#!/bin/sh

set -e

. /usr/share/debconf/confmodule
db_version 2.0

CONF=/etc/default/irqbalance
CONFCONVERT=/etc/default/irqbalance.dpkg-needs-convert
# config has no way to detect upgrade vs fresh installs,
# so preinst hands us a flag files.
UPGRADE_FLAG_FILE=/run/irqbalance.dpkg-upgrade
INSTALL_FLAG_FILE=/run/irqbalance.dpkg-install

is_irqbalance_enabled() {
    # If we are upgrading from a version without the .service file, we cannot
    # rely on systemctl is-enabled to tell us if the service was enabled or
    # not, we need to check if the LSB service was enabled in at least one
    # runlevel even if we are running systemd.
    if dpkg --compare-versions -- "$2" le-nl "1.1.0-2.2~"; then
        if ls /etc/rc*.d/S*irqbalance >/dev/null 2>&1; then
           return 0
        else
           return 1
        fi
    else
        # See https://bugs.debian.org/705254 but lets try ourselves for now...
        if [ -e /run/systemd/system ]; then
            if systemctl -q is-enabled irqbalance.service; then
                return 0
            else
                return 1
            fi
        else
            if ls /etc/rc*.d/S*irqbalance >/dev/null 2>&1; then
                return 0
            else
                return 1
           fi
        fi
    fi
}

if test -e $CONF || test -e $CONFCONVERT; then
    test -e $CONF && . $CONF || true
    test -e $CONFCONVERT && . $CONFCONVERT || true

    # ENABLED is the old format up for conversion,
    # will be switched to update-rc.d handling in postinst...
    if [ "$ENABLED" = "0" ]; then
        db_set irqbalance/enable false
    elif [ -e $UPGRADE_FLAG_FILE ] && ! is_irqbalance_enabled $*; then
        db_set irqbalance/enable false
    elif [ ! -e $INSTALL_FLAG_FILE ] && [ ! -e $UPGRADE_FLAG_FILE ]; then
        # dpkg-reconfigure
        if is_irqbalance_enabled $*; then
            db_set irqbalance/enable true
        else
            db_set irqbalance/enable false
        fi
    else
        db_set irqbalance/enable true
    fi
    # We no longer need flag files, clean up....
    rm -f $UPGRADE_FLAG_FILE $INSTALL_FLAG_FILE

    # ONESHOT is the old format used before conversion.
    # Note: irqbalance.c treats IRQBALANCE_ONESHOT as active if set to
    # anything (even empty string).
    if [ "$ONESHOT" = "1" ] || [ ! -z ${IRQBALANCE_ONESHOT+x} ]; then
        db_set irqbalance/oneshot true
    else
        db_set irqbalance/oneshot false
    fi
fi

db_input low irqbalance/enable || true
db_input medium irqbalance/oneshot || true
db_go || true

exit 0