# FUCK IT

usage() {
  echo "Usage: $0 BACKUP_SRC BACKUP_DST EXCLUDE_FILE"
  echo "USE FULL PATHS!!"
  exit 1
}

# Usage: cycle BACKUP_TYPE COPIES_TO_RETAIN
cycle() {
  echo "Moving "$1" backups and making a new one..."
  i="$2"
  while [ "$i" -gt "1" ]; do
    if [ -d "$dst"/"$1"."$i" ]; then
      echo "Removing "$1"."$i""
      echo rm -r "$dst"/"$1"."$i"
    fi
    if [ -d "$dst"/"$1".`expr "$i" - 1` ]; then
      echo "Moving "$1".`expr "$i" - 1` to "$1"."$i""
      mv "$dst"/"$1".`expr "$i" - 1` "$dst"/"$1"."$i"
    fi
    i=`expr "$i" - 1`
  done
  if [ "$1" -eq "hourly" ]; then
    reference="$dst"/hourly.2
  else
    reference="$dst"/hourly.1
  fi
  /usr/local/bin/rsync -av --exclude-from="$exclude" --link-dest="$reference" --delete "$src"/ "$dst"/"$1".1
}

if [ -z "$1" -o -z "$2" -o -z "$3" ]; then
  usage
fi

src="$1"
dst="$2"
exclude="$3"

cycle "hourly" "23"

# Do daily backups at 8:xx AM where xx is whenever this cron job is scheduled
if [ `date "+%k"` -eq "8" ]; then
  cycle "daily" "6"
fi

# Do weekly backups on Mondays
if [ `date "+%u"` -eq "1" -a `date "+%k"` -eq "0" ]; then
  cycle "weekly" "4"
fi