# This file is part of BEAM -*- shell-script -*-
# Copyright (C) 2012 Sergey Poznyakoff
#
# BEAM is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# BEAM 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 BEAM.  If not, see <http://www.gnu.org/licenses/>.

# The configuration variable "backup_bucket_name" must contain the name
# of the s3 bucket to use.

# Raw bucket is mounted to /mnt/s3backer
test -z "$backup_mp_s3backer" && backup_mp_s3backer=/mnt/s3backer
# The actual file system is mounted to /mnt/s3
test -z "$backup_mp" && backup_mp_s3=/mnt/s3

# This variable is populated by s3_mount and is used by s3_unmount to unmount
# s3-backed file system.
umount_list=""

s3_mount() {	
  # Make sure both mountpoints exist
  test -d $backup_mp_s3backer || mkdir $backup_mp_s3backer
  test -d $backup_mp_s3 || mkdir $backup_mp_s3backer

# Sample mount output, split into several lines:
# http://finox-backup-fs.s3.amazonaws.com/ on /mnt/s3backer type fuse.s3backer
#  (rw,nosuid,nodev,allow_other,default_permissions)
  set -- $(mount -tfuse.s3backer | 
           awk '/https?:\/\/'$backup_bucket_name'/ { print $3 }')
  if test -z "$1"; then
    $dry_run s3backer $backup_s3backer_options \
                      $backup_bucket_name $backup_mp_s3backer ||
	     abend 1 "unable to mount $backup_bucket_name"
    umount_list="$backup_mp_s3backer"
  else
    backup_mp_s3backer=$1
  fi
  set -- $(mount | grep "^${backup_mp_s3backer}/file" | awk '{ print $3 }')
  if test -z "$1"; then
    case $(basename $0) in
    beam-restore|restore) mountopt=",ro";;
    beam-backup|backup)   mountopt=",rw,data=writeback";;
    beam-s3)  ;;
    *)       error "called as $0: assuming default mount options"
    esac
    # NOTE: For ext4 add the journal_async_commit option.
    $dry_run mount -oloop$mountopt $backup_mp_s3backer/file $backup_mp_s3 || 
             abend 1 "unable to mount $backup_mp_s3backer/file"
    umount_list="$backup_mp_s3 $umount_list"
  else
    backup_mp_s3=$1
  fi
  epilogue_hook="s3_unmount $epilogue_hook"
}

s3_getmpoint()
{
  case $1 in
  backer)
    mount -tfuse.s3backer | 
           awk '/https?:\/\/'$backup_bucket_name'/ { print $3 }';;
  s3)
    mount | grep "^${backup_mp_s3backer}/file" | awk '{ print $3 }';;
  *)
    abent 1 "invalid usage of getmpoint"
  esac
}

s3_unmount()
{
  for id in s3 backer
  do
    mpoint=$(s3_getmpoint $id)
    test -n "$mpoint" && umount $mpoint
  done
}