#!/bin/bash
# postinst script for dump1090
#
# see: dh_installdeb(1)

set -e

# summary of how this script can be called:
#        * <postinst> `configure' <most-recently-configured-version>
#        * <old-postinst> `abort-upgrade' <new version>
#        * <conflictor's-postinst> `abort-remove' `in-favour' <package>
#          <new-version>
#        * <postinst> `abort-remove'
#        * <deconfigured's-postinst> `abort-deconfigure' `in-favour'
#          <failed-install-package> <version> `removing'
#          <conflicting-package> <version>
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package

NAME=dump1090-mutability
CONFIGFILE=/etc/default/$NAME
SRCCONFIGFILE=$CONFIGFILE
TEMPLATECONFIG=/usr/share/$NAME/config-template
CRONFILE=/etc/cron.d/$NAME
TEMPLATECRON=/usr/share/$NAME/cron-template
SEDSCRIPT=$CONFIGFILE.sed.tmp

subvar_raw() {
  # $1 = config value
  # $2 = config var name

  if ! grep -Eq "^ *$2=" $SRCCONFIGFILE; then
    # if not present in the config file, add it at the end
    echo "\$a $2=$1" >> $SEDSCRIPT
  else
    # otherwise, replace the current value
    echo "s@^ *$2=.*@$2=\"$1\"@" >>$SEDSCRIPT
  fi
}

subvar() {
  # $1 = db var name
  # $2 = config var name
  db_get $NAME/$1
  subvar_raw "$RET" "$2"
}

subvar_yn() {
  # $1 = db var name
  # $2 = config var name
  db_get $NAME/$1
  if [ "$RET" = "true" ]; then subvar_raw "yes" "$2"; else subvar_raw "no" "$2"; fi
}

case "$1" in
    configure)
        . /usr/share/debconf/confmodule

        # If we have no config file, start from the template.
        # Avoid copying the template to the config file
        # before substitution; this leaves an all-blank config
        # in place if something fails, which causes problems
        # on subsequent reconfiguration.
        SKIPLINES=0
        if [ ! -e $SRCCONFIGFILE ]; then
            SRCCONFIGFILE=$TEMPLATECONFIG
            SKIPLINES=4
        fi

        rm -f $SEDSCRIPT

        subvar_yn auto-start START_DUMP1090
        subvar run-as-user DUMP1090_USER
        subvar log-file LOGFILE
        subvar rtlsdr-device DEVICE
        subvar rtlsdr-gain GAIN
        subvar rtlsdr-ppm PPM
        subvar_yn decode-fixcrc FIX_CRC
        subvar decode-lat LAT
        subvar decode-lon LON
        subvar decode-max-range MAX_RANGE
        subvar net-ri-port RAW_INPUT_PORT
        subvar net-ro-port RAW_OUTPUT_PORT
        subvar net-bi-port BEAST_INPUT_PORT
        subvar net-bo-port BEAST_OUTPUT_PORT
        subvar net-sbs-port SBS_OUTPUT_PORT
        subvar net-heartbeat NET_HEARTBEAT
        subvar net-out-size NET_OUTPUT_SIZE
        subvar net-out-interval NET_OUTPUT_INTERVAL
        subvar net-buffer NET_BUFFER
        subvar net-bind-address NET_BIND_ADDRESS
        subvar stats-interval STATS_INTERVAL
        subvar json-dir JSON_DIR
        subvar json-interval JSON_INTERVAL
        subvar json-location-accuracy JSON_LOCATION_ACCURACY
        subvar_yn log-decoded-messages LOG_DECODED_MESSAGES
        subvar extra-args EXTRA_ARGS

        tail -n +$SKIPLINES < $SRCCONFIGFILE | sed -f $SEDSCRIPT > $CONFIGFILE.tmp
        if [ -e $CONFIGFILE ]; then
            chown --reference=$CONFIGFILE $CONFIGFILE.tmp
            chmod --reference=$CONFIGFILE $CONFIGFILE.tmp
        fi
        mv -f $CONFIGFILE.tmp $CONFIGFILE
        rm $SEDSCRIPT

        db_get $NAME/run-as-user
        RUNAS="$RET"
        if ! getent passwd "$RUNAS" >/dev/null
        then
            adduser --system --home /usr/share/$NAME --no-create-home --quiet "$RUNAS"
        fi

        # create log if missing; change ownership if needed so the cronjob works
        db_get $NAME/log-file
        touch $RET
        chown $RUNAS $RET

        # this config file has changed a few times, restart lighttpd to make sure we
        # have the latest version
        if [ -e /etc/lighttpd/conf-enabled/89-dump1090.conf ]; then
            echo "Restarting lighttpd.." >&2
            invoke-rc.d lighttpd restart || echo "Warning: lighttpd failed to restart." >&2
        fi
    ;;

    abort-upgrade|abort-remove|abort-deconfigure)
    ;;

    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

# dh_installdeb will replace this with shell code automatically
# generated by other debhelper scripts.

#DEBHELPER#

if [ "$1" = "configure" ]; then db_stop; fi
exit 0