/*
   Bacula® - The Network Backup Solution

   Copyright (C) 2002-2007 Free Software Foundation Europe e.V.

   The main author of Bacula is Kern Sibbald, with contributions from
   many others, a complete list can be found in the file AUTHORS.
   This program is Free Software; you can redistribute it and/or
   modify it under the terms of version two of the GNU General Public
   License as published by the Free Software Foundation and included
   in the file LICENSE.

   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 GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

   Bacula® is a registered trademark of John Walker.
   The licensor of Bacula is the Free Software Foundation Europe
   (FSFE), Fiduciary Program, Sumatrastrasse 25, 8006 Zürich,
   Switzerland, email:ftf@fsfeurope.org.
*/
/*
 *
 *  Routines for handling the autochanger.
 *
 *   Kern Sibbald, August MMII
 *                            
 *   Version $Id: autochanger.c 5713 2007-10-03 11:36:47Z kerns $
 */

#include "bacula.h"                   /* pull in global headers */
#include "stored.h"                   /* pull in Storage Deamon headers */

/* Forward referenced functions */
static void lock_changer(DCR *dcr);
static void unlock_changer(DCR *dcr);
static bool unload_other_drive(DCR *dcr, int slot);

/* Init all the autochanger resources found */
bool init_autochangers()
{
   bool OK = true;
   AUTOCHANGER *changer;
   /* Ensure that the media_type for each device is the same */
   foreach_res(changer, R_AUTOCHANGER) {
      DEVRES *device;
      foreach_alist(device, changer->device) {
         /*
          * If the device does not have a changer name or changer command
          *   defined, used the one from the Autochanger resource 
          */
         if (!device->changer_name && changer->changer_name) {
            device->changer_name = bstrdup(changer->changer_name);
         }
         if (!device->changer_command && changer->changer_command) {
            device->changer_command = bstrdup(changer->changer_command);
         }
         if (!device->changer_name) {
            Jmsg(NULL, M_ERROR, 0, 
               _("No Changer Name given for device %s. Cannot continue.\n"),
               device->hdr.name);
            OK = false;
         }   
         if (!device->changer_command) {
            Jmsg(NULL, M_ERROR, 0, 
               _("No Changer Command given for device %s. Cannot continue.\n"),
               device->hdr.name);
            OK = false;
         }   

#ifdef xxx_needed
         if (media_type == NULL) {
            media_type = device->media_type;     /* get Media Type of first device */
            continue;
         }     
         /* Ensure that other devices Media Types are the same */
         if (strcmp(media_type, device->media_type) != 0) {
            Jmsg(NULL, M_ERROR, 0, 
               _("Media Type not the same for all devices in changer %s. Cannot continue.\n"),
               changer->hdr.name);
            OK = false;
            continue;
         }
#endif
      }
   }
   return OK;
}


/*
 * Called here to do an autoload using the autochanger, if
 *  configured, and if a Slot has been defined for this Volume.
 *  On success this routine loads the indicated tape, but the
 *  label is not read, so it must be verified.
 *
 *  Note if dir is not NULL, it is the console requesting the
 *   autoload for labeling, so we respond directly to the
 *   dir bsock.
 *
 *  Returns: 1 on success
 *           0 on failure (no changer available)
 *          -1 on error on autochanger
 */
int autoload_device(DCR *dcr, int writing, BSOCK *dir)
{
   JCR *jcr = dcr->jcr;
   DEVICE *dev = dcr->dev;
   int slot;
   int drive = dev->drive_index;
   int rtn_stat = -1;                 /* error status */
   POOLMEM *changer;

   if (!dev->is_autochanger()) {
      Dmsg1(200, "Device %s is not an autochanger\n", dev->print_name());
      return 0;
   }

   /* An empty ChangerCommand => virtual disk autochanger */
   if (dcr->device->changer_command && dcr->device->changer_command[0] == 0) {
      return 1;                       /* nothing to load */
   }

   slot = dcr->VolCatInfo.InChanger ? dcr->VolCatInfo.Slot : 0;
   /*
    * Handle autoloaders here.  If we cannot autoload it, we
    *  will return 0 so that the sysop will be asked to load it.
    */
   if (writing && slot <= 0) {
      if (dir) {
         return 0;                    /* For user, bail out right now */
      }
      if (dir_find_next_appendable_volume(dcr)) {
         slot = dcr->VolCatInfo.InChanger ? dcr->VolCatInfo.Slot : 0;
      } else {
         slot = 0;
      }
   }
   Dmsg1(400, "Want changer slot=%d\n", slot);

