/*
 * 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 "db-simple-iterator.h"
#include "db-model-holder.h"
#include "db-param.h"

static void db_simple_iterator_set_iter (DbSimpleIterator * self, DbIter * iter);
static void db_simple_iterator_model_holder_init (DbModelHolderInterface * iface);
static void db_simple_iterator_iterator_init (DbIteratorInterface * iface);

/**
 * SECTION:db-simple-iterator
 * @short_description: manages a iterator with its events
 * @title: DbSimpleIterator
 *
 * The #DbSimpleIterator manages a connection with a data base. The function
 * db_simple_iterator_new() creates a new #DbSimpleIterator.
 */
G_DEFINE_TYPE_WITH_CODE (DbSimpleIterator, db_simple_iterator, G_TYPE_OBJECT,
	G_IMPLEMENT_INTERFACE (DB_TYPE_MODEL_HOLDER,
		db_simple_iterator_model_holder_init)
	G_IMPLEMENT_INTERFACE (DB_TYPE_ITERATOR,
		db_simple_iterator_iterator_init)
);

/**
 * DbSimpleIterator:
 * @params: (element-type Db.Param):
 **/

/**
 * db_simple_iterator_new:
 * @model: the #DbModel used by iterator.
 *
 * Creates a new #DbSimpleIterator.
 *
 * Return value: (transfer full): a #DbSimpleIterator.
 **/
DbIterator * db_simple_iterator_new (DbModel * model)
{
	return g_object_new (DB_TYPE_SIMPLE_ITERATOR, "model", model, NULL);
}

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

static void db_simple_iterator_unref_param (DbSimpleIterator * self, DbParam * param)
{
	self->params = g_list_remove (self->params, param);
}

/*
 * #DbSimpleIterator instances call this function every time line in
 * the model is changed.
 */
static void db_simple_iterator_row_num_changed (DbSimpleIterator * self)
{
	if (self->iter)
		self->row = db_model_get_path (self->model, self->iter);
	else if (!self->remember_selection)
		self->row = 0;

	db_iterator_row_num_changed (DB_ITERATOR (self));
}

/*
 * #DbSimpleIterator instances call this function every time the data of the
 * params must be updated.
 */
static void db_simple_iterator_iter_changed (DbSimpleIterator * self)
{
	db_simple_iterator_row_num_changed (self);
	db_iterator_iter_changed (DB_ITERATOR (self));
}


//+++++++++++++++++++++++++++++++++++++++++++++++++++ DbModelHolder methods

static void db_simple_iterator_set_model_mode (DbSimpleIterator * self)
{
	if (self->mode == DB_ITERATOR_MODE_ON_CHANGE)
		db_model_set_mode (self->model, DB_MODEL_MODE_ON_CHANGE);
	else
		db_model_set_mode (self->model, DB_MODEL_MODE_ON_DEMAND);
}

/*
 * Function called when row is inserted on the model.
 */
static void db_simple_iterator_on_model_line_inserted (DbModel * model, DbIter * iter, DbSimpleIterator * self)
{
	db_iterator_data_changed (DB_ITERATOR (self));
}

/*
 * Function called when row is updated on the model.
 */
static void db_simple_iterator_on_model_line_updated_after (DbModel * model, DbIter * iter, DbSimpleIterator * self)
{
	if (self->iter && db_iter_compare (iter, self->iter))
		db_simple_iterator_iter_changed (self);

	db_iterator_data_changed (DB_ITERATOR (self));
}

/*
 * Function called when row is deleted on the model.
 */
static void db_simple_iterator_on_model_line_deleted (DbModel * model, gint row, DbSimpleIterator * self)
{
	if (self->iter && row == self->row)
	{
		DbIter iter;

		if (db_model_get_iter (model, &iter, row + 1)
		|| db_model_get_iter (model, &iter, row - 1))
			db_simple_iterator_set_iter (self, &iter);
		else
			db_simple_iterator_set_iter (self, NULL);
	}
}

static void db_simple_iterator_on_model_line_deleted_after (DbModel * model, gint row, DbSimpleIterator * self)
{
	if (self->iter)
		db_simple_iterator_row_num_changed (self);

	db_iterator_data_changed (DB_ITERATOR (self));
}

/*
 * Function called when model rows are reordered.
 */
static void db_simple_iterator_on_model_lines_reordered (DbModel * model,
	gint column, gint * new_order, DbSimpleIterator * self)
{
	if (self->iter)
		db_simple_iterator_row_num_changed (self);
}

