/*

  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/>.

*/

 /*

  * Registration on server. Needs attention. Prevent account spamming.

  * distrenslave -c username email@example.com

 */

#include "blendjob.h"

#include "execio.h"

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <stdlib.h> /*< malloc(), free() */

#include <sys/stat.h>

#include <fcntl.h>

/** Generates a SSH key with ssh-keygen */

int ssh_keygen(){

	// distren.id_rsa and distren.id_rsa.pub are now generated in SYSCONFDIR (etc)

	// Checks to see if the keys are already present.

	int status;

	struct stat buffer;

	status = stat(SYSCONFDIR "/distren.id_rsa", &buffer);

	if(status == -1){

		fprintf(stderr, "Please delete etc/distren.id_rsa and etc/distren.id_rsa.pub to register.");

	}

/* start execio code */

	char *command = "ssh-keygen"; // @TODO: append .exe if win32?

	int ret;

	char *cmd[] = { command, "-q", "-f", SYSCONFDIR "/distren.id_rsa", "-N", "", (char *)NULL }; // TODO: Give me the correct args!

	char buf[10];

	struct execio *testrem;

	size_t readlen;

	buf[9] = '\0'; // null-terminating the array...

	while(!execio_read(testrem, buf, 9, &readlen))

	    {

	      if(readlen > 9) {

		fprintf(stderr, "Something is terribly wrong!\n");

	      }

	      buf[readlen] = '\0';

	      fprintf(stderr, "read \"%s\"\n", buf);

	    }

	execio_close(testrem);

/* end execio code */

	// Supposedly execio returns 1 if it has bad args.

	if(ret == 1){

		fprintf(stderr, "Generating your key failed. Ensure that ssh-keygen is present!\n"); // Use different executor that searches the path? there is one...

		return 0;

	}

	else{

		fprintf(stderr,"We successfully generated your key! Yay!");

		return 1;

	}

return 0;

}

/** Registers the user on the DistRen server */

int register_user(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",

      SYSCONFDIR "/setup_rsa", // default distributed key, account can only create users.

      "-p",

      "23",

      "newuser",

      "-M",

      "-c",

      email,

      "-d",

      "/home/distren",

      "--gid",

      "541",

      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))

    {

      if(readlen > 9) {

	fprintf(stderr, "!!!! Something is terribly wrong!\n");

      }

      buf[readlen] = '\0';

      fprintf(stderr, "read \"%s\"\n", buf);

    }

  execio_close(testrem);

  /* @TODO: Parse the output buffer or something to check when user creation fails due to duplicate users. This is pretty important. */

  conf_replace(username); // puts the person's username in the conf

  ssh_keygen(); // generates keys for login, @TODO: pub key must somehow be sent to the server.

  return 1;

}

/** Logs the user into the server with a nice ssh session */

int login_user(char *username)

{

  char *userhost;

  char *userkey;

  char buf[10];

  struct execio *testrem;

  char *execargv[] =

    {

      "ssh",

      "-i",

      (char *)NULL, // Key created from registeruser()

      "-p",

      "23",

      (char *)NULL,// username and hostname

      "echo",

      "hello", // This should eventually open a non-terminating connection to the server for communication,

      (char *)NULL

    };

  size_t readlen;

  /*< @TODO remove being tied to protofusion.org for no reason  */

  userhost = malloc(strlen(username) + strlen("@protofusion.org") + 1);

  if(!userhost)

    return 43;

  strcpy(userhost, username);

  strcat(userhost, "@protofusion.org"); // Throws @protofusion.org after the username

  userkey = malloc(strlen(username) + strlen(".rsa") + 1);

  if(!userkey)

    {

      free(userhost);

      return 44;

    }

  strcpy(userkey, username);

  strcat(userkey,".rsa");

  fprintf(stderr, "Logging you in to %s using key %s\n", userhost, userkey);

  if(fopen(userkey, "r") == NULL){

	  fprintf(stderr,"Your key, %s, has not been found! Re-register or somehow regenerate your key! We need a way to regenerate keys coded in, but we don't have the facilities yet!",userkey);

	  return 0;

  }

  fprintf(stderr, "Opening stream:\n", execio_open(&testrem, "ssh", execargv));

  buf[9] = '\0'; // null-terminating the array...

  while(!execio_read(testrem, buf, 9, &readlen))

    {

      if(readlen > 9) {

	fprintf(stderr, "!!!! Something is terribly wrong!\n");

      }

    buf[readlen] = '\0';

    fprintf(stderr, "read \"%s\"\n", buf);

    }

  execio_close(testrem);

  return 1; // 1 can be like... error-free login...

}

/** Replaces username and key in the slave's conf file */

void conf_replace(char *username){

  /* Note: SYSCONFDIR doesn't include a trailing slash */

  int maxlinelen = 120;

  char *fileOrig = SYSCONFDIR "/distrenslave.conf";

  char *fileRepl = SYSCONFDIR "/distrenslave.conf.edited";

  char *text2find = "!username";

  char *text2repl = username;

  char buffer[maxlinelen+2];

  char *buff_ptr, *find_ptr;

  FILE *fp1, *fp2;

  size_t find_len = strlen(text2find);

  fp1 = fopen(fileOrig,"r");

  fp2 = fopen(fileRepl,"w");

  if (fp1 ==NULL){

	  fprintf(stderr, "%s doesn't exist\n",fileOrig);

  }

  else if(fp2 ==NULL){

	  fprintf(stderr, "Can't write a file to disk! Check permissions.\n");

  }

  else{

    while(fgets(buffer,maxlinelen+2,fp1))

      {

          buff_ptr = buffer;

          while ((find_ptr = strstr(buff_ptr,text2find)))

          {

          while(buff_ptr < find_ptr)

          	fputc((int)*buff_ptr++,fp2);

          fputs(text2repl,fp2);

          buff_ptr += find_len;

          }

          fputs(buff_ptr,fp2);

      }

    rename(fileRepl, fileOrig);

  }

  fclose(fp2);

  fclose(fp1);

  fprintf(stderr,"Wrote conf file...\n");

}

/* Executors */

/*

  It seems that the client will need to know the job number. fixme.

*/

/** Executor function for Blender operations */

void exec_blender(struct blendjob* blendjob, char *input, char *output, int frame)

{

  char *frame_str;

  asprintf(frame,frame_str); // Converts the int frame to a string, so it can be in the cmd array. GNU/*nix compatible only, fix before releasing win32, although dll for windows for asprintf exists!

  ret = execv("/usr/bin/blender", cmd); // This path will be absolute for testing, should be relative to install on production

  /* start execio code */

  	int ret;

  	char buf[10];

  	struct execio *testrem;

  	size_t readlen;

  	buf[9] = '\0'; // null-terminating the array...

  	while(!execio_read(testrem, buf, 9, &readlen))

  	    {

  	      if(readlen > 9) {

  		fprintf(stderr, "Something is terribly wrong!\n");

  	      }

  	      buf[readlen] = '\0';

  	      fprintf(stderr, "read \"%s\"\n", buf);

  	    }

  	execio_close(testrem);

  /* end execio code */

}