/*                     G _ T R A N S F E R . C
 * BRL-CAD
 *
 * Copyright (c) 2006-2022 United States Government as represented by
 * the U.S. Army Research Laboratory.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; see the file named COPYING for more
 * information.
 */
/** @file g_transfer.c
 *
 * Relatively simple example database transfer program that shows how
 * to open a database, extract a serialized version of specified
 * geometry objects, transfer those objects to a remote host, and
 * using standard librt routines on the remote objects while keeping
 * the remote geometry in memory only.  The transfer program interface
 * is designed in a simple 'ttcp' fashion using libpkg.
 *
 * To compile from an install:
 * gcc -I/usr/brlcad/include/brlcad -L/usr/brlcad/lib -o g_transfer g_transfer.c -lpkg -lrt -lbu
 *
 */

#include "common.h"

/* system headers */
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include "bio.h"

/* interface headers */
#include "bu/app.h"
#include "bu/getopt.h"
#include "bu/units.h"
#include "bu/snooze.h"
#include "raytrace.h"
#include "pkg.h"


/* used by the client to pass the dbip and opened transfer file
 * descriptor.
 */
typedef struct _my_data_ {
    struct pkg_conn *connection;
    const char *server;
    int port;
} my_data;

/* simple network transport protocol. connection starts with a HELO,
 * then a variable number of GEOM/ARGS messages, then a CIAO to end.
 */
#define MAGIC_ID	"G_TRANSFER"
#define MSG_HELO	1
#define MSG_ARGS	2
#define MSG_GEOM	3
#define MSG_CIAO	4

/* static size used for temporary string buffers */
#define MAX_DIGITS	32

/* in-memory geometry database filled in by the server as it receives
 * geometry from the client.
 */
/*
 * Struct DBIP = null;
 * srv_argc = 0;
 * char **srv_argv = NULL;
 */
typedef struct _server_data_ {
	struct db_i *DBIP;
	/* used by server to stash what it should shoot at */
	int srv_argc;
	char **srv_argv;
} server_data;


server_data*
init_srv_data()
{
    server_data *stash = (server_data *)bu_malloc(sizeof *stash, "server data memory");
    stash->DBIP = NULL;
    stash->srv_argc = 0;
    stash->srv_argv = NULL;
    return stash;
}

/** print a usage statement when invoked with bad, help, or no arguments
 */
void
usage(const char *msg, const char *argv0)
{
    if (msg) {
	bu_log("%s\n", msg);
    }
    bu_log("Usage: %s [-t] [-p#] host gfile [geometry ...]\n\t-p#\tport number to send to (default 2000)\n\thost\thostname or IP address of receiving server\n\tgfile\tBRL-CAD .g database file\n\tgeometry\tname(s) of geometry to send (OPTIONAL)\n", argv0 ? argv0 : "g_transfer");
    bu_log("\nOR\n");
    bu_exit(1, "Usage: %s -r [-p#]\n\t-p#\tport number to listen on (default 2000)\n", argv0 ? argv0 : "g_transfer");
}


void
validate_port(int port)
{
    if (port < 0)
	bu_exit(EXIT_FAILURE, "Invalid negative port range\n");
}


int
hit(struct application *UNUSED(ap), struct partition *UNUSED(p), struct seg *UNUSED(s))
{
    bu_log("HIT!\n");
    return 0;
}

int
miss(struct application *UNUSED(ap))
{
    bu_log("MISSED!\n");
    return 0;
}

void
do_something(server_data *stash)
{
    /* shoot a ray at some geometry just to show that we can */
    struct application ap;
    struct rt_i *rtip;
    int i;

    if (!stash->DBIP) {
	return;
    }

    RT_APPLICATION_INIT(&ap);
    rtip = rt_new_rti(stash->DBIP); /* clone dbip */
    if (!rtip) {
	bu_log("Unable to create a database instance off of the raytrace instance\n");
	return;
    }
    rt_ck(rtip); /* gratuitous sanity check, test for corruption */
    ap.a_rt_i = rtip;
    ap.a_hit = hit;
    ap.a_miss = miss;
    VSET(ap.a_ray.r_pt, 0, 0, 10000);
    VSET(ap.a_ray.r_dir, 0, 0, -1);

