/********************************************************************\
 * gnc-tree-view-commodity.c -- GtkTreeView implementation to       *
 *                            display commodities in a GtkTreeView. *
 * Copyright (C) 2003,2005 David Hampton <hampton@employees.org>    *
 *                                                                  *
 * 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, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
 *                                                                  *
\********************************************************************/

#include <config.h>

#include <gtk/gtk.h>
#include <glib/gi18n.h>
#include <string.h>

#include "gnc-tree-view.h"
#include "gnc-tree-model-commodity.h"
#include "gnc-tree-view-commodity.h"

#include "gnc-commodity.h"
#include "gnc-component-manager.h"
#include "gnc-engine.h"
#include "gnc-glib-utils.h"
#include "gnc-gnome-utils.h"
#include "gnc-icons.h"
#include "gnc-ui-util.h"


/** Static Globals *******************************************************/

/* This static indicates the debugging module that this .o belongs to.  */
static QofLogModule log_module = GNC_MOD_GUI;

/** Declarations *********************************************************/
static void gnc_tree_view_commodity_class_init (GncTreeViewCommodityClass *klass);
static void gnc_tree_view_commodity_init (GncTreeViewCommodity *view);
static void gnc_tree_view_commodity_finalize (GObject *object);
static void gnc_tree_view_commodity_destroy (GtkWidget *widget);

typedef struct GncTreeViewCommodityPrivate
{
    gpointer dummy;
} GncTreeViewCommodityPrivate;

#define GNC_TREE_VIEW_COMMODITY_GET_PRIVATE(o)  \
   (G_TYPE_INSTANCE_GET_PRIVATE ((o), GNC_TYPE_TREE_VIEW_COMMODITY, GncTreeViewCommodityPrivate))


/************************************************************/
/*               g_object required functions                */
/************************************************************/

static GObjectClass *parent_class = NULL;

GType
gnc_tree_view_commodity_get_type (void)
{
    static GType gnc_tree_view_commodity_type = 0;

    if (gnc_tree_view_commodity_type == 0)
    {
        static const GTypeInfo our_info =
        {
            sizeof (GncTreeViewCommodityClass),
            NULL,
            NULL,
            (GClassInitFunc) gnc_tree_view_commodity_class_init,
            NULL,
            NULL,
            sizeof (GncTreeViewCommodity),
            0,
            (GInstanceInitFunc) gnc_tree_view_commodity_init
        };

        gnc_tree_view_commodity_type = g_type_register_static (GNC_TYPE_TREE_VIEW,
                                       "GncTreeViewCommodity",
                                       &our_info, 0);
    }

    return gnc_tree_view_commodity_type;
}

static void
gnc_tree_view_commodity_class_init (GncTreeViewCommodityClass *klass)
{
    GObjectClass *o_class;
    GtkWidgetClass *widget_class;

    parent_class = g_type_class_peek_parent (klass);

    o_class = G_OBJECT_CLASS (klass);
    widget_class = GTK_WIDGET_CLASS (klass);

    /* GObject signals */
    o_class->finalize = gnc_tree_view_commodity_finalize;

    /* GtkWidget signals */
    widget_class->destroy = gnc_tree_view_commodity_destroy;

    g_type_class_add_private(klass, sizeof(GncTreeViewCommodityPrivate));
}

static void
gnc_tree_view_commodity_init (GncTreeViewCommodity *view)
{
}

static void
gnc_tree_view_commodity_finalize (GObject *object)
{
    g_return_if_fail (object != NULL);
    g_return_if_fail (GNC_IS_TREE_VIEW_COMMODITY (object));

    ENTER("view %p", object);
    if (G_OBJECT_CLASS (parent_class)->finalize)
        (* G_OBJECT_CLASS (parent_class)->finalize) (object);
    LEAVE(" ");
}

static void
gnc_tree_view_commodity_destroy (GtkWidget *widget)
{
    g_return_if_fail (widget != NULL);
    g_return_if_fail (GNC_IS_TREE_VIEW_COMMODITY (widget));

    ENTER("view %p", widget);

    if (GTK_WIDGET_CLASS (parent_class)->destroy)
        (* GTK_WIDGET_CLASS (parent_class)->destroy) (widget);
    LEAVE(" ");
}


