#!/bin/sh
set -e

DEFAULTS=/etc/default/koha-common

# On a systemd host the daemons started by /etc/init.d/koha-common live in
# the cgroup of the koha-common.service that systemd-sysv-generator created
# for the init script. By the time this postinst runs, the init script has
# already been removed by koha-common's rm_conffile and the koha-* helpers
# already dispatch to systemd, so neither of them can stop those daemons
# any more. Kill the legacy cgroup, then sweep whatever still holds a pid
# file in the instances' run directories (daemon(1) supervisors, starman,
# the Z39.50 responder).
stop_legacy_daemons() {
    if systemctl is-active --quiet koha-common.service 2>/dev/null; then
        # The generated unit has KillMode=process; a plain stop would leave
        # the daemon(1) supervisors and their children running.
        systemctl kill --signal=SIGTERM koha-common.service 2>/dev/null || true
        systemctl stop koha-common.service 2>/dev/null || true
    fi

    for pidfile in /run/koha/*/*.pid; do
        [ -f "$pidfile" ] || continue
        pid=$(cat "$pidfile" 2>/dev/null) || continue
        case "$pid" in
            '' | *[!0-9]*) continue ;;
        esac
        kill -TERM "$pid" 2>/dev/null || true
    done

    # Wait (briefly) for them to release their sockets and pid files.
    i=0
    while [ "$i" -lt 10 ]; do
        alive=0
        for pidfile in /run/koha/*/*.pid; do
            [ -f "$pidfile" ] || continue
            pid=$(cat "$pidfile" 2>/dev/null) || continue
            case "$pid" in
                '' | *[!0-9]*) continue ;;
            esac
            if kill -0 "$pid" 2>/dev/null; then
                alive=1
            fi
        done
        [ "$alive" -eq 0 ] && break
        sleep 1
        i=$((i + 1))
    done
}

# First install (migration from the SysV-managed layout): enable the units
# that correspond to what the init script used to start for each enabled
# instance, then start everything.
enable_existing_instances() {
    USE_INDEXER_DAEMON="yes"
    if [ -f "$DEFAULTS" ]; then
        . "$DEFAULTS"
    fi

    plack_instances=$(koha-list --enabled --plack 2>/dev/null || true)
    z3950_instances=$(koha-list --enabled --z3950 2>/dev/null || true)
    es_instances=$(koha-list --enabled --elasticsearch 2>/dev/null || true)

    for instance in $(koha-list --enabled 2>/dev/null); do
        # Always on
        systemctl enable "koha-create-dirs@${instance}.service" 2>/dev/null || true
        systemctl enable "koha-zebra@${instance}.service" 2>/dev/null || true
        systemctl enable "koha-worker@${instance}.service" 2>/dev/null || true
        systemctl enable "koha-worker-long_tasks@${instance}.service" 2>/dev/null || true
        systemctl enable "koha@${instance}.target" 2>/dev/null || true

        # Plack: the init script started it for "koha-list --enabled --plack"
        # (Apache configuration), so do the same rather than for everyone.
        if echo "$plack_instances" | grep -qx "$instance"; then
            systemctl enable "koha-plack@${instance}.service" 2>/dev/null || true
        fi

        # SIP: read the SysV-era flag file DIRECTLY here, not via
        # koha-list --sip / is_sip_enabled. The latter consults
        # systemctl is-enabled on systemd hosts, which is "disabled" for
        # every instance during this very first install. The flag file is
        # the only signal for "did this instance have SIP enabled in the
        # SysV-era state we are migrating from?".
        if [ -e "/var/lib/koha/${instance}/sip.enabled" ]; then
            systemctl enable "koha-sip@${instance}.service" 2>/dev/null || true
        fi

        if echo "$z3950_instances" | grep -qx "$instance"; then
            systemctl enable "koha-z3950@${instance}.service" 2>/dev/null || true
        fi

        # Indexing: the ES indexer for Elasticsearch instances, otherwise
        # the Zebra indexer daemon if /etc/default/koha-common asks for it,
        # which is what the init script did.
        if echo "$es_instances" | grep -qx "$instance"; then
            systemctl enable "koha-es-indexer@${instance}.service" 2>/dev/null || true
        elif [ "$USE_INDEXER_DAEMON" = "yes" ]; then
            systemctl enable "koha-indexer@${instance}.service" 2>/dev/null || true
        fi
    done

    systemctl enable koha.target 2>/dev/null || true
    systemctl enable koha-common.service 2>/dev/null || true
}

case "$1" in
    configure)
        if [ -z "$2" ]; then
            stop_legacy_daemons
        fi

        systemctl daemon-reload || true

        if [ -z "$2" ]; then
            enable_existing_instances
            deb-systemd-invoke start koha.target koha-common.service >/dev/null || true
        else
            # Upgrade: restart the running per-component units so they pick
            # up new code and unit files. deb-systemd-invoke takes unit
            # names, not patterns, so enumerate them first.
            units=$(systemctl list-units --plain --no-legend --state=active 'koha-*@*.service' 2>/dev/null | awk '{print $1}')
            if [ -n "$units" ]; then
                # shellcheck disable=SC2086
                deb-systemd-invoke try-restart $units >/dev/null || true
            fi
        fi
        ;;
esac

#DEBHELPER#

exit 0