/*
  Copyright 2009 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/>.
*/

/*
 * **********************************************************************************
 * Slave functions / etc resides below. Wouldn't a seperate file make this easier??
 *
 * Slave listens on server for a command in the format of each function...
 * We need if's for returns... ==> watchdog
 * **********************************************************************************
*/


///////////////////// Semi-pseudo Slave Code ///////////////////////////

int slavestatus = 0;

if(no username in config file, no key present){
	fprintf(stderr "run distrend -c username] [emailaddr] to register")
}
if(they use a -c flag according to getopt, with 2 args){
	register_user(username, email); which returns a uniquely random url to a key
	get(uniquely-random-url-to-key);
	fprintf(stderr, "you registered, hopefully successfully. Invoke distrend with no args now.");
}
if(username is in conf file and key is present){
	loginuser(username);
}

if(slave recieves "start frame#, job#"){
	get(http://distren.protofusion.org/srv/job#.tgz);
	tar -xvf job#.tgz /tmp/distren/job#; somehow
	exec_blender(job#.blend, job#.frame#.JPG, job#); (check the args, we'll need to adjust for different output formats)... set SLAVESTATUS=1 while rendering, SLAVESTATUS=2 when done
}
if(SLAVESTATUS==2){
	tell the server "done with frame# in job#";
	SLAVESTATUS=0
}
if(SLAVESTATUS==0){
	tell the server "i ain't got no frames to render";
}
while(SLAVESTATUS==1){
	tell the server "rendering this friggn frame";
	delay(1000);
}












// Registration on server. Needs attention. Prevent account spamming.
// Key transfer?
// Set up something like: distrend -c username email@example.com
void registeruser(char *username, char *email){
  // Logs into sandboxed user on zserver2 and registers a user. Should eventually generate a key on the server and return it to the user.
  // All created user accounts should be sandboxed accordingly, requiring a different skel, and the default shell to be rbash. Also,
  // a custom path defined in the .bash_profile of the skel is needed.
  char buf[10];
  struct execio *testrem;
  char *execargv[] =
    {
  "ssh",
  "distren_setup@protofusion.org",
  "-i",
  "setup.rsa", // default distributed key, account can only create users.
  "-p",
  "23",
  "sudo /usr/sbin/useradd",
  "-M",
  "-c",
  email,
  "-d",
  "/home/distren",
  "--gid",
  "541", // Add in shellscript to generate ssh key and return it to the user somehow
  username,
  (char *)NULL
  };
  size_t readlen;
  fprintf(stderr, "Opening stream:\n", execio_open(&testrem, "ssh", execargv));
  buf[9] = '\0'; // null-terminating the array...
  while(!execio_read(testrem, buf, 9, &readlen)) // What's with the readlen stuff?
    {
      if(readlen > 9) {
	fprintf(stderr, "!!!! Something is terribly wrong!\n");
      }
    buf[readlen] = '\0'; // Null-terminating the end of it again based on how large the data is?
    fprintf(stderr, "read \"%s\"\n", buf);
    }
  execio_close(testrem);
}


void loginuser(char *username){
  // Logs into sandboxed user on zserver2 as a client, currently does nothing
  char buf[10];
  struct execio *testrem;
  char *execargv[] =
    {
  "ssh",
  "username@protofusion.org", // username must be read from the conf
  "-i",
  "username.rsa", // Key created from registeruser()
  "-p",
  "23",
  "echo",
  "hello", // This should eventually open a non-terminating connection to the server for communication
  (char *)NULL
  };
  size_t readlen;
  fprintf(stderr, "Opening stream:\n", execio_open(&testrem, "ssh", execargv));
  buf[9] = '\0'; // null-terminating the array...
  while(!execio_read(testrem, buf, 9, &readlen)) // What's with the readlen stuff?
    {
      if(readlen > 9) {
	fprintf(stderr, "!!!! Something is terribly wrong!\n");
      }
    buf[readlen] = '\0'; // Null-terminating the end of it again based on how large the data is?
    fprintf(stderr, "read \"%s\"\n", buf);
    }
  execio_close(testrem);
}


// Executors

/*
  It seems that the client will need to know the job number. Is finish_frame going to be on the client or the server? we gotta figure that out!
*/
void exec_blender(struct blendjob* blendjob, char *input, char *output, int frame)
{
  char *frame_str;
  asprintf(frame,frame_str); // GNU/*nix compatible only, fix before releasing win32, although dll for windows for asprintf exists!
  int ret;
  char *cmd[] = { "blender", "-b", "-o", output, input, "-f", frame_str, (char *)0 };
  ret = execv("/usr/bin/blender", cmd);
  finish_frame(blendjob, frame);
}