#! /bin/bash
# This file is part of BEAM
# 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/>.

# initdb item
# Initializes snapshot for the given basename.
initdb() {
  local filename
 
  if [ -n "$dry_run" ]; then
    logit "initializing snapshot for $1"
    return
  fi

  if [ $level -eq 0 ]; then
    filename=$backup_snapshot_dir/$1-$week-$round-$level.db
    test -r $filename && rm $filename
  else 
    if [ $level -eq 1 ]; then
      filename=$backup_snapshot_dir/$1-$week-0-0.db
    else
      filename=$backup_snapshot_dir/$1-$week-$round-$((level - 1)).db
    fi
    if [ -r $filename ]; then
      cp $filename $backup_snapshot_dir/$1-$week-$round-$level.db
    else
      abend 1 "previous snapshot file $filename not found; cannot backup at level $level"
      exit 1
    fi
  fi
}

# fs_check item
fs_check() {
  local rc=0

  eval root=\$${1}_dir
  eval files=\$${1}_files

  test -z "$root" && rc=1 && error "${1}_dir not set" 
  test -z "$files" && rc=1 && error "${1}_files not set"
  return $rc
}

# fs_backup item
fs_backup() {
  local basename text root files

  basename=$1-$week-$round-$level
  eval text=\$${1}_text
  eval root=\$${1}_dir
  eval files=\$${1}_files

  test -z "$root" && abend 1 "${1}_dir not set"
  test -z "$files" && abend 1 "${1}_files not set"
  test -z "$text" && text="$1"
  initdb $1
  logit "backing up $text ($basename.$tar_suffix)"
  $dry_run tar $verbose $taroptions \
    -f $backup_archive_dir/$basename.$tar_suffix \
    --listed=$backup_snapshot_dir/$basename.db \
    -C $root $files
  tarcode $?
}

# fs_restore item
fs_restore() {
  local i text root files tarcommand

  eval text=\$${1}_text
  eval root=\$${1}_dir
  eval files=\$${1}_files

  test -z "$root" && abend 1 "${1}_dir not set"
  test -z "$files" && abend 1 "${1}_files not set"
  test -z "$text" && text="$1"

  tarcommand="tar $verbose $taroptions -C $root --listed-incremental=/dev/null -f"
  
  logit "restoring $text"
  logit "restoring from level 0 backup"

  $dry_run $tarcommand $backup_archive_dir/$1-$week-0-0.$tar_suffix
  tarcode $?

  for i in $(seq 1 $level)
  do
    logit "restoring from the $round/$i backup"  
    $dry_run $tarcommand $backup_archive_dir/$1-$week-$round-$i.tar.bz2
    tarcode $?
  done
  logit "finished restoring $text"
}