/*
  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/>.

*/

/* This file contains the code which both processes (renders) jobs as a slave, and the code which distributes frames to slaves after receiving them from the client portion of the codebase. */

 /* Just some notes -- Ethan Zonca
 * ++ Make data availible for other apps to parse
 * Server<==>Client Communication
 * Upload while rendering
 */


#include "execio.h"
#include "options.h"
#include <confuse.h>
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <unistd.h> /* getopt */
#include <time.h>




typedef unsigned int jobnum_t;

/* ******************* Structs ************************ */

// Stores config info? editmycomment
struct distrend_config
{
  cfg_t *mycfg;
  struct options_common *options;
  struct distrend_listen **listens; /*< Null terminated array of structs */
};



/*
 frame[frame] Status Assignments:
  "NULL" - don't render me
  "0" - canceled
  "1" - unassigned
  "2" - assigned to slave
  "3" - completed by slave and uploaded

 Have a script crawl through each job in the arrays, priority-biased, and assign a frame to each slave.
 Then we will need some sort of watchdog to monitor slaves on the main server to check for stales. Maybe not worry about this for now.
*/

struct general_info {
	short int jobs_in_queue; //
	unsigned short int free_clients;
	unsigned short int rendering_clients;//
	unsigned short int total_finished_jobs; //
	unsigned int total_frames_rendered; //
} general_info;

// Stores Blender Job Info
struct blendjob {
  struct blendjob *next; /* next will be NULL unless if there is another blendjob */
  char *name;
  char *submitter;
  char *email;
  jobnum_t jobnum;
  int priority;  // 1 is lowest, 10 is highest, 0 means the job is done
  int percent_done;
  int completed_frames; // number of completed frames for stats/etc
  int assigned_frames; // number of assigned frames (that are not yet completed) for stats/etc
  int total_frames; // how many frames are in the animation for stats/etc (unassigned frames)
  int avg_render_time; // average seconds it took to render a frame
  unsigned int time_remaining; // estimated seconds remaining till render is complete (up to 49, 710 days)
							   // we can have the client computer convert it into days, hours, etc if they wish to view it
  struct frameset *frameset;
};


// Frameset Structure
struct frameset {
	int frame_num; // frame number to render
	char slave_name; // user that frame is assigned to
	int frame_status; // status of frame, 0= unassigned, 1= taken, 2= done
	clock_t start_time; // time the frame was started
	int time_to_render; // the total seconds it took to render the frame
} frameset[]; // Frameset array is generated by status_report_generator function
                         // Using this method to save memory, because if animation starts on a high frame number, it would waste a lot of RAM on empty structures


/*
  internally defined funcs's prototypes
*/
void status_report_generator();
void blendjob_remove(struct blendjob **head, struct blendjob *bj);

struct blendjob *blendjob_get(struct blendjob *head, jobnum_t jobnum);

/* Global Vars, try to cut down on these */
jobnum_t jobnum = 0; // The next job number to create in the queue
int hcfjob; // Highest consecutively finished job
int highest_jobnum; // The job number of the most recently created job, this is used when creating new jobs


/* ********************** Functions ************************* */

void start_data(){

	if(1 == 0){
		// retrieve total_finished_jobs and total_finished_frames from xml file
	}
	else{
		general_info.total_finished_jobs = 0;
		general_info.total_frames_rendered = 0;
	}
}

// **** Finish-Setter: Sets a frame to the "completed" status.
void finish_frame(struct blendjob *blendjob, int frame){
  blendjob->frameset[frame].frame_status = 2;
  blendjob->frameset[frame].time_to_render = (clock() - blendjob[jobnum].frameset[frame].start_time); // Consider changin time-to-render to time-for-frame or something?

  general_info.total_frames_rendered++; // Increase total frames var for stats
}


// **** Queuer: Adds files to the queue
void queue(struct blendjob *blendjob, int type, char *name, char *submitter, char *email, int priority, int mode, int spp, struct frameset *frameset) {
	// Type: 1 = blender, add more types later
	// jobnum is the next available job number
	if(type == 1){
    blendjob->name = name;
    blendjob->submitter = submitter;
    blendjob->email = email;
    blendjob->priority = priority;
    blendjob->frameset = frameset;
  }
  else{
    // Throw error.
  }
jobnum++; // Advance the jobnumber for the next queued job
}


