#!/bin/sh

set -e

. /usr/share/debconf/confmodule

MYNAME=resolvconf.postinst
report() { echo "${MYNAME}: $*" ; }
report_err() { report "Error: $*" >&2 ; }
report_info() { report "$*" >&2 ; }

standard_run_tmpfs_is_available() {
	:
	# Initscripts guarantees that /run is available.
}

### BEGIN BLOCK THAT SHOULD BE IDENTICAL TO THAT IN THE PREINST ###
standard_run_subdirs_created() {
	{ [ -d /run/resolvconf ] || mkdir -v /run/resolvconf ; } \
	&& { [ -d /run/resolvconf/interface ] || mkdir -v /run/resolvconf/interface ; }
}
### END BLOCK THAT SHOULD BE IDENTICAL TO THAT IN THE PREINST ###

# We use dh_installinit with --no-start
#DEBHELPER#

case "$1" in
  configure)
	if [ -L /etc/resolvconf/run ] ; then
		RUN_CANONICALPATH="$(readlink -f /etc/resolvconf/run || :)"
	fi

	### BEGIN BLOCK THAT SHOULD BE IDENTICAL TO THAT IN THE PREINST ###
	# /etc/resolvconf/run is not a non-canonicalizable symlink.
	# RUN_CANONICALPATH is the canonical path pointed to by /etc/resolvconf/run.
	# Attempt migration from old to new standard location
	if [ -L /etc/resolvconf/run ] ; then
		# It's a canonicalizable symlink
		# If it's standard then try to migrate from old to new standard location.
		[ "$RUN_CANONICALPATH" = "/lib/init/rw/resolvconf" ] \
		&& standard_run_tmpfs_is_available \
		&& standard_run_subdirs_created \
		&& {
			# /etc/resolvconf/run points to the old-standard location
			# and new-standard run directories are ready for use.
			# Switch from the old to the new standard location.
			{
				F="$(echo /lib/init/rw/resolvconf/*)" \
				&& [ "$F" ] \
				&& [ "$F" != '/lib/init/rw/resolvconf/*' ] \
				&& cp -a /lib/init/rw/resolvconf/* /run/resolvconf \
				&& report_info "Migrated resolvconf run-time data from /lib/init/rw/resolvconf to /run/resolvconf"
			}
			ln -nsf /run/resolvconf /etc/resolvconf/run
		}
	fi
	### END BLOCK THAT SHOULD BE IDENTICAL TO THAT IN THE PREINST ###

	# Link tail to original if appropriate
	if [ ! -e /etc/resolvconf/resolv.conf.d/tail ] ; then
		db_get resolvconf/link-tail-to-original
		if [ "$RET" = "true" ] ; then
			ln -nsf original /etc/resolvconf/resolv.conf.d/tail
		else
			: > /etc/resolvconf/resolv.conf.d/tail
		fi
	fi

	# Linkify /etc/resolv.conf if appropriate
	db_get resolvconf/linkify-resolvconf
	if [ "$RET" = "true" ] ; then
		if
			[ -f /etc/resolv.conf ] \
			&& {
				[ ! -L /etc/resolv.conf ] \
				|| [ ! "$(readlink /etc/resolv.conf)" = "/etc/resolvconf/run/resolv.conf" ]
			}
		then
			# Back up original file
			if [ ! -e /etc/resolvconf/resolv.conf.d/original ] ; then
				cp -a /etc/resolv.conf /etc/resolvconf/resolv.conf.d/original
			else
				cp -a /etc/resolv.conf /etc/resolv.conf.dpkg-old
			fi
			# Before creating the link, make sure that the original file is
			# at the target of the link.  /sbin/resolvconf will overwrite
			# this when it does an update, of course.
			if [ ! -e /etc/resolvconf/run/resolv.conf ] ; then
				cp -a /etc/resolv.conf /etc/resolvconf/run/resolv.conf
			fi
			# Add the original file to the database so that its contents
			# are included when resolvconf updates.
			# Yes, this is an ugly workaround for the problem that there
			# is no way to obtain nameserver information from interface
			# configurers after they have done their configuration work.
			cp -a /etc/resolv.conf /etc/resolvconf/run/interface/original.resolvconf
		fi
		# Create the link
		ln -nsf /etc/resolvconf/run/resolv.conf /etc/resolv.conf
	fi
	;;
  # abort-upgrade)
	# Don't do anything here since we don't do anything in the prerm on upgrade or on failed-upgrade
	# ;;
  # abort-remove)
	# Don't do anything extra here since we don't deconfigure anything in the prerm on remove
	# ;;
  # abort-deconfigure)
	# Don't do anything extra here since we don't do anything in the prerm on deconfigure
	# ;;
esac

db_stop

enable_updates() {
	if [ -x "/etc/init.d/resolvconf" ] ; then
		if which invoke-rc.d >/dev/null 2>&1 ; then
			invoke-rc.d resolvconf enable-updates || :
		else
			/etc/init.d/resolvconf enable-updates
		fi
	fi
}

case "$1" in
  configure)
	dpkg-trigger update-resolvconf
	;;
  triggered)
	# This runs after we and possibly other packages have been configured
        for trigger in $2 ; do
		case "$trigger" in
		  update-resolvconf)
			if [ -x /sbin/resolvconf ] ; then
				# Presumably we were just installed
				enable_updates
			fi
			;;
		esac
        done
	;;
  abort-remove)
	# We disable updates in the prerm on remove.
	# So, enable them again
	enable_updates
	;;
  # abort-upgrade)
	# Don't do anything here since we don't do anything in the prerm on upgrade or on failed-upgrade
	# ;;
  # abort-deconfigure)
	# Don't do anything extra here since we don't do anything in the prerm on deconfigure
	# ;;
esac