/*
  Copyright 2010 Nathan Phillip Brink, Ethan Zonca, Matthew Orlando

  This file is a part of DistRen.

  DistRen is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  DistRen 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 Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with DistRen.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "common/config.h"

#include "slavefuncs.h"

#include "common/asprintf.h"
#include "common/multiio.h"
#include "common/options.h"
#include "common/protocol.h"
#include "common/remoteio.h"
#include "common/request.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#define DEBUG 0

struct slave_state
{
  /* whether or not we've gotten past the copyright line */
  short copyright_done;

  /* number of bytes that we need to read before we have a whole packet */
  size_t expectlen;
  /* whether or not we should exit */
  int quit;

  /* the server's remoteio handle */
  struct remoteio *rem;
};

static void distren_slave_remoteio_close_handle(void *blah, void *data);
static size_t distren_slave_remoteio_read_handle(struct remoteio *rem,
						 void *blah,
						 void *buf,
						 size_t len,
						 void *data);

int main(int argc, char *argv[])
{
  multiio_context_t multiio;

  struct slave_state slave_state;

  char *datadir;
  char *server;
  char *username;
  char *password;
  char *hostname;

  cfg_opt_t myopts[] = {
    CFG_SIMPLE_STR("username", &username),
    CFG_SIMPLE_STR("password", &password),
    CFG_SIMPLE_STR("datadir", &datadir),
    CFG_SIMPLE_STR("server", &server),
    CFG_SIMPLE_STR("hostname", &hostname),
    CFG_END()
  };
  cfg_t * my_cfg;

  struct options_common *commonopts;

  // struct distrenjob *myjob; /* Structure to hold data gathered from the XML file - not needed anymore? */

  /**
     initializations
  */
  datadir = NULL;
  server = NULL;
  username = NULL;
  password = NULL;
  hostname = NULL;

  char curopt;
  int runBenchmark = 0;

  multiio = multiio_context_new();

  while(((char)-1) != (curopt = getopt(argc, argv, "u:rh")))
     {
       if(curopt == ':')
         {
           fprintf(stderr, "-%c: is missing an argument\n", optopt);
           return 1;
         }
       else if(curopt == '?')
         {
           fprintf(stderr, "-%c: invalid option specified\n", optopt);
           return 1;
         }
       else if(curopt == 'h')
         {
           fprintf(stderr, "Usage: distrenslave [option] \nStarts a distren slave\n\t-u\tset username (run after fresh install)\n\t-r\tRecalculate render power (benchmark)\n\t-h\tshow this help\n");
           return 2;
         }
       else if(curopt == 'r')
         {
           runBenchmark = 1;
           break;
         }
       else if(curopt == 'u')
         username = strdup(optarg);
         if(DEBUG)
           fprintf(stderr, "Putting username \"%s\" in distrenslave.conf\n", username);

         conf_replace("distrenslave.conf", "!username", username);
         fprintf(stderr, "Please invoke distrenslave with no arguments to run with the username you just set\n");
         return 0;
     }

  /* Get conf data */
  options_init(argc, argv, &my_cfg, myopts, "slave", &commonopts, multiio);

  if(!datadir)
    {
      fprintf(stderr, "datadir not set\n");
      return 1;
    }
  if(!server)
    {
      fprintf(stderr, "server not set\n");
      return 1;
    }
  if(!username)
    {
      fprintf(stderr, "username not set\n");
      return 1;
    }
  if(!password)
    {
      fprintf(stderr, "password not set\n");
      return 1;
    }
  if(!hostname)
    {
      fprintf(stderr, "hostname not set\n");
      return 1;
    }

  /* Notifies the user if there no username in .conf */
  if(checkUsername(username))
    return 1;
  if(!strncmp(password, "!password",10))
    {
      fprintf(stderr, "You haven't specified a password. Please edit distrenslave.conf!\n");
      return 1;
    }

  // Variables needed for main loop
  int jobnum = 0;
  int framenum = 0;
  int slavekey = atoi(username); // @TODO: Make this more friendly

  char *urltoTar;      /* Full URL to the server-side location of job#.tgz */
  char *pathtoTar;     /* Full path to the location of the job#.tgz */
  char *pathtoTardir;

  char *urltoOutput;   /* Full URL where output is posted */
  char *pathtoOutput;  /* Full path to the output (rendered) file */
  char *pathtoOutdir;  /* Full path to output directory */
  char *pathtoRenderOutput;  /* Contains blender framenum placeholder */

  char *urltoJobfile; /* No longer used, url to .blend on server */

  char *pathtoJob;     /* Full path to job data folder */
  char *pathtoJobfile; /* Full path to the job's main file */
  char *outputExt = "jpg";     /* Output Extension (e.g., JPG) */

  int haveWork = 0;

  int benchmarkTime = 0;
  int renderPower = 0;

  slave_state.copyright_done = 0;
  slave_state.expectlen = 0;
  slave_state.quit = 0;

  fprintf(stderr, "Connecting to server...\n");
  if(remoteio_open_server(&slave_state.rem, commonopts->remoteio, &distren_slave_remoteio_read_handle, &slave_state, &distren_slave_remoteio_close_handle, server))
    {
      fprintf(stderr, "Error connecting to server; exiting\n");
      return 1;
    }
  greet_server(slave_state.rem);


  fprintf(stderr,"\nDistRen Slave Pre-Alpha %s\n- Experimental build: Use at your own risk!\n\n", PACKAGE_VERSION);

