/* Copyright (c) 2000 Miller Puckette.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in the Pd distribution.  */

/* the "pdreceive" command.  This is a standalone program that receives messages
from Pd via the netsend/netreceive ("FUDI") protocol, and copies them to
standard output. */

#include <sys/types.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#ifdef UNIX
#include <sys/time.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#define SOCKET_ERROR -1
#else
#include <winsock.h>
#endif

typedef struct _fdpoll
{
    int fdp_fd;
    char *fdp_inbuf;
    int fdp_inhead;
    int fdp_intail;
    int fdp_udp;
} t_fdpoll;

static int nfdpoll;
static t_fdpoll *fdpoll;
static int maxfd;
static int sockfd;
static int protocol;

static void sockerror(char *s);
static void x_closesocket(int fd);
static void dopoll(void);
#define BUFSIZE 4096

int main(int argc, char **argv)
{
    int portno;
    struct sockaddr_in server;
    int nretry = 10;
#ifdef MSW
    short version = MAKEWORD(2, 0);
    WSADATA nobby;
#endif
    if (argc < 2 || sscanf(argv[1], "%d", &portno) < 1 || portno <= 0)
    	goto usage;
    if (argc >= 3)
    {
    	if (!strcmp(argv[2], "tcp"))
	    protocol = SOCK_STREAM;
	else if (!strcmp(argv[2], "udp"))
	    protocol = SOCK_DGRAM;
	else goto usage;
    }
    else protocol = SOCK_STREAM;
#ifdef MSW
    if (WSAStartup(version, &nobby)) sockerror("WSAstartup");
#endif
    sockfd = socket(AF_INET, protocol, 0);
    if (sockfd < 0)
    {
    	sockerror("socket()");
    	exit(1);
    }
    maxfd = sockfd + 1;
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;

#ifdef IRIX
    	/* this seems to work only in IRIX but is unnecessary in
	Linux.  Not sure what MSW needs in place of this. */
    if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, 0, 0) < 0)
    	post("setsockopt failed\n");
#endif

    	/* assign client port number */
    server.sin_port = htons((unsigned short)portno);

    	/* name the socket */
    if (bind(sockfd, (struct sockaddr *)&server, sizeof(server)) < 0)
    {
    	sockerror("bind");
	x_closesocket(sockfd);
    	return (0);
    }
    if (protocol == SOCK_STREAM)
    {
	if (listen(sockfd, 5) < 0)
	{
    	    sockerror("listen");
    	    x_closesocket(sockfd);
	    exit(1);
	}
    }
    	/* now loop forever selecting on sockets */
    while (1)
    	dopoll();

usage:
    fprintf(stderr, "usage: pdreceive <portnumber> [udp|tcp]\n");
    fprintf(stderr, "(default is tcp)\n");
    exit(1);
}

static void addport(int fd)
{
    int nfd = nfdpoll;
    t_fdpoll *fp;
    fdpoll = (t_fdpoll *)realloc(fdpoll,
    	(nfdpoll+1) * sizeof(t_fdpoll));
    fp = fdpoll + nfdpoll;
    fp->fdp_fd = fd;
    nfdpoll++;
    if (fd >= maxfd) maxfd = fd + 1;
    fp->fdp_inhead = fp->fdp_intail = 0;
    if (!(fp->fdp_inbuf = malloc(BUFSIZE)))
    {
    	fprintf(stderr, "out of memory");
	exit(1);
    }
    printf("number_connected %d;\n", nfdpoll);
}

static void rmport(t_fdpoll *x)
{
    int nfd = nfdpoll;
    int i, size = nfdpoll * sizeof(t_fdpoll);
    t_fdpoll *fp;
    for (i = nfdpoll, fp = fdpoll; i--; fp++)
    {
    	if (fp == x)
    	{
	    x_closesocket(fp->fdp_fd);
    	    free(fp->fdp_inbuf);
    	    while (i--)
    	    {
    	    	fp[0] = fp[1];
    	    	fp++;
    	    }
	    fdpoll = (t_fdpoll *)realloc(fdpoll,
    		(nfdpoll-1) * sizeof(t_fdpoll));
	    nfdpoll--;
    	    printf("number_connected %d;\n", nfdpoll);
	    return;
    	}
    }
    fprintf(stderr, "warning: item removed from poll list but not found");
}

static void doconnect(void)
{
    int fd = accept(sockfd, 0, 0);
    if (fd < 0)
    	perror("accept");
    else addport(fd);
}