/*
  Status Report Generator: figures out how much of the job is done, where jobnum corresponds to the job number

  blendjobs_head is a pointer to a pointer because the head of the blendjobs linked list may need to be changed by blendjob_remove
*/
void status_report_generator(struct blendjob **blendjobs_head)
{
  struct blendjob *blendjob_ptr;
  unsigned short workers_working; /*< used to count the total number of workers working */
  unsigned int numjobs; /*< used to track number of jobs */

  blendjob_ptr = *blendjobs_head;
  workers_working = 0;
  numjobs = 0;
  
  while(blendjob_ptr)
    {
      if(blendjob_ptr->priority != 0)
	/* If the job is not done, scan it */
	{
	  unsigned int framecounter;  /*< to scan through frames */
	  unsigned long finished_frames; /*< variable that counts the completed frames */
	  unsigned int pending_frames; /*< variable that counts the assigned frames */
	  float percent_frames_finished;  /*< variable that stores the percent done of the blendjob */
	  unsigned int total_time;  /*< total time taken to render all the completed frames for a job */

	  framecounter = 0;
	  finished_frames = 0;
	  pending_frames = 0;
	  percent_frames_finished = 0;
	  total_time = 0;

	  while(framecounter < blendjob_ptr->total_frames)
	    /* scans through frames, based on their status it runs a statement(s) */
	    {
	      if(blendjob_ptr->frameset[framecounter].frame_status == 2)
		/* If the frame is done */
		{
		  finished_frames ++;
		  total_time += blendjob_ptr->frameset[framecounter].time_to_render;
		}
	      
	      if(blendjob_ptr->frameset[framecounter].frame_status == 1)
		/* If the frame is assigned */
		{
		  pending_frames ++;
		  workers_working ++;
		}
	      
	      framecounter ++;
	    } /* while(framecounter < blendjob_ptr->total_frames) */

	  // find the percent of completed frames
	  percent_frames_finished = (finished_frames / blendjob_ptr->total_frames) * 100; /*< @LordofWar: extraneous parentheses! */

	  /* updates values in the blendjob struct */
	  blendjob_ptr->completed_frames = finished_frames;
	  blendjob_ptr->assigned_frames = pending_frames;
	  blendjob_ptr->percent_done = percent_frames_finished;
	  blendjob_ptr->avg_render_time = (total_time / finished_frames); /*< extraneous parentheses! */
	  blendjob_ptr->time_remaining = (blendjob_ptr->avg_render_time * (blendjob_ptr->total_frames - finished_frames)); /*< extraneous parentheses! */

	  if(finished_frames == blendjob_ptr->total_frames)
	    /* If all frames are complete */
	    {
	      blendjob_ptr->priority = 0; /*< set priority to zero to indicate job is complete */
	      blendjob_remove(blendjobs_head, blendjob_ptr); /*< remove this job from the linkedlist */
	      general_info.total_finished_jobs++; /*< add one to the total finished jobs */
	      
	    }
	  else if (finished_frames > blendjob_ptr->total_frames)
	    /* just in case ;-) */
	    {
	      fprintf(stderr, "%s:%d: finished_frames (%lu) > blendjob_ptr->total_frames (%d)",
		      __FILE__, __LINE__, 
		      finished_frames, 
		      blendjob_ptr->total_frames);
	      abort();
	    }
	}

      general_info.rendering_clients = workers_working; /*< should this be a +=? */
      
      blendjob_ptr = blendjob_ptr->next; /*< This is the essence of linked lists and iterating through them */
      numjobs ++;
    } /* while(blendjob_ptr) */
  
  general_info.jobs_in_queue = (highest_jobnum - general_info.total_finished_jobs); /*< extraneous parentheses! */
}


// **** Structure Builder: This function creates frame array based on the total number of frames to be rendered, which will then be parsed by function frame_farmer.
void frame_num_struct_builder(struct blendjob *job, unsigned int startframe, unsigned int numframes) {
  int jobnum_new = highest_jobnum + 1; /* global vars will someday leave us  */
  unsigned int counter;

	job->frameset = malloc(sizeof(struct frameset) * numframes);
	if(!job->frameset)
	  fprintf(stderr, "error allocating memory");

	job->total_frames = numframes; // sets the total number of frames in animation for status purposes
	job->jobnum = jobnum_new;

	for(counter = 0; counter < numframes; counter ++)
	  /* This builds the array, with the array starting at zero and the frame_num starting at sframe */
	  job->frameset[counter].frame_num = counter + startframe;

	highest_jobnum++; // After it has created the job, it adds one to the highest_jobnum interger
}



