/*
 * Copyright (C) 2012 - Juan Ferrer Toribio
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "vn-combo.h"
#include "../vn-grid-model.h"
#include <db/db.h>

/**
 * SECTION:vn-combo
 * @Short_description: a combo box widget
 * @Title: VnCombo
 * @See_also: #VnField
 * @Image: combo.png
 *
 * A combo box widget to select from a list of items, selected from a
 * database.
 */

static void vn_combo_model_holder_interface_init (DbModelHolderInterface * iface);

G_DEFINE_TYPE_WITH_CODE (VnCombo, vn_combo, VN_TYPE_FIELD,
	G_IMPLEMENT_INTERFACE (DB_TYPE_MODEL_HOLDER,
		vn_combo_model_holder_interface_init)
);

/**
 * vn_combo_new:
 * @model: the model used by combo box
 *
 * Creates a new #VnCombo
 *
 * Return value: a #VnCombo
 **/
VnField * vn_combo_new (DbModel * model)
{
	return g_object_new (VN_TYPE_COMBO, "model", model, NULL);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Private

static void vn_combo_on_changed (GtkComboBox * combo, VnCombo * self)
{
	GtkTreeIter iter;
	GValue value = G_VALUE_INIT;

	if (gtk_combo_box_get_active_iter (combo, &iter))
		gtk_tree_model_get_value (self->tree, &iter, self->index_column, &value);
	else
		g_value_init (&value, GVN_TYPE_NULL);

	VN_FIELD_GET_CLASS (self)->value_changed (VN_FIELD (self), &value);
	g_value_unset (&value);
}

static void vn_combo_on_model_ready (VnCombo * self, const GValue * value)
{
	DbIter iter;

	g_signal_handlers_block_by_func (self->combo,
		vn_combo_on_changed, self);

	if (!gvn_value_is_null (value)
	&& db_model_search_value (self->model, self->index_column, &iter, value))
	{
		GtkTreeIter tree_iter;
		
		vn_gtk_tree_iter_from_db_iter (&tree_iter, &iter);
		gtk_combo_box_set_active_iter (self->combo, &tree_iter);
	}
	else
		gtk_combo_box_set_active_iter (self->combo, NULL);

	g_signal_handlers_unblock_by_func (self->combo,
		vn_combo_on_changed, self);
}

static void vn_combo_set_value (VnCombo * self, const GValue * value)
{
	if (self->model && db_model_get_status (self->model) == DB_MODEL_STATUS_READY)
		vn_combo_on_model_ready (self, value);
}

static void vn_combo_on_status_changed (DbModel * model, DbModelStatus status, VnCombo * self)
{
	if (status == DB_MODEL_STATUS_READY)
	{
		gtk_combo_box_set_model (self->combo, self->tree);
		vn_combo_on_model_ready (self, gvn_param_get_value (GVN_PARAM (self)));

		db_model_use_null_row (model, vn_field_get_null (VN_FIELD (self)));
	}
	else
		gtk_combo_box_set_model (self->combo, NULL);
}


static DbModel * vn_combo_get_model (VnCombo * self)
{
	return self->model;
}

static void vn_combo_set_model (VnCombo * self, DbModel * model)
{
	g_return_if_fail (VN_IS_COMBO (self));
	g_return_if_fail (DB_IS_MODEL (model) || !model);
	
	if (self->model)
	{
		g_signal_handlers_disconnect_by_func (self->model,
			vn_combo_on_status_changed, self);
		g_clear_object (&self->model);
		g_clear_object (&self->tree);
	}
	if (model)
	{	
		self->tree = GTK_TREE_MODEL (vn_grid_model_new (model));
		self->model = g_object_ref (model);
		g_signal_connect (model, "status-changed",
			G_CALLBACK (vn_combo_on_status_changed), self);
		vn_combo_on_status_changed (model,
			db_model_get_status (model), self);
	}
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Public

/**
 * vn_combo_get_index_column:
 * @self: a #VnCombo
 *
 * Gets the combo column index.
 *
 * Return value: the column
 **/
guint vn_combo_get_index_column (VnCombo * self)
{
	g_return_val_if_fail (VN_IS_COMBO (self), 0);

	return self->index_column;
}

/**
 * vn_combo_set_index_column:
 * @self: a #VnCombo
 * @column: the column
 *
 * Sets the column index used by combo.
 **/
void vn_combo_set_index_column (VnCombo * self, guint column)
{
	g_return_if_fail (VN_IS_COMBO (self));

	self->index_column = column;
	vn_combo_set_value (self, gvn_param_get_value (GVN_PARAM (self)));
}

