/* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * Copyright (C) 2004-2012  HUBzero Foundation, LLC
 *
 * Author: Leif Delgass <ldelgass@purdue.edu>
 */

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cerrno>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/times.h>

#include <string>
#include <sstream>

#include <tcl.h>

#include <vtksys/SystemInformation.hxx>

#include "Trace.h"
#include "ReadBuffer.h"
#include "RenderServer.h"
#include "RendererCmd.h"
#include "Renderer.h"
#include "PPMWriter.h"
#include "TGAWriter.h"
#ifdef USE_THREADS
#include <pthread.h>
#include "ResponseQueue.h"
#endif 
#include <md5.h>

using namespace VtkVis;

Stats VtkVis::g_stats;

int VtkVis::g_statsFile = -1; ///< Stats output file descriptor.
int VtkVis::g_fdIn = STDIN_FILENO; ///< Input file descriptor
int VtkVis::g_fdOut = STDOUT_FILENO; ///< Output file descriptor
FILE *VtkVis::g_fOut = NULL; ///< Output file handle
FILE *VtkVis::g_fLog = NULL; ///< Trace logging file handle
Renderer *VtkVis::g_renderer = NULL; ///< Main render worker
ReadBuffer *VtkVis::g_inBufPtr = NULL; ///< Socket read buffer

#ifdef USE_THREADS
static void
queueFrame(ResponseQueue *queue, vtkUnsignedCharArray *imgData)
{
#ifdef DEBUG
    if (g_renderer->getCameraMode() == Renderer::IMAGE) {
        double xywh[4];
        g_renderer->getScreenWorldCoords(xywh);
        TRACE("Image bbox: %g %g %g %g", 
              xywh[0], 
              (xywh[1] + xywh[3]), 
              (xywh[0] + xywh[2]), 
              xywh[1]);
    }

#ifdef RENDER_TARGA
    writeTGAFile("/tmp/frame.tga",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
    writeTGAFile("/tmp/frame.tga",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL,
                 true);
#endif  /*RENDER_TARGA*/

#else
    if (g_renderer->getCameraMode() == Renderer::IMAGE) {
        double xywh[4];
        g_renderer->getCameraZoomRegion(xywh);
        std::ostringstream oss;
        oss.precision(12);
        // Send upper left and lower right corners as bbox
        oss << "nv>image -type image -bbox {"
            << std::scientific
            << xywh[0] << " "
            << xywh[1] << " "
            << xywh[2] << " "
            << xywh[3] << "} -bytes";

#ifdef RENDER_TARGA
        queueTGA(queue, oss.str().c_str(),
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
        queuePPM(queue, oss.str().c_str(),
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight());
#endif  /*RENDER_TARGA*/
    } else {
#ifdef RENDER_TARGA
        queueTGA(queue, "nv>image -type image -bytes",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
        queuePPM(queue, "nv>image -type image -bytes",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight());
#endif  /*RENDER_TARGA*/
    }
#endif  /*DEBUG*/
}

#else

static void
writeFrame(int fd, vtkUnsignedCharArray *imgData)
{
#ifdef DEBUG
    if (g_renderer->getCameraMode() == Renderer::IMAGE) {
        double xywh[4];
        g_renderer->getScreenWorldCoords(xywh);
        TRACE("Image bbox: %g %g %g %g", 
              xywh[0], 
              (xywh[1] + xywh[3]), 
              (xywh[0] + xywh[2]), 
              xywh[1]);
    }

#ifdef RENDER_TARGA
    writeTGAFile("/tmp/frame.tga",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
    writeTGAFile("/tmp/frame.tga",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL,
                 true);
#endif  /*RENDER_TARGA*/

#else
    if (g_renderer->getCameraMode() == Renderer::IMAGE) {
        double xywh[4];
        g_renderer->getCameraZoomRegion(xywh);
        std::ostringstream oss;
        oss.precision(12);
        // Send upper left and lower right corners as bbox
        oss << "nv>image -type image -bbox {"
            << std::scientific
            << xywh[0] << " "
            << xywh[1] << " "
            << xywh[2] << " "
            << xywh[3] << "} -bytes";

#ifdef RENDER_TARGA
        writeTGA(fd, oss.str().c_str(),
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
        writePPM(fd, oss.str().c_str(),
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight());
#endif  /*RENDER_TARGA*/
    } else {
#ifdef RENDER_TARGA
        writeTGA(fd, "nv>image -type image -bytes",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight(),
                 TARGA_BYTES_PER_PIXEL);
#else
        writePPM(fd, "nv>image -type image -bytes",
                 imgData->GetPointer(0),
                 g_renderer->getWindowWidth(),
                 g_renderer->getWindowHeight());
#endif  /*RENDER_TARGA*/
    }
#endif  /*DEBUG*/
}
#endif /*USE_THREADS*/

static int
sendAck(ClientData clientData, int fdOut)
{
    std::ostringstream oss;
    oss << "nv>ok -token " << g_stats.nCommands <<  "\n";
    int nBytes = oss.str().length();

