/*
 * Copyright 1996 Network Computing Devices
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of NCD. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  NCD. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * NCD. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL NCD.
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author:  Keith Packard, Network Computing Devices
 */

#include "scope.h"
#include "nas.h"

#include <sys/uio.h>            /* for struct iovec, used by socket.h */
#include <sys/socket.h>         /* for AF_INET, SOCK_STREAM, ... */
#include <sys/ioctl.h>          /* for FIONCLEX, FIONBIO, ... */
#if !defined(FIOCLEX) && defined(HAVE_SYS_FILIO_H)
#include <sys/filio.h>
#endif
#include <fcntl.h>
#include <netinet/in.h>         /* struct sockaddr_in */
#include <netinet/tcp.h>
#include <netdb.h>              /* struct servent * and struct hostent * */
#include <errno.h>              /* for EINTR, EADDRINUSE, ... */

static void
ReportFromAudioClient(FD fd, unsigned char *buf, long n)
{
    if (NasVerbose) {
        if (ScopeEnabled) {
            PrintTime();
            fprintf(stdout, "NAS Client%s --> %4ld %s\n",
                    ClientName(fd), n, (n == 1 ? "byte" : "bytes"));
        }
    }
    ProcessBuffer(fd, buf, n);
}

static void
ReportFromAudioServer(FD fd, const unsigned char *buf, long n)
{
    if (NasVerbose) {
        if (ScopeEnabled) {
            PrintTime();
            fprintf(stdout, "\t\t\t\t\t%4ld %s <-- NAS Server%s\n",
                    n, (n == 1 ? "byte" : "bytes"), ClientName(fd));
        }
    }
    ProcessBuffer(fd, buf, n);
}

static long StartAudioSetUpMessage(FD fd, const unsigned char *buf, long n);
static long FinishAudioSetUpMessage(FD fd, const unsigned char *buf, long n);
static long StartAudioRequest(FD fd, const unsigned char *buf, long n);
static long FinishAudioRequest(FD fd, const unsigned char *buf, long n);
static long StartAudioSetUpReply(FD fd, const unsigned char *buf, long n);
static long FinishAudioSetUpReply(FD fd, const unsigned char *buf, long n);
static long FinishAudioReply(FD fd, const unsigned char *buf, long n);
static long AudioServerPacket(FD fd, const unsigned char *buf, long n);

static void
StartAudioClientConnection(FD fd)
{
    enterprocedure("StartAudioClientConnection");
    /* when a new connection is started, we have no saved bytes */
    CS[fd].SavedBytes = NULL;
    CS[fd].SizeofSavedBytes = 0;
    CS[fd].NumberofSavedBytes = 0;
    CS[fd].NumberofBytesProcessed = 0;

    /* when a new connection is started, we have no reply Queue */
    FlushReplyQ(fd);

    /* each new connection gets a request sequence number */
    CS[fd].SequenceNumber = 0;

    /* we need 12 bytes to start a SetUp message */
    CS[fd].ByteProcessing = StartAudioSetUpMessage;
    CS[fd].NumberofBytesNeeded = 12;
}

static void
StopAudioClientConnection(FD fd)
{
    enterprocedure("StopAudioClientConnection");
    /* when a new connection is stopped, discard the old buffer */

    if (CS[fd].SizeofSavedBytes > 0)
        free(CS[fd].SavedBytes);
}

static long
StartAudioSetUpMessage(FD fd, const unsigned char *buf, long n)
{
    short namelength;
    short datalength;

    enterprocedure("StartSetUpMessage");
    /*
       we need the first 12 bytes to be able to determine if, and how many,
       additional bytes we need for name and data authorization.  However, we
       can't process the first 12 bytes until we get all of them, so
       return zero bytes used, and increase the number of bytes needed
     */

    CS[fd].littleEndian = (buf[0] == 'l');
    CS[ServerHalf(fd)].littleEndian = CS[fd].littleEndian;
    littleEndian = CS[fd].littleEndian;
    namelength = IShort(&buf[6]);
    datalength = IShort(&buf[8]);
    CS[fd].ByteProcessing = FinishAudioSetUpMessage;
    CS[fd].NumberofBytesNeeded = n
        + pad((long) namelength) + pad((long) datalength);
    debug(8, (stderr, "need %ld bytes to finish startup\n",
              CS[fd].NumberofBytesNeeded - n));
    return (0);
}

static long
FinishAudioSetUpMessage(FD fd, const unsigned char *buf, long n)
{
    enterprocedure("FinishSetUpMessage");
    if (ScopeEnabled)
        PrintAudioSetUpMessage(buf);