   changer = get_pool_memory(PM_FNAME);
   if (slot <= 0) {
      Jmsg(jcr, M_INFO, 0, _("Invalid slot=%d defined in catalog for Volume \"%s\" "
           "on %s. Manual load my be required.\n"), slot, dcr->VolCatInfo.VolCatName,
           dev->print_name());
      rtn_stat = 0;
   } else if (!dcr->device->changer_name) {
      Jmsg(jcr, M_INFO, 0, _("No \"Changer Device\" for %s. Manual load of Volume may be required.\n"),
           dev->print_name());
      rtn_stat = 0;
  } else if (!dcr->device->changer_command) {
      Jmsg(jcr, M_INFO, 0, _("No \"Changer Command\" for %s. Manual load of Volume may be requird.\n"),
           dev->print_name());
      rtn_stat = 0;
  } else {
      /* Attempt to load the Volume */

      uint32_t timeout = dcr->device->max_changer_wait;
      int loaded, status;

      loaded = get_autochanger_loaded_slot(dcr);

      if (loaded != slot) {
         POOL_MEM results(PM_MESSAGE);

         /* Unload anything in our drive */
         if (!unload_autochanger(dcr, loaded)) {
            goto bail_out;
         }
            
         /* Make sure desired slot is unloaded */
         if (!unload_other_drive(dcr, slot)) {
            goto bail_out;
         }

         /*
          * Load the desired cassette
          */
         lock_changer(dcr);
         Dmsg1(100, "Doing changer load slot %d\n", slot);
         Jmsg(jcr, M_INFO, 0,
              _("3304 Issuing autochanger \"load slot %d, drive %d\" command.\n"),
              slot, drive);
         dcr->VolCatInfo.Slot = slot;    /* slot to be loaded */
         changer = edit_device_codes(dcr, changer, dcr->device->changer_command, "load");
         dev->close();
         Dmsg1(200, "Run program=%s\n", changer);
         status = run_program_full_output(changer, timeout, results.c_str());
         if (status == 0) {
            Jmsg(jcr, M_INFO, 0, _("3305 Autochanger \"load slot %d, drive %d\", status is OK.\n"),
                    slot, drive);
            Dmsg2(100, "load slot %d, drive %d, status is OK.\n", slot, drive);
            dev->Slot = slot;         /* set currently loaded slot */
         } else {
            berrno be;
            be.set_errno(status);
            Dmsg3(100, "load slot %d, drive %d, bad stats=%s.\n", slot, drive,
               be.bstrerror());
            Jmsg(jcr, M_FATAL, 0, _("3992 Bad autochanger \"load slot %d, drive %d\": "
                 "ERR=%s.\nResults=%s\n"),
                    slot, drive, be.bstrerror(), results.c_str());
            rtn_stat = -1;            /* hard error */
            dev->Slot = -1;           /* mark unknown */
         }
         Dmsg2(100, "load slot %d status=%d\n", slot, status);
         unlock_changer(dcr);
      } else {
         status = 0;                  /* we got what we want */
         dev->Slot = slot;            /* set currently loaded slot */
      }
      Dmsg1(100, "After changer, status=%d\n", status);
      if (status == 0) {              /* did we succeed? */
         rtn_stat = 1;                /* tape loaded by changer */
      }
   }
   free_pool_memory(changer);
   return rtn_stat;

bail_out:
   free_pool_memory(changer);
   return -1;

}

/*
 * Returns: -1 if error from changer command
 *          slot otherwise
 *  Note, this is safe to do without releasing the drive
 *   since it does not attempt load/unload a slot.
 */
int get_autochanger_loaded_slot(DCR *dcr)
{
   JCR *jcr = dcr->jcr;
   DEVICE *dev = dcr->dev;
   int status, loaded;
   uint32_t timeout = dcr->device->max_changer_wait;
   int drive = dcr->dev->drive_index;
   POOL_MEM results(PM_MESSAGE);
   POOLMEM *changer;

   if (!dev->is_autochanger()) {
      return -1;
   }
   if (!dcr->device->changer_command) {
      Jmsg(jcr, M_FATAL, 0, _("3992 Missing Changer command.\n"));
      return -1;
   }
   if (dev->Slot > 0) {
      return dev->Slot;
   }
   /* Virtual disk autochanger */
   if (dcr->device->changer_command[0] == 0) {
      return 1;
   }