/************************************************************/
/*                      sort functions                      */
/************************************************************/

static gboolean
get_commodities_w_iters (GtkTreeModel *f_model,
                         GtkTreeIter *f_iter_a,
                         GtkTreeIter *f_iter_b,
                         GtkTreeModel **model_p,
                         GtkTreeIter *iter_a,
                         GtkTreeIter *iter_b,
                         gnc_commodity **comm_a,
                         gnc_commodity **comm_b)
{
    GncTreeModelCommodity *model;
    GtkTreeModel *tree_model;

    tree_model = gtk_tree_model_filter_get_model(GTK_TREE_MODEL_FILTER(f_model));
    model = GNC_TREE_MODEL_COMMODITY(tree_model);

    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER(f_model),
            iter_a,
            f_iter_a);

    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER(f_model),
            iter_b,
            f_iter_b);

    /* Both iters must point to commodities for this to be meaningful */
    if (!gnc_tree_model_commodity_iter_is_commodity (model, iter_a))
        return FALSE;
    if (!gnc_tree_model_commodity_iter_is_commodity (model, iter_b))
        return FALSE;

    *comm_a = gnc_tree_model_commodity_get_commodity (model, iter_a);
    *comm_b = gnc_tree_model_commodity_get_commodity (model, iter_b);
    if (model_p)
        *model_p = tree_model;
    return TRUE;
}

static gboolean
get_commodities (GtkTreeModel *f_model,
                 GtkTreeIter *f_iter_a,
                 GtkTreeIter *f_iter_b,
                 GtkTreeModel **model_p,
                 gnc_commodity **comm_a,
                 gnc_commodity **comm_b)
{
    GtkTreeIter iter_a, iter_b;

    return get_commodities_w_iters(f_model, f_iter_a, f_iter_b, model_p,
                                   &iter_a, &iter_b, comm_a, comm_b);
}

static gint
sort_namespace (GtkTreeModel *f_model,
                GtkTreeIter *f_iter_a,
                GtkTreeIter *f_iter_b)
{
    GncTreeModelCommodity *model;
    GtkTreeModel *tree_model;
    GtkTreeIter iter_a, iter_b;
    gnc_commodity_namespace *ns_a, *ns_b;

    tree_model = gtk_tree_model_filter_get_model(GTK_TREE_MODEL_FILTER(f_model));
    model = GNC_TREE_MODEL_COMMODITY(tree_model);

    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER(f_model),
            &iter_a,
            f_iter_a);
    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER(f_model),
            &iter_b,
            f_iter_b);

    ns_a = gnc_tree_model_commodity_get_namespace (model, &iter_a);
    ns_b = gnc_tree_model_commodity_get_namespace (model, &iter_b);
    return safe_utf8_collate (gnc_commodity_namespace_get_gui_name (ns_a),
                              gnc_commodity_namespace_get_gui_name (ns_b));
}

static gint
default_sort (gnc_commodity *comm_a, gnc_commodity *comm_b)
{
    gint fraction_a, fraction_b, result;

    result = safe_utf8_collate (gnc_commodity_get_namespace (comm_a),
                                gnc_commodity_get_namespace (comm_b));
    if (result != 0) return result;

    result = safe_utf8_collate (gnc_commodity_get_mnemonic (comm_a),
                                gnc_commodity_get_mnemonic (comm_b));
    if (result != 0) return result;

    result = safe_utf8_collate (gnc_commodity_get_fullname (comm_a),
                                gnc_commodity_get_fullname (comm_b));
    if (result != 0) return result;

    result = safe_utf8_collate (gnc_commodity_get_cusip (comm_a),
                                gnc_commodity_get_cusip (comm_b));
    if (result != 0) return result;

    fraction_a = gnc_commodity_get_fraction (comm_a);
    fraction_b = gnc_commodity_get_fraction (comm_b);

    if (fraction_a < fraction_b)
        return -1;

    if (fraction_b < fraction_a)
        return 1;

    return 0;
}

static gint
sort_by_commodity_string (GtkTreeModel *f_model,
                          GtkTreeIter *f_iter_a,
                          GtkTreeIter *f_iter_b,
                          gpointer user_data)
{
    GtkTreeModel *model;
    GtkTreeIter iter_a, iter_b;
    gnc_commodity *comm_a, *comm_b;
    gchar *str1, *str2;
    gint column = GPOINTER_TO_INT(user_data);
    gint result;

    if (!get_commodities_w_iters(f_model, f_iter_a, f_iter_b,
                                 &model, &iter_a, &iter_b, &comm_a, &comm_b))
        return sort_namespace (f_model, f_iter_a, f_iter_b);

