/*
 * 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-param.h"

static void db_param_param_init					(GvnParamInterface * iface);
static void db_param_on_master_value_changed	(GvnParam * master, const GValue * value, DbParam * self);

/**
 * SECTION: db-param
 * @Short_description: representation of the value of a field 
 * @Title: DbParam
 * 
 * This class represents the value of a field in a #DbIterator.
 **/
G_DEFINE_TYPE_WITH_CODE (DbParam, db_param, G_TYPE_OBJECT,
	G_IMPLEMENT_INTERFACE (GVN_TYPE_PARAM,
		db_param_param_init)
);

/**
 * db_param_new:
 * @column_name: col name of #DbModel associated to param.
 *
 * Creates a new #DbParam.
 *
 * Return value: (transfer full): the new #DbParam
 **/
GvnParam * db_param_new (const gchar * column_name)
{
	return g_object_new (DB_TYPE_PARAM, "column-name", column_name, NULL);
}

/**
 * db_param_new_with_index:
 * @column_index: col index of #DbModel associated to param.
 *
 * Creates a new #DbParam.
 *
 * Return value: (transfer full): the new #DbParam
 **/
GvnParam * db_param_new_with_index (guint column_index)
{
	return g_object_new (DB_TYPE_PARAM, "column-index", column_index, NULL);
}

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

static void db_param_put_value (DbParam * self, const GValue * value)
{
	if (!gvn_value_ccopy (value, self->value))
		return;

	g_signal_emit_by_name (self, "value-changed", value);
	
	if (self->master && self->change_master)
	{
		self->change_master = FALSE;
		gvn_param_request_value (self->master, value, NULL);
		self->change_master = TRUE;
	}
}

static const GValue * db_param_get_value (DbParam * self)
{
	return self->value;
}

static gboolean db_param_request_value (DbParam * self, const GValue * value, GError ** err)
{
	return db_iterator_set_value (self->iterator, self->column_index, value, err);
}

static void db_param_on_master_value_changed (GvnParam * master, const GValue * value, DbParam * self)
{
	if (self->change_master)
	{
		self->change_master = FALSE;
		gvn_param_set_value (GVN_PARAM (self), value);
		self->change_master = TRUE;
	}
}

static GvnParam * db_param_get_master (DbParam * self)
{
	return self->master;
}

static void db_param_set_master (DbParam * self, GvnParam * master)
{	
	if (self->master)
	{
		g_signal_handlers_disconnect_by_func (self->master,
			db_param_on_master_value_changed, self);
		g_clear_object (&self->master);
	}
	if (master)
	{
		self->master = g_object_ref_sink (master);
		g_signal_connect (master, "value-changed",
			G_CALLBACK (db_param_on_master_value_changed), self);
		db_param_on_master_value_changed (master,
			gvn_param_get_value (master), self);
	}
}

static const GvnParamSpec * db_param_get_spec (DbParam * self)
{
	if (self->column_index != -1)
		return db_iterator_get_spec (self->iterator, self->column_index);
		
	return NULL;
}

static GvnParamStatus db_param_get_status (DbParam * self)
{
	if (db_iterator_get_row (self->iterator) != -1 && self->column_index != -1)
		return GVN_PARAM_STATUS_OK;

	return GVN_PARAM_STATUS_BUSY;
}

static void db_param_on_iterator_status_changed (DbIterator * iterator, gboolean ready, DbParam * self)
{
	if (ready && self->column_name)
		self->column_index = db_iterator_get_column_index (self->iterator, self->column_name);

	g_signal_emit_by_name (self, "spec-changed");
}

static void db_param_on_iterator_iter_changed (DbIterator * iterator, DbParam * self)
{
	g_signal_emit_by_name (self, "status-changed");

	if (db_iterator_get_row (self->iterator) != -1 && self->column_index != -1)
	{
		const GValue * value = db_iterator_get_value (self->iterator, self->column_index);
		db_param_put_value (self, value);
	}
	else
	{
		GValue tmp_value = G_VALUE_INIT;
		g_value_init (&tmp_value, GVN_TYPE_NULL);
		db_param_put_value (self, &tmp_value);
		g_value_unset (&tmp_value);
	}
}

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

/**
 * db_param_get_column_index:
 * @self: a #DbParam
 *
 * Gets the iterator column referenced by the param.
 *
 * Return value: the column index.
 **/
guint db_param_get_column_index (DbParam * self)
{
	g_return_val_if_fail (DB_IS_PARAM (self), 0);

	return self->column_index;
}

/**
 * db_param_get_column_name:
 * @self: a #DbParam
 *
 * Gets the iterator column referenced by the param.
 *
 * Return value: the column name.
 **/
const gchar * db_param_get_column_name (DbParam * self)
{
	g_return_val_if_fail (DB_IS_PARAM (self), 0);