    TRACE("Sending OK for commands through %lu", g_stats.nCommands);
#ifdef USE_THREADS
    queueResponse(clientData, oss.str().c_str(), nBytes, Response::VOLATILE, Response::OK);
#else
    if (write(fdOut, oss.str().c_str(), nBytes) < 0) {
        ERROR("write failed: %s", strerror(errno));
        return -1;
    }
#endif
    return 0;
}

int
VtkVis::getStatsFile(Tcl_Interp *interp, Tcl_Obj *objPtr)
{
    Tcl_Obj **objv;
    int objc;
    int i;
    char fileName[33];
    md5_state_t state;
    md5_byte_t digest[16];
    char *string;
    int length;

    if ((objPtr == NULL) || (g_statsFile >= 0)) {
        return g_statsFile;
    }
    if (Tcl_ListObjGetElements(interp, objPtr, &objc, &objv) != TCL_OK) {
	return -1;
    }
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewStringObj("pid", 3));
    Tcl_ListObjAppendElement(interp, objPtr, Tcl_NewIntObj(getpid()));
    string = Tcl_GetStringFromObj(objPtr, &length);

    md5_init(&state);
    md5_append(&state, (const md5_byte_t *)string, length);
    md5_finish(&state, digest);
    for (i = 0; i < 16; i++) {
        sprintf(fileName + i * 2, "%02x", digest[i]);
    }
    std::ostringstream oss;
    oss << STATSDIR << "/" << fileName;
    std::string pathStr = oss.str();

    g_statsFile = open(pathStr.c_str(), O_EXCL | O_CREAT | O_WRONLY, 0600);
    if (g_statsFile < 0) {
	ERROR("can't open \"%s\": %s", pathStr.c_str(), strerror(errno));
	return -1;
    }
    return g_statsFile;
}

int
VtkVis::writeToStatsFile(int f, const char *s, size_t length)
{
    if (f >= 0) {
        ssize_t numWritten;

        numWritten = write(f, s, length);
        if (numWritten == (ssize_t)length) {
            close(dup(f));
        }
    }
    return 0;
}

static int
serverStats(int code) 
{
    double start, finish;
    char buf[BUFSIZ];
    Tcl_DString ds;
    int result;
    int f;

    {
	struct timeval tv;

	/* Get ending time.  */
	gettimeofday(&tv, NULL);
	finish = CVT2SECS(tv);
	tv = g_stats.start;
	start = CVT2SECS(tv);
    }
    /* 
     * Session information:
     *   - Name of render server
     *   - Process ID
     *   - Hostname where server is running
     *   - Start date of session
     *   - Start date of session in seconds
     *   - Number of data sets loaded from client
     *   - Number of data bytes total loaded from client
     *   - Number of frames returned
     *   - Number of bytes total returned (in frames)
     *   - Number of commands received
     *   - Total elapsed time of all commands
     *   - Total elapsed time of session
     *   - Exit code of vizserver
     *   - User time 
     *   - System time
     *   - User time of children 
     *   - System time of children 
     */

    Tcl_DStringInit(&ds);
    