/**
 * vn_combo_get_show_column:
 * @self: a #VnCombo
 *
 * Gets the column shown by combo.
 *
 * Return value: the column
 **/
guint vn_combo_get_show_column (VnCombo * self)
{
	g_return_val_if_fail (VN_IS_COMBO (self), 0);

	return self->show_column;
}

/**
 * vn_combo_set_show_column:
 * @self: a #VnCombo
 * @column: the column
 *
 * Sets the column shown by combo.
 **/
void vn_combo_set_show_column (VnCombo * self, guint column)
{
	g_return_if_fail (VN_IS_COMBO (self));

	self->show_column = column;
	gtk_cell_layout_clear_attributes (GTK_CELL_LAYOUT (self->combo), self->cell);
	gtk_cell_layout_add_attribute (GTK_CELL_LAYOUT (self->combo),
		self->cell, "text", (gint) self->show_column);
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Properties

enum
{
	 PROP_INDEX_COLUMN = 1
	,PROP_SHOW_COLUMN
	,PROP_MODEL
};

static void vn_combo_set_property (VnCombo * self, guint property_id,
	const GValue * value, GParamSpec * pspec)
{
	switch (property_id)
	{
		case PROP_INDEX_COLUMN:
			vn_combo_set_index_column (self, g_value_get_uint (value));
			break;
		case PROP_SHOW_COLUMN:
			vn_combo_set_show_column (self, g_value_get_uint (value));
			break;
		case PROP_MODEL:
			vn_combo_set_model (self, g_value_get_object (value));
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, property_id, pspec);
	}
}

static void vn_combo_get_property (VnCombo * self, guint property_id,
	GValue * value, GParamSpec * pspec)
{	
	switch (property_id)
	{
		case PROP_INDEX_COLUMN:
			g_value_set_uint (value, self->index_column);
			break;
		case PROP_SHOW_COLUMN:
			g_value_set_uint (value, self->show_column);
			break;
		case PROP_MODEL:
			g_value_set_object (value, self->model);
			break;
		default:		
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, property_id, pspec);
	}
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ Class

static void vn_combo_init (VnCombo * self)
{
	self->tree = NULL;
	self->model = NULL;

	self->combo = GTK_COMBO_BOX (gtk_combo_box_new ());
	g_signal_connect (self->combo, "changed",
		G_CALLBACK (vn_combo_on_changed), self);
	gtk_container_add (GTK_CONTAINER (self), GTK_WIDGET (self->combo));
	
	self->cell = gtk_cell_renderer_text_new ();
	gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (self->combo), self->cell, TRUE);

	VN_FIELD_GET_CLASS (self)->set_widget (VN_FIELD (self),
		GTK_WIDGET (self->combo));
}

static void vn_combo_finalize (VnCombo * self)
{
	vn_combo_set_model (self, NULL);
	G_OBJECT_CLASS (vn_combo_parent_class)->finalize (G_OBJECT (self));
}

static void vn_combo_class_init (VnComboClass * klass)
{
	GObjectClass * k = G_OBJECT_CLASS (klass);
	k->finalize = (GObjectFinalizeFunc) vn_combo_finalize;
	k->set_property = (GObjectSetPropertyFunc) vn_combo_set_property;
	k->get_property = (GObjectGetPropertyFunc) vn_combo_get_property;
	VN_FIELD_CLASS (klass)->set_value = (VnFieldSetValueFunc) vn_combo_set_value;

	g_object_class_override_property (k, PROP_MODEL, "model");

	g_object_class_install_property (k, PROP_INDEX_COLUMN,
		g_param_spec_uint ("index-column"
			,_("Index column")
			,_("The column index of the model")
			,0, 255, 0
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_SHOW_COLUMN,
		g_param_spec_uint ("show-column"
			,_("Show column")
			,_("The column of the model shown by combo")
			,0, 255, 1
			,G_PARAM_CONSTRUCT | G_PARAM_READWRITE
	));
}

static void vn_combo_model_holder_interface_init (DbModelHolderInterface * iface)
{
	iface->get_model = (DbModelHolderGetModelFunc) vn_combo_get_model;
	iface->set_model = (DbModelHolderSetModelFunc) vn_combo_set_model;
}