/*
 *
 *   Bacula Director -- next_vol -- handles finding the next
 *    volume for append.  Split out of catreq.c August MMIII
 *    catalog request from the Storage daemon.

 *     Kern Sibbald, March MMI
 *
 *   Version $Id: next_vol.c,v 1.20.2.3 2006/04/11 08:05:18 kerns Exp $
 */
/*
   Copyright (C) 2001-2006 Kern Sibbald

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   version 2 as amended with additional clauses defined in the
   file LICENSE in the main source directory.

   This program 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 
   the file LICENSE for additional details.

 */

#include "bacula.h"
#include "dird.h"

static bool get_scratch_volume(JCR *jcr, MEDIA_DBR *mr, bool InChanger);


/*
 *  Items needed:
 *   mr.PoolId must be set
 *   jcr->store
 *   jcr->db
 *   jcr->pool
 *   MEDIA_DBR mr (zeroed out)
 *   create -- whether or not to create a new volume
 */
int find_next_volume_for_append(JCR *jcr, MEDIA_DBR *mr, int index, bool create)
{
   int retry = 0;
   bool ok;
   bool InChanger;
   STORE *store = jcr->store;

   bstrncpy(mr->MediaType, store->media_type, sizeof(mr->MediaType));
   Dmsg2(100, "CatReq FindMedia: PoolId=%d, MediaType=%s\n", (int)mr->PoolId, mr->MediaType);
   /*
    * If we are using an Autochanger, restrict Volume
    *   search to the Autochanger on the first pass
    */
   InChanger = store->autochanger;
   /*
    * Find the Next Volume for Append
    */
   db_lock(jcr->db);
   for ( ;; ) {
      bstrncpy(mr->VolStatus, "Append", sizeof(mr->VolStatus));  /* want only appendable volumes */
      /*
       *  1. Look for volume with "Append" status.
       */
      ok = db_find_next_volume(jcr, jcr->db, index, InChanger, mr);
      Dmsg2(100, "catreq after find_next_vol ok=%d FW=%d\n", ok, mr->FirstWritten);

      if (!ok) {
         /*
          * 2. Try finding a recycled volume
          */
         ok = find_recycled_volume(jcr, InChanger, mr);
         Dmsg2(100, "find_recycled_volume %d FW=%d\n", ok, mr->FirstWritten);
         if (!ok) {
            /*
             * 3. Try recycling any purged volume
             */
            ok = recycle_oldest_purged_volume(jcr, InChanger, mr);
            if (!ok) {
               /*
                * 4. Try pruning Volumes
                */
               prune_volumes(jcr);
               ok = recycle_oldest_purged_volume(jcr, InChanger, mr);
               if (!ok) {
                  /*
                   * 5. Try pulling a volume from the Scratch pool
                   */ 
                  ok = get_scratch_volume(jcr, mr, InChanger);
               }
               /*
                * If we are using an Autochanger and have not found
                * a volume, retry looking for any volume. 
                */
               if (InChanger) {
                  InChanger = false;
                  if (!ok) {
                     continue;           /* retry again accepting any volume */
                  }
               }
            }
         }


         if (!ok && create) {
            /*
             * 6. Try "creating" a new Volume
             */
            ok = newVolume(jcr, mr);
         }
         /*
          *  Look at more drastic ways to find an Appendable Volume
          */
         if (!ok && (jcr->pool->purge_oldest_volume ||
                     jcr->pool->recycle_oldest_volume)) {
            Dmsg2(200, "No next volume found. PurgeOldest=%d\n RecyleOldest=%d",
                jcr->pool->purge_oldest_volume, jcr->pool->recycle_oldest_volume);
            /* Find oldest volume to recycle */
            ok = db_find_next_volume(jcr, jcr->db, -1, InChanger, mr);
            Dmsg1(400, "Find oldest=%d\n", ok);
            if (ok) {
               UAContext *ua;
               Dmsg0(400, "Try purge.\n");
               /*
                * 7.  Try to purging oldest volume only if not UA calling us.
                */
               ua = new_ua_context(jcr);
               if (jcr->pool->purge_oldest_volume && create) {
                  Jmsg(jcr, M_INFO, 0, _("Purging oldest volume \"%s\"\n"), mr->VolumeName);
                  ok = purge_jobs_from_volume(ua, mr);
               /*
                * 8. or try recycling the oldest volume
                */
               } else if (jcr->pool->recycle_oldest_volume) {
                  Jmsg(jcr, M_INFO, 0, _("Pruning oldest volume \"%s\"\n"), mr->VolumeName);
                  ok = prune_volume(ua, mr);
               }
               free_ua_context(ua);
               if (ok) {
                  ok = recycle_volume(jcr, mr);
                  Dmsg1(400, "Recycle after purge oldest=%d\n", ok);
               }
            }
         }
      }
      Dmsg2(100, "VolJobs=%d FirstWritten=%d\n", mr->VolJobs, mr->FirstWritten);
      if (ok) {
         /* If we can use the volume, check if it is expired */
         if (has_volume_expired(jcr, mr)) {
            if (retry++ < 200) {            /* sanity check */
               continue;                    /* try again from the top */
            } else {
               Jmsg(jcr, M_ERROR, 0, _(
"We seem to be looping trying to find the next volume. I give up.\n"));
            }
         }
      }
      break;
   } /* end for loop */
   db_unlock(jcr->db);
   return ok;
}

