/*-*- linux-c -*-*/

/*
 * ALSA <-> PulseAudio mixer control plugin
 *
 * Copyright (c) 2006 by Pierre Ossman <ossman@cendio.se>
 *
 * This library 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 2.1 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <sys/poll.h>

#include <alsa/asoundlib.h>
#include <alsa/control_external.h>

#include "pulse.h"

typedef struct snd_ctl_pulse {
	snd_ctl_ext_t ext;

	snd_pulse_t *p;

	char *source;
	char *sink;

	pa_cvolume sink_volume;
	pa_cvolume source_volume;

	int sink_muted;
	int source_muted;

	int subscribed;
	int updated;
} snd_ctl_pulse_t;

#define SOURCE_VOL_NAME "Capture Volume"
#define SOURCE_MUTE_NAME "Capture Switch"
#define SINK_VOL_NAME "Master Playback Volume"
#define SINK_MUTE_NAME "Master Playback Switch"

#define UPDATE_SINK_VOL     0x01
#define UPDATE_SINK_MUTE    0x02
#define UPDATE_SOURCE_VOL   0x04
#define UPDATE_SOURCE_MUTE  0x08

static void sink_info_cb(pa_context * c, const pa_sink_info * i,
			 int is_last, void *userdata)
{
	snd_ctl_pulse_t *ctl = (snd_ctl_pulse_t *) userdata;
	int changed = 0;

	assert(ctl);

	if (is_last) {
		pa_threaded_mainloop_signal(ctl->p->mainloop, 0);
		return;
	}

	assert(i);

	if (!!ctl->sink_muted != !!i->mute) {
		ctl->sink_muted = i->mute;
		ctl->updated |= UPDATE_SINK_MUTE;
		changed = 1;
	}

	if (!pa_cvolume_equal(&ctl->sink_volume, &i->volume)) {
		ctl->sink_volume = i->volume;
		ctl->updated |= UPDATE_SINK_VOL;
		changed = 1;
	}

	if (changed)
		pulse_poll_activate(ctl->p);
}

static void source_info_cb(pa_context * c, const pa_source_info * i,
			   int is_last, void *userdata)
{
	snd_ctl_pulse_t *ctl = (snd_ctl_pulse_t *) userdata;
	int changed = 0;

	assert(ctl);

	if (is_last) {
		pa_threaded_mainloop_signal(ctl->p->mainloop, 0);
		return;
	}

	assert(i);

	if (!!ctl->source_muted != !!i->mute) {
		ctl->source_muted = i->mute;
		ctl->updated |= UPDATE_SOURCE_MUTE;
		changed = 1;
	}

	if (!pa_cvolume_equal(&ctl->source_volume, &i->volume)) {
		ctl->source_volume = i->volume;
		ctl->updated |= UPDATE_SOURCE_VOL;
		changed = 1;
	}

	if (changed)
		pulse_poll_activate(ctl->p);

}

static void event_cb(pa_context * c, pa_subscription_event_type_t t,
		     uint32_t index, void *userdata)
{
	snd_ctl_pulse_t *ctl = (snd_ctl_pulse_t *) userdata;
	pa_operation *o;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop || !ctl->p->context)
		return;

	o = pa_context_get_sink_info_by_name(ctl->p->context, ctl->sink,
					     sink_info_cb, ctl);

	if (o)
		pa_operation_unref(o);

	o = pa_context_get_source_info_by_name(ctl->p->context,
					       ctl->source, source_info_cb,
					       ctl);

	if (o)
		pa_operation_unref(o);
}

static int pulse_update_volume(snd_ctl_pulse_t * ctl)
{
	int err;
	pa_operation *o;

	assert(ctl);

	if (!ctl->p)
		return -EBADFD;

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		return err;

	o = pa_context_get_sink_info_by_name(ctl->p->context, ctl->sink,
					     sink_info_cb, ctl);
	if (o) {
		err = pulse_wait_operation(ctl->p, o);
		pa_operation_unref(o);
	} else
		err = -EIO;

	if (err < 0)
		return err;

	o = pa_context_get_source_info_by_name(ctl->p->context,
					       ctl->source, source_info_cb,
					       ctl);
	if (o) {
		err = pulse_wait_operation(ctl->p, o);
		pa_operation_unref(o);
	} else
		err = -EIO;

	if (err < 0)
		return err;

	return 0;
}

static int pulse_elem_count(snd_ctl_ext_t * ext)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int count = 0, err;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0) {
		count = err;
		goto finish;
	}

	if (ctl->source)
		count += 2;
	if (ctl->sink)
		count += 2;

finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return count;
}

static int pulse_elem_list(snd_ctl_ext_t * ext, unsigned int offset,
			   snd_ctl_elem_id_t * id)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int err;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER);

