#!/bin/sh
#
# Description: Remove old dated copies (incs) according to policy
# Usage: rm
#

# shellcheck source=./includes
LIBDIR="$(dirname $0)" && . "${LIBDIR}/includes"

kill_or_clean_lockfile() {
    lock_file=${1:-}

    if [ -f "${lock_file}" ]; then
        # Get Process ID from the lock file
        pid=$(cat "${lock_file}")
        if [ -n "${pid}" ]; then
            if kill -0 "${pid}" 2> /dev/null; then
                # Kill the children
                pkill -9 --parent "${pid}"
                # Kill the parent
                kill -9 "${pid}"
                #  Only one bkctld-rm can run in parallel, the latest wins
                lockfile_date=$(date --date "@$(stat -c %Y ${lock_file})" +"%Y-%m-%d %H:%M:%S")
                warning "Process \`${pid}' (started at ${lockfile_date}) has been killed by \`$$'"
            else
                warning "Process not found at PID \`${pid}'. Ignoring lock file \`${lock_file}'."
            fi
        else
            warning "Empty lockfile \`${lock_file}'. It should contain a PID."
        fi
        # Remove the lock file
        rm -f ${lock_file}
    fi
}
incs_to_delete() {
    jail_name=${1:?}
    incs_policy_file=${2:?}

    incs_policy_keep_file=$(new_tmp_file "${jail_name}.incs_policy_keep")
    incs_list_file=$(new_tmp_file "${jail_name}.incs_list")

    # loop for each line in jail configuration
    for incs_policy_line in $(grep "^\+" ${incs_policy_file}); do
        # inc date in ISO format
        incs_policy_date=$(relative_date ${incs_policy_line})
        echo ${incs_policy_date} >> "${incs_policy_keep_file}"
    done
    for inc_name in $(incs_list "${jail_name}"); do
        echo "${inc_name}" >> ${incs_list_file}
    done

    # shellcheck disable=SC2046
    incs_to_delete=$(grep -v -f "${incs_policy_keep_file}" "${incs_list_file}")

    rm -f "${incs_policy_keep_file}" "${incs_list_file}"

    echo ${incs_to_delete}
}
delete_inc_btrfs() {
    jail_name=$1
    inc_name=$2

    inc_path=$(inc_path "${jail_name}" "${inc_name}")

    if dry_run; then
        echo "[dry-run] delete btrfs subvolume ${inc_path}"
    else
        /bin/btrfs subvolume delete "${inc_path}" | debug
    fi
}
delete_inc_ext4() {
    jail_name=$1
    inc_name=$2

    inc_path=$(inc_path "${jail_name}" "${inc_name}")

    if dry_run; then
        echo "[dry-run] delete ${inc_path} with rsync from empty directory"
    else
        empty=$(new_tmp_dir "empty")
        rsync --archive --delete "${empty}/" "${inc_path}/"
        rmdir "${inc_path}/"
        rmdir "${empty}"
    fi

}

lock_file="${LOCKDIR}/rm-global.lock"
# shellcheck disable=SC2064
trap "rm -f ${lock_file}; cleanup_tmp;" 0

kill_or_clean_lockfile "${lock_file}"
new_lock_file "${lock_file}"

jails_list=$(jails_list)
jails_total=$(echo $jails_list | wc -w)
jails_count=0

for jail_name in ${jails_list}; do
    jails_count=$((jails_count+1))
    incs_policy_file=$(current_jail_incs_policy_file ${jail_name})
    # If no incs policy is found, we don't remove incs
    if [ -n "${incs_policy_file}" ]; then
        # shellcheck disable=SC2046

        incs_to_delete=$(incs_to_delete "${jail_name}" "${incs_policy_file}")
        incs_total=$(echo ${incs_to_delete} | wc -w)
        incs_count=0

        if [ -n "${incs_to_delete}" ]; then
            debug "Incs to be deleted for \`${jail_name}' : $(echo "${incs_to_delete}" | tr '\n', ',' | sed 's/,$//')."
            for inc_name in ${incs_to_delete}; do
                incs_count=$((incs_count+1))
                info "Progress: jail ${jails_count} out of ${jails_total} - inc ${incs_count} out of ${incs_total}"
                notice "Delete inc \`${inc_name}' for jail \`${jail_name}' : start"

                inc_path=$(inc_path "${jail_name}" "${inc_name}")

                if is_btrfs "${inc_path}"; then
                    delete_inc_btrfs "${jail_name}" "${inc_name}"
                else
                    delete_inc_ext4 "${jail_name}" "${inc_name}"
                fi

                notice "Delete inc \`${inc_name}' for jail \`${jail_name}' : finish"
            done
        else
            notice "Skip jail \`${jail_name}' : no inc to delete"
        fi
    else
        notice "Skip jail \`${jail_name}' : incs policy is missing"
    fi
done

# Remove the lock file and cleanup tmp files
rm -f "${lock_file}"
cleanup_tmp