static void udpread(void)
{
    char buf[BUFSIZE];
    int ret = recv(sockfd, buf, BUFSIZE, 0);
    if (ret < 0)
    {
	sockerror("recv (udp)");
	x_closesocket(sockfd);
	exit(1);
    }
    else if (ret > 0)
    {
#ifdef UNIX
    	if (write(1, buf, ret) < ret)
	{
	    perror("write");
	    exit(1);
	}
#else
	int j;
	for (j = 0; j < ret; j++)
	    putchar(buf[j]);
#endif
    }
}

static int tcpmakeoutput(t_fdpoll *x)
{
    char messbuf[BUFSIZE+1], *bp = messbuf;
    int indx;
    int inhead = x->fdp_inhead;
    int intail = x->fdp_intail;
    char *inbuf = x->fdp_inbuf;
    if (intail == inhead)
    	return (0);
    for (indx = intail; indx != inhead; indx = (indx+1)&(BUFSIZE-1))
    {
    	    /* search for a semicolon.   */
    	char c = *bp++ = inbuf[indx];
    	if (c == ';')
    	{
    	    intail = (indx+1)&(BUFSIZE-1);
	    if (inbuf[intail] == '\n')
	    	intail = (intail+1)&(BUFSIZE-1);
	    *bp++ = '\n';
#ifdef UNIX
	    write(1, messbuf, bp - messbuf);
#else
	    {
	    	int j;
		for (j = 0; j < bp - messbuf; j++)
		    putchar(messbuf[j]);
	    }
#endif
	    x->fdp_inhead = inhead;
    	    x->fdp_intail = intail;
    	    return (1);
    	}
    }
    return (0);
}

static void tcpread(t_fdpoll *x)
{
    int readto =
	(x->fdp_inhead >= x->fdp_intail ? BUFSIZE : x->fdp_intail-1);
    int ret;

    	/* the input buffer might be full.  If so, drop the whole thing */
    if (readto == x->fdp_inhead)
    {
    	fprintf(stderr, "pd: dropped message from gui\n");
    	x->fdp_inhead = x->fdp_intail = 0;
    	readto = BUFSIZE;
    }
    else
    {
	ret = recv(x->fdp_fd, x->fdp_inbuf + x->fdp_inhead,
	    readto - x->fdp_inhead, 0);
	if (ret < 0)
	{
	    sockerror("recv (tcp)");
	    rmport(x);
	}
	else if (ret == 0)
	     rmport(x);
	else
	{
    	    x->fdp_inhead += ret;
    	    if (x->fdp_inhead >= BUFSIZE)
	    	x->fdp_inhead = 0;
    	    while (tcpmakeoutput(x))
	    	;
	}
    }
}

static void dopoll(void)
{
    int i;
    t_fdpoll *fp;
    fd_set readset, writeset, exceptset;
    FD_ZERO(&writeset);
    FD_ZERO(&readset);
    FD_ZERO(&exceptset);

    FD_SET(sockfd, &readset);
    if (protocol == SOCK_STREAM)
    {
    	for (fp = fdpoll, i = nfdpoll; i--; fp++)
    	    FD_SET(fp->fdp_fd, &readset);
    }
    if (select(maxfd+1, &readset, &writeset, &exceptset, 0) < 0)
    {
    	perror("select");
	exit(1);
    }
    if (protocol == SOCK_STREAM)
    {
	for (i = 0; i < nfdpoll; i++)
    	    if (FD_ISSET(fdpoll[i].fdp_fd, &readset))
    	    	tcpread(&fdpoll[i]);
    	if (FD_ISSET(sockfd, &readset))
	    doconnect();
    }
    else
    {
    	if (FD_ISSET(sockfd, &readset))
    	    udpread();
    }
}


static void sockerror(char *s)
{
#ifdef MSW
    int err = WSAGetLastError();
    if (err == 10054) return;
    else if (err == 10044)
    {
    	fprintf(stderr,
	    "Warning: you might not have TCP/IP \"networking\" turned on\n");
    }
#endif
#ifdef UNIX
    int err = errno;
#endif
    fprintf(stderr, "%s: %s (%d)\n", s, strerror(err), err);
}

static void x_closesocket(int fd)
{
#ifdef UNIX
    close(fd);
#endif
#ifdef MSW
    closesocket(fd);
#endif
}