    Tcl_DStringAppendElement(&ds, "render_stop");
    /* renderer */
    Tcl_DStringAppendElement(&ds, "renderer");
    Tcl_DStringAppendElement(&ds, "vtkvis");
    /* pid */
    Tcl_DStringAppendElement(&ds, "pid");
    sprintf(buf, "%d", getpid());
    Tcl_DStringAppendElement(&ds, buf);
    /* host */
    Tcl_DStringAppendElement(&ds, "host");
    gethostname(buf, BUFSIZ-1);
    buf[BUFSIZ-1] = '\0';
    Tcl_DStringAppendElement(&ds, buf);
    /* date */
    Tcl_DStringAppendElement(&ds, "date");
    strcpy(buf, ctime(&g_stats.start.tv_sec));
    buf[strlen(buf) - 1] = '\0';
    Tcl_DStringAppendElement(&ds, buf);
    /* date_secs */
    Tcl_DStringAppendElement(&ds, "date_secs");
    sprintf(buf, "%ld", g_stats.start.tv_sec);
    Tcl_DStringAppendElement(&ds, buf);
    /* num_data_sets */
    Tcl_DStringAppendElement(&ds, "num_data_sets");
    sprintf(buf, "%lu", (unsigned long int)g_stats.nDataSets);
    Tcl_DStringAppendElement(&ds, buf);
    /* data_set_bytes */
    Tcl_DStringAppendElement(&ds, "data_set_bytes");
    sprintf(buf, "%lu", (unsigned long int)g_stats.nDataBytes);
    Tcl_DStringAppendElement(&ds, buf);
    /* num_frames */
    Tcl_DStringAppendElement(&ds, "num_frames");
    sprintf(buf, "%lu", (unsigned long int)g_stats.nFrames);
    Tcl_DStringAppendElement(&ds, buf);
    /* frame_bytes */
    Tcl_DStringAppendElement(&ds, "frame_bytes");
    sprintf(buf, "%lu", (unsigned long int)g_stats.nFrameBytes);
    Tcl_DStringAppendElement(&ds, buf);
    /* num_commands */
    Tcl_DStringAppendElement(&ds, "num_commands");
    sprintf(buf, "%lu", (unsigned long int)g_stats.nCommands);
    Tcl_DStringAppendElement(&ds, buf);
    /* cmd_time */
    Tcl_DStringAppendElement(&ds, "cmd_time");
    sprintf(buf, "%g", g_stats.cmdTime);
    Tcl_DStringAppendElement(&ds, buf);
    /* session_time */
    Tcl_DStringAppendElement(&ds, "session_time");
    sprintf(buf, "%g", finish - start);
    Tcl_DStringAppendElement(&ds, buf);
    /* status */
    Tcl_DStringAppendElement(&ds, "status");
    sprintf(buf, "%d", code);
    Tcl_DStringAppendElement(&ds, buf);
    {
	long clocksPerSec = sysconf(_SC_CLK_TCK);
	double clockRes = 1.0 / clocksPerSec;
	struct tms tms;

	memset(&tms, 0, sizeof(tms));
	times(&tms);
	/* utime */
	Tcl_DStringAppendElement(&ds, "utime");
	sprintf(buf, "%g", tms.tms_utime * clockRes);
	Tcl_DStringAppendElement(&ds, buf);
	/* stime */
	Tcl_DStringAppendElement(&ds, "stime");
	sprintf(buf, "%g", tms.tms_stime * clockRes);
	Tcl_DStringAppendElement(&ds, buf);
	/* cutime */
	Tcl_DStringAppendElement(&ds, "cutime");
	sprintf(buf, "%g", tms.tms_cutime * clockRes);
	Tcl_DStringAppendElement(&ds, buf);
	/* cstime */
	Tcl_DStringAppendElement(&ds, "cstime");
	sprintf(buf, "%g", tms.tms_cstime * clockRes);
	Tcl_DStringAppendElement(&ds, buf);
    }
    Tcl_DStringAppend(&ds, "\n", -1);
    f = getStatsFile(NULL, NULL);
    result = writeToStatsFile(f, Tcl_DStringValue(&ds), 
                              Tcl_DStringLength(&ds));
    close(f);
    Tcl_DStringFree(&ds);
    return result;
}

static void
initService()
{
    // Create a stream associated with the output file descriptor
    g_fOut = fdopen(g_fdOut, "w");
    // If running without a socket, use stdout for debugging
    if (g_fOut == NULL && g_fdOut != STDOUT_FILENO) {
        g_fdOut = STDOUT_FILENO;
        g_fOut = stdout;
    }

    const char *user = getenv("USER");
    char *logName = NULL;
    int logNameLen = 0;

    if (user == NULL) {
        logNameLen = 19+1;
        logName = (char *)calloc(logNameLen, sizeof(char));
        strncpy(logName, "/tmp/vtkvis_log.txt", logNameLen);
    }
    else {
        logNameLen = 16+strlen(user)+4+1;
        logName = (char *)calloc(logNameLen, sizeof(char));
        strncpy(logName, "/tmp/vtkvis_log_", logNameLen);
        strncat(logName, user, strlen(user));
        strncat(logName, ".txt", 4);
    }

    // open log and map stderr to log file
    g_fLog = fopen(logName, "w");
    dup2(fileno(g_fLog), STDERR_FILENO);
    // If we are writing to socket, map stdout to log 
    if (g_fdOut != STDOUT_FILENO) { 
        dup2(fileno(g_fLog), STDOUT_FILENO); 
    }

    fflush(stdout);

    // clean up malloc'd memory
    if (logName != NULL) {
        free(logName);
    }
}

static void
exitService()
{
    serverStats(0);

    // close log file
    if (g_fLog != NULL) {
        fclose(g_fLog);
	g_fLog = NULL;
    }
}

#ifdef USE_THREADS

static void *
writerThread(void *clientData)
{
    ResponseQueue *queue = (ResponseQueue *)clientData;