   /* Find out what is loaded, zero means device is unloaded */
   changer = get_pool_memory(PM_FNAME);
   lock_changer(dcr);
   Jmsg(jcr, M_INFO, 0, _("3301 Issuing autochanger \"loaded? drive %d\" command.\n"),
        drive);
   changer = edit_device_codes(dcr, changer, dcr->device->changer_command, "loaded");
   *results.c_str() = 0;
   Dmsg1(100, "Run program=%s\n", changer);
   status = run_program_full_output(changer, timeout, results.c_str());
   Dmsg3(100, "run_prog: %s stat=%d result=%s", changer, status, results.c_str());
   if (status == 0) {
      loaded = str_to_int32(results.c_str());
      if (loaded > 0) {
         Jmsg(jcr, M_INFO, 0, _("3302 Autochanger \"loaded? drive %d\", result is Slot %d.\n"),
              drive, loaded);
         dev->Slot = loaded;
      } else {
         Jmsg(jcr, M_INFO, 0, _("3302 Autochanger \"loaded? drive %d\", result: nothing loaded.\n"),
              drive);
         dev->Slot = -1;    /* unknown */
      }
   } else {
      berrno be;
      be.set_errno(status);
      Jmsg(jcr, M_INFO, 0, _("3991 Bad autochanger \"loaded? drive %d\" command: "
           "ERR=%s.\nResults=%s\n"), drive, be.bstrerror(), results.c_str());
      loaded = -1;              /* force unload */
   }
   unlock_changer(dcr);
   free_pool_memory(changer);
   return loaded;
}

static void lock_changer(DCR *dcr)
{
   AUTOCHANGER *changer_res = dcr->device->changer_res;
   if (changer_res) {
      Dmsg1(200, "Locking changer %s\n", changer_res->hdr.name);
      P(changer_res->changer_mutex);  /* Lock changer script */
   }
}

static void unlock_changer(DCR *dcr)
{
   AUTOCHANGER *changer_res = dcr->device->changer_res;
   if (changer_res) {
      Dmsg1(200, "Unlocking changer %s\n", changer_res->hdr.name);
      V(changer_res->changer_mutex);  /* Unlock changer script */
   }
}

/*
 * Unload the volume, if any, in this drive
 *  On entry: loaded == 0 -- nothing to do
 *            loaded  < 0 -- check if anything to do
 *            loaded  > 0 -- load slot == loaded
 */
bool unload_autochanger(DCR *dcr, int loaded)
{
   DEVICE *dev = dcr->dev;
   JCR *jcr = dcr->jcr;
   int slot;
   uint32_t timeout = dcr->device->max_changer_wait;
   bool ok = true;

   if (loaded == 0) {
      return true;
   }

   if (!dev->is_autochanger() || !dcr->device->changer_name ||
       !dcr->device->changer_command) {
      return false;
   }

   if (loaded < 0) {
      loaded = get_autochanger_loaded_slot(dcr);
   }

   if (loaded > 0) {
      POOL_MEM results(PM_MESSAGE);
      POOLMEM *changer = get_pool_memory(PM_FNAME);
      lock_changer(dcr);
      Jmsg(jcr, M_INFO, 0,
           _("3307 Issuing autochanger \"unload slot %d, drive %d\" command.\n"),
           loaded, dev->drive_index);
      slot = dcr->VolCatInfo.Slot;
      dcr->VolCatInfo.Slot = loaded;
      changer = edit_device_codes(dcr, changer, 
                   dcr->device->changer_command, "unload");
      dev->close();
      Dmsg1(100, "Run program=%s\n", changer);
      *results.c_str() = 0;
      int stat = run_program_full_output(changer, timeout, results.c_str());
      dcr->VolCatInfo.Slot = slot;
      if (stat != 0) {
         berrno be;
         be.set_errno(stat);
         Jmsg(jcr, M_INFO, 0, _("3995 Bad autochanger \"unload slot %d, drive %d\": "
              "ERR=%s\nResults=%s\n"),
                 loaded, dev->drive_index, be.bstrerror(), results.c_str());
         ok = false;
         dev->Slot = -1;           /* unknown */
      } else {
         dev->Slot = 0;            /* nothing loaded */
      }
      free_volume(dev);            /* Free any volume associated with this drive */
      free_pool_memory(changer);
      unlock_changer(dcr);
   }
   return ok;
}