/*
 * Function called when model status changes.
 */
static void db_simple_iterator_on_model_status_changed (DbModel * model, DbModelStatus status, DbSimpleIterator * self)
{
	if (status == DB_MODEL_STATUS_READY)
	{
		DbIter iter;

		db_iterator_status_changed (DB_ITERATOR (self), TRUE);

		if (self->row >= 0 && self->row < db_model_get_nrows (model)
		&& db_model_get_iter (model, &iter, self->row))
			db_simple_iterator_set_iter (self, &iter);
		else
			db_simple_iterator_set_iter (self, NULL);
	}
	else
	{
		db_iterator_status_changed (DB_ITERATOR (self), FALSE);
		db_simple_iterator_set_iter (self, NULL);
	}
}

/*
 * Function called when model operations are done.
 */
static void db_simple_iterator_on_model_operations_done (DbModel * model, DbSimpleIterator * self)
{
	db_iterator_operations_done (DB_ITERATOR (self));
}

static DbModel * db_simple_iterator_get_model (DbSimpleIterator * self)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), NULL);

	return self->model;
}

static void db_simple_iterator_set_model (DbSimpleIterator * self, DbModel * model)
{
	if (!model)
		return;

	if (!self->model)
	{
		self->model = g_object_ref (model);
		g_object_connect (self->model
			,"signal::line-inserted", db_simple_iterator_on_model_line_inserted, self
			,"signal-after::line-updated", db_simple_iterator_on_model_line_updated_after, self
			,"signal::line-deleted", db_simple_iterator_on_model_line_deleted, self
			,"signal-after::line-deleted", db_simple_iterator_on_model_line_deleted_after, self
			,"signal::lines-reordered", db_simple_iterator_on_model_lines_reordered, self
			,"signal::status-changed", db_simple_iterator_on_model_status_changed, self
			,"signal::operations-done", db_simple_iterator_on_model_operations_done, self
			,NULL
		);
		db_simple_iterator_set_model_mode (self);
		db_simple_iterator_on_model_status_changed (model,
			db_model_get_status (model), self);
	}
	else
		g_warning ("DbSimpleIterator: Can't reassign the 'model' property");
}

//+++++++++++++++++++++++++++++++++++++++++++++++++++ DbIterator methods

static gint db_simple_iterator_get_row (DbSimpleIterator * self)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), -1);

	if (self->iter)
		return self->row;
	else
		return -1;
}

static DbIteratorMode db_simple_iterator_get_mode (DbSimpleIterator * self)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), 0);

	return self->mode;
}

static void db_simple_iterator_set_mode (DbSimpleIterator * self, DbIteratorMode mode)
{
	g_return_if_fail (DB_IS_SIMPLE_ITERATOR (self));
	
	self->mode = mode;

	if (self->model)
		db_simple_iterator_set_model_mode (self);
}

static gboolean db_simple_iterator_get_iter (DbSimpleIterator * self, DbIter ** iter)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), FALSE);

	if (!self->iter)
		return FALSE;

	*iter = self->iter;
	return TRUE;
}

static void db_simple_iterator_set_iter (DbSimpleIterator * self, DbIter * iter)
{
	if (iter)
	{
		db_iter_free (self->iter);
		self->iter = db_iter_copy (iter);
		db_simple_iterator_iter_changed (self);
	}
	else if (self->iter)
	{
		if (!self->remember_selection)
			self->row = 0;

		db_iter_free (self->iter);
		self->iter = NULL;
		db_simple_iterator_iter_changed (self);
	}
}

static gboolean db_simple_iterator_move_iter (DbSimpleIterator * self, DbIter * iter)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), FALSE);

	if (self->iter && db_iter_compare (self->iter, iter))
		return FALSE;

	if (self->iter && self->mode != DB_ITERATOR_MODE_ON_DEMAND)
	{
		if (db_model_get_row_operations (self->model, self->iter) == DB_MODEL_ROW_OP_INSERT)
			db_model_reverse_operations (self->model);

		db_model_perform_operations (self->model, FALSE);
	}

	db_simple_iterator_set_iter (self, iter);
	return TRUE;
}

static GList * db_simple_iterator_get_param_list (DbSimpleIterator * self)
{
	g_return_val_if_fail (DB_IS_SIMPLE_ITERATOR (self), NULL);