/*
 * Check if any time limits or use limits have expired
 *   if so, set the VolStatus appropriately.
 */
bool has_volume_expired(JCR *jcr, MEDIA_DBR *mr)
{
   bool expired = false;
   /*
    * Check limits and expirations if "Append" and it has been used
    * i.e. mr->VolJobs > 0
    *
    */
   if (strcmp(mr->VolStatus, "Append") == 0 && mr->VolJobs > 0) {
      /* First handle Max Volume Bytes */
      if ((mr->MaxVolBytes > 0 && mr->VolBytes >= mr->MaxVolBytes)) {
         Jmsg(jcr, M_INFO, 0, _("Max Volume bytes exceeded. "
             "Marking Volume \"%s\" as Full.\n"), mr->VolumeName);
         bstrncpy(mr->VolStatus, "Full", sizeof(mr->VolStatus));
         expired = true;

      /* Now see if Volume should only be used once */
      } else if (mr->VolBytes > 0 && jcr->pool->use_volume_once) {
         Jmsg(jcr, M_INFO, 0, _("Volume used once. "
             "Marking Volume \"%s\" as Used.\n"), mr->VolumeName);
         bstrncpy(mr->VolStatus, "Used", sizeof(mr->VolStatus));
         expired = true;

      /* Now see if Max Jobs written to volume */
      } else if (mr->MaxVolJobs > 0 && mr->MaxVolJobs <= mr->VolJobs) {
         Jmsg(jcr, M_INFO, 0, _("Max Volume jobs exceeded. "
             "Marking Volume \"%s\" as Used.\n"), mr->VolumeName);
         bstrncpy(mr->VolStatus, "Used", sizeof(mr->VolStatus));
         expired = true;

      /* Now see if Max Files written to volume */
      } else if (mr->MaxVolFiles > 0 && mr->MaxVolFiles <= mr->VolFiles) {
         Jmsg(jcr, M_INFO, 0, _("Max Volume files exceeded. "
             "Marking Volume \"%s\" as Used.\n"), mr->VolumeName);
         bstrncpy(mr->VolStatus, "Used", sizeof(mr->VolStatus));
         expired = true;

      /* Finally, check Use duration expiration */
      } else if (mr->VolUseDuration > 0) {
         utime_t now = time(NULL);
         /* See if Vol Use has expired */
         if (mr->VolUseDuration <= (now - mr->FirstWritten)) {
            Jmsg(jcr, M_INFO, 0, _("Max configured use duration exceeded. "
               "Marking Volume \"%s\" as Used.\n"), mr->VolumeName);
            bstrncpy(mr->VolStatus, "Used", sizeof(mr->VolStatus));
            expired = true;
         }
      }
   }
   if (expired) {
      /* Need to update media */
      if (!db_update_media_record(jcr, jcr->db, mr)) {
         Jmsg(jcr, M_ERROR, 0, _("Catalog error updating volume \"%s\". ERR=%s"),
              mr->VolumeName, db_strerror(jcr->db));
      }
   }
   return expired;
}

/*
 * Try hard to recycle the current volume
 *
 *  Returns: on failure - reason = NULL
 *           on success - reason - pointer to reason
 */
void check_if_volume_valid_or_recyclable(JCR *jcr, MEDIA_DBR *mr, const char **reason)
{
   int ok;

   *reason = NULL;

   /*  Check if a duration or limit has expired */
   if (has_volume_expired(jcr, mr)) {
      *reason = _("volume has expired");
      /* Keep going because we may be able to recycle volume */
   }

   /*
    * Now see if we can use the volume as is
    */
   if (strcmp(mr->VolStatus, "Append") == 0 ||
       strcmp(mr->VolStatus, "Recycle") == 0) {
      *reason = NULL;
      return;
   }

   /*
    * Check if the Volume is already marked for recycling
    */
   if (strcmp(mr->VolStatus, "Purged") == 0) {
      if (recycle_volume(jcr, mr)) {
         Jmsg(jcr, M_INFO, 0, _("Recycled current volume \"%s\"\n"), mr->VolumeName);
         *reason = NULL;
         return;
      } else {
         /* In principle this shouldn't happen */
         *reason = _("and recycling of current volume failed");
         return;
      }
   }