    /* shoot at any geometry specified */
    for (i = 0; i < stash->srv_argc; i++) {
	if (rt_gettree(rtip, stash->srv_argv[i]) != 0) {
	    bu_log("Unable to validate %s for raytracing\n", stash->srv_argv[i]);
	    continue;
	}
	rt_prep(rtip);
	bu_log("Shooting at %s from (0, 0, 10000) in the (0, 0, -1) direction\n", stash->srv_argv[i]);
	(void)rt_shootray(&ap);
	rt_clean(rtip);
    }
    rt_free_rti(rtip);
}


void
server_helo(struct pkg_conn *UNUSED(connection), char *buf)
{
    /* should not encounter since we listened for it specifically
     * before beginning processing of packets.
     */
    bu_log("Unexpected HELO encountered\n");
    free(buf);
}


void
server_args(struct pkg_conn *connection, char *buf)
{
    /* updates the srv_argc and srv_argv application globals used to
     * show that we can shoot at geometry in-memory.
     */
    server_data *stash;
    stash = init_srv_data();
    stash->srv_argc++;

    if (!stash->srv_argv) {
	stash->srv_argv = (char **)bu_calloc(1, stash->srv_argc * sizeof(char *), "server_args() srv_argv calloc");
    } else {
	stash->srv_argv = (char **)bu_realloc(stash->srv_argv, stash->srv_argc * sizeof(char *), "server_args() srv_argv realloc");
    }
    stash->srv_argv[stash->srv_argc - 1] = (char *)bu_calloc(1, strlen(buf)+1, "server_args() srv_argv[] calloc");
    bu_strlcpy(stash->srv_argv[stash->srv_argc - 1], buf, strlen(buf)+1);

    bu_log("Planning to shoot at %s\n", buf);
    connection->pkc_server_data = stash;
    free(buf);
}


void
server_geom(struct pkg_conn *connection, char *buf)
{
    struct bu_external ext;
    struct db5_raw_internal raw;
    int flags;

    server_data *stash;
    stash =(server_data*) connection->pkc_server_data;

    if (stash->DBIP == NULL) {
	/* first geometry received, initialize */
	stash->DBIP = db_open_inmem();
    }

    if (db5_get_raw_internal_ptr(&raw, (const unsigned char *)buf) == NULL) {
	bu_log("Corrupted serialized geometry?  Could not deserialize.\n");
	free(buf);
	return;
    }

    /* initialize an external structure since the data seems valid and add/export
     * it to the directory.
     */
    BU_EXTERNAL_INIT(&ext);
    ext.ext_buf = (uint8_t *)buf;
    ext.ext_nbytes = raw.object_length;
    flags = db_flags_raw_internal(&raw) | RT_DIR_INMEM;
    wdb_export_external(stash->DBIP->dbi_wdbp, &ext, (const char *)raw.name.ext_buf, flags, raw.minor_type);

    bu_log("Received %s (MAJOR=%d, MINOR=%d)\n", raw.name.ext_buf, raw.major_type, raw.minor_type);
}


void
server_ciao(struct pkg_conn* connection, char *buf)
{
    server_data *stash;

    bu_log("CIAO encountered\n");
    stash = (server_data*) connection->pkc_server_data;
    /* shoot some rays just to show that we can if server was
     * invoked with specific geometry.
     */
    do_something(stash);

    if (stash->DBIP != NULL) {
	/* uncomment to avoid an in-mem dbip close bug */
	/* DBIP->dbi_fp = fopen("/dev/null", "rb");*/
	db_close(stash->DBIP);
	stash->DBIP = NULL;
    }

    free(buf);
}


/** start up a server that listens for a single client.
 */
void
run_server(int port)
{
    struct pkg_conn *client;
    int netfd;
    char portname[MAX_DIGITS] = {0};
    int pkg_result  = 0;
    char *title;

    struct pkg_switch callbacks[] = {
	{MSG_HELO, server_helo, "HELO", NULL},
	{MSG_ARGS, server_args, "ARGS", NULL},
	{MSG_GEOM, server_geom, "GEOM", NULL},
	{MSG_CIAO, server_ciao, "CIAO", NULL},
	{0, 0, NULL, NULL}
    };

    validate_port(port);

    /* start up the server on the given port */
    snprintf(portname, MAX_DIGITS - 1, "%d", port);
    netfd = pkg_permserver(portname, "tcp", 0, 0);
    if (netfd < 0)
	bu_exit(EXIT_FAILURE, "Unable to start the server");

    /* listen for a good client indefinitely */
    do {
	client = pkg_getclient(netfd, callbacks, NULL, 0);
	if (client == PKC_NULL) {
	    bu_log("Connection seems to be busy, waiting...\n");
	    bu_snooze(BU_SEC2USEC(10));
	    continue;
	} else if (client == PKC_ERROR) {
	    bu_log("Fatal error accepting client connection.\n");
	    pkg_close(client);
	    client = PKC_NULL;
	    continue;
	}

