/* acme-volume-alsa.c

   Copyright (C) 2002, 2003 Bastien Nocera

   The Gnome Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The Gnome Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the Gnome Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.

   Author: Bastien Nocera <hadess@hadess.net>
 */

#ifdef HAVE_CONFIG
#include "config.h"
#endif

#include "acme-volume-alsa.h"

#include <alsa/asoundlib.h>

#ifndef DEFAULT_CARD
#define DEFAULT_CARD "default"
#endif

#undef LOG
#ifdef LOG
#define D(x...) g_message (x)
#else
#define D(x...)
#endif

#define ROUND(x) ((x - (int)x > 0.5) ? x+1 : x)

struct AcmeVolumeAlsaPrivate
{
	long pmin, pmax;
	gboolean has_mute, has_master;
	snd_mixer_t *handle;
	snd_mixer_elem_t *elem;
	int saved_volume;
	guint timer_id;
};

static int acme_volume_alsa_get_volume (AcmeVolume *self);
static void acme_volume_alsa_set_volume (AcmeVolume *self, int val);
static gboolean acme_volume_alsa_open (AcmeVolumeAlsa *self);
static void acme_volume_alsa_close (AcmeVolumeAlsa *self);
static gboolean acme_volume_alsa_close_real (AcmeVolumeAlsa *self);

G_DEFINE_TYPE (AcmeVolumeAlsa, acme_volume_alsa, ACME_TYPE_VOLUME)

static void
acme_volume_alsa_finalize (GObject *object)
{
	AcmeVolumeAlsa *self;

	self = ACME_VOLUME_ALSA (object);

	if (self->_priv)
	{
		if (self->_priv->timer_id != 0)
		{
			g_source_remove (self->_priv->timer_id);
			self->_priv->timer_id = 0;
		}

		acme_volume_alsa_close_real (self);
		g_free (self->_priv);
		self->_priv = NULL;
	}

	G_OBJECT_CLASS (acme_volume_alsa_parent_class)->finalize (object);
}

static void
acme_volume_alsa_set_mute (AcmeVolume *vol, gboolean val)
{
	AcmeVolumeAlsa *self = (AcmeVolumeAlsa *) vol;

	if (acme_volume_alsa_open (self) == FALSE)
		return;

	/* If we have a hardware mute */
	if (self->_priv->has_mute)
	{
		snd_mixer_selem_set_playback_switch_all
			(self->_priv->elem, !val);
		acme_volume_alsa_close (self);
		return;
	}

	acme_volume_alsa_close (self);

	/* If we don't */
	if (val == TRUE)
	{
		self->_priv->saved_volume = acme_volume_alsa_get_volume (vol);
		acme_volume_alsa_set_volume (vol, 0);
	} else {
		if (self->_priv->saved_volume != -1)
			acme_volume_alsa_set_volume (vol,
					self->_priv->saved_volume);
	}
}

static gboolean
acme_volume_alsa_get_mute (AcmeVolume *vol)
{
	AcmeVolumeAlsa *self = (AcmeVolumeAlsa *) vol;
	int ival;

	if (acme_volume_alsa_open (self) == FALSE)
		return FALSE;

	if (self->_priv->has_mute)
	{
		snd_mixer_selem_get_playback_switch(self->_priv->elem,
				SND_MIXER_SCHN_FRONT_LEFT, &ival);

		acme_volume_alsa_close (self);

		return !ival;
	} else {
		acme_volume_alsa_close (self);

		return (acme_volume_alsa_get_volume (vol) == 0);
	}
}

static int
acme_volume_alsa_get_volume (AcmeVolume *vol)
{
	AcmeVolumeAlsa *self = (AcmeVolumeAlsa *) vol;
	long lval, rval;
	int tmp;
	float alsa_vol;

	if (acme_volume_alsa_open (self) == FALSE)
		return 0;

	snd_mixer_selem_get_playback_volume(self->_priv->elem,
			SND_MIXER_SCHN_FRONT_LEFT, &lval);
	snd_mixer_selem_get_playback_volume(self->_priv->elem,
			SND_MIXER_SCHN_FRONT_RIGHT, &rval);

	acme_volume_alsa_close (self);

	alsa_vol = (lval + rval) / 2;
	alsa_vol = alsa_vol * 100 / (self->_priv->pmax - self->_priv->pmin);
	tmp = ROUND (alsa_vol);

	return tmp;
}

static void
acme_volume_alsa_set_volume (AcmeVolume *vol, int val)
{
	AcmeVolumeAlsa *self = (AcmeVolumeAlsa *) vol;
	float volume;
	int tmp;

