/*
 * midinator.c
 *
 * Poke MIDI devices
 *
 * (c) 2012 Thomas White <taw@bitwiz.org.uk>
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


static void show_help(const char *s)
{
	printf("Syntax: %s [options]\n\n", s);
	printf(
"Do MIDI stuff\n"
"\n"
" -h, --help              Display this help message.\n"
);
}


static void midi_readable(int fd)
{
	int rval, i;
	unsigned char buf[32];

	rval = read(fd, buf, 32);

	if ( (rval == -1) || (rval == 0) ) {
		fprintf(stderr, "Read error.\n");
		return;
	}

	if ( buf[0] == 0xfe ) {
		write(fd, buf, 1);
		return;
	}

	for ( i=0; i<rval; i++ ) {
		if ( i != 0 ) printf(" : ");
		printf("%hhx", buf[i]);
	}
	printf("\n");

	if ( (buf[0] & 0xf0) == 0x90 ) {
		unsigned char sbuf[32];
		sbuf[0] = 0x91;
		sbuf[1] = buf[1] + 12;
		sbuf[2] = buf[2] >> 0;
		write(fd, sbuf, 3);
	}

	if ( (buf[0] & 0xf0) == 0xc0 ) {
		unsigned char sbuf[32];
		sbuf[0] = 0xc1;
		sbuf[1] = buf[1];
		write(fd, sbuf, 2);
	}

	if ( (buf[0] & 0xf0) == 0xf0 ) {
		unsigned char sbuf[32];
		sbuf[0] = buf[0];
		sbuf[1] = buf[1];
		sbuf[2] = buf[2];
		write(fd, sbuf, 3);
	}
}


int main(int argc, char *argv[])
{
	int c;
	int fd;
	int rval;

	/* Long options */
	const struct option longopts[] = {
		{"help",               0, NULL,               'h'},
		{0, 0, NULL, 0}
	};

	/* Short options */
	while ((c = getopt_long(argc, argv, "h",
	                        longopts, NULL)) != -1) {

		switch (c) {
		case 'h' :
			show_help(argv[0]);
			return 0;

		case 0 :
			break;

		default :
			return 1;
		}

	}

	fd = open("/dev/snd/midiC1D0", O_RDWR);
	if ( fd == -1 ) {
		fprintf(stderr, "Couldn't open MIDI device.\n");
		return 1;
	}

	int i;
	for ( i=0; i<8; i++ ) {
		unsigned char sbuf[32];
		sbuf[0] = 0xb0 || i;
		sbuf[1] = 0x78;
		sbuf[2] = 0x00;
		write(fd, sbuf, 3);
	}

	do {

		fd_set fds;
		struct timeval tv;
		int sval;

		FD_ZERO(&fds);
		FD_SET(fd, &fds);

		tv.tv_sec = 1;
		tv.tv_usec = 0;

		sval = select(fd+1, &fds, NULL, NULL, &tv);

		rval = 0;
		if ( sval == -1 ) {
			int err = errno;
			fprintf(stderr, "select() failed: %s\n", strerror(err));
			rval = 1;
		} else if ( sval != 0 ) {

			midi_readable(fd);

		} /* else timeout */

	} while ( !rval );

	close(fd);

	return 0;
}