// Frame Assigner: matches your computer up with a lovely frame to render
// Major issue here, the client needs to know the frame number, AND the job number!
int frame_finder(){
	int your_frame = 0;  // your_frame is an interger value that will be given to the client as the frame number to render
	int finder_jobnum = 0;
	int frameset_count = 0; // the frameset number, note* frames in an animation don't start at zero
	short int done = 0;
	short int priority = 10;

	while(priority >= 1){ // start the scan for the next job with the highest priority, decreases priority before it loops
		finder_jobnum = hcfjob + 1; // reset it to start scanning at first uncompleted job for the pass at each priority level

		while(finder_jobnum <= highest_jobnum){  // This keeps increasing the finder_jobnum until it is higher than the highest_jobnum
			if(blendjob[finder_jobnum].priority == priority){  // looks for a job with the current priority value
				done = 1;									  // notice it starts by looking at the oldest job first
				break;
			}

			if((done) == 1)  // If it has found a job with the current priority value, it will break out of the loop
				break;    // If none is found it goes to the next job to see if it is of the current priority value
			else
				finder_jobnum++;
		} // End of increasing finder_jobnum

		if(done == 1) // if job has been found, it lets it out of the priority changer loop
			break;

		priority--; // end of decreasing priority
	}

	while(your_frame < blendjob[finder_jobnum].total_frames){ // Finds the frameset number with a frame that needs to be rendered
		if (blendjob[finder_jobnum].frameset[frameset_count].frame_status == 0)  // If frame that is not assigned has been found, frameset_count is not changed
			break;																// and frameset_count is used to give the frame number later in this funciton

		frameset_count++;  // If frame is assigned or done, it goes to next frame
	}

blendjob[jobnum].frameset[frameset_count].frame_status++; // sets the value of the frame to 2, which means its taken

your_frame = blendjob[jobnum].frameset[frameset_count].frame_num; //  Takes the frameset found in the while statement above, and extracts the frame number from it and assigns it to the int your_frame

if(your_frame == 0)  // If that job had no open frames for some reason, run the status report generator so that
	status_report_generator();  //the job priority can be changed to 0

blendjob[jobnum].frameset[frameset_count].start_time = clock();

return your_frame; // your_frame is returned as the frame to be rendered
}

void blend_frame_watchdog(struct blendjob *blendjob_head)
{
  unsigned short int watchdog_forgiveness; /*< seconds to wait on a frame before re-assigning it */
  struct blendjob *blendjob_ptr;
  unsigned int counter;

  watchdog_forgiveness = 3; /*< hours of forgiveness before frame is re-assigned */
  blendjob_ptr = blendjob_head;

  for(blendjob_ptr = blendjob_head; blendjob_ptr; blendjob_ptr = blendjob_ptr->next)
    /* iterate through jobs */

    for(counter = 0; counter < blendjob_ptr->total_frames; counter ++)
      /* iterate through all frames for this job*/
      {
	if((blendjob_ptr->frameset[counter].start_time + (watchdog_forgiveness * 3600)) < clock()) 
	  /*
	    If frame is not completed within the number of hours specified by watchdog_forgiveness 
	    Then change the frame status to unassigned
	  */
	  blendjob_ptr->frameset[counter].frame_status = 0;
      }

}

/**
   Finds a blendjob struct based on the jobnum
   @arg jobnum job number to search for
   @return NULL on job doesn't exist
 */
struct blendjob *blendjob_get(struct blendjob *head, jobnum_t jobnum)
{
  struct blendjob *blendjob_ptr;
  
  /*
    The conditions of the for loop will leave blendjob_ptr at NULL if the end of the list is reached. It will leave it pointing to the correct job if it is found.
   */
  for(blendjob_ptr = head;
      blendjob_ptr
	&& blendjob_ptr->jobnum != jobnum;
      blendjob_ptr = blendjob_ptr->next);
  
  return blendjob_ptr;
}


/**
   Removes a blendjob from the blendjob linkelist.