	if (acme_volume_alsa_open (self) == FALSE)
		return;

	volume = (float) val / 100 * (self->_priv->pmax - self->_priv->pmin);
	volume = CLAMP (volume, self->_priv->pmin, self->_priv->pmax);
	tmp = ROUND (volume);

	snd_mixer_selem_set_playback_volume_all (self->_priv->elem, tmp);

	acme_volume_alsa_close (self);
}

static int
acme_volume_alsa_get_threshold (AcmeVolume *vol)
{
	AcmeVolumeAlsa *self = (AcmeVolumeAlsa *) vol;
	int steps;

	if (acme_volume_alsa_open (self) == FALSE)
		return 1;

	acme_volume_alsa_close (self);

	steps = self->_priv->pmax - self->_priv->pmin;
	return (steps > 0) ? 100 / steps + 1 : 1;
}

static gboolean
acme_volume_alsa_close_real (AcmeVolumeAlsa *self)
{
	if (self->_priv == NULL)
		return FALSE;

	if (self->_priv->handle != NULL)
	{
		snd_mixer_detach (self->_priv->handle, DEFAULT_CARD);
		snd_mixer_free (self->_priv->handle);
		self->_priv->handle = NULL;
		self->_priv->elem = NULL;
	}

	self->_priv->timer_id = 0;

	return FALSE;
}

static gboolean
acme_volume_alsa_open (AcmeVolumeAlsa *self)
{
	snd_mixer_selem_id_t *sid;
	snd_mixer_t *handle;
	snd_mixer_elem_t *elem;

	if (self->_priv->timer_id != 0)
	{
		g_source_remove (self->_priv->timer_id);
		self->_priv->timer_id = 0;
		return TRUE;
	}

	/* open the mixer */
	if (snd_mixer_open (&handle, 0) < 0)
	{
		D("snd_mixer_open");
		return FALSE;
	}
	/* attach the handle to the default card */
	if (snd_mixer_attach (handle, DEFAULT_CARD) <0)
	{
		D("snd_mixer_attach");
		goto bail;
	}
	/* ? */
	if (snd_mixer_selem_register (handle, NULL, NULL) < 0)
	{
		D("snd_mixer_selem_register");
		goto bail;
	}
	if (snd_mixer_load (handle) < 0)
	{
		D("snd_mixer_load");
		goto bail;
	}

	snd_mixer_selem_id_alloca (&sid);
	snd_mixer_selem_id_set_name (sid, "Master");
	elem = snd_mixer_find_selem (handle, sid);
	if (!elem)
	{
		snd_mixer_selem_id_alloca (&sid);
		snd_mixer_selem_id_set_name (sid, "PCM");
		elem = snd_mixer_find_selem (handle, sid);
		if (!elem)
		{
			D("snd_mixer_find_selem");
			goto bail;
		}
	}

	if (!snd_mixer_selem_has_playback_volume (elem))
	{
		D("snd_mixer_selem_has_playback_volume");
		goto bail;
	}

	snd_mixer_selem_get_playback_volume_range (elem,
			&(self->_priv->pmin),
			&(self->_priv->pmax));

	self->_priv->has_mute = snd_mixer_selem_has_playback_switch (elem);
	self->_priv->handle = handle;
	self->_priv->elem = elem;

	return TRUE;

bail:
	acme_volume_alsa_close_real (self);
	return FALSE;
}

static void
acme_volume_alsa_close (AcmeVolumeAlsa *self)
{
	self->_priv->timer_id = g_timeout_add_seconds (4,
			(GSourceFunc) acme_volume_alsa_close_real, self);
}

static void
acme_volume_alsa_init (AcmeVolumeAlsa *self)
{
	self->_priv = g_new0 (AcmeVolumeAlsaPrivate, 1);
}

static void
acme_volume_alsa_class_init (AcmeVolumeAlsaClass *klass)
{
	AcmeVolumeClass *volume_class = ACME_VOLUME_CLASS (klass);
	G_OBJECT_CLASS (klass)->finalize = acme_volume_alsa_finalize;

	volume_class->set_volume = acme_volume_alsa_set_volume;
	volume_class->get_volume = acme_volume_alsa_get_volume;
	volume_class->set_mute = acme_volume_alsa_set_mute;
	volume_class->get_mute = acme_volume_alsa_get_mute;
	volume_class->get_threshold = acme_volume_alsa_get_threshold;
}