    /* after a set-up message, we expect a string of requests */
    CS[fd].ByteProcessing = StartAudioRequest;
    CS[fd].NumberofBytesNeeded = 4;
    return (n);
}

static long
StartAudioRequest(FD fd, const unsigned char *buf, long n)
{
    unsigned short requestlength;

    enterprocedure("StartRequest");

    /* bytes 0,1 are ignored now; bytes 2,3 tell us the request length */
    requestlength = IShort(&buf[2]);
    CS[fd].ByteProcessing = FinishAudioRequest;
    CS[fd].NumberofBytesNeeded = 4 * requestlength;
    debug(8, (stderr, "need %ld more bytes to finish request\n",
              CS[fd].NumberofBytesNeeded - n));
    return (0);
}

static long
FinishAudioRequest(FD fd, const unsigned char *buf, long n)
{
    enterprocedure("FinishRequest");
    CS[fd].ByteProcessing = StartAudioRequest;
    CS[fd].NumberofBytesNeeded = 4;
    if (ScopeEnabled)
        DecodeAudioRequest(fd, buf, n);
    return (n);
}

static void
StartAudioServerConnection(FD fd)
{
    enterprocedure("StartAudioServerConnection");
    /* when a new connection is started, we have no saved bytes */
    CS[fd].SavedBytes = NULL;
    CS[fd].SizeofSavedBytes = 0;
    CS[fd].NumberofSavedBytes = 0;
    CS[fd].NumberofBytesProcessed = 0;

    /* when a new connection is started, we have no reply Queue */
    FlushReplyQ(fd);

    /* we need 8 bytes to start a SetUp reply */
    CS[fd].ByteProcessing = StartAudioSetUpReply;
    CS[fd].NumberofBytesNeeded = 8;
}

static void
StopAudioServerConnection(FD fd)
{
    enterprocedure("StopAudioServerConnection");
    /* when a new connection is stopped, discard the old buffer */

    if (CS[fd].SizeofSavedBytes > 0)
        free(CS[fd].SavedBytes);
}

static long
StartAudioSetUpReply(FD fd, const unsigned char *buf, long n)
{
    short replylength;

    enterprocedure("StartSetUpReply");
    replylength = IShort(&buf[6]);
    CS[fd].ByteProcessing = FinishAudioSetUpReply;
    CS[fd].NumberofBytesNeeded = n + 4 * replylength;
    debug(8, (stderr, "need %ld bytes to finish startup reply\n",
              CS[fd].NumberofBytesNeeded - n));
    return (0);
}

static long
FinishAudioSetUpReply(FD fd, const unsigned char *buf, long n)
{
    enterprocedure("FinishSetUpReply");
    if (ScopeEnabled)
        PrintAudioSetUpReply(buf);
    CS[fd].ByteProcessing = AudioServerPacket;
    CS[fd].NumberofBytesNeeded = 32;
    return (n);
}

/* ************************************************************ */

static long
AudioErrorPacket(FD fd, const unsigned char *buf, long n)
{
    CS[fd].ByteProcessing = AudioServerPacket;
    CS[fd].NumberofBytesNeeded = 32;
    DecodeAudioError(fd, buf, n);
    return (n);
}

static long
AudioEventPacket(FD fd, const unsigned char *buf, long n)
{
    CS[fd].ByteProcessing = AudioServerPacket;
    CS[fd].NumberofBytesNeeded = 32;
    if (ScopeEnabled)
        DecodeAudioEvent(fd, buf, n);
    return (n);
}

static long
AudioReplyPacket(FD fd, const unsigned char *buf, long n)
{
    long replylength;

    replylength = ILong(&buf[4]);

    /*
       Replies may need more bytes, so we compute how many more
       bytes are needed and ask for them, not using any of the bytes
       we were given (return(0) to say that no bytes were used).
       If the replylength is zero (we don't need any more bytes), the
       number of bytes needed will be the same as what we have, and
       so the top-level loop will call the next routine immediately
       with the same buffer of bytes that we were given.
     */

    CS[fd].ByteProcessing = FinishAudioReply;
    CS[fd].NumberofBytesNeeded = n + 4 * replylength;
    debug(8, (stderr, "need %ld bytes to finish reply\n", (4 * replylength)));
    return (0);
}

static long
FinishAudioReply(FD fd, const unsigned char *buf, long n)
{
    CS[fd].ByteProcessing = AudioServerPacket;
    CS[fd].NumberofBytesNeeded = 32;
    enterprocedure("FinishAudioReply");
    if (ScopeEnabled)
        DecodeAudioReply(fd, buf, n);
    return (n);
}

static long
AudioServerPacket(FD fd, const unsigned char *buf, long n)
{
    short PacketType;

    enterprocedure("ServerPacket");

