/*

 *  amidi.c - read from/write to RawMIDI ports

 *

 *  Copyright (c) Clemens Ladisch <clemens@ladisch.de>

 *

 *

 *   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 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#define _GNU_SOURCE

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <string.h>

#include <ctype.h>

#include <math.h>

#include <getopt.h>

#include <errno.h>

#include <signal.h>

#include <sys/timerfd.h>

#include <sys/types.h>

#include <poll.h>

#include <sys/stat.h>

#include <unistd.h>

#include <fcntl.h>

#include <alsa/asoundlib.h>

#include "aconfig.h"

#include "version.h"

#define NSEC_PER_SEC 1000000000L

static int do_device_list, do_rawmidi_list;

static char *port_name = "default";

static char *send_file_name;

static char *receive_file_name;

static char *send_hex;

static char *send_data;

static int send_data_length;

static int receive_file;

static int dump;

static float timeout;

static int stop;

static int sysex_interval;

static snd_rawmidi_t *input, **inputp;

static snd_rawmidi_t *output, **outputp;

static void error(const char *format, ...)

{

	va_list ap;

	va_start(ap, format);

	vfprintf(stderr, format, ap);

	va_end(ap);

	putc('\n', stderr);

}

static void usage(void)

{

	printf(

		"Usage: amidi options\n"

		"\n"

		"-h, --help                      this help\n"

		"-V, --version                   print current version\n"

		"-l, --list-devices              list all hardware ports\n"

		"-L, --list-rawmidis             list all RawMIDI definitions\n"

		"-p, --port=name                 select port by name\n"

		"-s, --send=file                 send the contents of a (.syx) file\n"

		"-r, --receive=file              write received data into a file\n"

		"-S, --send-hex=\"...\"            send hexadecimal bytes\n"

		"-d, --dump                      print received data as hexadecimal bytes\n"

		"-t, --timeout=seconds           exits when no data has been received\n"

		"                                for the specified duration\n"

		"-a, --active-sensing            include active sensing bytes\n"

		"-c, --clock                     include clock bytes\n"

		"-i, --sysex-interval=mseconds   delay in between each SysEx message\n");

}

static void version(void)

{

	puts("amidi version " SND_UTIL_VERSION_STR);

}

static void *my_malloc(size_t size)

{

	void *p = malloc(size);

	if (!p) {

		error("out of memory");

		exit(EXIT_FAILURE);

	}

	return p;

}

static void list_device(snd_ctl_t *ctl, int card, int device)

{

	snd_rawmidi_info_t *info;

	const char *name;

	const char *sub_name;

	int subs, subs_in, subs_out;

	int sub;

	int err;

	snd_rawmidi_info_alloca(&info;;

	snd_rawmidi_info_set_device(info, device);

	snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_INPUT);

	err = snd_ctl_rawmidi_info(ctl, info);

	if (err >= 0)

		subs_in = snd_rawmidi_info_get_subdevices_count(info);

	else

		subs_in = 0;

	snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_OUTPUT);

	err = snd_ctl_rawmidi_info(ctl, info);

	if (err >= 0)

		subs_out = snd_rawmidi_info_get_subdevices_count(info);

	else

		subs_out = 0;

	subs = subs_in > subs_out ? subs_in : subs_out;

	if (!subs)

		return;

	for (sub = 0; sub < subs; ++sub) {

		snd_rawmidi_info_set_stream(info, sub < subs_in ?