  // @TODO: add call to function to force recalc if $render_power == ""
  if(runBenchmark)
    {
      if(slaveBenchmark(datadir, &benchmarkTime, &renderPower))
        {
          fprintf(stderr,"Benchmark failed! Exiting.\n");
          return 1;
        }
      else
        {
          fprintf(stderr,"Benchmark successful, time taken was %d seconds, giving you a render power of %d.\n",
                  benchmarkTime, renderPower);
          _web_setrenderpower(slavekey, password, renderPower);
          return 0;
        }
    }

  if(!DEBUG)
    fprintf(stderr, "Running..");


  // Main loop
  while(!slave_state.quit)
    {
      multiio_poll(multiio, 15000);

      if(slave_state.quit)
	break;

    // request work
    fprintf(stderr, "Waiting...\n");
    haveWork = getwork(slave_state.rem, &jobnum, &framenum);

    /* If we got a frame */
    if(haveWork)
      {
        fprintf(stderr,"Got work from server...\n");
        /* @TODO: Add remotio hooks */
        // jobnum = remoteio_read(jobnum); /* Set jobnum from remoteio (we could use info from struct, but we need this info to download the xmlfile */
        // framenum = remoteio_read(jobnum); /* Set framenum from remoteio */
        // outputExt = remotio)read(outputExt); /* Set output extension from remotio */

        if(DEBUG)
          fprintf(stderr, "Preparing to render frame %d in job %d\n", framenum, jobnum);

        prepareJobPaths(jobnum, framenum, outputExt, datadir, &urltoTar, &pathtoTar,&pathtoTardir,&pathtoJob, &pathtoJobfile, &urltoJobfile, &urltoOutput, &pathtoOutput, &pathtoRenderOutput, &pathtoOutdir);

        int dlret = downloadTar(urltoTar, pathtoTar);
        if(dlret == 0)
          fprintf(stderr,"Data retrieved successfully!\n");
        else if(dlret == 3){
          resetframe(slave_state.rem, jobnum, framenum);  // Unassign the frame on the server so other slaves can render it
          return 0; // ouput dir doesn't exist
        }
        else
          if(DEBUG)
            fprintf(stderr,"Using existing tarball %s...\n", pathtoTar);

        // Decompress tarball
        struct stat jbuffer;
        int jstatus = stat(pathtoTar, &jbuffer);
        if(jstatus == -1){
          if(DEBUG)
            fprintf(stderr,"Main job file does not exist, extracting...\n");

          // If error unpacking tarball
          if(unpackJob(pathtoJob, pathtoTar)){
            resetframe(slave_state.rem, jobnum, framenum);  // Unassign the frame on the server so other slaves can render it
            fprintf(stderr,"Error decompressing tarball! Exiting.\n");
            return 1;
          }
        }

        /* ignore return because directory may exist already */
        if(DEBUG)
          fprintf(stderr,"Creating output directory %s\n", pathtoOutdir);
        mkdir(pathtoOutdir, 0700);

        if(DEBUG)
          fprintf(stderr,"Marking frame started on server... ");
        _web_startframe(slavekey, password, jobnum, framenum);

        /* Execute blender */
        if(DEBUG){
          fprintf(stderr,"Executing blender on file %s\n", pathtoJobfile);
          fprintf(stderr,"Directing output to file %s\n", pathtoOutput);
        }

        /* Execute blender */
        if(exec_blender(pathtoJobfile, pathtoOutput, framenum))
          {
            fprintf(stderr,"Error running Blender. Check your installation and/or your PATH.\n");
            resetframe(slave_state.rem, jobnum, framenum);  // Unassign the frame on the server so other slaves can render it
            return 1;
          }
        free(pathtoJobfile);
        pathtoJobfile = NULL;

        struct stat buffer;
        int fstatus = stat(pathtoOutput, &buffer);
        if(fstatus == -1){
          fprintf(stderr,"*** %s doesn't exist! Scene may not have camera, or your blender installation is not working.\n", pathtoOutput);
          resetframe(slave_state.rem, jobnum, framenum);  // Unassign the frame on the server so other slaves can render it
          return 1;
        }
        else{
          /* Post-execution */
          if(DEBUG)
            fprintf(stderr, "Finished frame %d in job %d, uploading...\n", framenum, jobnum);
          else
            fprintf(stderr,"Finished frame.\n");
          uploadOutput(pathtoOutput, urltoOutput, jobnum, framenum, slavekey); // @TODO: Handle return value

          free(urltoOutput);
          free(pathtoOutput);
          urltoOutput = NULL;
          pathtoOutput = NULL;