    TRACE("Starting writer thread");
    for (;;) {
        Response *response = queue->dequeue();
        if (response == NULL)
            continue;
        if (fwrite(response->message(), sizeof(unsigned char), response->length(),
                   g_fOut) != response->length()) {
            ERROR("short write while trying to write %ld bytes", 
                  response->length());
        }
        fflush(g_fOut);
        TRACE("Wrote response of type %d", response->type());
        delete response;
        if (feof(g_fOut))
            break;
    }    
    return NULL;
}

#endif  /*USE_THREADS*/

int
main(int argc, char *argv[])
{
    // Ignore SIGPIPE.  **Is this needed? **
    signal(SIGPIPE, SIG_IGN);

    while (1) {
        int c = getopt(argc, argv, "i:o:");
        if (c == -1) {
            break;
        }
        switch (c) {
        case 'i': {
            int fd = atoi(optarg);
            if (fd >=0 && fd < 5) {
                g_fdIn = fd;
            }
        }
            break;
        case 'o': {
            int fd = atoi(optarg);
            if (fd >=0 && fd < 5) {
                g_fdOut = fd;
            }
        }
            break;
        case '?':
            break;
        default:
            return 1;
        }
    }

    initService();
    initLog();

    memset(&g_stats, 0, sizeof(g_stats));
    gettimeofday(&g_stats.start, NULL);

    TRACE("Starting VTKVis Server");

    // Sanity check: log descriptor can't be used for client IO
    if (fileno(g_fLog) == g_fdIn) {
        ERROR("Invalid input file descriptor");
        return 1;
    }
    if (fileno(g_fLog) == g_fdOut) {
        ERROR("Invalid output file descriptor");
        return 1;
    }
    TRACE("File descriptors: in %d out %d log %d", g_fdIn, g_fdOut, fileno(g_fLog));

#ifdef WANT_TRACE
    vtksys::SystemInformation::SetStackTraceOnError(1);
#endif

    /* This synchronizes the client with the server, so that the client 
     * doesn't start writing commands before the server is ready. It could
     * also be used to supply information about the server (version, memory
     * size, etc). */
    fprintf(g_fOut, "VtkVis %s (build %s)\n", VTKVIS_VERSION_STRING, SVN_VERSION);
    fflush(g_fOut);

    g_renderer = new Renderer();
    g_inBufPtr = new ReadBuffer(g_fdIn, 1<<12);

    Tcl_Interp *interp = Tcl_CreateInterp();
    ClientData clientData = NULL;
#ifdef USE_THREADS
    ResponseQueue *queue = new ResponseQueue();
    clientData = (ClientData)queue;
    initTcl(interp, clientData);

    pthread_t writerThreadId;
    if (pthread_create(&writerThreadId, NULL, &writerThread, queue) < 0) {
        ERROR("Can't create writer thread: %s", strerror(errno));
    }
#else 
    initTcl(interp, clientData);
#endif

    vtkSmartPointer<vtkUnsignedCharArray> imgData = 
        vtkSmartPointer<vtkUnsignedCharArray>::New();

    // Start main server loop
    for (;;) {
        if (processCommands(interp, clientData, g_inBufPtr, g_fdOut) < 0)
            break;

        if (g_renderer->render()) {
            TRACE("Rendering new frame");
            g_renderer->getRenderedFrame(imgData);
#ifdef USE_THREADS
            queueFrame(queue, imgData);
#else
            writeFrame(g_fdOut, imgData);
#endif
            g_stats.nFrames++;
            g_stats.nFrameBytes += imgData->GetDataSize() * imgData->GetDataTypeSize();
        } else {
            TRACE("No render required");
            sendAck(clientData, g_fdOut);
        }

        if (g_inBufPtr->status() == ReadBuffer::ENDFILE)
            break;
    }
#ifdef USE_THREADS
    // Writer thread is probably blocked on sem_wait, so cancel instead
    // of joining
    if (pthread_cancel(writerThreadId) < 0) {
        ERROR("Can't cancel writer thread: %s", strerror(errno));
    } else {
        TRACE("Cancelled writer thread");
    }

    TRACE("Deleting ResponseQueue");
    delete queue;
    queue = NULL;
#endif

    TRACE("Stopping Tcl interpreter");
    exitTcl(interp);
    interp = NULL;

    TRACE("Deleting ReadBuffer");
    delete g_inBufPtr;
    g_inBufPtr = NULL;

    TRACE("Deleting renderer");
    delete g_renderer;
    g_renderer = NULL;

    TRACE("Exiting VTKVis Server");

    closeLog();
    exitService();

    return 0;
}