#!/bin/sh -e
# Work from the snap
export PATH=/snap/bin/:${PATH}
export LANG=C.UTF-8

# Functions
maskcidr() {
   local x=${1##*255.}
   set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
   x=${1%%$3*}
   echo $(( $2 + (${#x}/4) ))
}

# Skip if already converted
if [ ! -e /etc/default/lxd-bridge ]; then
    echo "LXD bridge already converted"
    exit 0
fi

# Source current configuration
. /etc/default/lxd-bridge

# Setup temporary config dir
export LXD_CONF=$(mktemp -d)

# Check if LXD is functional (chroot detection)
if ! lxc info --force-local >/dev/null 2>&1; then
    echo "This system isn't running LXD, assuming stock configuration."
    mv /etc/default/lxd-bridge /etc/default/lxd-bridge.upgraded

    echo "Cleaning up lxd-bridge state files"
    rm -Rf /var/lib/lxd-bridge /run/lxd-bridge "${LXD_CONF}"
    exit 0
fi

# Clear deprecated settings
echo "Unsetting deprecated profile options"
lxc profile unset default user.network_mode --force-local || true
lxc profile unset default environment.http_proxy --force-local || true

# Done for unconfigured bridges
if [ "${USE_LXD_BRIDGE}" != "true" ] || [ -z "${LXD_BRIDGE}" ]; then
    echo "No bridge configuration to convert"
    mv /etc/default/lxd-bridge /etc/default/lxd-bridge.upgraded

    echo "Cleaning up lxd-bridge state files"
    rm -Rf /var/lib/lxd-bridge /run/lxd-bridge "${LXD_CONF}"
    exit 0
fi

# Attempting to kill existing lxd-bridge
echo "Attempting to kill current lxd-bridge"
if [ -e "/run/systemd/system" ] && systemctl -q is-active lxd-bridge; then
    systemctl stop lxd-bridge || true
fi

if [ -e "/run/lxd-bridge/network_up" ] && [ -e "/usr/lib/lxd/lxd-bridge" ]; then
    /usr/lib/lxd/lxd-bridge stop || true
fi

if [ -e "/run/lxd-bridge/dnsmasq.pid" ]; then
    kill -9 "$(cat /run/lxd-bridge/dnsmasq.pid)" >/dev/null 2>&1 || true
fi

# Check if the bridge exists
EXISTING=false
if [ -e "/sys/class/net/${LXD_BRIDGE}" ]; then
    EXISTING=true
fi

# Check for stock installation
if [ "${EXISTING}" = "false" ] && [ "$(md5sum /etc/default/lxd-bridge | cut -d' ' -f1)" = "e8cfb4997d9443fe48302bb75326b09f" ]; then
    echo "Stock LXD installation detected, resetting to new defaults"
    lxc profile device remove default eth0 --force-local >/dev/null 2>&1 || true
    mv /etc/default/lxd-bridge /etc/default/lxd-bridge.upgraded

    echo "Cleaning up lxd-bridge state files"
    rm -Rf /var/lib/lxd-bridge /run/lxd-bridge "${LXD_CONF}"
    exit 0
fi

# Bring down and rename an existing bridge
if [ "${EXISTING}" = "true" ]; then
    if [ -e "/sys/class/net/lxd-upgrade" ]; then
        ip link del lxd-upgrade
    fi

    echo "Bringing down and renaming existing bridge ${LXD_BRIDGE} to lxd-upgrade"
    ip link set "${LXD_BRIDGE}" down
    ip link set "${LXD_BRIDGE}" name lxd-upgrade
fi

# Define the bridge in LXD
echo "Creating a new LXD bridge"
if ! lxc network show "${LXD_BRIDGE}" >/dev/null 2>&1; then
    lxc network create "${LXD_BRIDGE}" ipv4.address=none ipv6.address=none dns.mode=dynamic --force-local
fi

# Move the old bridge into place
if [ "${EXISTING}" = "true" ]; then
    echo "Moving the old bridge into place"
    [ -e "/sys/class/net/${LXD_BRIDGE}" ] && ip link del "${LXD_BRIDGE}"
    ip link set lxd-upgrade name "${LXD_BRIDGE}" up
fi

# Configure the bridge
echo "Configuring the new LXD bridge"
if [ -n "${LXD_CONFILE}" ] && [ -e "${LXD_CONFILE}" ]; then
    echo "Setting dnsmasq conf-file to ${LXD_CONFILE}"
    lxc network set "${LXD_BRIDGE}" raw.dnsmasq "conf-file=${LXD_CONFILE}" --force-local
fi

if [ "${LXD_DOMAIN}" != "lxd" ]; then
    echo "Setting DNS domain to ${LXD_DOMAIN}"
    lxc network set "${LXD_BRIDGE}" dns.domain "${LXD_DOMAIN}" --force-local
fi

if [ -n "${LXD_IPV4_ADDR}" ] && [ -n "${LXD_IPV4_NETMASK}" ]; then
    IPV4_CIDR="${LXD_IPV4_ADDR}/$(maskcidr "${LXD_IPV4_NETMASK}")"
    echo "Setting IPv4 network to ${IPV4_CIDR}"
    lxc network set "${LXD_BRIDGE}" ipv4.address "${IPV4_CIDR}" --force-local

    if [ -n "${LXD_IPV4_DHCP_RANGE}" ]; then
        IPV4_RANGE=$(echo "${LXD_IPV4_DHCP_RANGE}" | sed "s/,/-/")
        echo "Setting IPv4 DHCP range to ${IPV4_RANGE}"
        lxc network set "${LXD_BRIDGE}" ipv4.dhcp.ranges "${IPV4_RANGE}" --force-local
    fi

    if [ "${LXD_IPV4_NAT}" = "true" ]; then
        echo "Enabling IPv4 NAT"
        lxc network set "${LXD_BRIDGE}" ipv4.nat true --force-local
    fi
fi

if [ -e /proc/sys/net/ipv6 ] && [ -n "${LXD_IPV6_ADDR}" ] && [ -n "${LXD_IPV6_MASK}" ]; then
    IPV6_CIDR="${LXD_IPV6_ADDR}/${LXD_IPV6_MASK}"
    echo "Setting IPv6 network to ${IPV6_CIDR}"
    lxc network set "${LXD_BRIDGE}" ipv6.address "${IPV6_CIDR}" --force-local

    if [ "${LXD_IPV6_NAT}" = "true" ]; then
        echo "Enabling IPv6 NAT"
        lxc network set "${LXD_BRIDGE}" ipv6.nat true --force-local
    fi
fi

echo "Done converting your bridge, renaming old configuration"
mv /etc/default/lxd-bridge /etc/default/lxd-bridge.upgraded

echo "Cleaning up lxd-bridge state files"
rm -Rf /var/lib/lxd-bridge /run/lxd-bridge "${LXD_CONF}"