/*

  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 "asprintf.h"

#include <confuse.h>

#include <stdio.h>

#include <stdlib.h>

#include <malloc.h>

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

#include <time.h>

#include <sys/stat.h>

#include <string.h>

#include <libxml/xmlmemory.h>

#include <libxml/parser.h>

#include <libxml/tree.h>

#include <libxml/encoding.h>

#include <libxml/xmlwriter.h>

#include <libxml/xmlreader.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;

};

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;

  short int hibernate;

} general_info;

/*

  internally defined funcs's prototypes @TODO: Make all functions nice and proper */

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

struct distrenjob *distrenjob_get(struct distrenjob *head, jobnum_t jobnum);

void distrenjob_enqueue(struct distrenjob *head, struct distrenjob *job);

void mortition(struct distrenjob *head, struct distrenjob *job);

int makeJobDataXML(struct distrenjob *job);

int updateJobListXML(struct distrenjob *head);

int createQueueFromXML(struct distrenjob *head);

int reCreateQueueFromXML(struct distrenjob *head, xmlDocPtr doc, xmlNodePtr current);

/* Global Vars, eliminate 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 distrenjob *head)

{

  general_info.hibernate = 0;

  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");

    createQueueFromXML(head);

    return 1;

  }

  else{

    general_info.total_finished_jobs = 0;

    general_info.total_frames_rendered = 0;

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

    return 2;

  }

}

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

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

{

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

  distrenjob->total_render_time = distrenjob->total_render_time + (clock() - distrenjob[jobnum].frameset[frame].start_time);

  distrenjob->completed_frames++;

  distrenjob->assigned_frames--;

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

  if(distrenjob->completed_frames == distrenjob->total_frames)

    {

      mortition(head, distrenjob);

    }

}

/** "mortition" check to see if a job is actually done by scanning the folder of the job to make sure all frames are present*/

void mortition(struct distrenjob *head, struct distrenjob *job)

{

  short int isJobDone;

  int counter;

  char *path_and_number;

  struct stat buffer;

  isJobDone = 1; // set isJobDone to true

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

    {

      _distren_asprintf(&path_and_number, "stor/job%d/out/%d.%s", job->jobnum, job->frameset[counter].num, job->output_format);

      if(stat(path_and_number, &buffer) == -1)

        {

          job->frameset[counter].status = FRAMESETSTATUS_UNASSIGNED;

          job->completed_frames--;

          isJobDone = 0; // if a missing frame is found, set isJobDone to false

        }

    }

  if(isJobDone) // if all frames were accounted for

    {

      distrenjob_remove(head, job);

      distrenjob_free(&job);

      general_info.jobs_in_queue--;

      updateJobListXML(head);

    }

  else{

    job->prev_frame_index = 0; // if the job isn't done, have frame_finder() start from the first frame, allowing it to see the frames that are now unassigned

  }

}

/** scans the frames of a job to initialize a job after server */

/* returns 1 if the job is completely done and there are no missing frames */

/* returns 0 if a missing frame is found */

int restoreJobState(struct distrenjob *job)

{

  short int isJobDone;

  int counter;

  char *path_and_number;

  struct stat buffer;

  isJobDone = 1;

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

    {

      _distren_asprintf(&path_and_number, "stor/job%d/out/%d.%s", job->jobnum, job->frameset[counter].num, job->output_format);

      if(stat(path_and_number, &buffer) == 0)

        {

          job->frameset[counter].status = FRAMESETSTATUS_ASSIGNED;

          job->completed_frames++;

        }

      else

        isJobDone = 0;

    }

  return isJobDone;

}

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

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

{

  int counter2;

  int counter;

  struct distrenjob *distrenjob;

  distrenjob_new(&distrenjob);

  distrenjob->type = 1;

  distrenjob->name = name;

  distrenjob->submitter = submitter;

  distrenjob->email = email;

  distrenjob->priority = priority;

  distrenjob->width = width;

  distrenjob->height = height;

  distrenjob->total_frames = (end_frame - start_frame + 1); // sets the total number of frames in animation for status purposes

  /* prepares all the frames by setting that status to "unassigned" */

  counter2 = start_frame;

  for(counter = 0; counter <= (end_frame- start_frame + 1); counter++){

    distrenjob->frameset[counter].num = counter2;

    distrenjob->frameset[counter].status = FRAMESETSTATUS_UNASSIGNED;

    counter2++;

  }

  /* add job to queue */

  makeJobDataXML(distrenjob);

  distrenjob_enqueue(head, distrenjob);

  general_info.jobs_in_queue++;

