/*
 * 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 "sql-batch.h"
#include "sql-value.h"

/**
 * SECTION: sql_batch
 * @Short_description: represents an SQL statement or a part of it
 * @Title: SqlBatch
 * 
 * The #SqlBatch is the base class for all objects in SqlLib.
 **/
G_DEFINE_TYPE (SqlBatch, sql_batch, G_TYPE_INITIALLY_UNOWNED);
 
enum {
	 CHANGED
	,LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = {0};

SqlBatch * sql_batch_new ()
{
	return g_object_new (SQL_TYPE_BATCH, NULL);
}

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

static void sql_batch_child_changed (SqlObject * child, SqlBatch * obj)
{
	sql_batch_changed (obj);
}

static void sql_batch_free_child (SqlBatch * obj, SqlObject * child)
{
	g_signal_handlers_disconnect_by_func (child,
		sql_batch_child_changed, obj);
	g_object_unref (child);
}

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

/**
 * sql_batch_is_ready:
 * @obj: a #SqlBatch
 *
 * Checks if @obj and all of its elements are ready to be rendered.
 * 
 * Return value: %TRUE if ready, %FALSE otherwise.
 **/
gboolean sql_batch_is_ready (SqlBatch * obj)
{
	gboolean is_ready = TRUE;

	g_return_val_if_fail (SQL_IS_BATCH (obj), FALSE);
	
	if (obj->items)
	{
		GList * i;
		GList * items = g_hash_table_get_values (obj->items);
		
		for (i = items; i && is_ready; i = i->next)
			is_ready = sql_object_is_ready (i->data);
		
		g_list_free (items);
	}
	
	return is_ready;
}

/**
 * sql_batch_get:
 * @obj: a #SqlBatch
 * @id: the id of the #SqlHolder
 *
 * Gets a held object by its id.
 *
 * Return value: the #SqlObject if an object with that id exists, %NULL otherwise
 **/
SqlObject * sql_batch_get (SqlBatch * obj, const gchar * id)
{
	g_return_val_if_fail (SQL_IS_BATCH (obj), NULL);
	g_return_val_if_fail (id, NULL);
	
	if (obj->items)
		return g_hash_table_lookup (obj->items, id);
	
	return NULL;
}

/**
 * sql_batch_add:
 * @obj: a #SqlBatch
 * @id: the id of the #SqlHolder
 * @held_object: the held object
 *
 * Adds a held object.
 **/
void sql_batch_add (SqlBatch * obj, const gchar * id, SqlObject * object)
{
	g_return_if_fail (SQL_IS_BATCH (obj));
	g_return_if_fail (id);
	
	sql_batch_remove (obj, id);
	
	if (!obj->items)
		obj->items = g_hash_table_new_full (
			 g_str_hash
			,g_str_equal
			,g_free
			,NULL
		);
	
	g_signal_connect (object, "changed",
		G_CALLBACK (sql_batch_child_changed), obj);
	g_hash_table_replace (obj->items,
		g_strdup (id), g_object_ref_sink (object));
}

/**
 * sql_batch_add_from_param:
 * @obj: a #SqlBatch
 * @id: the id assigned to the item
 **/
void sql_batch_add_from_param (SqlBatch * obj, const gchar * id, GvnParam * param)
{
	g_return_if_fail (SQL_IS_BATCH (obj));
	g_return_if_fail (id);
	g_return_if_fail (GVN_IS_PARAM (param));

	SqlObject * value = sql_value_new ();
	sql_value_set_param (SQL_VALUE (value), param);
	sql_batch_add (obj, id, value);
	g_object_unref (value);
}

/**
 * sql_batch_add_from_value:
 * @obj: a #SqlBatch
 * @id: the id assigned to the item
 **/
void sql_batch_add_from_value (SqlBatch * obj, const gchar * id, GType type, gpointer content)
{
	g_return_if_fail (SQL_IS_BATCH (obj));
	g_return_if_fail (id);

	GValue gvalue = {0};
	SqlObject * value;

	gvn_value_new_with_content (&gvalue, type, content);
	value = sql_value_new ();
	sql_value_set_value (SQL_VALUE (value), &gvalue);
	sql_batch_add (obj, id, value);
	g_object_unref (value);
	g_value_unset (&gvalue);
}

/**
 * sql_batch_remove:
 * @obj: a #SqlBatch
 * @id: the id of the #SqlHolder
 *
 * Removes a held object from the batch.
 **/
void sql_batch_remove (SqlBatch * obj, const gchar * id)
{
	g_return_val_if_fail (SQL_IS_BATCH (obj), NULL);
	g_return_val_if_fail (id, NULL);

	SqlObject * child = sql_batch_get (obj, id);
	
	if (child)
	{
		sql_batch_free_child (obj, child);
		g_hash_table_remove (obj->items, id);
	}
}

/**
 * sql_batch_merge:
 * @obj: a #SqlBatch
 * @batch: a #SqlBatch
 *
 * Meges the batch with another batch.
 **/
void sql_batch_merge (SqlBatch * obj, SqlBatch * batch)
{
	GHashTableIter iter;
	gpointer key, value;

	g_return_if_fail (SQL_IS_BATCH (obj));
	g_return_if_fail (SQL_IS_BATCH (batch) || !batch);
	
	if (!batch)
		return;

	g_hash_table_iter_init (&iter, batch->items);
	
	while (g_hash_table_iter_next (&iter, &key, &value))
		sql_batch_add (obj, key, value);
}

/**
 * sql_batch_changed:
 * @obj: a #SqlBatch
 *
 * Emits the changed signal on #SqlBatch.
 **/
void sql_batch_changed (SqlBatch * obj)
{
	g_return_if_fail (SQL_IS_BATCH (obj));

	g_signal_emit (obj, signals[CHANGED], 0);
}

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

static void sql_batch_init (SqlBatch * obj)
{
	obj->items = NULL;
}

static void sql_batch_finalize (SqlBatch * obj)
{
	if (obj->items)
	{
		GHashTableIter iter;
		gpointer child;

		g_hash_table_iter_init (&iter, obj->items);

		while (g_hash_table_iter_next (&iter, NULL, &child))
			sql_batch_free_child (obj, child);
	
		g_hash_table_destroy (obj->items);
	}

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

static void sql_batch_class_init (SqlBatchClass * klass)
{
	G_OBJECT_CLASS (klass)->finalize = (GObjectFinalizeFunc) sql_batch_finalize;

	/** 
	 * SqlBatch::changed:
	 * @obj: the object which emit the signal.
	 * 
	 * This signal is emitted every time the batch or one of its attributes
	 * is modified. 
	 */
	signals[CHANGED] = g_signal_new ("changed", SQL_TYPE_BATCH,
		G_SIGNAL_RUN_FIRST, 0, NULL, NULL,
			g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0
	);
}