/*
 * Unload the slot if mounted in a different drive
 */
static bool unload_other_drive(DCR *dcr, int slot)
{
   DEVICE *dev = NULL;
   DEVICE *save_dev;
   JCR *jcr = dcr->jcr;
   int save_slot;
   uint32_t timeout = dcr->device->max_changer_wait;
   bool ok = true;
   AUTOCHANGER *changer = dcr->dev->device->changer_res;
   DEVRES *device;
   bool found = false;
   int retries = 0;                /* wait for device retries */

   if (!changer) {
      return false;
   }
   if (changer->device->size() == 1) {
      return true;
   }

   foreach_alist(device, changer->device) {
      if (device->dev && device->dev->Slot == slot) {
         found = true;
         dev = device->dev;
         break;
      }
   }
   if (!found) {
      return true;
   }

   /* The Volume we want is on another device. */
   if (dev->is_busy()) {
      Dmsg4(100, "Vol %s for dev=%s in use dev=%s slot=%d\n",
           dcr->VolumeName, dcr->dev->print_name(),
           dev->print_name(), slot);
   }   
   for (int i=0; i < 3; i++) {
      if (dev->is_busy()) {
         wait_for_device(dcr->jcr, retries);
         continue;
      }
      break;
   }
   dev->dlock();
   if (dev->is_busy()) {
      Jmsg(jcr, M_WARNING, 0, _("Volume \"%s\" is in use by device %s\n"),
           dcr->VolumeName, dev->print_name());
      Dmsg4(100, "Vol %s for dev=%s is busy dev=%s slot=%d\n",
           dcr->VolumeName, dcr->dev->print_name(), dev->print_name(), slot);
      Dmsg2(100, "num_writ=%d reserv=%d\n", dev->num_writers, dev->reserved_device);
      dev->dunlock();
      return false;
   }

   POOLMEM *changer_cmd = get_pool_memory(PM_FNAME);
   POOL_MEM results(PM_MESSAGE);
   lock_changer(dcr);
   Jmsg(jcr, M_INFO, 0,
        _("3307 Issuing autochanger \"unload slot %d, drive %d\" command.\n"),
        slot, dev->drive_index);

   Dmsg2(100, "Issuing autochanger \"unload slot %d, drive %d\" command.\n",
        slot, dev->drive_index);

   save_dev = dcr->dev;
   dcr->dev = dev;
   save_slot = dcr->VolCatInfo.Slot;
   dcr->VolCatInfo.Slot = slot;
   changer_cmd = edit_device_codes(dcr, changer_cmd, 
                dcr->device->changer_command, "unload");
   dev->close();
   Dmsg2(200, "close dev=%s reserve=%d\n", dev->print_name(), 
      dev->reserved_device);
   Dmsg1(100, "Run program=%s\n", changer_cmd);
   int stat = run_program_full_output(changer_cmd, timeout, results.c_str());
   dcr->VolCatInfo.Slot = save_slot;
   dcr->dev = save_dev;
   if (stat != 0) {
      berrno be;
      be.set_errno(stat);
      Jmsg(jcr, M_INFO, 0, _("3995 Bad autochanger \"unload slot %d, drive %d\": ERR=%s.\n"),
              slot, dev->drive_index, be.bstrerror());

      Dmsg3(100, "Bad autochanger \"unload slot %d, drive %d\": ERR=%s.\n",
              slot, dev->drive_index, be.bstrerror());
      ok = false;
      dev->Slot = -1;          /* unknown */
   } else {
      dev->Slot = 0;           /* nothing loaded */
      Dmsg0(100, "Slot unloaded\n");
   }
   free_volume(dev);               /* Free any volume associated with this drive */
   unlock_changer(dcr);
   dev->dunlock();
   free_pool_memory(changer_cmd);
   return ok;
}



