/*

  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. */

#include "execio.h"

#include "options.h"

#include "distrenjob.h"

#include "protocol.h"

#include "slavefuncs.h"

#include <confuse.h>

#include <stdio.h>

#include <stdlib.h>

#include <malloc.h>

#include <unistd.h> /* getopt */

#include <time.h>

#include <sys/stat.h>

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

// Gets config info from confs

struct distrend_config

{

  cfg_t *mycfg;

  struct options_common *options;

  struct distrend_listen **listens; /*< Null terminated array of structs */

  char *datadir;

};

/*

 frame[frame] Status Assignments:

  "NULL" - don't render me

  "0" - canceled

  "1" - unassigned

  "2" - assigned to slave

  "3" - completed by slave and uploaded

*/

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; //

  unsigned int highest_jobnum;

} general_info;

/*

  internally defined funcs's prototypes

*/

void status_report_generator(struct distrenjob **distrenjobs_head);

void distrenjob_remove(struct distrenjob **head, struct distrenjob *bj);

struct distrenjob *distrenjob_get(struct distrenjob *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 ************************* */

/** Dumps all data in RAM to an xml file (such as current jobs, etc) which is parsed by start_data. Remember to invoke this before shutting down! */

int xml_dump()

{

  return 0;

}

/**

   Performs command stored in a client's request.

*/

int distrend_do()

{

  return 0;

}

/**

   Accepts a client's connection

 */

void distrend_accept()

{

}

/**

   Frees the action

*/

void distrend_action_free()

{

}

/**

   Start listening

*/

void distrend_listen()

{

}

/**

   Stop listening

*/

void distrend_unlisten()

{

}

/**

   This is probably just a placeholder for remotio

*/

void remotio_send_to_client()

{

	// I am futile!

}

/** Fill variables after crash / shutdown from XML dumps */

int start_data(){

  struct stat buffer;

  if(stat(SYSCONFDIR "/data.xml", &buffer) == 0){

    // @TODO: retrieve total_finished_jobs and total_finished_frames from xml file

    fprintf(stderr,"Parsing XML files and restoring previous state...\n");

    return 1;

  }

  else{

    general_info.total_finished_jobs = 0;

    general_info.total_frames_rendered = 0;

    fprintf(stderr,"Can't find XML dump, starting up fresh.\n");

    return 2;

  }

  free(&buffer); // @TODO: Is this pointless?

}

/** Finish-Setter: Sets a frame to the "completed" status.*/

void finish_frame(struct distrenjob *distrenjob, int frame){

  distrenjob->frameset[frame].status = 2;

  distrenjob->frameset[frame].time_to_render = (clock() - distrenjob[jobnum].frameset[frame].start_time); // Consider changing time-to-render to time-for-frame or something?

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

}

/**

   creates a structure from starting data, then calls another function to actually add that struct to the queue

*/

void prepare_distrenjob(struct frameset *head, int type, char *name, char *submitter, char *email, int priority, int start_frame, int end_frame)

{

  int counter2;

  int counter;

  struct distrenjob *distrenjob;

  distrenjob->type = 1; /*@TODO: add type to blendjob struct*/

  distrenjob->name = name;

	  float percent_frames_finished;  /*< variable that stores the percent done of the distrenjob */

	  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 < distrenjob_ptr->total_frames)

	    /* scans through frames, based on their status it runs a statement(s) */

	    {

	      if(distrenjob_ptr->frameset[framecounter].status == 2)

		/* If the frame is done */

		{

		  finished_frames ++;

		  total_time += distrenjob_ptr->frameset[framecounter].time_to_render;

		}

	      if(distrenjob_ptr->frameset[framecounter].status == 1)

		/* If the frame is assigned */

		{

		  pending_frames ++;

		  workers_working ++;

		}

	      framecounter ++;

	    } /* while(framecounter < distrenjob_ptr->total_frames) */

	  // find the percent of completed frames

	  percent_frames_finished = (finished_frames / distrenjob_ptr->total_frames) * 100; /*< @LordofWar: extraneous parentheses! */

	  /* updates values in the distrenjob struct */

	  distrenjob_ptr->completed_frames = finished_frames;

	  distrenjob_ptr->assigned_frames = pending_frames;

	  distrenjob_ptr->percent_done = percent_frames_finished;

	  distrenjob_ptr->avg_render_time = (total_time / finished_frames); /*< extraneous parentheses! */

	  distrenjob_ptr->time_remaining = (distrenjob_ptr->avg_render_time * (distrenjob_ptr->total_frames - finished_frames)); /*< extraneous parentheses! */

	  if(finished_frames == distrenjob_ptr->total_frames)

	    /* If all frames are complete */

	    {

	      distrenjob_ptr->priority = 0; /*< set priority to zero to indicate job is complete */

	      distrenjob_remove(distrenjobs_head, distrenjob_ptr); /*< remove this job from the linkedlist */

	      distrenjob_free(distrenjob_ptr);

	      general_info.total_finished_jobs++; /*< add one to the total finished jobs */

	    }

	  else if (finished_frames > distrenjob_ptr->total_frames)