					    SND_RAWMIDI_STREAM_INPUT :

					    SND_RAWMIDI_STREAM_OUTPUT);

		snd_rawmidi_info_set_subdevice(info, sub);

		err = snd_ctl_rawmidi_info(ctl, info);

		if (err < 0) {

			error("cannot get rawmidi information %d:%d:%d: %s\n",

			      card, device, sub, snd_strerror(err));

			return;

		}

		name = snd_rawmidi_info_get_name(info);

		sub_name = snd_rawmidi_info_get_subdevice_name(info);

		if (sub == 0 && sub_name[0] == '\0') {

			printf("%c%c  hw:%d,%d    %s",

			       sub < subs_in ? 'I' : ' ',

			       sub < subs_out ? 'O' : ' ',

			       card, device, name);

			if (subs > 1)

				printf(" (%d subdevices)", subs);

			putchar('\n');

			break;

		} else {

			printf("%c%c  hw:%d,%d,%d  %s\n",

			       sub < subs_in ? 'I' : ' ',

			       sub < subs_out ? 'O' : ' ',

			       card, device, sub, sub_name);

		}

	}

}

static void list_card_devices(int card)

{

	snd_ctl_t *ctl;

	char name[32];

	int device;

	int err;

	sprintf(name, "hw:%d", card);

	if ((err = snd_ctl_open(&ctl, name, 0)) < 0) {

		error("cannot open control for card %d: %s", card, snd_strerror(err));

		return;

	}

	device = -1;

	for (;;) {

		if ((err = snd_ctl_rawmidi_next_device(ctl, &device)) < 0) {

			error("cannot determine device number: %s", snd_strerror(err));

			break;

		}

		if (device < 0)

			break;

		list_device(ctl, card, device);

	}

	snd_ctl_close(ctl);

}

static void device_list(void)

{

	int card, err;

	card = -1;

	if ((err = snd_card_next(&card)) < 0) {

		error("cannot determine card number: %s", snd_strerror(err));

		return;

	}

	if (card < 0) {

		error("no sound card found");

		return;

	}

	puts("Dir Device    Name");

	do {

		list_card_devices(card);

		if ((err = snd_card_next(&card)) < 0) {

			error("cannot determine card number: %s", snd_strerror(err));

			break;

		}

	} while (card >= 0);

}

static void rawmidi_list(void)

{

	snd_output_t *output;

	snd_config_t *config;

	int err;

	if ((err = snd_config_update()) < 0) {

		error("snd_config_update failed: %s", snd_strerror(err));

		return;

	}

	if ((err = snd_output_stdio_attach(&output, stdout, 0)) < 0) {

		error("snd_output_stdio_attach failed: %s", snd_strerror(err));

		return;

	}

	if (snd_config_search(snd_config, "rawmidi", &config) >= 0) {

		puts("RawMIDI list:");

		snd_config_save(config, output);

	}

	snd_output_close(output);

}

static int send_midi_interleaved(void)

{

	int err;

	char *data = send_data;

	size_t buffer_size;

	snd_rawmidi_params_t *param;

	snd_rawmidi_status_t *st;

	snd_rawmidi_status_alloca(&st);

	snd_rawmidi_params_alloca(¶m;;

	snd_rawmidi_params_current(output, param);

	buffer_size = snd_rawmidi_params_get_buffer_size(param);

	while (data < (send_data + send_data_length)) {

		int len = send_data + send_data_length - data;

		char *temp;

		if (data > send_data) {

			snd_rawmidi_status(output, st);

			do {

				/* 320 µs per byte as noted in Page 1 of MIDI spec */

				usleep((buffer_size - snd_rawmidi_status_get_avail(st)) * 320);

				snd_rawmidi_status(output, st);

			} while(snd_rawmidi_status_get_avail(st) < buffer_size);

			usleep(sysex_interval * 1000);

		}

		/* find end of SysEx */

		if ((temp = memchr(data, 0xf7, len)) != NULL)

			len = temp - data + 1;

		if ((err = snd_rawmidi_write(output, data, len)) < 0)

			return err;

		data += len;

	}

	return 0;

}

static void load_file(void)

{

	int fd;

	off_t length;

	fd = open(send_file_name, O_RDONLY);

	if (fd == -1) {

		error("cannot open %s - %s", send_file_name, strerror(errno));

		return;

	}

	length = lseek(fd, 0, SEEK_END);

	if (length == (off_t)-1) {

		error("cannot determine length of %s: %s", send_file_name, strerror(errno));

		goto _error;

