#!/bin/sh

set -e

# Source debconf library.
. /usr/share/debconf/confmodule

NGIRCD=/usr/sbin/ngircd
CONFIG=/etc/ngircd/ngircd.conf
CONVERT=/usr/share/ngircd/ngircd-conf-convert

[ -x "$NGIRCD" ] || exit 0
[ -f "$CONFIG" ] || exit 0
[ -x "$CONVERT" ] || exit 0

TEMPDIR=

# conversion required?
if grep -qiE '^[ \t]*\[(Limits|Options|SSL)\]' "$CONFIG" ; then
    # Using new section names, we're done
    exit 0
fi

while true ; do
    # Shall we do conversion?
    db_reset ngircd/conversion-do
    db_input high ngircd/conversion-do || true
    db_go
    db_get ngircd/conversion-do
    if [ "$RET" = "false" ]; then
	break
    fi

    # Check old configuration
    if </dev/null "$NGIRCD" --configtest --config "$CONFIG" >/dev/null ; then
	:
    else
	# broken
	db_input high ngircd/broken-oldconfig || true
	db_go
	break
    fi

    # have a temporary directory
    TEMPDIR=$(mktemp -d /tmp/ngircd.XXXXX)
    [ "$TEMPDIR" ] && [ -d "$TEMPDIR" ] || exit 0
    chmod 700 "$TEMPDIR"

    # create new configuration
    CONFIG_NEW="$TEMPDIR/ngircd.conf"
    touch "$CONFIG_NEW"
    "$CONVERT" "$CONFIG" "$CONFIG_NEW"
    if cmp -s "$CONFIG" "$CONFIG_NEW" ; then
	echo "Nothing to do."
	break
    fi

    # create dumps from --configtest and compare
    DUMP_OLD="$TEMPDIR/dump.old"
    </dev/null "$NGIRCD" --configtest --config "$CONFIG" |
    sed -n '/GLOBAL/,$p' >"$DUMP_OLD"
    DUMP_NEW="$TEMPDIR/dump.new"
    </dev/null "$NGIRCD" --configtest --config "$CONFIG_NEW" |
    sed -n '/GLOBAL/,$p' >"$DUMP_NEW"

    if cmp -s "$DUMP_OLD" "$DUMP_NEW" ; then
	# success
	CONFIG_BAK="$CONFIG.pre18"
	chown --reference="$CONFIG" "$CONFIG_NEW"
	chmod --reference="$CONFIG" "$CONFIG_NEW"
	mv "$CONFIG" "$CONFIG_BAK"
	mv "$CONFIG_NEW" "$CONFIG"

	echo "Conversion and verification sucessfull. Your configuration file is at"
	echo "    $CONFIG"
	echo "A backup of the old configuration has been saved to"
	echo "    $CONFIG_BAK"
	break
    fi

    DIFF="$(sdiff -BbW "$DUMP_OLD" "$DUMP_NEW")"
    db_capb escape
    db_subst ngircd/conversion-fail DIFF "$(printf %s "$DIFF" | debconf-escape -e)"
    db_input critical ngircd/conversion-fail || true
    db_go
    db_reset ngircd/conversion-fail
    db_capb

    break
done

# cleanup
db_purge
[ "$TEMPDIR" ] && rm -rf "$TEMPDIR"

exit 0