        comp_data->icalcomp = icalcomponent_new_clone (l->data);

        g_ptr_array_add (priv->objects, comp_data);
    }

    e_table_model_rows_inserted (E_TABLE_MODEL (model), start_row, priv->objects->len - start_row);
}

static void
query_objects_modified_cb (CalQuery *query, GList *objects, gpointer user_data)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) user_data;
    GList *l;
    
    priv = model->priv;

    for (l = objects; l; l = l->next) {
        ECalModelComponent *comp_data;

        e_table_model_pre_change (E_TABLE_MODEL (model));

        comp_data = search_by_uid_and_client (priv, cal_query_get_client (query), icalcomponent_get_uid (l->data));
        g_assert (comp_data);
    
        if (comp_data->icalcomp)
            icalcomponent_free (comp_data->icalcomp);
        if (comp_data->dtstart) {
            g_free (comp_data->dtstart);
            comp_data->dtstart = NULL;
        }
        if (comp_data->dtend) {
            g_free (comp_data->dtend);
            comp_data->dtend = NULL;
        }
        if (comp_data->due) {
            g_free (comp_data->due);
            comp_data->due = NULL;
        }
        if (comp_data->completed) {
            g_free (comp_data->completed);
            comp_data->completed = NULL;
        }
             
        comp_data->icalcomp = icalcomponent_new_clone (l->data);

        e_table_model_row_changed (E_TABLE_MODEL (model), get_position_in_array (priv->objects, comp_data));
    }
}

static void
query_objects_removed_cb (CalQuery *query, GList *uids, gpointer user_data)
{
    ECalModelPrivate *priv;
    ECalModel *model = (ECalModel *) user_data;
    GList *l;
    
    priv = model->priv;

    for (l = uids; l; l = l->next) {
        ECalModelComponent *comp_data;
        int pos;

        e_table_model_pre_change (E_TABLE_MODEL (model));
        
        comp_data = search_by_uid_and_client (priv, cal_query_get_client (query), l->data);
        g_assert (comp_data);
        
        pos = get_position_in_array (priv->objects, comp_data);
            
        g_ptr_array_remove (priv->objects, comp_data);
        free_comp_data (comp_data);
        
        e_table_model_row_deleted (E_TABLE_MODEL (model), pos);
    }
}

static void
query_progress_cb (CalQuery *query, const char *message, int percent, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    /* FIXME Update status bar */
}

static void
query_done_cb (CalQuery *query, ECalendarStatus status, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    /* FIXME Clear status bar */
}

/* Builds a complete query sexp for the calendar model by adding the predicates
 * to filter only for the type of objects that the model supports, and
 * whether we want completed tasks.
 */
static char *
adjust_query_sexp (ECalModel *model, const char *sexp)
{
    ECalModelPrivate *priv;
    char *type_sexp, *new_sexp;

    priv = model->priv;

    if (priv->kind == ICAL_NO_COMPONENT)
        type_sexp = g_strdup ("#t");
    else {
        if (priv->kind == ICAL_VEVENT_COMPONENT)
            type_sexp = g_strdup ("(or (= (get-vtype) \"VEVENT\"))");
        else if (priv->kind == ICAL_VTODO_COMPONENT)
            type_sexp = g_strdup ("(or (= (get-vtype) \"VTODO\"))");
        else if (priv->kind == ICAL_VJOURNAL_COMPONENT)
            type_sexp = g_strdup ("(or (= (get-vtype) \"VJOURNAL\"))");
        else
            type_sexp = g_strdup ("#t");
    }

    new_sexp = g_strdup_printf ("(and %s %s)", type_sexp, sexp);
    g_free (type_sexp);

    return new_sexp;
}

static void
update_query_for_client (ECalModel *model, ECalModelClient *client_data)
{
    ECalModelPrivate *priv;
    gchar *real_sexp;

    priv = model->priv;

    /* free the previous query, if any */
    if (client_data->query) {
        g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA,
                              0, 0, NULL, NULL, model);
        g_object_unref (client_data->query);
        client_data->query = NULL;
    }

