/*
 * MOC - music on console
 * Copyright (C) 2003 - 2005 Damian Pietras <daper@daper.net>
 *
 * 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.
 *
 */

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

#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <assert.h>

#ifdef HAVE_SYS_SOUNDCARD_H
# include <sys/soundcard.h>
#else
# include <soundcard.h>
#endif

#include "common.h"
#include "server.h"
#include "audio.h"
#include "log.h"
#include "options.h"

#if OSS_VERSION >= 0x40000 || SOUND_VERSION >= 0x40000
#define OSSv4_MIXER
#else
#define OSSv3_MIXER
#endif

static bool started = false;
static int volatile dsp_fd = -1;
#ifdef OSSv3_MIXER
static int mixer_fd = -1;
static int mixer_channel1 = -1;
static int mixer_channel2 = -1;
static int mixer_channel_current;
#endif

static struct sound_params params = { 0, 0, 0 };

static const struct {
	const char *name;
	const int num;
} mixer_channels[] = {
	{ "pcm", SOUND_MIXER_PCM },
	{ "master", SOUND_MIXER_VOLUME },
	{ "speaker", SOUND_MIXER_SPEAKER }
};

#define MIXER_CHANNELS_NUM	(ARRAY_SIZE(mixer_channels))

static int open_dev ()
{
	if ((dsp_fd = open (options_get_str ("OSSDevice"), O_WRONLY)) == -1) {
		char *err = xstrerror (errno);
		error ("Can't open %s: %s", options_get_str ("OSSDevice"), err);
		free (err);
		return 0;
	}

	logit ("Audio device opened");

	return 1;
}

/* Fill caps with the device capabilities.  Return 0 on error. */
static int set_capabilities (struct output_driver_caps *caps)
{
	int format_mask;

	if (!open_dev ()) {
		error ("Can't open the device.");
		return 0;
	}

	if (ioctl (dsp_fd, SNDCTL_DSP_GETFMTS, &format_mask) == -1) {
		error_errno ("Can't get supported audio formats", errno);
		close (dsp_fd);
		return 0;
	}

	caps->formats = 0;
	if (format_mask & AFMT_S8)
		caps->formats |= SFMT_S8;
	if (format_mask & AFMT_U8)
		caps->formats |= SFMT_U8;

	if (format_mask & AFMT_S16_LE)
		caps->formats |= SFMT_S16 | SFMT_LE;
	if (format_mask & AFMT_S16_BE)
		caps->formats |= SFMT_S16 | SFMT_BE;

	if (!caps->formats) {
		/* Workaround for vmix that lies that it doesn't support any
		 * format. */
		error ("The driver claims that no format known to me is "
		       "supported. I will assume that SFMT_S8 and "
		       "SFMT_S16 (native endian) are supported.");
		caps->formats = SFMT_S8 | SFMT_S16 | SFMT_NE;
	}

	caps->min_channels = caps->max_channels = 1;
	if (ioctl (dsp_fd, SNDCTL_DSP_CHANNELS, &caps->min_channels)) {
		error_errno ("Can't set number of channels", errno);
		close (dsp_fd);
		return 0;
	}

	close (dsp_fd);
	if (!open_dev ()) {
		error ("Can't open the device.");
		return 0;
	}

	if (caps->min_channels != 1)
		caps->min_channels = 2;
	caps->max_channels = 2;
	if (ioctl (dsp_fd, SNDCTL_DSP_CHANNELS, &caps->max_channels)) {
		error_errno ("Can't set number of channels", errno);
		close (dsp_fd);
		return 0;
	}

	if (caps->max_channels != 2) {
		if (caps->min_channels == 2) {
			error ("Can't get any supported number of channels.");
			close (dsp_fd);
			return 0;
		}
		caps->max_channels = 1;
	}

	close (dsp_fd);

	return 1;
}

/* Get PCM volume.  Return -1 on error. */
static int oss_read_mixer ()
{
	int vol;

	if (!started)
		return -1;

