/*
 * 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-grid.h"

G_DEFINE_TYPE (VnGrid, vn_grid, GTK_TYPE_TREE_VIEW);

/**
 * vn_grid_new:
 * 
 * Creates a new grid
 *
 * Return value: #VnGrid created.  
 **/
VnGrid * vn_grid_new ()
{
	return g_object_new (VN_TYPE_GRID, "rules-hint", TRUE, NULL);
}

/**
 * vn_grid_new_with_iterator:
 * @iterator: #DbIterator where the grid will be created
 * 
 * Creates a new grid into a iterator
 *
 * Return value: #VnGrid created.  
 **/
VnGrid * vn_grid_new_with_iterator (DbIterator * iterator)
{
	VnGrid * obj = vn_grid_new ();
	g_object_set (obj, "iterator", iterator, NULL);
	return obj;
}

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

static void vn_grid_on_iter_changed (DbIterator * iterator, GtkTreeView * obj);

static void vn_grid_on_selection_changed (GtkTreeSelection * selection, GtkTreeView * obj)
{
	GtkTreeIter iter;
	GList * l, * list;

	if (gtk_tree_selection_count_selected_rows (selection) <= 1)
		return;

	list = gtk_tree_selection_get_selected_rows (selection, NULL);

	for (l = list; l; l = l->next)
	if (gtk_tree_model_get_iter (gtk_tree_view_get_model (obj), &iter, l->data))
	{
		DbIter dbiter;
		vn_gtk_tree_iter_to_db_iter (&iter, &dbiter);
		db_iterator_select_iter (VN_GRID (obj)->iterator, &dbiter);
	}

	g_list_free_full (list, (GDestroyNotify) gtk_tree_path_free);
}

static void vn_grid_on_cursor_changed (GtkTreeView * tree_view, VnGrid * obj)
{
	gint selected_rows;
	
	if (!db_iterator_is_ready (obj->iterator))
		return;

	selected_rows = gtk_tree_selection_count_selected_rows (gtk_tree_view_get_selection (tree_view));

	if (selected_rows == 1)
	{
		GtkTreeIter iter;
		GtkTreePath * path;

		gtk_tree_view_get_cursor (tree_view, &path, NULL);

		if (path && gtk_tree_model_get_iter (gtk_tree_view_get_model (tree_view), &iter, path))
		{
			DbIter dbiter;
			vn_gtk_tree_iter_to_db_iter (&iter, &dbiter);

			g_signal_handlers_block_by_func (obj->iterator, vn_grid_on_iter_changed, obj);
			db_iterator_move_iter (obj->iterator, &dbiter);
			g_signal_handlers_unblock_by_func (obj->iterator, vn_grid_on_iter_changed, obj);
		}

		gtk_tree_path_free (path);
	}
	else if (selected_rows == 0)
		db_iterator_move_iter (obj->iterator, NULL);
}

static void vn_grid_on_iter_changed (DbIterator * iterator, GtkTreeView * obj)
{
	DbIter dbiter;
	GtkTreeSelection * selection = gtk_tree_view_get_selection (obj);

	if (db_iterator_get_iter (iterator, &dbiter) && gtk_tree_view_get_model (obj))
	{
		GtkTreeIter iter;
		GtkTreePath * path;

		vn_gtk_tree_iter_from_db_iter (&iter, &dbiter);
		path = gtk_tree_model_get_path (gtk_tree_view_get_model (obj), &iter);

		g_signal_handlers_block_by_func (obj, vn_grid_on_cursor_changed, iterator);
		gtk_tree_view_set_cursor (obj, path, NULL, FALSE);
		g_signal_handlers_unblock_by_func (obj, vn_grid_on_cursor_changed, iterator);

		gtk_tree_path_free (path);
	}
	else if (selection)
		gtk_tree_selection_unselect_all (selection);
}

static void vn_grid_on_model_changed (VnGrid * obj, GParamSpec * spec, gpointer data)
{
	GList * n, * columns = gtk_tree_view_get_columns (GTK_TREE_VIEW (obj));

	for (n = columns; n; n = n->next)
	if (VN_IS_COLUMN (n->data))
		vn_column_model_changed (n->data);