    /* prepare the query */
    g_assert (priv->sexp != NULL);
    real_sexp = adjust_query_sexp (model, priv->sexp);

    if (!cal_client_get_query (client_data->client, real_sexp, &client_data->query, NULL)) {
        g_warning (G_STRLOC ": Unable to get query");
        g_free (real_sexp);

        return;
    }   
    g_free (real_sexp);

    g_signal_connect (client_data->query, "objects_added", G_CALLBACK (query_objects_added_cb), model);
    g_signal_connect (client_data->query, "objects_modified", G_CALLBACK (query_objects_modified_cb), model);
    g_signal_connect (client_data->query, "objects_removed", G_CALLBACK (query_objects_removed_cb), model);
    g_signal_connect (client_data->query, "query_progress", G_CALLBACK (query_progress_cb), model);
    g_signal_connect (client_data->query, "query_done", G_CALLBACK (query_done_cb), model);

    cal_query_start (client_data->query);
}

static void
backend_died_cb (CalClient *client, gpointer user_data)
{
    ECalModel *model;

    model = E_CAL_MODEL (user_data);

    e_cal_model_remove_client (model, client);
}

static void
add_new_client (ECalModel *model, CalClient *client)
{
    ECalModelPrivate *priv;
    ECalModelClient *client_data;

    priv = model->priv;

    client_data = g_new0 (ECalModelClient, 1);
    client_data->client = client;
    client_data->query = NULL;
    g_object_ref (client_data->client);

    priv->clients = g_list_append (priv->clients, client_data);

    g_signal_connect (G_OBJECT (client_data->client), "backend_died",
              G_CALLBACK (backend_died_cb), model);

    update_query_for_client (model, client_data);
}

static void
cal_opened_cb (CalClient *client, CalClientOpenStatus status, gpointer user_data)
{
    ECalModel *model = (ECalModel *) user_data;

    if (status != CAL_CLIENT_OPEN_SUCCESS)
        return;

    add_new_client (model, client);
}

/**
 * e_cal_model_add_client
 */
void
e_cal_model_add_client (ECalModel *model, CalClient *client)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (IS_CAL_CLIENT (client));

    priv = model->priv;

    if (cal_client_get_load_state (client) == CAL_CLIENT_LOAD_LOADED)
        add_new_client (model, client);
    else
        g_signal_connect (client, "cal_opened", G_CALLBACK (cal_opened_cb), model);
}

static void
remove_client (ECalModel *model, ECalModelClient *client_data)
{
    gint i;

    g_signal_handlers_disconnect_matched (client_data->client, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, model);
    g_signal_handlers_disconnect_matched (client_data->query, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, model);

    model->priv->clients = g_list_remove (model->priv->clients, client_data);

    /* remove all objects belonging to this client */
    e_table_model_pre_change (E_TABLE_MODEL (model));
    for (i = 0; i < model->priv->objects->len; i++) {
        ECalModelComponent *comp_data = (ECalModelComponent *) g_ptr_array_index (model->priv->objects, i);

        g_assert (comp_data != NULL);

        if (comp_data->client == client_data->client) {
            g_ptr_array_remove (model->priv->objects, comp_data);
            free_comp_data (comp_data);
        }
    }
    e_table_model_changed (E_TABLE_MODEL (model));

    /* free all remaining memory */
    g_object_unref (client_data->client);
    g_object_unref (client_data->query);
    g_free (client_data);

}

/**
 * e_cal_model_remove_client
 */
void
e_cal_model_remove_client (ECalModel *model, CalClient *client)
{
    GList *l;
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (IS_CAL_CLIENT (client));

    priv = model->priv;
    for (l = priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data = (ECalModelClient *) l->data;

        if (client_data->client == client) {
            remove_client (model, client_data);
            break;
        }
    }
}

/**
 * e_cal_model_remove_all_clients
 */
void
e_cal_model_remove_all_clients (ECalModel *model)
{
    ECalModelPrivate *priv;

    g_return_if_fail (E_IS_CAL_MODEL (model));

    priv = model->priv;
    while (priv->clients != NULL) {
        ECalModelClient *client_data = (ECalModelClient *) priv->clients->data;
        remove_client (model, client_data);
    }
}

/**
 * e_cal_model_set_query
 */
void
e_cal_model_set_query (ECalModel *model, const char *sexp)
{
    ECalModelPrivate *priv;
    GList *l;

    g_return_if_fail (E_IS_CAL_MODEL (model));
    g_return_if_fail (sexp != NULL);

    priv = model->priv;

    if (priv->sexp)
        g_free (priv->sexp);

    priv->sexp = g_strdup (sexp);

    /* clean up the current contents */
    e_table_model_pre_change (E_TABLE_MODEL (model));
    clear_objects_array (priv);
    e_table_model_changed (E_TABLE_MODEL (model));