	}

	send_data = my_malloc(length);

	lseek(fd, 0, SEEK_SET);

	if (read(fd, send_data, length) != length) {

		error("cannot read from %s: %s", send_file_name, strerror(errno));

		goto _error;

	}

	if (length >= 4 && !memcmp(send_data, "MThd", 4)) {

		error("%s is a Standard MIDI File; use aplaymidi to send it", send_file_name);

		goto _error;

	}

	send_data_length = length;

	goto _exit;

_error:

	free(send_data);

	send_data = NULL;

_exit:

	close(fd);

}

static int hex_value(char c)

{

	if ('0' <= c && c <= '9')

		return c - '0';

	if ('A' <= c && c <= 'F')

		return c - 'A' + 10;

	if ('a' <= c && c <= 'f')

		return c - 'a' + 10;

	error("invalid character %c", c);

	return -1;

}

static void parse_data(void)

{

	const char *p;

	int i, value;

	send_data = my_malloc(strlen(send_hex)); /* guesstimate */

	i = 0;

	value = -1; /* value is >= 0 when the first hex digit of a byte has been read */

	for (p = send_hex; *p; ++p) {

		int digit;

		if (isspace((unsigned char)*p)) {

			if (value >= 0) {

				send_data[i++] = value;

				value = -1;

			}

			continue;

		}

		digit = hex_value(*p);

		if (digit < 0) {

			send_data = NULL;

			return;

		}

		if (value < 0) {

			value = digit;

		} else {

			send_data[i++] = (value << 4) | digit;

			value = -1;

		}

	}

	if (value >= 0)

		send_data[i++] = value;

	send_data_length = i;

}

/*

 * prints MIDI commands, formatting them nicely

 */

static void print_byte(unsigned char byte)

{

	static enum {

		STATE_UNKNOWN,

		STATE_1PARAM,

		STATE_1PARAM_CONTINUE,

		STATE_2PARAM_1,

		STATE_2PARAM_2,

		STATE_2PARAM_1_CONTINUE,

		STATE_SYSEX

	} state = STATE_UNKNOWN;

	int newline = 0;

	if (byte >= 0xf8)

		newline = 1;

	else if (byte >= 0xf0) {

		newline = 1;

		switch (byte) {

		case 0xf0:

			state = STATE_SYSEX;

			break;

		case 0xf1:

		case 0xf3:

			state = STATE_1PARAM;

			break;

		case 0xf2:

			state = STATE_2PARAM_1;

			break;

		case 0xf4:

		case 0xf5:

		case 0xf6:

			state = STATE_UNKNOWN;

			break;

		case 0xf7:

			newline = state != STATE_SYSEX;

			state = STATE_UNKNOWN;

			break;

		}

	} else if (byte >= 0x80) {

		newline = 1;

		if (byte >= 0xc0 && byte <= 0xdf)

			state = STATE_1PARAM;

		else

			state = STATE_2PARAM_1;

	} else /* b < 0x80 */ {

		int running_status = 0;

		newline = state == STATE_UNKNOWN;

		switch (state) {

		case STATE_1PARAM:

			state = STATE_1PARAM_CONTINUE;

			break;

		case STATE_1PARAM_CONTINUE:

			running_status = 1;

			break;

		case STATE_2PARAM_1:

			state = STATE_2PARAM_2;

			break;

		case STATE_2PARAM_2:

			state = STATE_2PARAM_1_CONTINUE;

			break;

		case STATE_2PARAM_1_CONTINUE:

			running_status = 1;

			state = STATE_2PARAM_2;

			break;

		default:

			break;

		}

		if (running_status)

			fputs("\n  ", stdout);

	}

	printf("%c%02X", newline ? '\n' : ' ', byte);

}

static void sig_handler(int dummy)

{

	stop = 1;

}

static void add_send_hex_data(const char *str)

{

	int length;

	char *s;

	length = (send_hex ? strlen(send_hex) + 1 : 0) + strlen(str) + 1;

	s = my_malloc(length);

	if (send_hex) {

		strcpy(s, send_hex);

		strcat(s, " ");