    PacketType = IByte(&buf[0]);
    if (PacketType == 0)
        return (AudioErrorPacket(fd, buf, n));
    if (PacketType == 1)
        return (AudioReplyPacket(fd, buf, n));
    return (AudioEventPacket(fd, buf, n));
}

static void
CloseAudioConnection(FD fd)
{
    debug(4, (stderr, "close %d and %d\n", fd, FDPair(fd)));
    StopAudioClientConnection(ServerHalf(fd));
    StopAudioServerConnection(ClientHalf(fd));

    (void) close(fd);
    NotUsingFD(fd);
    (void) close(FDPair(fd));
    NotUsingFD(FDPair(fd));
}

/* when we get data from a client, we read it in, copy it to the
   server for this client, then dump it to the client. Note, we don't
   have to have a server, if there isn't one. */

static void
DataFromAudioClient(FD fd)
{
    long n;
    FD ServerFD;

    Verbose = NasVerbose;
    enterprocedure("DataFromAudioClient");
    ServerFD = FDPair(fd);
    if (ServerFD < 0) {
        ServerFD = ConnectToServer(false);
        if (ServerFD < 0) {
            CloseAudioConnection(fd);
            return;
        }
        SetUpPair(fd, ServerFD);
    }

    n = read(fd, FDinfo[ServerFD].buffer, BUFFER_SIZE);
    debug(4, (stderr, "read %ld bytes from Client%s\n", n, ClientName(fd)));
    if (n < 0) {
        PrintTime();
        perror("Client --> read error:");
        CloseAudioConnection(fd);
        return;
    }
    if (n == 0) {
        PrintTime();
        if (NasVerbose >= 0)
            fprintf(stdout, "Client%s --> EOF\n", ClientName(fd));
        CloseAudioConnection(fd);
        return;
    }

    FDinfo[ServerFD].bufcount = n;
    FDinfo[ServerFD].bufstart = 0;

    FlushFD(ServerFD);
    /* also report the bytes to standard out */
    ReportFromAudioClient(fd, FDinfo[ServerFD].buffer, n);
}

/* ********************************************** */
/*                                                */
/* ********************************************** */

/* similar situation for the server, but note that if there is no client,
   we close the connection down -- don't need a server with no client. */

static void
DataFromAudioServer(FD fd)
{
    long n;
    FD ClientFD;

    Verbose = NasVerbose;
    ClientFD = FDPair(fd);
    if (ClientFD < 0) {
        CloseAudioConnection(fd);
        return;
    }

    enterprocedure("DataFromAudioServer");
    n = read(fd, (char *) FDinfo[ClientFD].buffer, BUFFER_SIZE);
    debug(4, (stderr, "read %ld bytes from Server%s\n", n, ClientName(fd)));
    if (n < 0) {
        PrintTime();
        perror("read error <- Server");
        CloseAudioConnection(fd);
        return;
    }
    if (n == 0) {
        PrintTime();
        if (NasVerbose >= 0)
            fprintf(stdout, "EOF <-- Server%s\n", ClientName(fd));
        CloseAudioConnection(fd);
        return;
    }

    FDinfo[ClientFD].bufcount = n;
    FDinfo[ClientFD].bufstart = 0;
    FlushFD(ClientFD);

    /* also report the bytes to standard out */
    ReportFromAudioServer(fd, FDinfo[ClientFD].buffer, n);
}

static FD
ConnectToAudioClient(FD ConnectionSocket)
{
    FD ClientFD;

    ClientFD = AcceptConnection(ConnectionSocket);
    UsingFD(ClientFD, DataFromAudioClient, FlushFD, NULL);
    StartAudioClientConnection(ClientFD);
    return (ClientFD);
}

static FD
ConnectToAudioServer(Boolean report)
{
    FD ServerFD;
    XtransConnInfo trans_conn = NULL;   /* transport connection object */

    if (!AudioServerHostName[0])
        strcpy(AudioServerHostName, ServerHostName);
    ServerFD =
        MakeConnection(AudioServerHostName, GetServerport() + 2000, report,
                       &trans_conn);
    if (ServerFD >= 0) {
        UsingFD(ServerFD, DataFromAudioServer, FlushFD, trans_conn);
        StartAudioServerConnection(ServerFD);
    }
    return (ServerFD);
}

void
NewAudio(FD fd)
{
    FD ServerFD = -1;
    FD ClientFD = -1;

    ClientFD = ConnectToAudioClient(fd);
    ServerFD = ConnectToAudioServer(true);
    SetUpPair(ClientFD, ServerFD);
}

void
InitializeAudio(void)
{
    InitializeAudioDecode();
}