/*
 * 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_cursor_changed (GtkTreeView * obj, DbIterator * iterator)
{
	GtkTreeIter iter;
	GtkTreeSelection * selection = gtk_tree_view_get_selection (obj);

	if (selection && gtk_tree_selection_get_selected (selection, NULL, &iter))
	{
		DbIter dbiter;
		vn_gtk_tree_iter_to_db_iter (&iter, &dbiter);

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

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);
		g_signal_handlers_block_by_func (obj, vn_grid_on_cursor_changed, iterator);
		gtk_tree_selection_select_iter (selection, &iter);
		g_signal_handlers_unblock_by_func (obj, vn_grid_on_cursor_changed, iterator);

		path = gtk_tree_model_get_path (
			gtk_tree_view_get_model (obj), &iter);
		gtk_tree_view_scroll_to_cell (obj, path, NULL, FALSE, 0, 0);
		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_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)
{
	guint count, i;
	GList * n, * columns;
	GtkTreePath * path;
	GtkTreeViewColumn * col, * next_col = NULL;
	GtkCellArea * area;

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

	gtk_tree_view_get_cursor (obj, &path, &col);

	g_object_get (col, "cell-area", &area, NULL);
	gtk_cell_editable_editing_done (gtk_cell_area_get_edit_widget (area));
	g_object_unref (area);

	columns = gtk_tree_view_get_columns (obj);
	count = gtk_tree_view_get_n_columns (obj);

	if (event->keyval == GDK_KEY_Tab)
	{
		i = 0;

		for (n = columns; n; n = n->next, i++)
		if (n->data == col)
		{
			if (n->next && i + 1 < gtk_tree_view_get_n_columns (obj))
			{
				if (n->next->data && VN_IS_COLUMN (n->next->data)
				&& !vn_column_get_editable ((VN_COLUMN (n->next->data))))
				{
					col = n->next->data;
					continue;
				}
				else
					next_col = n->next->data;
			}
			else
			{
				gtk_tree_path_next (path);

				if (VN_IS_COLUMN (columns->data)
				&& !vn_column_get_editable ((VN_COLUMN (columns->data))))
				{
					for (n = columns->next; n; n = n->next)
					if (n->data && VN_IS_COLUMN (n->data)
					&& vn_column_get_editable ((VN_COLUMN (n->data))))
					{
						next_col = n->data;
						break;
					}
				}
				else
					next_col = columns->data;

				if (gtk_tree_path_get_indices (path)[0] >= db_model_get_nrows
					(VN_GRID (obj)->model))
				{
					gtk_tree_path_free (path);
					return FALSE;
				}
			}

			break;
		}
	}
	else // Shift + Tab pressed
	{
		GList * inv_columns = g_list_last (columns);
		i = count - 1;

		for (n = inv_columns; n; n = n->prev, i--)
		if (n->data == col)
		{
			if (n->prev && i > 0)
			{
				if (n->prev->data && VN_IS_COLUMN (n->prev->data)
				&& !vn_column_get_editable ((VN_COLUMN (n->prev->data))))
				{
					col = n->prev->data;
					continue;
				}
				else
					next_col = n->prev->data;
			}
			else
			{
				gint current = gtk_tree_path_get_indices (path)[0];
				gtk_tree_path_prev (path);
				
				if (VN_IS_COLUMN (inv_columns->data)
				&& !vn_column_get_editable ((VN_COLUMN (inv_columns->data))))
				{
					for (n = inv_columns->prev; n; n = n->prev)
					if (n->data && VN_IS_COLUMN (n->data)
					&& vn_column_get_editable ((VN_COLUMN (n->data))))
					{
						next_col = n->data;
						break;
					}
				}
				else
					next_col = inv_columns->data;

				if (current == 0 && gtk_tree_path_get_indices (path)[0] == 0)
				{
					gtk_tree_path_free (path);
					return FALSE;
				}
			}

			break;
		}
	}

	g_list_free (columns);
	gtk_tree_view_set_cursor (obj, path, next_col, TRUE);
	gtk_tree_path_free (path);

	return TRUE;
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ 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_signal_handlers_disconnect_by_func (obj,
			vn_grid_on_cursor_changed, 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);
			
		g_signal_connect (obj, "cursor-changed",
			G_CALLBACK (vn_grid_on_cursor_changed), iterator);
	}
}