#ifdef OSSv3_MIXER
	if (mixer_fd != -1 && mixer_channel_current != -1) {
		if (ioctl (mixer_fd, MIXER_READ(mixer_channel_current), &vol) == -1)
#else
	if (dsp_fd != -1) {
		if (ioctl (dsp_fd, SNDCTL_DSP_GETPLAYVOL, &vol) == -1)
#endif
		{
			error ("Can't read from mixer");
		}
		else {
			/* Average between left and right */
			return ((vol & 0xFF) + ((vol >> 8) & 0xFF)) / 2;
		}
	}

	return -1;
}

static int oss_mixer_name_to_channel (const char *name)
{
	size_t ix;

	for (ix = 0; ix < MIXER_CHANNELS_NUM; ix += 1) {
		if (!strcasecmp (mixer_channels[ix].name, name))
			return ix;
	}

	return -1;
}

static int oss_init (struct output_driver_caps *caps)
{
#ifdef OSSv3_MIXER
	/* Open the mixer device */
	mixer_fd = open (options_get_str ("OSSMixerDevice"), O_RDWR);
	if (mixer_fd == -1) {
		char *err = xstrerror (errno);
		error ("Can't open mixer device %s: %s",
		        options_get_str ("OSSMixerDevice"), err);
		free (err);
	}
	else {
		mixer_channel1 = oss_mixer_name_to_channel (
				options_get_symb ("OSSMixerChannel1"));
		mixer_channel2 = oss_mixer_name_to_channel (
				options_get_symb ("OSSMixerChannel2"));

		if (mixer_channel1 == -1)
			fatal ("Bad first OSS mixer channel!");
		if (mixer_channel2 == -1)
			fatal ("Bad second OSS mixer channel!");

		/* test mixer channels */
		mixer_channel_current = mixer_channel1;
		if (oss_read_mixer () == -1)
			mixer_channel1 = -1;

		mixer_channel_current = mixer_channel2;
		if (oss_read_mixer () == -1)
			mixer_channel2 = -1;

		if (mixer_channel1 != -1)
			mixer_channel_current = mixer_channel1;
	}
#endif

	return set_capabilities (caps);
}

static void oss_shutdown ()
{
#ifdef OSSv3_MIXER
	if (mixer_fd != -1) {
		close (mixer_fd);
		mixer_fd = -1;
	}
#endif
}

static void oss_close ()
{
	if (dsp_fd != -1) {
		close (dsp_fd);
		dsp_fd = -1;
		logit ("Audio device closed");
	}

	started = false;
	params.channels = 0;
	params.rate = 0;
	params.fmt = 0;
}

/* Return 0 on error. */
static int oss_set_params ()
{
	int req_format;
	int req_channels;
	char fmt_name[SFMT_STR_MAX];

	/* Set format */
	switch (params.fmt & SFMT_MASK_FORMAT) {
		case SFMT_S8:
			req_format = AFMT_S8;
			break;
		case SFMT_U8:
			req_format = AFMT_U8;
			break;
		case SFMT_S16:
			if (params.fmt & SFMT_LE)
				req_format = AFMT_S16_LE;
			else
				req_format = AFMT_S16_BE;
			break;
		default:
			error ("Format %s is not supported by the device",
			        sfmt_str (params.fmt, fmt_name, sizeof (fmt_name)));
			return 0;
	}

	if (ioctl (dsp_fd, SNDCTL_DSP_SETFMT, &req_format) == -1) {
		error_errno ("Can't set audio format", errno);
		oss_close ();
		return 0;
	}

	/* Set number of channels */
	req_channels = params.channels;
	if (ioctl (dsp_fd, SNDCTL_DSP_CHANNELS, &req_channels) == -1) {
		char *err = xstrerror (errno);
		error ("Can't set number of channels to %d: %s",
		        params.channels, err);
		free (err);
		oss_close ();
		return 0;
	}
	if (params.channels != req_channels) {
		error ("Can't set number of channels to %d, "
		       "device doesn't support this value",
				params.channels);
		oss_close ();
		return 0;
	}