    /* update the query for all clients */
    for (l = priv->clients; l != NULL; l = l->next) {
        ECalModelClient *client_data;

        client_data = (ECalModelClient *) l->data;
        update_query_for_client (model, client_data);
    }
}

/**
 * e_cal_model_create_component_with_defaults
 */
icalcomponent *
e_cal_model_create_component_with_defaults (ECalModel *model)
{
    ECalModelPrivate *priv;
    CalComponent *comp;
    icalcomponent *icalcomp;
    CalClient *client;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (priv->clients != NULL, NULL);

    client = e_cal_model_get_default_client (model);
    if (!client)
        return icalcomponent_new (priv->kind);

    switch (priv->kind) {
    case ICAL_VEVENT_COMPONENT :
        comp = cal_comp_event_new_with_defaults (client);
        break;
    case ICAL_VTODO_COMPONENT :
        comp = cal_comp_task_new_with_defaults (client);
        break;
    default:
        return NULL;
    }

    if (!comp)
        return icalcomponent_new (priv->kind);

    icalcomp = icalcomponent_new_clone (cal_component_get_icalcomponent (comp));
    g_object_unref (comp);

    /* make sure the component has an UID */
    if (!icalcomponent_get_uid (icalcomp)) {
        char *uid;

        uid = cal_component_gen_uid ();
        icalcomponent_set_uid (icalcomp, uid);

        g_free (uid);
    }

    return icalcomp;
}

/**
 * e_cal_model_get_color_for_component
 */
const gchar *
e_cal_model_get_color_for_component (ECalModel *model, ECalModelComponent *comp_data)
{
    ECalModelClass *model_class;
    const gchar *color = NULL;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);
    g_return_val_if_fail (comp_data != NULL, NULL);

    model_class = (ECalModelClass *) G_OBJECT_GET_CLASS (model);
    if (model_class->get_color_for_component != NULL)
        color = model_class->get_color_for_component (model, comp_data);

    if (!color)
        color = ecm_get_color_for_component (model, comp_data);

    return color;
}

/**
 * e_cal_model_get_component_at
 */
ECalModelComponent *
e_cal_model_get_component_at (ECalModel *model, gint row)
{
    ECalModelPrivate *priv;

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    g_return_val_if_fail (row >= 0 && row < priv->objects->len, NULL);

    return g_ptr_array_index (priv->objects, row);
}

/**
 * e_cal_model_date_value_to_string
 */
gchar*
e_cal_model_date_value_to_string (ECalModel *model, const void *value)
{
    ECalModelPrivate *priv;
    ECellDateEditValue *dv = (ECellDateEditValue *) value;
    struct icaltimetype tt;
    struct tm tmp_tm;
    char buffer[64];

    g_return_val_if_fail (E_IS_CAL_MODEL (model), NULL);

    priv = model->priv;

    if (!dv)
        return g_strdup ("");

    /* We currently convert all the dates to the current timezone. */
    tt = dv->tt;
    icaltimezone_convert_time (&tt, dv->zone, priv->zone);

    tmp_tm.tm_year = tt.year - 1900;
    tmp_tm.tm_mon = tt.month - 1;
    tmp_tm.tm_mday = tt.day;
    tmp_tm.tm_hour = tt.hour;
    tmp_tm.tm_min = tt.minute;
    tmp_tm.tm_sec = tt.second;
    tmp_tm.tm_isdst = -1;

    tmp_tm.tm_wday = time_day_of_week (tt.day, tt.month - 1, tt.year);

    memset (buffer, 0, sizeof (buffer));
    e_time_format_date_and_time (&tmp_tm, priv->use_24_hour_format,
                     TRUE, FALSE,
                     buffer, sizeof (buffer));
    return g_strdup (buffer);
}

/**
 * e_cal_model_free_component_data
 */
void
e_cal_model_free_component_data (ECalModelComponent *comp_data)
{
    g_return_if_fail (comp_data != NULL);

    if (comp_data->icalcomp)
        icalcomponent_free (comp_data->icalcomp);
    if (comp_data->dtstart)
        g_free (comp_data->dtstart);
    if (comp_data->dtend)
        g_free (comp_data->dtend);
    if (comp_data->due)
        g_free (comp_data->due);
    if (comp_data->completed)
        g_free (comp_data->completed);

    g_free (comp_data);
}