}

/** distrenjob_enqueue: This function adds the job to the queue based on its priority */

void distrenjob_enqueue(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) */

}

/** Changes the priority of an existing (and maybe running) job. @arg head I may end up changing the head if job == head */

void change_job_priority(struct distrenjob *head, struct distrenjob *job, int new_priority){

  distrenjob_remove(head, job);

  job->priority = new_priority;

  struct distrenjob *current_job;

  struct distrenjob *prev_job = head;

  if(job->frameset[0].status == FRAMESETSTATUS_UNASSIGNED)

    /* if job was not yet started */

    distrenjob_enqueue(head, job);

  else{ // if job has already been started, place it before the jobs with the same priority

    // 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 or equal to 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;

    }

  }

  updateJobListXML(head);

}

/**

  Frame Finder: matches your computer up with a lovely frame to render, starts looking at oldest job first

  @TODO: We must return both jobnum and framenum

  @TODO: Add calls in main()

  @return 0 success, other: error

*/

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

{

  if(general_info.hibernate)

    return 1;

  unsigned int frame_counter;

  short int your_job_type;

  unsigned short int found;

  struct distrenjob *distrenjob_ptr;

  your_job_type = 0;

  found = 0;

  /* iterate through jobs from first to last */

  for(distrenjob_ptr = head->next; (!found && !distrenjob_ptr) && !distrenjob_ptr->hibernate; distrenjob_ptr = distrenjob_ptr->next)

    for(frame_counter = (distrenjob_ptr->prev_frame_index + 1); !found && frame_counter < distrenjob_ptr->total_frames; frame_counter ++)

      if(distrenjob_ptr->frameset[frame_counter].status == FRAMESETSTATUS_UNASSIGNED) // jobframe found

	{

	  found = 1;

	  your_job_type = distrenjob_ptr->type;

	  distrenjob_ptr->frameset[frame_counter].status = FRAMESETSTATUS_ASSIGNED;

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

	  distrenjob_ptr->assigned_frames++;

	  distrenjob_ptr->prev_frame_index = frame_counter;

	}

  if(!found)

    {

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

      sleep(1); /*< @todo eliminate the need for this line*/

      return 1;

    }

  *job = distrenjob_ptr;

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

  return 0;

}

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

void frame_watchdog(struct distrenjob *distrenjob_head)

{

  struct distrenjob *distrenjob_ptr;

  unsigned int counter;

  /*watchdog_forgiveness = seconds of forgiveness before frame is re-assigned */

  distrenjob_ptr = distrenjob_head;

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

  /* iterate through jobs */

    /* if the job has been started, checks by seeing if either to first or second frame has been started */

    if(distrenjob_ptr->frameset[0].status != FRAMESETSTATUS_UNASSIGNED || distrenjob_ptr->frameset[1].status != FRAMESETSTATUS_UNASSIGNED)

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

      /* iterate through all frames for this job*/

        if((distrenjob_ptr->frameset[counter].start_time + distrenjob_ptr->watchdog_forgiveness) < clock())

        /*

        If frame is not completed within the number of seconds specified by watchdog_forgiveness

        Then change the frame status to unassigned

        */

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

}

/**

   Finds a distrenjob struct based on the jobnum

   @arg jobnum job number to search for

   @return NULL on job doesn't exist

 */

struct distrenjob *distrenjob_get(struct distrenjob *head, jobnum_t jobnum)

{

  struct distrenjob *distrenjob_ptr;

  /*

    The conditions of the for loop will leave distrenjob_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(distrenjob_ptr = head;

      distrenjob_ptr

        && distrenjob_ptr->jobnum != jobnum;

      distrenjob_ptr = distrenjob_ptr->next);

  return distrenjob_ptr;

}

/**

   Removes a distrenjob from the distrenjob linked list. It does not free the distrenjob, however. You should do that with distrenjob_free() from distrenjob.h

   @arg head pointer to the head of the linkedlist of distrenjobs

 */

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

{

  struct distrenjob *previous_distrenjob;

  for(previous_distrenjob = head;

      previous_distrenjob

	&& previous_distrenjob->next != bj; /*< stop on the distrenjob that comes before bj */

      previous_distrenjob = previous_distrenjob->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_distrenjob->next = bj->next;

  general_info.jobs_in_queue--;

}

/* Grabs config info from confs */

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_SIMPLE_STR("datadir", NULL),

      CFG_END()

    };

  struct distrenjob *distrenjob;

  int tmp;

  xmlinit();