	/* got a connection, process it */
	title = pkg_bwaitfor (MSG_HELO, client);
	if (title == NULL) {
	    bu_log("Failed to process the client connection, still waiting\n");
	    pkg_close(client);
	    client = PKC_NULL;
	} else {
	    /* validate magic header */
	    if (!BU_STR_EQUAL(title, MAGIC_ID)) {
		bu_log("Bizarre corruption, received a HELO without at matching MAGIC ID!\n");
		pkg_close(client);
		client = PKC_NULL;
	    } else {
		title += strlen(MAGIC_ID) + 1;
		bu_log("Preparing to receive data for geometry from a database with the following title:\n%s\n", title);
	    }
	}
    } while (client == PKC_NULL);

    /* read from the connection */
    bu_log("Processing objects from client\n");
    do {
	/* process packets potentially received in a processing callback */
	pkg_result = pkg_process(client);
	if (pkg_result < 0) {
	    bu_log("Unable to process packets? Weird.\n");
	} else {
	    bu_log("Processed %d packet%s\n", pkg_result, pkg_result == 1 ? "" : "s");
	}

	/* suck in data from the network */
	pkg_result = pkg_suckin(client);
	if (pkg_result < 0) {
	    bu_log("Seemed to have trouble sucking in packets.\n");
	    break;
	} else if (pkg_result == 0) {
	    bu_log("Client closed the connection.\n");
	    break;
	}

	/* process packets received */
	pkg_result = pkg_process(client);
	if (pkg_result < 0) {
	    bu_log("Unable to process packets? Weird.\n");
	} else {
	    bu_log("Processed %d packet%s\n", pkg_result, pkg_result == 1 ? "" : "s");
	}
    } while (client != NULL);

    /* shut down the server */
    pkg_close(client);
}


/**
 * base routine that the client uses to send an object to the server.
 * this is the hook callback function for both the primitives and
 * combinations encountered during a db_functree() traversal.
 *
 * returns 0 if unsuccessful
 * returns 1 if successful
 */
void
send_to_server(struct db_i *dbip, struct directory *dp, void *connection)
{
    my_data *stash;
    struct bu_external ext;
    int bytes_sent = 0;

    RT_CK_DBI(dbip);
    RT_CK_DIR(dp);

    stash = (my_data *)connection;

    if (db_get_external(&ext, dp, dbip) < 0) {
	bu_log("Failed to read %s, skipping\n", dp->d_namep);
	return;
    }

    /* send the external representation over the wire */
    bu_log("Sending %s\n", dp->d_namep);

    /* pad the data with the length in ascii for convenience */
    bytes_sent = pkg_send(MSG_GEOM, (const char *)ext.ext_buf, ext.ext_nbytes, stash->connection);
    if (bytes_sent < 0) {
	pkg_close(stash->connection);
	stash->connection = NULL;
	bu_log("Unable to successfully send %s to %s, port %d.\n", dp->d_namep, stash->server, stash->port);
	return;
    }

    /* our responsibility to free the stuff we got */
    bu_free_external(&ext);
}


/**
 * start up a client that connects to the given server, and sends
 * serialized .g data.  if the user specified geometry, only that
 * geometry is sent via send_to_server().
 */
void
run_client(const char *server, int port, struct db_i *dbip, int geomc, const char **geomv)
{
    my_data stash;
    int i;
    struct directory *dp;
    char s_port[MAX_DIGITS] = {0};
    int bytes_sent = 0;

    RT_CK_DBI(dbip);

    /* open a connection to the server */
    validate_port(port);

    snprintf(s_port, MAX_DIGITS - 1, "%d", port);
    stash.connection = pkg_open(server, s_port, "tcp", NULL, NULL, NULL, NULL);
    if (stash.connection == PKC_ERROR) {
	bu_log("Connection to %s, port %d, failed.\n", server, port);
	bu_exit(EXIT_FAILURE, "ERROR: Unable to open a connection to the server\n");
    }
    stash.server = server;
    stash.port = port;

    /* let the server know we're cool.  also, send the database title
     * along with the MAGIC ident just because we can.
     */
    bytes_sent = pkg_2send(MSG_HELO, MAGIC_ID, strlen(MAGIC_ID) + 1, dbip->dbi_title, strlen(dbip->dbi_title), stash.connection);
    if (bytes_sent < 0) {
	pkg_close(stash.connection);
	bu_log("Connection to %s, port %d, seems faulty.\n", server, port);
	bu_exit(EXIT_FAILURE, "ERROR: Unable to communicate with the server\n");
    }

    bu_log("Database title is:\n%s\n", dbip->dbi_title);
    bu_log("Units: %s\n", bu_units_string(dbip->dbi_local2base));