	return self->column_name;
}

/**
 * db_param_set_iterator:
 * @self: a #DbParam
 * @iterator: the #DbIterator
 *
 * Sets the iterator that updates the param value, this property can be set if
 * the parameter does not have a iterator associated yet.
 **/
void db_param_set_iterator (DbParam * self, DbIterator * iterator)
{
	g_return_if_fail (DB_IS_PARAM (self));
	g_return_if_fail (DB_IS_ITERATOR (iterator));
	g_return_if_fail (!self->iterator);

	self->iterator = g_object_ref (iterator);
	g_object_connect (iterator
		,"signal::iter-changed", db_param_on_iterator_iter_changed, self
		,"signal::status-changed", db_param_on_iterator_status_changed, self
		,NULL
	);
	db_param_on_iterator_status_changed (self->iterator,
		db_iterator_is_ready (iterator), self);
	db_param_on_iterator_iter_changed (self->iterator, self);
}

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

enum
{
	 PROP_VALUE = 1
	,PROP_MASTER
	,PROP_ITERATOR
	,PROP_COLUMN_INDEX
	,PROP_COLUMN_NAME
};

static void db_param_set_property (DbParam * self, guint property_id,
	const GValue * value, GParamSpec * pspec)
{
	switch (property_id)
	{
		case PROP_VALUE:
			db_param_request_value (self, g_value_get_boxed (value), NULL);
			break;
		case PROP_MASTER:
			db_param_set_master (self, g_value_get_object (value));
			break;
		case PROP_ITERATOR:
			db_param_set_iterator (self, g_value_get_object (value));
			break;
		case PROP_COLUMN_INDEX:
			self->column_index = g_value_get_int (value);
			break;
		case PROP_COLUMN_NAME:
			g_free (self->column_name);
			self->column_name = g_value_dup_string (value);
			break;
		default:
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, property_id, pspec);
	}
}

static void db_param_get_property (DbParam * self, guint property_id,
	GValue * value, GParamSpec * pspec)
{	
	switch (property_id)
	{
		case PROP_VALUE:
			g_value_set_boxed (value, self->value);
			break;
		case PROP_MASTER:
			g_value_set_object (value, self->master);
			break;
		case PROP_ITERATOR:
			g_value_set_object (value, self->iterator);
			break;
		case PROP_COLUMN_INDEX:
			g_value_set_int (value, self->column_index);
			break;
		case PROP_COLUMN_NAME:
			g_value_set_string (value, self->column_name);
			break;
		default:		
			G_OBJECT_WARN_INVALID_PROPERTY_ID (self, property_id, pspec);
	}
}

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

static void db_param_init (DbParam * self)
{
	self->master = NULL;
	self->change_master = TRUE;
	self->column_index = -1;
	self->column_name = NULL;
	self->iterator = NULL;

	self->value = g_new0 (GValue, 1);
	g_value_init (self->value, GVN_TYPE_NULL);
}

static void db_param_finalize (DbParam * self)
{
	db_param_set_master (self, NULL);

	if (self->iterator)
	{
		g_object_disconnect (self->iterator
			,"any_signal", db_param_on_iterator_iter_changed, self
			,"any_signal", db_param_on_iterator_status_changed, self
			,NULL
		);
		g_clear_object (&self->iterator);
	}

	g_value_unset (self->value);
	g_free (self->value);
	g_free (self->column_name);
	G_OBJECT_CLASS (db_param_parent_class)->finalize (G_OBJECT (self));
}

static void db_param_class_init (DbParamClass * klass)
{
	GObjectClass * k = G_OBJECT_CLASS (klass);
	k->finalize = (GObjectFinalizeFunc) db_param_finalize;
	k->set_property = (GObjectSetPropertyFunc) db_param_set_property;
	k->get_property = (GObjectGetPropertyFunc) db_param_get_property;

	g_object_class_override_property (k, PROP_VALUE, "value");
	g_object_class_override_property (k, PROP_MASTER, "master");

	g_object_class_install_property (k, PROP_ITERATOR,
		g_param_spec_object ("iterator"
			,_("Iterator")
			,_("The iterator owner of param")
			,DB_TYPE_ITERATOR
			,G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_COLUMN_INDEX,
		g_param_spec_int ("column-index"
			,_("Column index")
			,_("The referenced column index")
			,-1 ,G_MAXINT ,-1
			,G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE
	));
	g_object_class_install_property (k, PROP_COLUMN_NAME,
		g_param_spec_string ("column-name"
			,_("Column name")
			,_("The referenced column name")
			,NULL
			,G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE
	));
}

static void db_param_param_init (GvnParamInterface * iface)
{
	iface->get_value = (GvnParamGetValueFunc) db_param_get_value;
	iface->request_value = (GvnParamRequestValueFunc) db_param_request_value;
	iface->get_master = (GvnParamGetMasterFunc) db_param_get_master;
	iface->set_master = (GvnParamSetMasterFunc) db_param_set_master;
	iface->get_spec = (GvnParamGetSpecFunc) db_param_get_spec;
	iface->get_status = (GvnParamGetStatusFunc) db_param_get_status;
}