/*
 * connect / disconnect two subscriber ports
 *   ver.0.1.3
 *
 * Copyright (C) 1999 Takashi Iwai
 * 
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 * 
 *  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.
 *
 */

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdarg.h>
#include <sys/ioctl.h>
#include <sys/asoundlib.h>

static void error_handler(const char *file, int line, const char *function, int err, const char *fmt, ...)
{
	va_list arg;

	if (err == ENOENT)	/* Ignore those misleading "warnings" */
		return;
	va_start(arg, fmt);
	fprintf(stderr, "ALSA lib %s:%i:(%s) ", file, line, function);
	vfprintf(stderr, fmt, arg);
	if (err)
		fprintf(stderr, ": %s", snd_strerror(err));
	putc('\n', stderr);
	va_end(arg);
}

static void usage(void)
{
	fprintf(stderr, "aconnect - ALSA sequencer connection manager\n");
	fprintf(stderr, "Copyright (C) 1999-2000 Takashi Iwai\n");
	fprintf(stderr, "Usage:\n");
	fprintf(stderr, " * Connection/disconnection betwen two ports\n");
	fprintf(stderr, "   aconnect [-options] sender receiver\n");
	fprintf(stderr, "     sender, receiver = client:port pair\n");
	fprintf(stderr, "     -d,--disconnect     disconnect\n");
	fprintf(stderr, "     -e,--exclusive      exclusive connection\n");
	fprintf(stderr, "     -r,--real #         convert real-time-stamp on queue\n");
	fprintf(stderr, "     -t,--tick #         convert tick-time-stamp on queue\n");
	fprintf(stderr, "     -g,--group name     set the group name\n");
	fprintf(stderr, " * List connected ports (no subscription action)\n");
	fprintf(stderr, "   aconnect -i|-o [-options]\n");
	fprintf(stderr, "     -i,--input          list input (readable) ports\n");
	fprintf(stderr, "     -o,--output         list output (writable) ports\n");
	fprintf(stderr, "     -g,--group name     specify the group name\n");
	fprintf(stderr, "     -l,--list           list current connections of each port\n");
	fprintf(stderr, " * Remove all exported connections\n");
	fprintf(stderr, "     -x, --removeall\n");
}

/*
 * parse command line to client:port
 * NB: the given string will be broken.
 */
static int parse_address(snd_seq_t *seq, snd_seq_addr_t *addr, char *arg)
{
	char *p;
	int client, port;

	if ((p = strpbrk(arg, ":.")) == NULL)
		return -1;
	if ((port = atoi(p + 1)) < 0)
		return -1;
	addr->port = port;
	if (isdigit(*arg)) {
		client = atoi(arg);
		if (client < 0)
			return -1;
		addr->client = client;
	} else {
		/* convert from the name */
		snd_seq_client_info_t cinfo;
		int len;

		*p = 0;
		len = strlen(arg);
		if (len <= 0)
			return -1;
		cinfo.client = -1;
		while (snd_seq_query_next_client(seq, &cinfo) >= 0) {
			if (! strncmp(cinfo.name, arg, len)) {
				addr->client = cinfo.client;
				return 0;
			}
		}
		return -1; /* not found */
	}
	return 0;
}

/*
 * check permission (capability) of specified port
 */
static int check_permission(snd_seq_port_info_t *pinfo, char *group, int perm)
{
	if ((pinfo->capability & perm) == perm &&
	    ! (pinfo->capability & SND_SEQ_PORT_CAP_NO_EXPORT))
		return 1;
	if (*group && (pinfo->cap_group & perm) == perm &&
	    ! (pinfo->cap_group & SND_SEQ_PORT_CAP_NO_EXPORT))
		return 1;
	return 0;
}

/*
 * list subscribers of specified type
 */
static void list_each_subs(snd_seq_t *seq, snd_seq_query_subs_t *subs, int type, char *msg)
{
	subs->type = type;
	subs->index = 0;
	while (snd_seq_query_port_subscribers(seq, subs) >= 0) {
		if (subs->index == 0)
			printf("\t%s: ", msg);
		else
			printf(", ");
		printf("%d:%d", subs->addr.client, subs->addr.port);
		if (subs->exclusive)
			printf("[ex]");
		if (subs->convert_time)
			printf("[%s:%d]",
			       (subs->realtime ? "real" : "tick"),
			       subs->queue);
		subs->index++;
	}
	if (subs->index)
		printf("\n");
}

/*
 * list subscribers
 */
static void list_subscribers(snd_seq_t *seq, int client, int port)
{
	snd_seq_query_subs_t subs;
	memset(&subs, 0, sizeof(subs));
	subs.client = client;
	subs.port = port;
	list_each_subs(seq, &subs, SND_SEQ_QUERY_SUBS_READ, "Connecting To");
	list_each_subs(seq, &subs, SND_SEQ_QUERY_SUBS_WRITE, "Connected From");
}