/**
 * 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;
}

/**
 * vn_grid_insert_column:
 * @obj: #VnGrid where the new column will be appended
 * @position: the position where the column will be inserted
 * @column_index: the index of the source column in the model
 * @title: the title
 * @column_type: the #GType of the assigned #VnColumn
 * @editable: a %gboolean indicating whether the column is editable
 * @expand: a %gboolean indicating whether the column is expandable
 * 
 * Creates and inserts a new column in the grid with the given column and
 * position, if @position is -1 the column will be appended to the end.
 *
 * Return value: (transfer none): the #VnColumn assigned to the new column.
 **/
VnColumn * vn_grid_insert_column (VnGrid * obj, gint position, gint column_index,
	const gchar * title, GType column_type, gboolean editable, gboolean expand)
{
	GtkTreeViewColumn * column;

	g_return_val_if_fail (VN_IS_GRID (obj), NULL);
	g_return_val_if_fail (index >= 0, NULL);
	g_return_val_if_fail (g_type_is_a (column_type, VN_TYPE_COLUMN), NULL);

	column = g_object_new (column_type
		,"title"			,title
		,"expand"			,expand
		,"resizable"		,TRUE
		,"sort-indicator"	,TRUE
		,"sizing"			,GTK_TREE_VIEW_COLUMN_GROW_ONLY
		,"column-index"		,column_index
		,"editable"			,editable
		,NULL
	);

	gtk_tree_view_append_column (GTK_TREE_VIEW (obj), column);
	return VN_COLUMN (column);
}

/**
 * vn_grid_append_column:
 * @obj: #VnGrid where the new column will be appended
 * @column_index: the index of the source column in the model
 * @title: the title
 * @column_type: the #GType of the assigned #VnCell
 * @editable: a %gboolean indicating whether the column is editable
 * @expand: a %gboolean indicating whether the column is expandable
 * 
 * Creates and appends a new column at the end of the grid with the given column.
 *
 * Return value: (transfer none): the #VnCell assigned to the new column.
 **/
VnColumn * vn_grid_append_column (VnGrid * obj, gint column_index, const gchar * title,
	GType column_type, gboolean editable, gboolean expand)
{
	g_return_val_if_fail (VN_IS_GRID (obj), NULL);
	g_return_val_if_fail (index >= 0, NULL);
	g_return_val_if_fail (g_type_is_a (column_type, VN_TYPE_COLUMN), NULL);

	return vn_grid_insert_column (obj, -1, column_index, title, column_type, editable, expand);
}

/**
 * vn_grid_append_columns:
 * @obj: the #VnGrid
 * @...: columns information, see vn_grid_append_column(), terminated with -1
 * 
 * Appends columns into a #VnGrid.
 **/
void vn_grid_append_columns (VnGrid * obj, ...)
{
	va_list vl;
	gint index;
	gchar * title;
	GType column_type;
	gboolean editable;
	gboolean expand;

	g_return_if_fail (VN_IS_GRID (obj));

	va_start (vl, obj);

	while ((index = va_arg (vl, gint)) != -1)
	{
		title = va_arg (vl, gchar *);
		column_type = va_arg (vl, GType);
		editable = va_arg (vl, gboolean);
		expand = va_arg (vl, gboolean);

		vn_grid_append_column (obj,
			index, title, column_type, editable, expand);
	}	

	va_end (vl);
	gtk_tree_view_columns_autosize (GTK_TREE_VIEW (obj));
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ 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)
{
	obj->iterator = NULL;
	obj->model = NULL;
	gtk_tree_selection_set_mode (
		gtk_tree_view_get_selection (GTK_TREE_VIEW (obj)),
		GTK_SELECTION_SINGLE
	);

	g_signal_connect (obj, "notify::model",
		G_CALLBACK (vn_grid_on_model_changed), NULL);

	g_signal_connect (obj, "key-press-event",
		G_CALLBACK (vn_grid_on_cursor_key_pressed), 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
	));
}