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	if (ctl->source) {
		if (offset == 0)
			snd_ctl_elem_id_set_name(id, SOURCE_VOL_NAME);
		else if (offset == 1)
			snd_ctl_elem_id_set_name(id, SOURCE_MUTE_NAME);
	} else
		offset += 2;

	err = 0;

finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	if (err >= 0) {
		if (offset == 2)
			snd_ctl_elem_id_set_name(id, SINK_VOL_NAME);
		else if (offset == 3)
			snd_ctl_elem_id_set_name(id, SINK_MUTE_NAME);
	}

	return err;
}

static snd_ctl_ext_key_t pulse_find_elem(snd_ctl_ext_t * ext,
					 const snd_ctl_elem_id_t * id)
{
	const char *name;
	unsigned int numid;

	numid = snd_ctl_elem_id_get_numid(id);
	if (numid > 0 && numid <= 4)
		return numid - 1;

	name = snd_ctl_elem_id_get_name(id);

	if (strcmp(name, SOURCE_VOL_NAME) == 0)
		return 0;
	if (strcmp(name, SOURCE_MUTE_NAME) == 0)
		return 1;
	if (strcmp(name, SINK_VOL_NAME) == 0)
		return 2;
	if (strcmp(name, SINK_MUTE_NAME) == 0)
		return 3;

	return SND_CTL_EXT_KEY_NOT_FOUND;
}

static int pulse_get_attribute(snd_ctl_ext_t * ext, snd_ctl_ext_key_t key,
			       int *type, unsigned int *acc,
			       unsigned int *count)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int err = 0;

	if (key > 3)
		return -EINVAL;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	err = pulse_update_volume(ctl);
	if (err < 0)
		goto finish;

	if (key & 1)
		*type = SND_CTL_ELEM_TYPE_BOOLEAN;
	else
		*type = SND_CTL_ELEM_TYPE_INTEGER;

	*acc = SND_CTL_EXT_ACCESS_READWRITE;

	if (key == 0)
		*count = ctl->source_volume.channels;
	else if (key == 2)
		*count = ctl->sink_volume.channels;
	else
		*count = 1;

      finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return err;
}

static int pulse_get_integer_info(snd_ctl_ext_t * ext,
				  snd_ctl_ext_key_t key, long *imin,
				  long *imax, long *istep)
{
	*istep = 1;
	*imin = 0;
	*imax = PA_VOLUME_NORM;

	return 0;
}

static int pulse_read_integer(snd_ctl_ext_t * ext, snd_ctl_ext_key_t key,
			      long *value)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int err = 0, i;
	pa_cvolume *vol = NULL;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	err = pulse_update_volume(ctl);
	if (err < 0)
		goto finish;

	switch (key) {
	case 0:
		vol = &ctl->source_volume;
		break;
	case 1:
		*value = !ctl->source_muted;
		break;
	case 2:
		vol = &ctl->sink_volume;
		break;
	case 3:
		*value = !ctl->sink_muted;
		break;
	default:
		err = -EINVAL;
		goto finish;
	}

	if (vol) {
		for (i = 0; i < vol->channels; i++)
			value[i] = vol->values[i];
	}

      finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return err;
}

static int pulse_write_integer(snd_ctl_ext_t * ext, snd_ctl_ext_key_t key,
			       long *value)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int err = 0, i;
	pa_operation *o;
	pa_cvolume *vol = NULL;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	err = pulse_update_volume(ctl);
	if (err < 0)
		goto finish;

	switch (key) {
	case 0:
		vol = &ctl->source_volume;
		break;
	case 1:
		if (!!ctl->source_muted == !*value)
			goto finish;
		ctl->source_muted = !*value;
		break;
	case 2:
		vol = &ctl->sink_volume;
		break;
	case 3:
		if (!!ctl->sink_muted == !*value)
			goto finish;
		ctl->sink_muted = !*value;
		break;
	default:
		err = -EINVAL;
		goto finish;
	}

	if (vol) {
		for (i = 0; i < vol->channels; i++)
			if (value[i] != vol->values[i])
				break;

		if (i == vol->channels)
			goto finish;

		for (i = 0; i < vol->channels; i++)
			vol->values[i] = value[i];