	g_list_free (columns);
}

static void vn_grid_on_status_changed (DbIterator * iterator, gboolean ready, VnGrid * obj)
{
	obj->model = db_model_holder_get_model (DB_MODEL_HOLDER (iterator));
	vn_grid_on_model_changed (obj, NULL, NULL);

	if (ready)
	{
		GtkTreeModel * tree_model = GTK_TREE_MODEL (vn_grid_model_new (obj->model));
		gtk_tree_view_set_model (GTK_TREE_VIEW (obj), tree_model);
		vn_grid_on_iter_changed (obj->iterator, GTK_TREE_VIEW (obj));

		g_object_unref (tree_model);
	}
	else
		gtk_tree_view_set_model (GTK_TREE_VIEW (obj), NULL);
}

static gboolean vn_grid_on_cursor_key_pressed (GtkTreeView * obj,
	GdkEventKey * event, gpointer data)
{
	gboolean inverted, passed = FALSE;
	gint sel_tab_index;
	VnColumn * first = NULL;
	GList * n, * columns;
	GtkTreePath * path;
	GtkTreeViewColumn * col;
	VnColumn * selected, * next = NULL;
	GtkCellArea * area;
	GtkCellEditable * editable;

	if (!(event->type == GDK_KEY_PRESS
	&& (event->keyval == GDK_KEY_Tab
		|| event->keyval == GDK_KEY_ISO_Left_Tab
		|| event->keyval == GDK_KEY_KP_Enter)))
		return FALSE;

	gtk_tree_view_get_cursor (obj, &path, &col);
	selected = VN_COLUMN (col);

	g_object_get (col, "cell-area", &area, NULL);
	editable = gtk_cell_area_get_edit_widget (area);

	if (editable)
		gtk_cell_editable_editing_done (editable);

	g_object_unref (area);

	columns = gtk_tree_view_get_columns (obj);
	inverted = event->keyval == GDK_KEY_ISO_Left_Tab ? TRUE : FALSE;
	sel_tab_index = vn_column_get_tab_index (selected);
	first = NULL;

	for (n = columns; n; n = n->next)
	{
		gint cur_tab_index;
		VnColumn * current = n->data;

		if (current == selected)
			passed = TRUE;
		else if (VN_IS_COLUMN (current)
		&& vn_column_get_editable (current)
		&& (cur_tab_index = vn_column_get_tab_index (current)) != -1)
		{
			if (!inverted)
			{
				if (!first || cur_tab_index < vn_column_get_tab_index (first))
					first = current;

				if (cur_tab_index == sel_tab_index && passed)
				{
					next = current;
					break;
				}

				if ((!next || cur_tab_index < vn_column_get_tab_index (next))
				&& cur_tab_index > sel_tab_index)
					next = current;
			}
			else
			{
				if (!first || cur_tab_index >= vn_column_get_tab_index (first))
					first = current;

				if ((cur_tab_index == sel_tab_index && !passed)
				|| (cur_tab_index < sel_tab_index
					&& (!next || cur_tab_index >= vn_column_get_tab_index (next))))
					next = current;
			}
		}
	}

	g_list_free (columns);

	if (!next)
	{
		gboolean leave = FALSE;
		next = first ? first : selected;

		if (inverted)
			leave = !gtk_tree_path_prev (path);
		else
		{
			DbIter iter;

			if (db_model_get_iter (VN_GRID (obj)->model, &iter, gtk_tree_path_get_indices (path)[0])
			&& db_model_get_row_operations (VN_GRID (obj)->model, &iter) == DB_MODEL_ROW_OP_INSERT)
				leave = TRUE;
			else
			{
				gtk_tree_path_next (path);

				if (gtk_tree_path_get_indices (path)[0] >=
					db_model_get_nrows (VN_GRID (obj)->model))
				{
					if (db_model_get_update_flags (VN_GRID (obj)->model) &
						DB_MODEL_INSERT)
						db_iterator_insert (VN_GRID (obj)->iterator);
					else
						leave = TRUE;
				}
			}
		}

		if (leave)
		{
			gtk_tree_path_free (path);
			return FALSE;
		}
	}

	gtk_tree_view_set_cursor (obj, path, GTK_TREE_VIEW_COLUMN (next), TRUE);
	gtk_tree_path_free (path);
	return TRUE;
}