   @arg head a double pointer. the head pointer will have to be changed if blendjob == *head. Thus, make sure that the pointer points to the pointer to the head that all functions use. (I'm going to come back to this and misunderstand myself ;-))
 */
void blendjob_remove(struct blendjob **head, struct blendjob *bj)
{
  struct blendjob *previous_blendjob;
  
  if(bj == *head)
    *head = bj->next;
  else
    {
      
      for(previous_blendjob = *head;
	  previous_blendjob
	    && previous_blendjob->next != bj; /*< stop on the blendjob that comes before bj */
	  previous_blendjob = previous_blendjob->next)
	/* all of the action is in the definition of the for loop itself */;
  
      /*
	This removes references to bj from the linked list. I.E., we now skip bj when iterating through the list
       */
      previous_blendjob->next = bj->next;
    }
  
  /* 
     @lordofwar: the magic deallocation of memory ;-)
   */
  free(bj);
}


/* ************************** Main ************************* */

int main(int argc, char *argv[])
{
//// Begin Getopt Sample, EDITME!Sometime
		   int aflag = 0;
	       int bflag = 0;
	       char *cvalue = NULL;
	       int index;
	       int c;

	       opterr = 0;

	       while ((c = getopt (argc, argv, "abc:")) != -1)
	         switch (c)
	           {
	           case 'a':
	             aflag = 1;
	             break;
	           case 'b':
	             bflag = 1;
	             break;
	           case 'c':
	             cvalue = optarg;
	             break;
	           case '?':
	             if (optopt == 'c')
	               fprintf (stderr, "Option -%c requires an argument.\n", optopt);
	             else if (isprint (optopt))
	               fprintf (stderr, "Unknown option `-%c'.\n", optopt);
	             else
	               fprintf (stderr,
	                        "Unknown option character `\\x%x'.\n",
	                        optopt);
	             return 1;
	           default:
	             abort ();
	           }

	       printf ("aflag = %d, bflag = %d, cvalue = %s\n",
	               aflag, bflag, cvalue);

	       for (index = optind; index < argc; index++)
	         printf ("Non-option argument %s\n", argv[index]);
//// End getopt sample


// Just wrote this to try and piece everything together after writing it on paper :D --ethanzonca
///////////////////// Semi-pseudo-code for server //////////////////////////////////////////
/*

start_data();
status_report_generator();
blend_frame_watchdog();

	if(client says "i ain't got nuthin to render!"){
		frame_finder() ==> returns jobnum/framenum that are sent to slave, "render jobnum framenum"
	}
	if(client says "done with frame # in job #"){
		finish_frame(jobnum, frame);
		frame_finder() ==> returns jobnum/framenum that are sent to slave, "render jobnum framenum"
	}

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







// Begin non-working framework?
	int distrend_do_config(int argc, char *argv[], struct distrend_config *config)
	{
	  cfg_opt_t myopts_listen[] =
	    {
	      CFG_SIMPLE_STR("type", NULL),
	      CFG_SIMPLE_STR("path", NULL),
	      CFG_SIMPLE_INT("port", NULL),
	      CFG_END()
	  };
	  cfg_opt_t myopts[] =
	    {
	      CFG_SEC("listen",  /* this must be imported into struct listens (which must still be declared) */
		      myopts_listen
		      ,
		      CFGF_MULTI),
	      CFG_END()
	    };

	  config = malloc(sizeof(struct distrend_config));
	  options_init(argc, argv, &config->mycfg, myopts, "server", &config->options);

	  return 0;
	}
	int distrend_config_free(struct distrend_config *config)
	{
	  options_free(config->options);
	  free(config);

	  return 0;
	}
// End non-working framework?



  int cont = 1;
  struct distrend_listenset *listenset;
  struct distrend_config *config;
  distrend_do_config(argc, argv, config);

  distrend_listen(&listenset, config);
  /* This is called the ``main loop'' */
  while(cont)
    {
      struct distren_action *action;

      distrend_accept(&action);
      cont = distrend_do(action);
      distrend_action_free(action);
    }

  distrend_unlisten(listenset);
  distrend_config_free(config);

  return 0;
}







/*
 * **********************************************************************************
 * 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(char *input, char *output, int frame, int jobnum) {
  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(jobnum, frame);
}