		if (key == 0)
			o = pa_context_set_source_volume_by_name(ctl->p->
								 context,
								 ctl->
								 source,
								 vol,
								 pulse_context_success_cb,
								 ctl->p);
		else
			o = pa_context_set_sink_volume_by_name(ctl->p->
							       context,
							       ctl->sink,
							       vol,
							       pulse_context_success_cb,
							       ctl->p);
	} else {
		if (key == 1)
			o = pa_context_set_source_mute_by_name(ctl->p->
							       context,
							       ctl->source,
							       ctl->
							       source_muted,
							       pulse_context_success_cb,
							       ctl->p);
		else
			o = pa_context_set_sink_mute_by_name(ctl->p->
							     context,
							     ctl->sink,
							     ctl->
							     sink_muted,
							     pulse_context_success_cb,
							     ctl->p);
	}

	if (!o) {
		err = -EIO;
		goto finish;
	}

	err = pulse_wait_operation(ctl->p, o);
	pa_operation_unref(o);

	if (err < 0)
		goto finish;

	err = 1;

      finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return err;
}

static void pulse_subscribe_events(snd_ctl_ext_t * ext, int subscribe)
{
	snd_ctl_pulse_t *ctl = ext->private_data;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	ctl->subscribed = !!(subscribe & SND_CTL_EVENT_MASK_VALUE);

	pa_threaded_mainloop_unlock(ctl->p->mainloop);
}

static int pulse_read_event(snd_ctl_ext_t * ext, snd_ctl_elem_id_t * id,
			    unsigned int *event_mask)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int offset;
	int err;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	if (!ctl->updated || !ctl->subscribed) {
		err = -EAGAIN;
		goto finish;
	}

	if (ctl->source)
		offset = 2;
	else
		offset = 0;

	if (ctl->updated & UPDATE_SOURCE_VOL) {
		pulse_elem_list(ext, 0, id);
		ctl->updated &= ~UPDATE_SOURCE_VOL;
	} else if (ctl->updated & UPDATE_SOURCE_MUTE) {
		pulse_elem_list(ext, 1, id);
		ctl->updated &= ~UPDATE_SOURCE_MUTE;
	} else if (ctl->updated & UPDATE_SINK_VOL) {
		pulse_elem_list(ext, offset + 0, id);
		ctl->updated &= ~UPDATE_SINK_VOL;
	} else if (ctl->updated & UPDATE_SINK_MUTE) {
		pulse_elem_list(ext, offset + 1, id);
		ctl->updated &= ~UPDATE_SINK_MUTE;
	}

	*event_mask = SND_CTL_EVENT_MASK_VALUE;

	if (!ctl->updated)
		pulse_poll_deactivate(ctl->p);

	err = 1;

      finish:
	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return err;
}

static int pulse_ctl_poll_revents(snd_ctl_ext_t * ext, struct pollfd *pfd,
				  unsigned int nfds,
				  unsigned short *revents)
{
	snd_ctl_pulse_t *ctl = ext->private_data;
	int err;

	assert(ctl);

	if (!ctl->p || !ctl->p->mainloop)
		return -EBADFD;

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	err = pulse_check_connection(ctl->p);
	if (err < 0)
		goto finish;

	if (ctl->updated)
		*revents = POLLIN;
	else
		*revents = 0;

	err = 0;

finish:

	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	return err;
}

static void pulse_close(snd_ctl_ext_t * ext)
{
	snd_ctl_pulse_t *ctl = ext->private_data;

	assert(ctl);

	if (ctl->p)
		pulse_free(ctl->p);

	free(ctl->source);
	free(ctl->sink);
	free(ctl);
}

static const snd_ctl_ext_callback_t pulse_ext_callback = {
	.elem_count = pulse_elem_count,
	.elem_list = pulse_elem_list,
	.find_elem = pulse_find_elem,
	.get_attribute = pulse_get_attribute,
	.get_integer_info = pulse_get_integer_info,
	.read_integer = pulse_read_integer,
	.write_integer = pulse_write_integer,
	.subscribe_events = pulse_subscribe_events,
	.read_event = pulse_read_event,
	.poll_revents = pulse_ctl_poll_revents,
	.close = pulse_close,
};

static void server_info_cb(pa_context * c, const pa_server_info * i,
			   void *userdata)
{
	snd_ctl_pulse_t *ctl = (snd_ctl_pulse_t *) userdata;

	assert(ctl && i);

	if (i->default_source_name && !ctl->source)
		ctl->source = strdup(i->default_source_name);
	if (i->default_sink_name && !ctl->sink)
		ctl->sink = strdup(i->default_sink_name);

	pa_threaded_mainloop_signal(ctl->p->mainloop, 0);
}

SND_CTL_PLUGIN_DEFINE_FUNC(pulse)
{
	snd_config_iterator_t i, next;
	const char *server = NULL;
	const char *device = NULL;
	const char *source = NULL;
	const char *sink = NULL;
	const char *fallback_name = NULL;
	int err;
	snd_ctl_pulse_t *ctl;
	pa_operation *o;