    /* Get the strings. */
    gtk_tree_model_get(GTK_TREE_MODEL(model), &iter_a,  column, &str1, -1);
    gtk_tree_model_get(GTK_TREE_MODEL(model), &iter_b,  column, &str2, -1);

    result = safe_utf8_collate(str1, str2);
    g_free(str1);
    g_free(str2);
    if (result != 0)
        return result;
    return default_sort(comm_a, comm_b);
}


static gint
sort_by_fraction (GtkTreeModel *f_model,
                  GtkTreeIter *f_iter_a,
                  GtkTreeIter *f_iter_b,
                  gpointer user_data)
{
    gnc_commodity *comm_a, *comm_b;
    gint fraction_a, fraction_b;

    if (!get_commodities (f_model, f_iter_a, f_iter_b, NULL, &comm_a, &comm_b))
        return sort_namespace (f_model, f_iter_a, f_iter_b);

    fraction_a = gnc_commodity_get_fraction (comm_a);
    fraction_b = gnc_commodity_get_fraction (comm_b);

    if (fraction_a < fraction_b)
        return -1;

    if (fraction_b < fraction_a)
        return 1;

    return default_sort(comm_a, comm_b);
}

static gint
sort_by_quote_flag (GtkTreeModel *f_model,
                    GtkTreeIter *f_iter_a,
                    GtkTreeIter *f_iter_b,
                    gpointer user_data)
{
    gnc_commodity *comm_a, *comm_b;
    gboolean flag_a, flag_b;

    if (!get_commodities (f_model, f_iter_a, f_iter_b, NULL, &comm_a, &comm_b))
        return sort_namespace (f_model, f_iter_a, f_iter_b);

    flag_a = gnc_commodity_get_quote_flag(comm_a);
    flag_b = gnc_commodity_get_quote_flag(comm_b);

    if (flag_a < flag_b)
        return -1;
    else if (flag_a > flag_b)
        return 1;
    return default_sort(comm_a, comm_b);
}

/************************************************************/
/*                    New View Creation                     */
/************************************************************/

/*
 * Create a new commodity tree view with (optional) top level root node.
 * This view will be based on a model that is common to all view of
 * the same set of books, but will have its own private filter on that
 * model.
 */
GtkTreeView *
gnc_tree_view_commodity_new (QofBook *book,
                             const gchar *first_property_name,
                             ...)
{
    GncTreeView *view;
    GtkTreeModel *model, *f_model, *s_model;
    GtkTreeViewColumn *col;
    gnc_commodity_table *ct;
    va_list var_args;

    ENTER(" ");
    /* Create/get a pointer to the existing model for this set of books. */
    ct = gnc_commodity_table_get_table (book);
    model = gnc_tree_model_commodity_new (book, ct);

    /* Set up the view private filter on the common model. */
    f_model = gtk_tree_model_filter_new (model, NULL);
    g_object_unref(G_OBJECT(model));
    s_model = gtk_tree_model_sort_new_with_model (f_model);
    g_object_unref(G_OBJECT(f_model));

    /* Create our view */
    view = g_object_new (GNC_TYPE_TREE_VIEW_COMMODITY,
                         "name", "commodity_tree", NULL);
    gtk_tree_view_set_model (GTK_TREE_VIEW (view), s_model);
    g_object_unref(G_OBJECT(s_model));

    DEBUG("model ref count is %d",   G_OBJECT(model)->ref_count);
    DEBUG("f_model ref count is %d", G_OBJECT(f_model)->ref_count);
    DEBUG("s_model ref count is %d", G_OBJECT(s_model)->ref_count);