static gboolean vn_grid_on_escape_pressed  (VnGrid * obj,
	GdkEventKey * event, gpointer data)
{
	if (event->type == GDK_KEY_PRESS
	&& event->keyval == GDK_KEY_Escape
	&& db_iterator_get_mode (obj->iterator) != DB_ITERATOR_MODE_ON_DEMAND)
		db_iterator_reverse_operations (obj->iterator);

	return FALSE;
}

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

/**
 * vn_grid_get_iterator:
 * @obj: a #VnGrid
 * 
 * Gets the iterator used by @obj.
 *
 * Return value: (transfer none): the #DbIterator
 **/
DbIterator * vn_grid_get_iterator (VnGrid * obj)
{
	g_return_val_if_fail (VN_IS_GRID (obj), NULL);

	return obj->iterator;
}

/**
 * vn_grid_set_iterator:
 * @obj: a #VnGrid
 * @iterator: the #DbIterator
 * 
 * Sets the iterator handled by tree view.
 **/
void vn_grid_set_iterator (VnGrid * obj, DbIterator * iterator)
{
	g_return_if_fail (VN_IS_GRID (obj));
	g_return_if_fail (DB_IS_ITERATOR (iterator) || !iterator);

	if (obj->iterator)
	{
		g_object_disconnect (obj->iterator
			,"any-signal", vn_grid_on_iter_changed, obj
			,"any-signal", vn_grid_on_status_changed, obj
			,NULL
		);
		g_clear_object (&obj->iterator);

		obj->model = NULL;
	}
	if (iterator)
	{	
		obj->iterator = g_object_ref (iterator);
		g_object_connect (iterator
			,"signal::iter-changed", vn_grid_on_iter_changed, obj
			,"signal::status-changed", vn_grid_on_status_changed, obj
			,NULL
		);

		vn_grid_on_status_changed (iterator,
			db_iterator_is_ready (iterator), obj);
	}
}

/**
 * vn_grid_get_model:
 * @obj: a #VnGrid
 * 
 * Gets the model used by @obj.
 *
 * Return value: (transfer none): the #DbModel
 **/
DbModel * vn_grid_get_model (VnGrid * obj)
{
	g_return_val_if_fail (VN_IS_GRID (obj), NULL);

	return obj->model;
}

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

typedef enum
{
	 PROP_ITERATOR = 1
}
VnGridProp;

static void vn_grid_set_property (VnGrid * obj, guint id,
	const GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_ITERATOR:
			vn_grid_set_iterator (obj, g_value_get_object (value));
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

static void vn_grid_get_property (VnGrid * obj, guint id,
	GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_ITERATOR:
			g_value_set_object (value, obj->iterator);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, id, pspec);
	}
}

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

static void vn_grid_init (VnGrid * obj)
{
	GtkTreeSelection * selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (obj));
	obj->iterator = NULL;
	obj->model = NULL;
	gtk_tree_selection_set_mode (selection, GTK_SELECTION_MULTIPLE);
	g_signal_connect (selection, "changed",
		G_CALLBACK (vn_grid_on_selection_changed), obj);

	g_object_connect (obj
		,"signal::notify::model", vn_grid_on_model_changed, obj
		,"signal::key-press-event", vn_grid_on_cursor_key_pressed, obj
		,"signal::key-press-event", vn_grid_on_escape_pressed, obj
		,"signal-after::cursor-changed", vn_grid_on_cursor_changed, obj
		,NULL
	);
}

static void vn_grid_finalize (VnGrid * obj)
{
	vn_grid_set_iterator (obj, NULL);

	G_OBJECT_CLASS (vn_grid_parent_class)->finalize (G_OBJECT (obj));
}

static void vn_grid_class_init (VnGridClass * k)
{
	GObjectClass * klass = G_OBJECT_CLASS (k);
	klass->set_property = (GObjectSetPropertyFunc) vn_grid_set_property;
	klass->get_property = (GObjectGetPropertyFunc) vn_grid_get_property;
	klass->finalize = (GObjectFinalizeFunc) vn_grid_finalize;

	g_object_class_install_property (klass, PROP_ITERATOR,
		g_param_spec_object ("iterator"
			,_("Iterator")
			,_("The iterator used by VnGrid")
			,DB_TYPE_ITERATOR
			,G_PARAM_READWRITE
	));
}