#!/bin/sh
set -e

success_v2()
{
	rm -f /etc/default/ubuntu-fan
	exit 0
}

migrate_config_v2()
{
	# If we have not already made a new style configuration, attempt to convert
	# the old.
	if [ -f /etc/network/fan ]; then
		return
	fi

	if [ ! -f /etc/default/ubuntu-fan ]; then
		return
	fi
	. /etc/default/ubuntu-fan

	echo "Migrating Ubuntu Fan configuration from /etc/default/ubuntu-fan to /etc/network/fan"

	# If disabled nothing to convert.
	if [ -z "${FAN_OVERLAY}" ]; then
		success_v2
	fi

	# If we have no FAN_BRIDGE then nothing to do.
	if [ -z "${FAN_BRIDGE}" ]; then
		success_v2
	fi

	# If we have a FAN_PRIMARY_ADDR then we will use that address as underlay.
	if [ ! -z "${FAN_PRIMARY_ADDR}" ]; then
		FAN_UNDERLAY="${FAN_PRIMARY_ADDR}/16"

	elif [ ! -z "${FAN_PRIMARY}" ]; then
		FAN_UNDERLAY="${FAN_PRIMARY}/16"

	else
		FAN_UNDERLAY="default/16"
	fi

	cat - <<EOM >/etc/network/fan
# Automatically converted from /etc/default/ubuntu-fan at `date`
# dnsmasq configuration created in /etc/dnsmasq.d/ubuntu-fan-migrated
${FAN_OVERLAY} ${FAN_UNDERLAY} dhcp bridge ${FAN_BRIDGE}
EOM
	cat - <<EOM >/etc/dnsmasq.d/ubuntu-fan-migrated
# Automatically converted from /etc/default/ubuntu-fan at `date`
${FAN_BRIDGE}
EOM
	success_v2
}

migrate_config_v3()
{
	# Convert up the static configuration.
	if [ -f "/etc/network/fan" -a ! -f "/etc/network/fan.v3" ]; then
		echo "fanctl: upgrading /etc/network/fan v3"
		while read -r line
		do
			case "$line" in
			\#*)                            ;; # Comment
			'')                             ;; # Blank line
			*\ mode\ *|*\ type\ *)          ;; # Real entry already converted
			*)
				# Real and needing migration
				line="$line type ipip mode sliced"
				;;
			esac
			echo "$line"
		done <"/etc/network/fan" >"/etc/network/fan.new"
		mv -f "/etc/network/fan" "/etc/network/fan.v3"
		mv -f "/etc/network/fan.new" "/etc/network/fan"
	fi
}

migrate_config_v6()
{
	# Convert up the static configuration.
	if [ -f "/etc/network/fan" -a ! -f "/etc/network/fan.v6" ]; then
		echo "fanctl: upgrading /etc/network/fan v6"
		while read -r line
		do
			case "$line" in
			\#*)                            ;; # Comment
			'')                             ;; # Blank line
			*)
				# switch underlay/overlay order
				# flip no argument flags to option form
				# flip one argument flags to option form
				echo "$line" | sed \
					-e 's/^\(\s*\)\([^    ][^     ]*\)\(\s*\)\([^         ][^     ]*\)/\1\4\3\2/' \
					-e 's/\<\(dhcp\|auto\|off\)\>/--\1/g' \
					-e 's/\<\(host-reserve\|bridge\|type\|mode\)[ \t][ \t]*\([^ \t]\)/--\1=\2/'
				continue
				;;
			esac
			echo "$line"
		done <"/etc/network/fan" >"/etc/network/fan.new"
		mv -f "/etc/network/fan" "/etc/network/fan.v6"
		mv -f "/etc/network/fan.new" "/etc/network/fan"
	fi
}

create_default_config()
{
	if [ -f /etc/network/fan ]; then
		return
	fi

	cat - <<EOM >/etc/network/fan
# FAN overlay network map.

# The FAN is a very fast overlay network system for docker in cloud
# environments with limited IP addresses. The FAN multiplies host
# addresses by mapping them to a larger overlay network. It eliminates
# the need for a central database and myriad tunnels by mapping
# addresses mathematically.

# This map file specifies the list of maps which can be enabled in
# /etc/network/interfaces or using the "fanctl config" command. See also
# fanatic(1) for a tool that will configure docker to use your fans.
# The only absolute rule is that all your participating machines use
# the same mapping for active fans.

# The map translates a local address range to an overlay range.

# RFC1918 - we recommend you use these for easy interop with other
# FAN users on small private networks. They provide around 250 IP's
# per 192.168.0.0/16 address, or 16 per 172.16.0.0/12 address.

# local          overlay       options
192.168.0.0/16   250.0.0.0/8
172.16.0.0/12    251.0.0.0/8

# RFC1918 VPC - we recommend you use the higher ranges of 10.0.0.0/8
# for your docker-centric VPC. This example provides 1,000 IP's per
# base IP in 10.254.0.0/16.

10.254.0.0/16    252.0.0.0/8
10.254.0.0/16    253.0.0.0/8
10.254.0.0/16    254.0.0.0/8

# CUSTOM
#
# You can map large ranges onto your own, smaller, ranges for address
# space expansion purposes. We recommend you adopt a common mapping for
# your entire institution.

# local          overlay
EOM
}

case "$1" in
configure)
	if dpkg --compare-versions "$2" lt-nl "0.3.0~"; then
		migrate_config_v2
	fi
	if dpkg --compare-versions "$2" lt-nl "0.4.0~"; then
		migrate_config_v3
		fanctl __upgrade
	fi
	if dpkg --compare-versions "$2" lt-nl "0.7.0~"; then
		migrate_config_v6
	fi
	create_default_config
	;;
esac

# Automatically added by dh_systemd_enable/12.10ubuntu1
if [ "$1" = "configure" ] || [ "$1" = "abort-upgrade" ] || [ "$1" = "abort-deconfigure" ] || [ "$1" = "abort-remove" ] ; then
	# This will only remove masks created by d-s-h on package removal.
	deb-systemd-helper unmask 'ubuntu-fan.service' >/dev/null || true

	# was-enabled defaults to true, so new installations run enable.
	if deb-systemd-helper --quiet was-enabled 'ubuntu-fan.service'; then
		# Enables the unit on first installation, creates new
		# symlinks on upgrades if the unit file has changed.
		deb-systemd-helper enable 'ubuntu-fan.service' >/dev/null || true
	else
		# Update the statefile to add new symlinks (if any), which need to be
		# cleaned up on purge. Also remove old symlinks.
		deb-systemd-helper update-state 'ubuntu-fan.service' >/dev/null || true
	fi
fi
# End automatically added section
# Automatically added by dh_installinit/12.10ubuntu1
if [ "$1" = "configure" ] || [ "$1" = "abort-upgrade" ] || [ "$1" = "abort-deconfigure" ] || [ "$1" = "abort-remove" ] ; then
	if [ -x "/etc/init.d/ubuntu-fan" ]; then
		update-rc.d ubuntu-fan defaults >/dev/null
		invoke-rc.d ubuntu-fan start || exit 1
	fi
fi
# End automatically added section