/*
 * search all ports
 */
typedef void (*action_func_t)(snd_seq_t *seq, snd_seq_client_info_t *cinfo, snd_seq_port_info_t *pinfo, int count);

static void do_search_port(snd_seq_t *seq, char *group, int perm, action_func_t do_action)
{
	snd_seq_client_info_t cinfo;
	snd_seq_port_info_t pinfo;
	int count;

	cinfo.client = -1;
	while (snd_seq_query_next_client(seq, &cinfo) >= 0) {
		/* reset query info */
		pinfo.client = cinfo.client;
		pinfo.port = -1;
		count = 0;
		while (snd_seq_query_next_port(seq, &pinfo) >= 0) {
			if (*group && strcmp(pinfo.group, group))
				continue;
			if (check_permission(&pinfo, group, perm)) {
				do_action(seq, &cinfo, &pinfo, count);
				count++;
			}
		}
	}
}


static void print_port(snd_seq_t *seq, snd_seq_client_info_t *cinfo,
		       snd_seq_port_info_t *pinfo, int count)
{
	if (! count) {
		printf("client %d: '%s' [group=%s] [type=%s]\n",
		       cinfo->client, cinfo->name, cinfo->group,
		       (cinfo->type == USER_CLIENT ? "user" : "kernel"));
	}
	printf("  %3d '%-16s' [group=%s]\n",
	       pinfo->port, pinfo->name, pinfo->group);
}

static void print_port_and_subs(snd_seq_t *seq, snd_seq_client_info_t *cinfo,
				snd_seq_port_info_t *pinfo, int count)
{
	print_port(seq, cinfo, pinfo, count);
	list_subscribers(seq, pinfo->client, pinfo->port);
}


/*
 * list all ports
 */

static void list_ports(snd_seq_t *seq, char *group, int perm, int list_subs)
{
	if (list_subs)
		do_search_port(seq, group, perm, print_port_and_subs);
	else
		do_search_port(seq, group, perm, print_port);
}

/*
 * remove all (exported) connections
 */
static void remove_connection(snd_seq_t *seq, snd_seq_client_info_t *cinfo,
			      snd_seq_port_info_t *pinfo, int count)
{
	snd_seq_query_subs_t query;

	memset(&query, 0, sizeof(query));
	query.client = pinfo->client;
	query.port = pinfo->port;

	query.type = SND_SEQ_QUERY_SUBS_READ;
	query.index = 0;
	for (query.index = 0; snd_seq_query_port_subscribers(seq, &query) >= 0;
	     query.index++) {
		snd_seq_port_info_t port;
		snd_seq_port_subscribe_t subs;
		if (snd_seq_get_any_port_info(seq, query.addr.client, query.addr.port, &port) < 0)
			continue;
		if (!(port.capability & SND_SEQ_PORT_CAP_SUBS_READ))
			continue;
		if (port.capability & SND_SEQ_PORT_CAP_NO_EXPORT)
			continue;
		memset(&subs, 0, sizeof(subs));
		subs.queue = query.queue;
		subs.sender.client = query.client;
		subs.sender.port = query.port;
		subs.dest.client = query.addr.client;
		subs.dest.port = query.addr.port;
		snd_seq_unsubscribe_port(seq, &subs);
	}

	query.type = SND_SEQ_QUERY_SUBS_WRITE;
	query.index = 0;
	for (query.index = 0; snd_seq_query_port_subscribers(seq, &query) >= 0;
	     query.index++) {
		snd_seq_port_info_t port;
		snd_seq_port_subscribe_t subs;
		if (snd_seq_get_any_port_info(seq, query.addr.client, query.addr.port, &port) < 0)
			continue;
		if (!(port.capability & SND_SEQ_PORT_CAP_SUBS_WRITE))
			continue;
		if (port.capability & SND_SEQ_PORT_CAP_NO_EXPORT)
			continue;
		memset(&subs, 0, sizeof(subs));
		subs.queue = query.queue;
		subs.sender.client = query.addr.client;
		subs.sender.port = query.addr.port;
		subs.dest.client = query.client;
		subs.dest.port = query.port;
		snd_seq_unsubscribe_port(seq, &subs);
	}
}

static void remove_all_connections(snd_seq_t *seq)
{
	do_search_port(seq, "", 0, remove_connection);
}