/*
 * List the Volumes that are in the autoloader possibly
 *   with their barcodes.
 *   We assume that it is always the Console that is calling us.
 */
bool autochanger_cmd(DCR *dcr, BSOCK *dir, const char *cmd)  
{
   DEVICE *dev = dcr->dev;
   uint32_t timeout = dcr->device->max_changer_wait;
   POOLMEM *changer;
   BPIPE *bpipe;
   int len = sizeof_pool_memory(dir->msg) - 1;
   bool ok = false;
   int stat;

   if (!dev->is_autochanger() || !dcr->device->changer_name ||
       !dcr->device->changer_command) {
      if (strcmp(cmd, "drives") == 0) {
         dir->fsend("drives=1\n");
      }
      dir->fsend(_("3993 Device %s not an autochanger device.\n"),
         dev->print_name());
      return false;
   }

   if (strcmp(cmd, "drives") == 0) {
      AUTOCHANGER *changer_res = dcr->device->changer_res;
      int drives = 1;
      if (changer_res) {
         drives = changer_res->device->size();
      }
      dir->fsend("drives=%d\n", drives);
      Dmsg1(100, "drives=%d\n", drives);
      return true;
   }

   changer = get_pool_memory(PM_FNAME);
   lock_changer(dcr);
   /* Now issue the command */
   changer = edit_device_codes(dcr, changer, 
                 dcr->device->changer_command, cmd);
   dir->fsend(_("3306 Issuing autochanger \"%s\" command.\n"), cmd);
   bpipe = open_bpipe(changer, timeout, "r");
   if (!bpipe) {
      dir->fsend(_("3996 Open bpipe failed.\n"));
      goto bail_out;
   }
   if (strcmp(cmd, "list") == 0) {
      /* Get output from changer */
      while (fgets(dir->msg, len, bpipe->rfd)) {
         dir->msglen = strlen(dir->msg);
         Dmsg1(100, "<stored: %s\n", dir->msg);
         bnet_send(dir);
      }
   } else if (strcmp(cmd, "slots") == 0 ) {
      char buf[100], *p;
      /* For slots command, read a single line */
      buf[0] = 0;
      fgets(buf, sizeof(buf)-1, bpipe->rfd);
      buf[sizeof(buf)-1] = 0;
      /* Strip any leading space in front of # of slots */
      for (p=buf; B_ISSPACE(*p); p++)
        { }
      dir->fsend("slots=%s", p);
      Dmsg1(100, "<stored: %s", dir->msg);
   } 
                 
   stat = close_bpipe(bpipe);
   if (stat != 0) {
      berrno be;
      be.set_errno(stat);
      dir->fsend(_("Autochanger error: ERR=%s\n"), be.bstrerror());
   }
   bnet_sig(dir, BNET_EOD);
   ok = true;

bail_out:
   unlock_changer(dcr);
   free_pool_memory(changer);
   return true;
}


/*
 * Edit codes into ChangerCommand
 *  %% = %
 *  %a = archive device name
 *  %c = changer device name
 *  %d = changer drive index
 *  %f = Client's name
 *  %j = Job name
 *  %o = command
 *  %s = Slot base 0
 *  %S = Slot base 1
 *  %v = Volume name
 *
 *
 *  omsg = edited output message
 *  imsg = input string containing edit codes (%x)
 *  cmd = command string (load, unload, ...)
 *
 */
char *edit_device_codes(DCR *dcr, char *omsg, const char *imsg, const char *cmd)
{
   const char *p;
   const char *str;
   char add[20];

   *omsg = 0;
   Dmsg1(1800, "edit_device_codes: %s\n", imsg);
   for (p=imsg; *p; p++) {
      if (*p == '%') {
         switch (*++p) {
         case '%':
            str = "%";
            break;
         case 'a':
            str = dcr->dev->archive_name();
            break;
         case 'c':
            str = NPRT(dcr->device->changer_name);
            break;
         case 'd':
            sprintf(add, "%d", dcr->dev->drive_index);
            str = add;
            break;
         case 'o':
            str = NPRT(cmd);
            break;
         case 's':
            sprintf(add, "%d", dcr->VolCatInfo.Slot - 1);
            str = add;
            break;
         case 'S':
            sprintf(add, "%d", dcr->VolCatInfo.Slot);
            str = add;
            break;
         case 'j':                    /* Job name */
            str = dcr->jcr->Job;
            break;
         case 'v':
            str = NPRT(dcr->VolumeName);
            break;
         case 'f':
            str = NPRT(dcr->jcr->client_name);
            break;

         default:
            add[0] = '%';
            add[1] = *p;
            add[2] = 0;
            str = add;
            break;
         }
      } else {
         add[0] = *p;
         add[1] = 0;
         str = add;
      }
      Dmsg1(1900, "add_str %s\n", str);
      pm_strcat(&omsg, (char *)str);
      Dmsg1(1800, "omsg=%s\n", omsg);
   }
   Dmsg1(800, "omsg=%s\n", omsg);
   return omsg;
}