	    /* just in case ;-) */

	    {

	      fprintf(stderr, "%s:%d: finished_frames (%lu) > distrenjob_ptr->total_frames (%d)",

		      __FILE__, __LINE__,

		      finished_frames,

		      distrenjob_ptr->total_frames);

	      abort();

	    }

	}

      general_info.rendering_clients = workers_working; /*< should this be a +=? */

      distrenjob_ptr = distrenjob_ptr->next; /*< This is the essence of linked lists and iterating through them */

      numjobs ++;

    } /* while(distrenjob_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. 

*/

/** 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 add_job_to_queue(struct distrenjob *head, struct distrenjob *job) {

  struct distrenjob *prev_job = head; // create pointer to previous job

  struct distrenjob *current_job;     // create pointer to current_job (which job is being compared to)

  // iterate through linked list of jobs

  for(current_job = head; current_job != NULL; current_job = current_job->next){

    if(current_job == NULL){ // if it has reached the end of the list, add job there

      current_job = job;

      break;

    }

    else if(job->priority < current_job->priority){ // if job's priority is less than current_job's priority, insert job

      prev_job->next = job;                        // keep in mind 1 is the highest priority given to jobs, head has a

      job->next = current_job;                     // priority of zero so it will always be before other jobs

      break;

    }

    prev_job = current_job;

  } /* for(current_job) */

}

/**

   @arg head I may end up changing the head if job == head

 */

  distrenjob_remove(head, job);

  job->priority = new_priority;

  add_job_to_queue(head, job);

}

/**

  Frame Finder: matches your computer up with a lovely frame to render

  TODO: Major issue here, the client needs to know the frame number, AND the job number!

  Notice that this function starts by looking at the oldest job first

	TODO: Link this up with the main() function to check if there are frames available or not and provide jobnum/framenum to the client

  @return 0 success, other: error

*/

int frame_finder(struct distrenjob *head, struct distrenjob **job, struct frameset **frame)

{

  int your_frame;  // your_frame is an integer value that will be given to the client as the frame number to render

  int your_job;	   // @TODO: Fixme: do we need this var? you_job is an integer value that must ALSO be given to the client

  unsigned short int found;

  unsigned short int priority;

  struct distrenjob *distrenjob_ptr;

  found = 0;

  while(!found)

    {

      /* enumerate through priority levels */

      for(priority = 10;

        priority > 0

            && !found;

           priority --)

	/* Find the job with the highest priority */

        for(distrenjob_ptr = head;

            distrenjob_ptr != NULL

            && !found;

            distrenjob_ptr = distrenjob_ptr->next)

          if(distrenjob_ptr->priority == priority)

	    found = 1;

      if(!found)

        {

          fprintf(stderr, "No more jobs to render\n");

          return 1;

        }

      found = 0;

      for(your_frame = 0;

        your_frame < distrenjob_ptr->total_frames;

        your_frame ++)

        if(distrenjob_ptr->frameset[your_frame].status == 0)

          found = 1;

      if(!found)

        {

          /* there are no frames left in this job */

          distrenjob_ptr->priority --;

	  /* If that job had no open frames for some reason, run the status report generator so that */

          status_report_generator(&head);

          /* should the job be removed now? */

          fprintf(stderr, "Job %d is finished, this is probably the place to call the job-removal function\n", distrenjob_ptr->jobnum);

          /* @TODO: At this point, all slaves should be instructed to delete the source data for this job. */

        }

    }

  /* Sets the value of the frame to 1, which means it is taken */

  distrenjob_ptr->frameset[your_frame].status++;

  distrenjob_ptr->frameset[your_frame].start_time = clock();

  *job = distrenjob_ptr;

  *frame =  &distrenjob_ptr->frameset[your_frame];

  return 0;

}

/** Checks for dead, laggy, or stale slaves */

void blend_frame_watchdog(struct distrenjob *distrenjob_head)

{

  unsigned short int watchdog_forgiveness; /*< seconds to wait on a frame before re-assigning it */

  struct distrenjob *distrenjob_ptr;

  unsigned int counter;

  watchdog_forgiveness = 1; /*< hours of forgiveness before frame is re-assigned @TODO: Make this more user-configurable (maybe per-job), 3 hours is a LONG time */

  distrenjob_ptr = distrenjob_head;

  for(distrenjob_ptr = distrenjob_head; distrenjob_ptr; distrenjob_ptr = distrenjob_ptr->next)

    /* iterate through jobs */

    for(counter = 0; counter < distrenjob_ptr->total_frames; counter ++)

      /* iterate through all frames for this job*/

      {

        if((distrenjob_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

           */

          distrenjob_ptr->frameset[counter].status = 0;