          // Tell the server that rendering and upload are complete of "jobjum.framenum"
          finishframe(slave_state.rem, jobnum, framenum);

  free(urltoTar);
  free(pathtoTar);
  free(pathtoTardir);
  free(pathtoJob);
  free(pathtoJobfile);
  free(urltoJobfile);
  free(urltoOutput);
  free(pathtoRenderOutput);
  free(pathtoOutdir);

        }
     }
    else{
      if(DEBUG)
        fprintf(stderr,"Nothing to do. Idling...\n");
      else
        fprintf(stderr,".");

      /**
	 to prevent infinite loops from burning CPU, we just sleep(1) ;-)
      */
      sleep(1);
    }

    /* @TODO: If the server says that every frame for the last jobnum is finished, OR if the data is getting old */
    if(1 == 0)
      {
        // Note: individual frames are already deleted after uploading,
        // except for ones that couldn't be uploaded
        delete_jobdata(jobnum, datadir);
      }

    sleep(5); // Poll 5 seconds. @TODO: Remove all polling
  }

  fprintf(stderr, "Quitting...\n");

  free(my_cfg);
  free(datadir);
  fprintf(stderr, "Goodbye!\n");
  return 0;
}

static void distren_slave_remoteio_close_handle(void *blah, void *data)
{
  struct slave_state *slave_state = (struct slave_state *)data;

  fprintf(stderr, "Lost connection to server\n");

  slave_state->quit = 1;
}

static size_t distren_slave_remoteio_read_handle(struct remoteio *rem,
						 void *blah,
						 void *buf,
						 size_t len,
						 void *data)
{
  struct slave_state *slave_state = (struct slave_state *)data;

  struct distren_request *req, *my_req;
  void *req_data, *my_req_data;

  size_t to_return;

  size_t counter;
  fprintf(stderr, "expected to eat %d bytes\n", len);

  /* to_return shall record how much of buf we've eaten already */
  to_return = 0;

  if(!slave_state->copyright_done)
    {
      putchar('\n');
      /* we have to flush through data until we hit a newline */
      for(counter = 0;
	  counter + slave_state->expectlen < 256 && counter < len && ((char *)buf)[counter] != '\n';
	  counter ++)
	{
	  putchar(((char *)buf)[counter]);
	}
      slave_state->expectlen += counter - 1;
      if(slave_state->expectlen == 256)
	{
	  fprintf(stderr, "\nThe server's greeting is too long. Maybe it speaks a foreign language\n");
	  slave_state->quit = 1;
	}
      if(counter < len && ((char *)buf)[counter] == '\n')
	{
	  putchar('\n');
	  counter ++;
	  slave_state->expectlen = 0;
	  slave_state->copyright_done = 1;
	  to_return += counter;
	  buf += counter;
	  len -= counter;
	}
      if(!slave_state->copyright_done)
	return to_return;
    }

  while(1)
    {
      /* if we haven't read a full header yet: */
      if(!slave_state->expectlen)
	{
	  if(len < sizeof(struct distren_request))
	    return to_return;

	  /* figure out how much we need to read in before we can get anywhere */
	  if(distren_request_new_fromdata(&req, buf, len))
	    {
	      fprintf(stderr, "Failing to interpret data from server, exiting\n");
	      slave_state->quit = 1;
	      return to_return;
	    }
	  slave_state->expectlen = sizeof(struct distren_request) + req->len;
	  distren_request_free(req);
	}

      if(slave_state->expectlen
	    && slave_state->expectlen <= len)
	{
	  distren_request_new_fromdata(&req, buf, len);
	  req_data = buf + sizeof(struct distren_request);

	  switch((enum distren_request_type)req->type)
	    {
	    case DISTREN_REQUEST_VERSION:
	      fprintf(stderr, "The server runs ");
	      for(counter = 0; counter < req->len; counter ++)
		putc(((char *)req_data)[counter], stderr);
	      putc('\n', stderr);
	      break;

	    case DISTREN_REQUEST_PING:
	      fprintf(stderr, "PONG ! :-D\n");

	      distren_request_poing(&my_req, &my_req_data, 0, req_data, req->len);
	      remoteio_write(slave_state->rem, my_req, sizeof(struct distren_request));
	      remoteio_write(slave_state->rem, my_req_data, req->len);
	      distren_request_free_with_data(my_req, my_req_data);
	      break;

	    case DISTREN_REQUEST_DISCONNECT:
	      /* hopefully this ends up being a useful message... */
	      printf("You have been disconnected: \"");
	      for(counter = 0; counter < req->len; counter ++)
		putchar(((char *)buf)[counter]);
	      putchar('"');
	      putchar('\n');
	      break;

	    default:
	      fprintf(stderr, "something\n");
	      break;
	    }

	  counter = req->len + sizeof(struct distren_request);

	  distren_request_free(req);
	  slave_state->expectlen = 0;

	  len -= counter;
	  buf += counter;
	  to_return += counter;
	}
    }

  fprintf(stderr, "ate %d bytes\n", to_return);
  return to_return;
}