	/* Set sample rate */
	if (ioctl (dsp_fd, SNDCTL_DSP_SPEED, &params.rate) == -1) {
		char *err = xstrerror (errno);
		error ("Can't set sampling rate to %d: %s", params.rate, err);
		free (err);
		oss_close ();
		return 0;
	}

	logit ("Audio parameters set to: %s, %d channels, %dHz",
	        sfmt_str (params.fmt, fmt_name, sizeof (fmt_name)),
	        params.channels, params.rate);

	return 1;
}

/* Return 0 on failure. */
static int oss_open (struct sound_params *sound_params)
{
	params = *sound_params;

	if (!open_dev ())
		return 0;

	if (!oss_set_params ()) {
		oss_close ();
		return 0;
	}

	started = true;

	return 1;
}

/* Return -1 on error, or number of bytes played when okay. */
static int oss_play (const char *buff, const size_t size)
{
	ssize_t ssize = (ssize_t) size;
	ssize_t count = 0;

	if (dsp_fd == -1) {
		error ("Can't play: audio device isn't opened!");
		return -1;
	}

	while (count < ssize) {
		ssize_t rc;

		rc = write (dsp_fd, buff + count, ssize - count);
		if (rc == -1) {
			error_errno ("Error writing pcm sound", errno);
			return -1;
		}

		count += rc;
	}

	return count;
}

/* Set PCM volume */
static void oss_set_mixer (int vol)
{
#ifdef OSSv3_MIXER
	if (mixer_fd != -1)
#else
	if (dsp_fd != -1)
#endif
	{
		vol = CLAMP(0, vol, 100);
		vol = vol | (vol << 8);
#ifdef OSSv3_MIXER
		if (ioctl (mixer_fd, MIXER_WRITE(mixer_channel_current), &vol) == -1)
#else
		if (ioctl (dsp_fd, SNDCTL_DSP_SETPLAYVOL, &vol) == -1)
#endif
		{
			error ("Can't set mixer: ioctl() failed");
		}
	}
}

/* Return number of bytes in device buffer. */
static int oss_get_buff_fill ()
{
	audio_buf_info buff_info;

	if (dsp_fd == -1)
		return 0;

	if (ioctl (dsp_fd, SNDCTL_DSP_GETOSPACE, &buff_info) == -1) {
		error ("SNDCTL_DSP_GETOSPACE failed");
		return 0;
	}

	return (buff_info.fragstotal * buff_info.fragsize) - buff_info.bytes;
}

/* Reset device buffer and stop playing immediately.  Return 0 on error. */
static int oss_reset ()
{
	if (dsp_fd == -1) {
		logit ("Reset when audio device is not opened");
		return 0;
	}

	logit ("Resetting audio device");

	if (ioctl (dsp_fd, SNDCTL_DSP_RESET, NULL) == -1)
		error ("Resetting audio device failed");
	close (dsp_fd);
	dsp_fd = -1;
	if (!open_dev () || !oss_set_params ()) {
		error ("Failed to open audio device after resetting");
		return 0;
	}

	return 1;
}

static void oss_toggle_mixer_channel ()
{
#ifdef OSSv3_MIXER
	if (mixer_channel_current == mixer_channel1 && mixer_channel2 != -1)
		mixer_channel_current = mixer_channel2;
	else if (mixer_channel1 != -1)
		mixer_channel_current = mixer_channel1;
#endif
}

static char *oss_get_mixer_channel_name ()
{
#ifdef OSSv3_MIXER
	if (mixer_channel_current == mixer_channel1)
		return xstrdup (options_get_symb ("OSSMixerChannel1"));
	return xstrdup (options_get_symb ("OSSMixerChannel2"));
#else
	return xstrdup ("moc");
#endif
}

static int oss_get_rate ()
{
	return params.rate;
}

void oss_funcs (struct hw_funcs *funcs)
{
	funcs->init = oss_init;
	funcs->shutdown = oss_shutdown;
	funcs->open = oss_open;
	funcs->close = oss_close;
	funcs->play = oss_play;
	funcs->read_mixer = oss_read_mixer;
	funcs->set_mixer = oss_set_mixer;
	funcs->get_buff_fill = oss_get_buff_fill;
	funcs->reset = oss_reset;
	funcs->get_rate = oss_get_rate;
	funcs->toggle_mixer_channel = oss_toggle_mixer_channel;
	funcs->get_mixer_channel_name = oss_get_mixer_channel_name;
}
