/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*

 * Copyright (C) 2006 Imendio AB

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation; either version 2 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this program; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#include <config.h>

#include "lm-message-queue.h"

#include "lm-debug.h"

struct _LmMessageQueue {

	GQueue                  *messages;

	GMainContext            *context;

	GSource                 *source;

	LmMessageQueueCallback  callback;

	gpointer                user_data;

	gint                    ref_count;

};

typedef struct {

	GSource         source;

	LmMessageQueue *queue;

} MessageQueueSource;

static void        message_queue_free            (LmMessageQueue *queue);

static gboolean    message_queue_prepare_func    (GSource         *source,

						  gint            *timeout);

static gboolean    message_queue_check_func      (GSource         *source);

static gboolean    message_queue_dispatch_func   (GSource         *source,

						  GSourceFunc      callback,

						  gpointer         user_data);

static GSourceFuncs source_funcs = {

	message_queue_prepare_func,

	message_queue_check_func,

	message_queue_dispatch_func,

	NULL

};

static void

foreach_free_message (LmMessage *m, gpointer user_data)

{

	lm_message_unref (m);

	UNUSED_FORMAL_PARAM(user_data);

}

static void

message_queue_free (LmMessageQueue *queue)

{

	lm_message_queue_detach (queue);

	g_queue_foreach (queue->messages, (GFunc) foreach_free_message, NULL);

	g_queue_free (queue->messages);

	g_free (queue);

}

//Prepare has to return true for check method to be called.

static gboolean

message_queue_prepare_func (GSource *source, gint *timeout)

{

	LmMessageQueue *queue;

	queue = ((MessageQueueSource *)source)->queue;

	UNUSED_FORMAL_PARAM(timeout);

	return !g_queue_is_empty (queue->messages);

}

//check has to return true for Dispatch method to be called.

static gboolean

message_queue_check_func (GSource *source)

{

//	return FALSE;

UNUSED_FORMAL_PARAM(source);

return TRUE;

}

static gboolean

message_queue_dispatch_func (GSource     *source,

			     GSourceFunc  callback,

			     gpointer     user_data)

{

	LmMessageQueue *queue;

	queue = ((MessageQueueSource *)source)->queue;

	if (queue->callback) {

		(queue->callback) (queue, queue->user_data);

	}

	UNUSED_FORMAL_PARAM(source);

	UNUSED_FORMAL_PARAM(callback);

	return TRUE;

}

LmMessageQueue *

lm_message_queue_new (LmMessageQueueCallback  callback,

		      gpointer                user_data)

{

	LmMessageQueue *queue;

	queue = g_new0 (LmMessageQueue, 1);

	queue->messages = g_queue_new ();

	queue->context = NULL;

	queue->source = NULL;

	queue->ref_count = 1;

	queue->callback = callback;

	queue->user_data = user_data;

	return queue;

}

void

lm_message_queue_attach (LmMessageQueue *queue, GMainContext *context)

{

	GSource *source;

	if (queue->source) {

		if (queue->context == context) {

			/* Already attached */

			return;

		}

		lm_message_queue_detach (queue);

	}

	if (context)  {

		queue->context = g_main_context_ref (context);

	}

	source = g_source_new (&source_funcs, sizeof (MessageQueueSource));

	((MessageQueueSource *)source)->queue = queue;

	queue->source = source;

	g_source_attach (source, queue->context);

}

void

lm_message_queue_detach (LmMessageQueue *queue)

{

	if (queue->source) {

		g_source_destroy (queue->source);

		g_source_unref (queue->source);

	}

	if (queue->context) {

		g_main_context_unref (queue->context);

	}

	queue->source = NULL;

	queue->context = NULL;

}

void

lm_message_queue_push_tail (LmMessageQueue *queue, LmMessage *m)

{

	g_return_if_fail (queue != NULL);

	g_return_if_fail (m != NULL);

	g_queue_push_tail (queue->messages, m);

}

LmMessage *

lm_message_queue_peek_nth (LmMessageQueue *queue, guint n)

{

	g_return_val_if_fail (queue != NULL, NULL);

	return (LmMessage *) g_queue_peek_nth (queue->messages, n);

}

LmMessage *

lm_message_queue_pop_nth (LmMessageQueue *queue, guint n)

{

	g_return_val_if_fail (queue != NULL, NULL);

	return (LmMessage *) g_queue_pop_nth (queue->messages, n);

}

guint

lm_message_queue_get_length (LmMessageQueue *queue)

{

	g_return_val_if_fail (queue != NULL, 0);

	return g_queue_get_length (queue->messages);

}

gboolean 

lm_message_queue_is_empty (LmMessageQueue *queue)

{

	g_return_val_if_fail (queue != NULL, TRUE);

	return g_queue_is_empty (queue->messages);

}

LmMessageQueue *

lm_message_queue_ref (LmMessageQueue *queue)

{

	g_return_val_if_fail (queue != NULL, NULL);

	queue->ref_count++;

	return queue;

}

void

lm_message_queue_unref (LmMessageQueue *queue)

{

	g_return_if_fail (queue != NULL);

	queue->ref_count--;

	if (queue->ref_count <= 0) {

		message_queue_free (queue);

	}

}