	return self->params;
}

static void db_simple_iterator_delete_selection (DbSimpleIterator * self)
{
	g_return_if_fail (DB_IS_SIMPLE_ITERATOR (self));

	if (self->model && self->iter)
		db_model_delete (self->model, self->iter);
}

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

enum
{
	 PROP_MODEL = 1
	,PROP_MODE
	,PROP_REMEMBER_SELECTION
};

static void db_simple_iterator_set_property (DbSimpleIterator * self, guint id,
	const GValue * value, GParamSpec * pspec)
{
	switch (id)
	{
		case PROP_MODEL:
			db_simple_iterator_set_model (self, g_value_get_object (value));
			break;
		case PROP_MODE:
			db_simple_iterator_set_mode (self, g_value_get_enum (value));
			break;
		case PROP_REMEMBER_SELECTION:
			self->remember_selection = g_value_get_boolean (value);
			db_simple_iterator_row_num_changed (self);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, id, pspec);
	}
}

static void db_simple_iterator_get_property (DbSimpleIterator * self, guint id,
	GValue * value, GParamSpec * pspec)
{	
	switch (id)
	{
		case PROP_MODEL:
			g_value_set_object (value, self->model);
			break;
		case PROP_MODE:
			g_value_set_enum (value, self->mode);
			break;
		case PROP_REMEMBER_SELECTION:
			g_value_set_boolean (value, self->remember_selection);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, id, pspec);
	}
}

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

static void db_simple_iterator_init (DbSimpleIterator * self)
{
	self->params = NULL;
	self->iter = NULL;
	self->row = 0;
	self->model = NULL;
}

static void db_simple_iterator_finalize (DbSimpleIterator * self)
{
	GList * n;

	for (n = self->params; n; n = n->next)
		g_object_weak_unref (n->data,
			(GWeakNotify) db_simple_iterator_unref_param, self);

	g_list_free (self->params);

	db_iter_free (self->iter);
	self->iter = NULL;

	if (self->model)
	{
		g_object_disconnect (self->model
			,"any_signal", db_simple_iterator_on_model_line_inserted, self
			,"any_signal", db_simple_iterator_on_model_line_updated_after, self
			,"any_signal", db_simple_iterator_on_model_line_deleted, self
			,"any_signal", db_simple_iterator_on_model_line_deleted_after, self
			,"any_signal", db_simple_iterator_on_model_lines_reordered, self
			,"any_signal", db_simple_iterator_on_model_status_changed, self
			,"any_signal", db_simple_iterator_on_model_operations_done, self
			,NULL
		);
		g_object_unref (self->model);
	}

	G_OBJECT_CLASS (db_simple_iterator_parent_class)->finalize (G_OBJECT (self));
}

static void db_simple_iterator_class_init (DbSimpleIteratorClass * klass)
{
	GObjectClass * k = G_OBJECT_CLASS (klass);
	k->set_property = (GObjectSetPropertyFunc) db_simple_iterator_set_property;
	k->get_property = (GObjectGetPropertyFunc) db_simple_iterator_get_property;
	k->finalize = (GObjectFinalizeFunc) db_simple_iterator_finalize;

	g_object_class_override_property (k, PROP_MODEL, "data-model");

	g_object_class_override_property (k, PROP_MODE, "mode");
	g_object_class_override_property (k, PROP_REMEMBER_SELECTION, "remember-selection");
}

static void db_simple_iterator_model_holder_init (DbModelHolderInterface * iface)
{
	iface->get_model = (DbModelHolderGetModelFunc) db_simple_iterator_get_model;
	iface->set_model = (DbModelHolderSetModelFunc) db_simple_iterator_set_model;
}

static void db_simple_iterator_iterator_init (DbIteratorInterface * iface)
{
	iface->get_mode = (DbIteratorGetMode) db_simple_iterator_get_mode;
	iface->set_mode = (DbIteratorSetMode) db_simple_iterator_set_mode;
	iface->get_row = (DbIteratorGetRow) db_simple_iterator_get_row;
	iface->get_iter = (DbIteratorGetIter) db_simple_iterator_get_iter;
	iface->set_iter = (DbIteratorSetIter) db_simple_iterator_set_iter;
	iface->move_iter = (DbIteratorMoveIter) db_simple_iterator_move_iter;
	iface->get_param_list = (DbIteratorGetParamList) db_simple_iterator_get_param_list;
	iface->delete_selection = (DbIteratorDeleteSelection) db_simple_iterator_delete_selection;
}