	snd_config_for_each(i, next, conf) {
		snd_config_t *n = snd_config_iterator_entry(i);
		const char *id;
		if (snd_config_get_id(n, &id) < 0)
			continue;
		if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0
		    || strcmp(id, "hint") == 0)
			continue;
		if (strcmp(id, "server") == 0) {
			if (snd_config_get_string(n, &server) < 0) {
				SNDERR("Invalid type for %s", id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(id, "device") == 0) {
			if (snd_config_get_string(n, &device) < 0) {
				SNDERR("Invalid type for %s", id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(id, "source") == 0) {
			if (snd_config_get_string(n, &source) < 0) {
				SNDERR("Invalid type for %s", id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(id, "sink") == 0) {
			if (snd_config_get_string(n, &sink) < 0) {
				SNDERR("Invalid type for %s", id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(id, "fallback") == 0) {
			if (snd_config_get_string(n, &fallback_name) < 0) {
				SNDERR("Invalid value for %s", id);
				return -EINVAL;
			}
			continue;
		}
		SNDERR("Unknown field %s", id);
		return -EINVAL;
	}

	if (fallback_name && name && !strcmp(name, fallback_name))
		fallback_name = NULL; /* no fallback for the same name */

	ctl = calloc(1, sizeof(*ctl));
	if (!ctl)
		return -ENOMEM;

	ctl->p = pulse_new();
	if (!ctl->p) {
		err = -EIO;
		goto error;
	}

	err = pulse_connect(ctl->p, server, fallback_name != NULL);
	if (err < 0)
		goto error;

	if (source)
		ctl->source = strdup(source);
	else if (device)
		ctl->source = strdup(device);

	if ((source || device) && !ctl->source) {
		err = -ENOMEM;
		goto error;
	}

	if (sink)
		ctl->sink = strdup(sink);
	else if (device)
		ctl->sink = strdup(device);

	if ((sink || device) && !ctl->sink) {
		err = -ENOMEM;
		goto error;
	}

	if (!ctl->source || !ctl->sink) {
		pa_threaded_mainloop_lock(ctl->p->mainloop);

		o = pa_context_get_server_info(ctl->p->context,
					       server_info_cb, ctl);

		if (o) {
			err = pulse_wait_operation(ctl->p, o);
			pa_operation_unref(o);
		} else
			err = -EIO;

		pa_threaded_mainloop_unlock(ctl->p->mainloop);

		if (err < 0)
			goto error;
	}

	pa_threaded_mainloop_lock(ctl->p->mainloop);

	pa_context_set_subscribe_callback(ctl->p->context, event_cb, ctl);

	o = pa_context_subscribe(ctl->p->context,
				 PA_SUBSCRIPTION_MASK_SINK |
				 PA_SUBSCRIPTION_MASK_SOURCE,
				 pulse_context_success_cb, ctl->p);

	if (o) {
		err = pulse_wait_operation(ctl->p, o);
		pa_operation_unref(o);
	} else
		err = -EIO;

	pa_threaded_mainloop_unlock(ctl->p->mainloop);

	if (err < 0)
		goto error;

	ctl->ext.version = SND_CTL_EXT_VERSION;
	ctl->ext.card_idx = 0;
	strncpy(ctl->ext.id, "pulse", sizeof(ctl->ext.id) - 1);
	strncpy(ctl->ext.driver, "PulseAudio plugin",
		sizeof(ctl->ext.driver) - 1);
	strncpy(ctl->ext.name, "PulseAudio", sizeof(ctl->ext.name) - 1);
	strncpy(ctl->ext.longname, "PulseAudio",
		sizeof(ctl->ext.longname) - 1);
	strncpy(ctl->ext.mixername, "PulseAudio",
		sizeof(ctl->ext.mixername) - 1);
	ctl->ext.poll_fd = ctl->p->main_fd;

	ctl->ext.callback = &pulse_ext_callback;
	ctl->ext.private_data = ctl;

	err = snd_ctl_ext_create(&ctl->ext, name, mode);
	if (err < 0)
		goto error;

	*handlep = ctl->ext.handle;

	return 0;

error:
	if (ctl->p)
		pulse_free(ctl->p);

	free(ctl->source);
	free(ctl->sink);
	free(ctl);

	if (fallback_name)
		return snd_ctl_open_fallback(handlep, root,
					     fallback_name, name, mode);

	return err;
}

SND_CTL_PLUGIN_SYMBOL(pulse);