    /* Set default visibilities */
    gtk_tree_view_set_headers_visible (GTK_TREE_VIEW(view), FALSE);

    col = gnc_tree_view_add_text_column (
              view, _("Namespace"), "namespace", NULL, "NASDAQ",
              GNC_TREE_MODEL_COMMODITY_COL_NAMESPACE,
              GNC_TREE_VIEW_COLUMN_VISIBLE_ALWAYS,
              sort_by_commodity_string);
    col = gnc_tree_view_add_text_column (
              view, _("Symbol"), "symbol", NULL, "ACMEACME",
              GNC_TREE_MODEL_COMMODITY_COL_MNEMONIC,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));
    col = gnc_tree_view_add_text_column (
              view, _("Name"), "name", NULL, "Acme Corporation, Inc.",
              GNC_TREE_MODEL_COMMODITY_COL_FULLNAME,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));
    col = gnc_tree_view_add_text_column (
              view, _("Print Name"), "printname", NULL,
              "ACMEACME (Acme Corporation, Inc.)",
              GNC_TREE_MODEL_COMMODITY_COL_PRINTNAME,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    col = gnc_tree_view_add_text_column (
              view, _("Display symbol"), "user_symbol", NULL, "ACME",
              GNC_TREE_MODEL_COMMODITY_COL_USER_SYMBOL,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));
    col = gnc_tree_view_add_text_column (
              view, _("Unique Name"), "uniquename", NULL,
              "NASDAQ::ACMEACME", GNC_TREE_MODEL_COMMODITY_COL_UNIQUE_NAME,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    col = gnc_tree_view_add_text_column (
              /* Translators: Again replace CUSIP by the name of your
                 National Securities Identifying Number. */
              view, _("ISIN/CUSIP"), "cusip_code", NULL, "QWERTYUIOP",
              GNC_TREE_MODEL_COMMODITY_COL_CUSIP,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));
    col = gnc_tree_view_add_numeric_column (
              view, _("Fraction"), "fraction", "10000",
              GNC_TREE_MODEL_COMMODITY_COL_FRACTION,
              GNC_TREE_VIEW_COLUMN_COLOR_NONE,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_fraction);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));
    col = gnc_tree_view_add_toggle_column(
              view, _("Get Quotes"),
              /* Translators: This string has a context prefix; the translation
                 must only contain the part after the | character. */
              Q_("Column letter for 'Get Quotes'|Q"), "quote_flag",
              GNC_TREE_MODEL_COMMODITY_COL_QUOTE_FLAG,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_quote_flag,
              NULL);
    col = gnc_tree_view_add_text_column (
              view, _("Source"), "quote_source", NULL, "alphavantage",
              GNC_TREE_MODEL_COMMODITY_COL_QUOTE_SOURCE,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    col = gnc_tree_view_add_text_column (
              view, _("Timezone"), "quote_timezone", NULL, "America/New_York",
              GNC_TREE_MODEL_COMMODITY_COL_QUOTE_TZ,
              GNC_TREE_MODEL_COMMODITY_COL_VISIBILITY,
              sort_by_commodity_string);
    g_object_set_data(G_OBJECT(col), DEFAULT_VISIBLE, GINT_TO_POINTER(1));

    gnc_tree_view_configure_columns(view);

    /* Set properties */
    va_start (var_args, first_property_name);
    g_object_set_valist (G_OBJECT(view), first_property_name, var_args);
    va_end (var_args);

    /* Sort on the name column by default. This allows for a consistent
     * sort if commodities are briefly removed and re-added. */
    if (!gtk_tree_sortable_get_sort_column_id(GTK_TREE_SORTABLE(s_model),
            NULL, NULL))
    {
        gtk_tree_sortable_set_sort_column_id(GTK_TREE_SORTABLE(s_model),
                                             GNC_TREE_MODEL_COMMODITY_COL_FULLNAME,
                                             GTK_SORT_ASCENDING);
    }

    gtk_widget_show(GTK_WIDGET(view));
    LEAVE(" %p", view);
    return GTK_TREE_VIEW(view);
}

/************************************************************/
/*                   Auxiliary Functions                    */
/************************************************************/

#define debug_path(fn, path) {				\
    gchar *path_string = gtk_tree_path_to_string(path); \
    fn("tree path %s", path_string);			\
    g_free(path_string);				\
  }

#if 0 /* Not Used */
static gboolean
gnc_tree_view_commodity_get_iter_from_commodity (GncTreeViewCommodity *view,
        gnc_commodity *commodity,
        GtkTreeIter *s_iter)
{
    GtkTreeModel *model, *f_model, *s_model;
    GtkTreeIter iter, f_iter;

    g_return_val_if_fail(GNC_IS_TREE_VIEW_COMMODITY(view), FALSE);
    g_return_val_if_fail(commodity != NULL, FALSE);
    g_return_val_if_fail(s_iter != NULL, FALSE);

