#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/soundcard.h>

static int fd;

static void panic (const char *s) {
	fprintf (stderr, "oss: %s\n", s);
	exit (1);
}

/* PROC C.oss.init (VAL INT sample.rate) */
void _oss_init (int *w) {
	int speed = w[0];
	int channels = 2;
	int format = AFMT_S16_LE;

	fd = open ("/dev/dsp", O_RDWR);
	if (fd < 0)
		panic ("cannot open /dev/dsp");

	if (ioctl (fd, SNDCTL_DSP_SETFMT, &format) < 0)
		panic ("cannot set format");
	if (ioctl (fd, SNDCTL_DSP_CHANNELS, &channels) < 0)
		panic ("cannot set channels");
	if (ioctl (fd, SNDCTL_DSP_SPEED, &speed) < 0)
		panic ("cannot set speed");
}

/* PROC B.oss.play (VAL []INT16 data) */
void _oss_play (int *w) {
	unsigned short *data = (unsigned short *) w[0];
	int count = w[1];

	while (count > 0) {
		int r = write (fd, (const char *) data, count * 2);
		if (r < 0)
			panic ("write failed");
		count -= r;
	}
}