	} else {

		s[0] = '\0';

	}

	strcat(s, str);

	free(send_hex);

	send_hex = s;

}

int main(int argc, char *argv[])

{

	static const char short_options[] = "hVlLp:s:r:S::dt:aci:";

	static const struct option long_options[] = {

		{"help", 0, NULL, 'h'},

		{"version", 0, NULL, 'V'},

		{"list-devices", 0, NULL, 'l'},

		{"list-rawmidis", 0, NULL, 'L'},

		{"port", 1, NULL, 'p'},

		{"send", 1, NULL, 's'},

		{"receive", 1, NULL, 'r'},

		{"send-hex", 2, NULL, 'S'},

		{"dump", 0, NULL, 'd'},

		{"timeout", 1, NULL, 't'},

		{"active-sensing", 0, NULL, 'a'},

		{"clock", 0, NULL, 'c'},

		{"sysex-interval", 1, NULL, 'i'},

		{0}

	};

	int c, err, ok = 0;

	int ignore_active_sensing = 1;

	int ignore_clock = 1;

	int do_send_hex = 0;

	struct itimerspec itimerspec = { .it_interval = { 0, 0 } };

	while ((c = getopt_long(argc, argv, short_options,

		     		long_options, NULL)) != -1) {

		switch (c) {

		case 'h':

			usage();

			return 0;

		case 'V':

			version();

			return 0;

		case 'l':

			do_device_list = 1;

			break;

		case 'L':

			do_rawmidi_list = 1;

			break;

		case 'p':

			port_name = optarg;

			break;

		case 's':

			send_file_name = optarg;

			break;

		case 'r':

			receive_file_name = optarg;

			break;

		case 'S':

			do_send_hex = 1;

			if (optarg)

				add_send_hex_data(optarg);

			break;

		case 'd':

			dump = 1;

			break;

		case 't':

			if (optarg)

				timeout = atof(optarg);

			break;

		case 'a':

			ignore_active_sensing = 0;

			break;

		case 'c':

			ignore_clock = 0;

			break;

		case 'i':

			sysex_interval = atoi(optarg);

			break;

		default:

			error("Try `amidi --help' for more information.");

			return 1;

		}

	}

	if (do_send_hex) {

		/* data for -S can be specified as multiple arguments */

		if (!send_hex && !argv[optind]) {

			error("Please specify some data for --send-hex.");

			return 1;

		}

		for (; argv[optind]; ++optind)

			add_send_hex_data(argv[optind]);

	} else {

		if (argv[optind]) {

			error("%s is not an option.", argv[optind]);

			return 1;

		}

	}

	if (do_rawmidi_list)

		rawmidi_list();

	if (do_device_list)

		device_list();

	if (do_rawmidi_list || do_device_list)

		return 0;

	if (!send_file_name && !receive_file_name && !send_hex && !dump) {

		error("Please specify at least one of --send, --receive, --send-hex, or --dump.");

		return 1;

	}

	if (send_file_name && send_hex) {

		error("--send and --send-hex cannot be specified at the same time.");

		return 1;

	}

	if (send_file_name)

		load_file();

	else if (send_hex)

		parse_data();

	if ((send_file_name || send_hex) && !send_data)

		return 1;

	if (receive_file_name) {

		receive_file = creat(receive_file_name, 0666);

		if (receive_file == -1) {

			error("cannot create %s: %s", receive_file_name, strerror(errno));

			return -1;

		}

	} else {

		receive_file = -1;

	}

	if (receive_file_name || dump)

		inputp = &input;

	else

		inputp = NULL;

	if (send_data)

		outputp = &output;

	else

		outputp = NULL;

	if ((err = snd_rawmidi_open(inputp, outputp, port_name, SND_RAWMIDI_NONBLOCK)) < 0) {

		error("cannot open port \"%s\": %s", port_name, snd_strerror(err));

		goto _exit2;