/*
 * main..
 */

enum {
	SUBSCRIBE, UNSUBSCRIBE, LIST_INPUT, LIST_OUTPUT, REMOVE_ALL
};

static struct option long_option[] = {
	{"disconnect", 0, NULL, 'd'},
	{"input", 0, NULL, 'i'},
	{"output", 0, NULL, 'o'},
	{"group", 1, NULL, 'g'},
	{"real", 1, NULL, 'r'},
	{"tick", 1, NULL, 't'},
	{"exclusive", 0, NULL, 'e'},
	{"list", 0, NULL, 'l'},
	{"removeall", 0, NULL, 'x'},
	{NULL, 0, NULL, 0},
};

int main(int argc, char **argv)
{
	int c;
	snd_seq_t *seq;
	int queue = 0, convert_time = 0, convert_real = 0, exclusive = 0;
	int command = SUBSCRIBE;
	char *group = "";
	int client;
	int list_subs = 0;
	snd_seq_client_info_t cinfo;
	snd_seq_port_subscribe_t subs;

	while ((c = getopt_long(argc, argv, "diog:r:t:elx", long_option, NULL)) != -1) {
		switch (c) {
		case 'd':
			command = UNSUBSCRIBE;
			break;
		case 'i':
			command = LIST_INPUT;
			break;
		case 'o':
			command = LIST_OUTPUT;
			break;
		case 'g':
			group = optarg;
			break;
		case 'e':
			exclusive = 1;
			break;
		case 'r':
			queue = atoi(optarg);
			convert_time = 1;
			convert_real = 1;
			break;
		case 't':
			queue = atoi(optarg);
			convert_time = 1;
			convert_real = 0;
			break;
		case 'l':
			list_subs = 1;
			break;
		case 'x':
			command = REMOVE_ALL;
			break;
		default:
			usage();
			exit(1);
		}
	}

	if (snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0) {
		fprintf(stderr, "can't open sequencer\n");
		return 1;
	}
	
	snd_lib_error_set_handler(error_handler);

	switch (command) {
	case LIST_INPUT:
		list_ports(seq, group, SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ, list_subs);
		snd_seq_close(seq);
		return 0;
	case LIST_OUTPUT:
		list_ports(seq, group, SND_SEQ_PORT_CAP_WRITE|SND_SEQ_PORT_CAP_SUBS_WRITE, list_subs);
		snd_seq_close(seq);
		return 0;
	case REMOVE_ALL:
		remove_all_connections(seq);
		snd_seq_close(seq);
		return 0;
	}

	/* connection or disconnection */

	if (optind + 2 > argc) {
		snd_seq_close(seq);
		usage();
		exit(1);
	}

	if ((client = snd_seq_client_id(seq)) < 0) {
		snd_seq_close(seq);
		fprintf(stderr, "can't get client id\n");
		return 1;
	}

	/* set client info */
	memset(&cinfo, 0, sizeof(cinfo));
	cinfo.client = client;
	cinfo.type = USER_CLIENT;
	strcpy(cinfo.name, "ALSA Connector");
	strncpy(cinfo.group, group, sizeof(cinfo.group) - 1);
	if (snd_seq_set_client_info(seq, &cinfo) < 0) {
		snd_seq_close(seq);
		fprintf(stderr, "can't set client info\n");
		return 0;
	}

	/* set subscription */
	memset(&subs, 0, sizeof(subs));
	if (parse_address(seq, &subs.sender, argv[optind]) < 0) {
		fprintf(stderr, "invalid sender address %s\n", argv[optind]);
		return 1;
	}
	if (parse_address(seq, &subs.dest, argv[optind + 1]) < 0) {
		fprintf(stderr, "invalid destination address %s\n", argv[optind + 1]);
		return 1;
	}
	subs.queue = queue;
	subs.exclusive = exclusive;
	subs.convert_time = convert_time;
	subs.realtime = convert_real;

	if (command == UNSUBSCRIBE) {
		if (snd_seq_get_port_subscription(seq, &subs) < 0) {
			snd_seq_close(seq);
			fprintf(stderr, "No subscription is found\n");
			return 1;
		}
		if (snd_seq_unsubscribe_port(seq, &subs) < 0) {
			snd_seq_close(seq);
			fprintf(stderr, "Disconnection failed (%s)\n", snd_strerror(errno));
			return 1;
		}
	} else {
		if (snd_seq_get_port_subscription(seq, &subs) == 0) {
			snd_seq_close(seq);
			fprintf(stderr, "Connection is already subscribed\n");
			return 1;
		}
		if (snd_seq_subscribe_port(seq, &subs) < 0) {
			snd_seq_close(seq);
			fprintf(stderr, "Connection failed (%s)\n", snd_strerror(errno));
			return 1;
		}
	}

	snd_seq_close(seq);

	return 0;
}