   /* At this point, the volume is not valid for writing */
   *reason = _("but should be Append, Purged or Recycle");

   /*
    * What we're trying to do here is see if the current volume is
    * "recyclable" - ie. if we prune all expired jobs off it, is
    * it now possible to reuse it for the job that it is currently
    * needed for?
    */
   if ((mr->LastWritten + mr->VolRetention) < (utime_t)time(NULL)
         && mr->Recycle && jcr->pool->recycle_current_volume
         && (strcmp(mr->VolStatus, "Full") == 0 ||
            strcmp(mr->VolStatus, "Used") == 0)) {
      /*
       * Attempt prune of current volume to see if we can
       * recycle it for use.
       */
      UAContext *ua;

      ua = new_ua_context(jcr);
      ok = prune_volume(ua, mr);
      free_ua_context(ua);

      if (ok) {
         /* If fully purged, recycle current volume */
         if (recycle_volume(jcr, mr)) {
            Jmsg(jcr, M_INFO, 0, _("Recycled current volume \"%s\"\n"), mr->VolumeName);
            *reason = NULL;
         } else {
            *reason = _("but should be Append, Purged or Recycle (recycling of the "
               "current volume failed)");
         }
      } else {
         *reason = _("but should be Append, Purged or Recycle (cannot automatically "
            "recycle current volume, as it still contains unpruned data "
            "or the Volume Retention time has not expired.)");
      }
   }
}

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

static bool get_scratch_volume(JCR *jcr, MEDIA_DBR *mr, bool InChanger)
{
   MEDIA_DBR smr;
   POOL_DBR spr, pr;
   bool ok = false;
   char ed1[50], ed2[50];

   /* Only one thread at a time can pull from the scratch pool */
   P(mutex);
   /* 
    * Get Pool record for Scratch Pool
    */
   memset(&spr, 0, sizeof(spr));
   bstrncpy(spr.Name, "Scratch", sizeof(spr.Name));
   if (db_get_pool_record(jcr, jcr->db, &spr)) {
      memset(&smr, 0, sizeof(smr));
      smr.PoolId = spr.PoolId;
      if (InChanger) {       
         smr.StorageId = mr->StorageId;  /* want only Scratch Volumes in changer */
      }
      bstrncpy(smr.VolStatus, "Append", sizeof(smr.VolStatus));  /* want only appendable volumes */
      bstrncpy(smr.MediaType, mr->MediaType, sizeof(smr.MediaType));
      if (db_find_next_volume(jcr, jcr->db, 1, InChanger, &smr)) {
         POOL_MEM query(PM_MESSAGE);

         /*   
          * Get pool record where the Scratch Volume will go to ensure
          * that we can add a Volume.
          */
         memset(&pr, 0, sizeof(pr));
         bstrncpy(pr.Name, jcr->pool->hdr.name, sizeof(pr.Name));
         if (!db_get_pool_record(jcr, jcr->db, &pr)) {
            Jmsg(jcr, M_WARNING, 0, _("Unable to get Pool record: ERR=%s"), 
                 db_strerror(jcr->db));
            goto bail_out;
         }
         if (pr.MaxVols > 0 && pr.NumVols >= pr.MaxVols) {
            Jmsg(jcr, M_WARNING, 0, _("Unable add Scratch Volume, Pool \"%s\" full MaxVols=%d\n"),
               jcr->pool->hdr.name, pr.MaxVols);
            goto bail_out;
         }

         /* OK, now move Scratch Volume */
         db_lock(jcr->db);
         Mmsg(query, "UPDATE Media SET PoolId=%s WHERE MediaId=%s",
              edit_int64(mr->PoolId, ed1),
              edit_int64(smr.MediaId, ed2));
         ok = db_sql_query(jcr->db, query.c_str(), NULL, NULL);  
         db_unlock(jcr->db);
         if (!ok) {
            Jmsg(jcr, M_WARNING, 0, _("Failed to move Scratch Volume. ERR=%s\n"),
               db_strerror(jcr->db));
           goto bail_out;
          }
         Jmsg(jcr, M_INFO, 0, _("Using Volume \"%s\" from 'Scratch' pool.\n"), 
              smr.VolumeName);
         /* Set new Pool Id in smr record, then copy it to mr */
         smr.PoolId = mr->PoolId;
         memcpy(mr, &smr, sizeof(MEDIA_DBR));
         /* Set default parameters from current pool */
         set_pool_dbr_defaults_in_media_dbr(mr, &pr);
         if (!db_update_media_record(jcr, jcr->db, mr)) {
            Jmsg(jcr, M_WARNING, 0, _("Unable to update Volume record: ERR=%s"), 
                 db_strerror(jcr->db));
            ok = false;
         }
      }
   }
bail_out:
   V(mutex);
   return ok;
}