	}

	if (inputp)

		snd_rawmidi_read(input, NULL, 0); /* trigger reading */

	if (send_data) {

		if ((err = snd_rawmidi_nonblock(output, 0)) < 0) {

			error("cannot set blocking mode: %s", snd_strerror(err));

			goto _exit;

		}

		if (!sysex_interval) {

			if ((err = snd_rawmidi_write(output, send_data, send_data_length)) < 0) {

				error("cannot send data: %s", snd_strerror(err));

				return err;

			}

		} else {

			if ((err = send_midi_interleaved()) < 0) {

				error("cannot send data: %s", snd_strerror(err));

				return err;

			}

		}

	}

	if (inputp) {

		int read = 0;

		int npfds;

		struct pollfd *pfds;

		npfds = 1 + snd_rawmidi_poll_descriptors_count(input);

		pfds = alloca(npfds * sizeof(struct pollfd));

		if (timeout > 0) {

			pfds[0].fd = timerfd_create(CLOCK_MONOTONIC, 0);

			if (pfds[0].fd == -1) {

				error("cannot create timer: %s", strerror(errno));

				goto _exit;

			}

			pfds[0].events = POLLIN;

		} else {

			pfds[0].fd = -1;

		}

		snd_rawmidi_poll_descriptors(input, &pfds[1], npfds - 1);

		signal(SIGINT, sig_handler);

		if (timeout > 0) {

			float timeout_int;

			itimerspec.it_value.tv_nsec = modff(timeout, &timeout_int) * NSEC_PER_SEC;

			itimerspec.it_value.tv_sec = timeout_int;

			err = timerfd_settime(pfds[0].fd, 0, &itimerspec, NULL);

			if (err < 0) {

				error("cannot set timer: %s", strerror(errno));

				goto _exit;

			}

		}

		for (;;) {

			unsigned char buf[256];

			int i, length;

			unsigned short revents;

			err = poll(pfds, npfds, -1);

			if (stop || (err < 0 && errno == EINTR))

				break;

			if (err < 0) {

				error("poll failed: %s", strerror(errno));

				break;

			}

			err = snd_rawmidi_poll_descriptors_revents(input, &pfds[1], npfds - 1, &revents);

			if (err < 0) {

				error("cannot get poll events: %s", snd_strerror(errno));

				break;

			}

			if (revents & (POLLERR | POLLHUP))

				break;

			if (!(revents & POLLIN)) {

				if (pfds[0].revents & POLLIN)

					break;

				continue;

			}

			err = snd_rawmidi_read(input, buf, sizeof(buf));

			if (err == -EAGAIN)

				continue;

			if (err < 0) {

				error("cannot read from port \"%s\": %s", port_name, snd_strerror(err));

				break;

			}

			length = 0;

			for (i = 0; i < err; ++i)

				if ((buf[i] != MIDI_CMD_COMMON_CLOCK &&

				     buf[i] != MIDI_CMD_COMMON_SENSING) ||

				    (buf[i] == MIDI_CMD_COMMON_CLOCK   && !ignore_clock) ||

				    (buf[i] == MIDI_CMD_COMMON_SENSING && !ignore_active_sensing))

					buf[length++] = buf[i];

			if (length == 0)

				continue;

			read += length;

			if (receive_file != -1)

				write(receive_file, buf, length);

			if (dump) {

				for (i = 0; i < length; ++i)

					print_byte(buf[i]);

				fflush(stdout);

			}

			if (timeout > 0) {

				err = timerfd_settime(pfds[0].fd, 0, &itimerspec, NULL);

				if (err < 0) {

					error("cannot set timer: %s", strerror(errno));

					break;

				}

			}

		}

		if (isatty(fileno(stdout)))

			printf("\n%d bytes read\n", read);

	}

	ok = 1;

_exit:

	if (inputp)

		snd_rawmidi_close(input);

	if (outputp)

		snd_rawmidi_close(output);

_exit2:

	if (receive_file != -1)

		close(receive_file);

	return !ok;

}