    ENTER("view %p, commodity %p (%s)", view, commodity, gnc_commodity_get_mnemonic(commodity));

    /* Reach down to the real model and get an iter for this commodity */
    s_model = gtk_tree_view_get_model(GTK_TREE_VIEW(view));
    f_model = gtk_tree_model_sort_get_model(GTK_TREE_MODEL_SORT(s_model));
    model = gtk_tree_model_filter_get_model(GTK_TREE_MODEL_FILTER(f_model));
    if (!gnc_tree_model_commodity_get_iter_from_commodity (GNC_TREE_MODEL_COMMODITY(model), commodity, &iter))
    {
        LEAVE("model_get_iter_from_commodity failed");
        return FALSE;
    }

    /* convert back to a sort iter */
    gtk_tree_model_filter_convert_child_iter_to_iter (GTK_TREE_MODEL_FILTER(f_model),
            &f_iter, &iter);
    gtk_tree_model_sort_convert_child_iter_to_iter (GTK_TREE_MODEL_SORT(s_model),
            s_iter, &f_iter);
    LEAVE(" ");
    return TRUE;
}
#endif /* Not Used */

/************************************************************/
/*          Commodity Tree View Visibility Filter           */
/************************************************************/

typedef struct
{
    gnc_tree_view_commodity_ns_filter_func user_ns_fn;
    gnc_tree_view_commodity_cm_filter_func user_cm_fn;
    gpointer                               user_data;
    GDestroyNotify                         user_destroy;
} filter_user_data;

static void
gnc_tree_view_commodity_filter_destroy (gpointer data)
{
    filter_user_data *fd = data;

    if (fd->user_destroy)
        fd->user_destroy(fd->user_data);
    g_free(fd);
}

static gboolean
gnc_tree_view_commodity_filter_helper (GtkTreeModel *model,
                                       GtkTreeIter *iter,
                                       gpointer data)
{
    gnc_commodity_namespace *name_space;
    gnc_commodity *commodity;
    filter_user_data *fd = data;

    g_return_val_if_fail (GNC_IS_TREE_MODEL_COMMODITY (model), FALSE);
    g_return_val_if_fail (iter != NULL, FALSE);

    if (gnc_tree_model_commodity_iter_is_namespace (GNC_TREE_MODEL_COMMODITY(model), iter))
    {
        if (fd->user_ns_fn)
        {
            name_space = gnc_tree_model_commodity_get_namespace (GNC_TREE_MODEL_COMMODITY(model), iter);
            return fd->user_ns_fn(name_space, fd->user_data);
        }
        return TRUE;
    }

    if (gnc_tree_model_commodity_iter_is_commodity (GNC_TREE_MODEL_COMMODITY(model), iter))
    {
        if (fd->user_cm_fn)
        {
            commodity = gnc_tree_model_commodity_get_commodity (GNC_TREE_MODEL_COMMODITY(model), iter);
            return fd->user_cm_fn(commodity, fd->user_data);
        }
        return TRUE;
    }

    return FALSE;
}

/*
 * Set an GtkTreeModel visible filter on this commodity.  This filter will be
 * called for each commodity that the tree is about to show, and the
 * commodity will be passed to the callback function.
 */
void
gnc_tree_view_commodity_set_filter (GncTreeViewCommodity *view,
                                    gnc_tree_view_commodity_ns_filter_func ns_func,
                                    gnc_tree_view_commodity_cm_filter_func cm_func,
                                    gpointer data,
                                    GDestroyNotify destroy)
{
    GtkTreeModel *f_model, *s_model;
    filter_user_data *fd = data;

    g_return_if_fail(GNC_IS_TREE_VIEW_COMMODITY(view));
    g_return_if_fail((ns_func != NULL) || (cm_func != NULL));

