#!/bin/bash

set -e

echo "This script will prune each archive in the backups of all backed up hosts"
echo "Enter 'noop' to test, or 'prune' to actually prune"
read -p "Operation: " borg_op

if [[ ${borg_op} == 'noop' ]]; then
    BORG_OP='--dry-run'
elif [[ ${borg_op} == 'prune' ]]; then
    BORG_OP=''
    LOG_FILE="/opt/backups/prune-$(date '+%Y-%m-%d-%H-%M-%S').log"
    echo "*** Logging output to ${LOG_FILE}"
    exec 1>${LOG_FILE}
    exec 2>&1
else
    echo "*** Invalid input"
    exit 1
fi

pushd /opt/backups

for u in borg-*; do
    BORG_REPO=/opt/backups/$u/backup

    sudo BORG_OP=${BORG_OP} BORG_RELOCATED_REPO_ACCESS_IS_OK=y BORG_REPO=${BORG_REPO} -u ${u} -s  <<'EOF'

    # Look at all archives and strip the timestamp, leaving just the archive names
    # We limit the prune by --prefix so each archive is considered separately
    # Long-running aborted backups might leave a ".checkpoint" archive around; ignore
    # these as prune will remove them automatically
    archives=$(/opt/borg/bin/borg list ${BORG_REPO} | awk '$1 !~ /\.checkpoint$/ { print substr($1, 0, length($1)-20) }' | sort | uniq)

    for prefix in ${archives};
    do
      echo
      echo
      echo "+------"
      echo "| $(date) Pruning ${BORG_REPO} archive ${prefix}"
      echo "+------"
     /opt/borg/bin/borg prune --prefix ${prefix} ${BORG_OP} --verbose --list --show-rc --keep-daily 7 --keep-weekly 4 --keep-monthly 12
    done

EOF
done