/*
 *  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 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 Library General Public License for more details.
 *
 *  You should have received a copy of the GNU 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <assert.h>

#include <linux/videodev2.h>
#include "v4l2.h"

typedef struct _V4L2RadioDev V4L2RadioDev;
struct _V4L2RadioDev
{
	struct _RadioDev parent;

	int fd;
	int freq_fact;
	int radio_rangelow;
	int radio_rangehigh;
};

static int
v4l2_radio_init(RadioDev *radio_dev, char *device)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	struct v4l2_capability caps;
	struct v4l2_tuner tuner;
	
	if ((dev->fd = open(device, O_RDONLY))< 0)
		goto err;
	
	/* does this device provide a tuner? */
	memset(&caps, 0, sizeof(caps));
	if (ioctl(dev->fd, VIDIOC_QUERYCAP, &caps) < 0) {
		perror("VIDIOC_QUERYCAP");
		goto err;
	}
	if ((caps.capabilities & V4L2_CAP_TUNER) == 0) {
		fprintf(stderr, "Not a radio tuner\n");
		goto err;
	}

	/* check the tuner */
	memset(&tuner, 0, sizeof(tuner));
	tuner.index = 0;
	if (ioctl(dev->fd, VIDIOC_G_TUNER, &tuner) < 0) {
		perror("VIDIOC_G_TUNER");
		goto err;
	}
	if (tuner.type != V4L2_TUNER_RADIO) {
		fprintf(stderr, "Not a radio tuner\n");
		goto err;
	}
	/* Does this tuner expect data in 62.5Hz or 62.5kHz multiples? */
	dev->radio_rangelow = tuner.rangelow;
	dev->radio_rangehigh = tuner.rangehigh;
	if ((tuner.capability & V4L2_TUNER_CAP_LOW) != 0)
		dev->freq_fact = 16000;
	else
		dev->freq_fact = 16;
	
	return 1;

 err:
	if (dev->fd >= 0)
		close(dev->fd);
	dev->fd = -1;
	return 0;
}

static int
v4l2_radio_is_init(RadioDev *radio_dev)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	return (dev->fd >= 0);
}

static void
v4l2_radio_set_freq(RadioDev *radio_dev, float frequency)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	struct v4l2_frequency freq;

	if (dev->fd<0)
		return;

	memset(&freq, 0, sizeof(freq));
	freq.tuner = 0;
	freq.type = V4L2_TUNER_RADIO;
	freq.frequency = frequency * dev->freq_fact;

	if (freq.frequency < dev->radio_rangelow ||
	    freq.frequency > dev->radio_rangehigh)
		return;
	if (ioctl(dev->fd, VIDIOC_S_FREQUENCY, &freq) < 0)
		perror("VIDIOC_S_FREQUENCY");
}

static void
v4l2_radio_mute(RadioDev *radio_dev, int mute)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	struct v4l2_control control;

	if (dev->fd<0)
		return;

	memset(&control, 0, sizeof(control));
	control.id = V4L2_CID_AUDIO_MUTE;
	control.value = mute;
	if (ioctl(dev->fd, VIDIOC_S_CTRL, &control) < 0)
		perror("VIDIOC_S_CTRL");
}

static int
v4l2_radio_get_stereo(RadioDev *radio_dev)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	struct v4l2_tuner tuner;

	if (dev->fd<0)
		return -1;

	memset(&tuner, 0, sizeof(tuner));
	tuner.index = 0;
	if (ioctl(dev->fd, VIDIOC_G_TUNER, &tuner) < 0) {
		perror("VIDIOC_G_TUNER");
		return -1;
	}

	return tuner.audmode == V4L2_TUNER_MODE_STEREO;
}

static int
v4l2_radio_get_signal(RadioDev *radio_dev)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	struct v4l2_tuner tuner;

	if (dev->fd<0)
		return -1;

	memset(&tuner, 0, sizeof(tuner));
	tuner.index = 0;
	if (ioctl(dev->fd, VIDIOC_G_TUNER, &tuner) < 0) {
		perror("VIDIOC_G_TUNER");
		return -1;
	}

	return tuner.signal >> 13;
}

static void
v4l2_radio_finalize(RadioDev *radio_dev)
{
	V4L2RadioDev *dev = (V4L2RadioDev*)radio_dev;
	
	if (dev->fd >= 0)
		close(dev->fd);
	free (dev);
}

RadioDev*
v4l2_radio_dev_new (void)
{
    RadioDev *dev;
	V4L2RadioDev *v4l2_dev;

	v4l2_dev = malloc (sizeof (V4L2RadioDev));
	v4l2_dev->fd = -1;

	dev = (RadioDev*)v4l2_dev;
	dev->init       = v4l2_radio_init;
	dev->is_init    = v4l2_radio_is_init;
	dev->set_freq   = v4l2_radio_set_freq;
	dev->mute       = v4l2_radio_mute;
	dev->get_stereo = v4l2_radio_get_stereo;
	dev->get_signal = v4l2_radio_get_signal;
	dev->finalize   = v4l2_radio_finalize;

	return dev;
}