    ENTER("view %p, ns func %p, cm func %p, data %p, destroy %p",
          view, ns_func, cm_func, data, destroy);

    fd = g_malloc(sizeof(filter_user_data));
    fd->user_ns_fn   = ns_func;
    fd->user_cm_fn   = cm_func;
    fd->user_data    = data;
    fd->user_destroy = destroy;

    s_model = gtk_tree_view_get_model(GTK_TREE_VIEW(view));
    f_model = gtk_tree_model_sort_get_model(GTK_TREE_MODEL_SORT(s_model));
    gtk_tree_model_filter_set_visible_func (GTK_TREE_MODEL_FILTER (f_model),
                                            gnc_tree_view_commodity_filter_helper,
                                            fd,
                                            gnc_tree_view_commodity_filter_destroy);

    /* Whack any existing levels. The top two levels have been created
     * before this routine can be called. */
    gtk_tree_model_filter_refilter (GTK_TREE_MODEL_FILTER (f_model));
    LEAVE(" ");
}

/*
 * Forces the entire commodity tree to be re-evaluated for visibility.
 */
void
gnc_tree_view_commodity_refilter (GncTreeViewCommodity *view)
{
    GtkTreeModel *f_model, *s_model;

    g_return_if_fail(GNC_IS_TREE_VIEW_COMMODITY(view));

    ENTER("view %p", view);
    s_model = gtk_tree_view_get_model (GTK_TREE_VIEW(view));
    f_model = gtk_tree_model_sort_get_model (GTK_TREE_MODEL_SORT (s_model));
    gtk_tree_model_filter_refilter (GTK_TREE_MODEL_FILTER (f_model));
    LEAVE(" ");
}


/************************************************************/
/*           Commodity Tree View Get/Set Functions            */
/************************************************************/

/*
 * Retrieve the selected commodity from an commodity tree view.  The
 * commodity tree must be in single selection mode.
 */
gnc_commodity *
gnc_tree_view_commodity_get_selected_commodity (GncTreeViewCommodity *view)
{
    GtkTreeSelection *selection;
    GtkTreeModel *model, *f_model, *s_model;
    GtkTreeIter iter, f_iter, s_iter;
    gnc_commodity *commodity;

    g_return_val_if_fail (GNC_IS_TREE_VIEW_COMMODITY (view), NULL);

    ENTER("view %p", view);

    selection = gtk_tree_view_get_selection (GTK_TREE_VIEW(view));
    if (!gtk_tree_selection_get_selected (selection, &s_model, &s_iter))
    {
        LEAVE("no commodity, get_selected failed");
        return FALSE;
    }

    gtk_tree_model_sort_convert_iter_to_child_iter (GTK_TREE_MODEL_SORT (s_model),
            &f_iter, &s_iter);

    f_model = gtk_tree_model_sort_get_model(GTK_TREE_MODEL_SORT(s_model));
    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER (f_model),
            &iter, &f_iter);

    model = gtk_tree_model_filter_get_model(GTK_TREE_MODEL_FILTER(f_model));
    commodity = gnc_tree_model_commodity_get_commodity (GNC_TREE_MODEL_COMMODITY(model),
                &iter);
    LEAVE("commodity %p (%s)", commodity,
          commodity ? gnc_commodity_get_mnemonic(commodity) : "");
    return commodity;
}


#if 0 /* Not Used */
/*
 * This helper function is called once for each row in the tree view
 * that is currently selected.  Its task is to an the corresponding
 * commodity to the end of a glist.
 */
static void
get_selected_commodities_helper (GtkTreeModel *s_model,
                                 GtkTreePath *s_path,
                                 GtkTreeIter *s_iter,
                                 gpointer data)
{
    GList **return_list = data;
    GtkTreeModel *model, *f_model;
    GtkTreeIter iter, f_iter;
    gnc_commodity *commodity;

    gtk_tree_model_sort_convert_iter_to_child_iter (GTK_TREE_MODEL_SORT (s_model),
            &f_iter, s_iter);

    f_model = gtk_tree_model_sort_get_model(GTK_TREE_MODEL_SORT(s_model));
    gtk_tree_model_filter_convert_iter_to_child_iter (GTK_TREE_MODEL_FILTER (f_model),
            &iter, &f_iter);

    model = gtk_tree_model_filter_get_model(GTK_TREE_MODEL_FILTER(f_model));
    commodity = gnc_tree_model_commodity_get_commodity (GNC_TREE_MODEL_COMMODITY(model),
                &iter);
    *return_list = g_list_append(*return_list, commodity);
}
#endif /* Not Used */