    /* send geometry to the server */
    if (geomc > 0) {
	/* geometry was specified. look it up and process the
	 * hierarchy using db_functree() where all combinations and
	 * primitives are sent that get encountered.
	 */
	for (i = 0; i < geomc; i++) {
	    /* send the geometry as an ARGS packet so the server can
	     * know what to shoot at.
	     */
	    bytes_sent = pkg_send(MSG_ARGS, geomv[i], strlen(geomv[i]) + 1, stash.connection);
	    if (bytes_sent < 0) {
		pkg_close(stash.connection);
		bu_log("Unable to request server shot at %s\n", geomv[i]);
		bu_exit(EXIT_FAILURE, "ERROR: Unable to communicate request to server\n");
	    }

	    dp = db_lookup(dbip, geomv[i], LOOKUP_NOISY);
	    if (dp == RT_DIR_NULL) {
		pkg_close(stash.connection);
		bu_log("Unable to lookup %s\n", geomv[i]);
		bu_exit(EXIT_FAILURE, "ERROR: requested geometry could not be found\n");
	    }
	    db_functree(dbip, dp, send_to_server, send_to_server, &rt_uniresource, (void *)&stash);
	}
    } else {
	/* no geometry was specified so traverse the array of linked
	 * lists contained in the database instance and send
	 * everything.
	 */
	FOR_ALL_DIRECTORY_START(dp, dbip) {
	    send_to_server(dbip, dp, (void *)&stash);
	} FOR_ALL_DIRECTORY_END;
    }

    if (stash.connection) {
	/* let the server know we're done.  not necessary, but polite. */
	bytes_sent = pkg_send(MSG_CIAO, "BYE", 4, stash.connection);
	if (bytes_sent < 0) {
	    bu_log("Unable to cleanly disconnect from %s, port %d.\n", server, port);
	}

	/* flush output and close */
	pkg_close(stash.connection);
    }

    return;
}


int
main(int argc, char *argv[]) {
    const char * const argv0 = argv[0];
    int c;
    int server = 0; /* not a server by default */
    int port = 2000;

    /* client stuff */
    const char *server_name = NULL;
    const char *geometry_file = NULL;
    const char ** geometry = NULL;
    int ngeometry = 0;
    struct db_i *dbip = NULL;

    bu_setprogname(argv[0]);

    if (argc < 2) {
	usage(NULL, argv[0]);
    }

    /* process the command-line arguments after the application name */
    while ((c = bu_getopt(argc, argv, "tTrRp:P:h?")) != -1) {
	switch (c) {
	    case 't':
	    case 'T':
		/* sending */
		server = 0;
		break;
	    case 'r':
	    case 'R':
		/* receiving */
		server = 1;
		break;
	    case 'p':
	    case 'P':
		port = atoi(bu_optarg);
		break;
	    default:
		/* help */
		usage(NULL, argv0);
	}
    }

    argc -= bu_optind;
    argv += bu_optind;

    if (server) {
	if (argc > 0) {
	    usage("ERROR: Unexpected extra arguments", argv0);
	}

	/* mark the database as in-memory only */
	/* XXX = wdb_dbopen(dbip, RT_WDB_TYPE_DB_INMEM); */

	/* ignore broken pipes */
#ifdef SIGPIPE
	(void)signal(SIGPIPE, SIG_IGN);
#endif

	/* fire up the server */
	bu_log("Listening on port %d\n", port);
	run_server(port);

	return 0;
    }

    /* prep up the client */
    if (argc < 1) {
	usage("ERROR: Missing hostname and geometry file arguments", argv0);
    } else if (argc < 2) {
	usage("ERROR: Missing geometry file argument", argv0);
    } else {
	geometry = (const char **)(argv + 2);
	ngeometry = argc - 2;
    }

    server_name = *argv++;
    geometry_file = *argv++;

    /* make sure the geometry file exists */
    if (!bu_file_exists(geometry_file, NULL)) {
	bu_log("Geometry file does not exist: %s\n", geometry_file);
	bu_exit(EXIT_FAILURE, "Need a BRL-CAD .g geometry database file\n");
    }

    /* make sure the geometry file is a geometry database, get a
     * database instance pointer.
     */
    dbip = db_open(geometry_file, DB_OPEN_READONLY);
    if (dbip == DBI_NULL) {
	bu_log("Cannot open geometry database file %s\n", geometry_file);
	perror(argv0);
	bu_exit(EXIT_FAILURE, "Need a geometry database file");
    }

    /* load the database directory into memory */
    if (db_dirbuild(dbip) < 0) {
	db_close(dbip);
	bu_log("Unable to load the database directory for file: %s\n", geometry_file);
	bu_exit(EXIT_FAILURE, "Can't read geometry file");
    }

    /* fire up the client */
    bu_log("Connecting to %s, port %d\n", server_name, port);
    run_client(server_name, port, dbip, ngeometry, geometry);

    /* done with the database */
    db_close(dbip);

    return 0;
}

/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * indent-tabs-mode: t
 * c-file-style: "stroustrup"
 * End:
 * ex: shiftwidth=4 tabstop=8
 */
