#!/bin/sh

PROGRAM=setup-interfaces
PREFIX=

for i in ./libalpine.sh $PREFIX/lib/libalpine.sh; do
	[ -e $i ] && . $i && break
done

unconfigured_add() {
	touch $1.noconf
}

unconfigured_detect() {
	local i=
	for i in ${INTERFACES:-$(available_ifaces)}; do
		if [ "$i" != "lo" ]; then
			unconfigured_add $i
		fi
	done
}

unconfigured_get_first() {
	ls *.noconf 2>/dev/null | head -n 1 | sed 's/.noconf//'
}

unconfigured_del() {
	rm $1.noconf
}

unconfigured_all_done() {
	local i=
	for i in *.noconf; do
		[ -e $i ] && return 1
	done
	return 0
}

unconfigured_list() {
	local list= i=
	for i in *.noconf; do
		[ -e "$i" ] || continue
		list="${list} ${i%.noconf}"
	done
	echo $list
}

unconfigured_isin() {
	[ -f $1.noconf ]
}

iface_exists() {
	test -e /sys/class/net/$1
}

get_default_addr() {
	# check if dhcpcd is running
	if pidof dhcpcd > /dev/null && [ -f "$ROOT/var/lib/dhcpc/dhcpcd-$1.info" ]; then
		echo dhcp
	elif iface_exists; then
		ip addr show $1 | awk '/inet / {print $2}' | head -n 1 | sed 's:/.*::'
	fi
}

get_default_mask() {
	if [ "$1" ] ; then
		ipcalc -m $1 | sed 's/.*=//'
	else
		echo "255.255.255.0"
	fi
}

get_default_gateway() {
	ip route show dev $1 | awk '/^default/ {print $3}'
}

ipaddr_help() {
	cat <<__EOF__

For static ip:
Enter the ip address in the format x.x.x.x

For dhcp:
Enter 'dhcp'

To add this interface to a bridge enter the bridge name (eg 'br0' or 'bridge0')

__EOF__
}

bridge_add_iface() {
	local bridge=$1 iface=
	shift
	for iface; do
		echo $iface >> $bridge.bridge_ports
		unconfigured_add $bridge
		unconfigured_del $iface
	done
}

config_iface() {
	local iface=$1
	local prefix=$2
	local address= netmask= gateway= bridge_ports=
	local bridge
	local conf=$prefix$iface.conf
	local answer=

	while [ -n "$ask_bridge" ]; do
		ask "Do you want to bridge the interface $iface?" no
		case "$resp" in
			yes|y) resp=yes; break;;
			no|n) break;;
		esac
	done

	if [ "$resp" = "yes" ]; then
		bridge="br"`echo $iface | sed 's/[^0-9]//g'`
		ask "Name of the bridge you want add $iface to:" $bridge
		bridge_add_iface $resp $iface
		return
	fi

	if [ -r "$iface.bridge_ports" ]; then
		bridge_ports=$(sed 's/\n/ /' $iface.bridge_ports)
		echo "bridge_ports=\"$bridge_ports\"" >> $conf
	fi
	# use ipcalc to validate the address. we do accept /mask
	# we are no interested in the result, only error code, so
	# we send result to /dev/null
	while ! ipcalc -s -m $address >/dev/null 2>&1; do
		address=`get_default_addr $iface`
		[ -z "$address" ] && address="dhcp"
		ask "Ip address for $iface? (or 'dhcp' or '?')" $address
		address=$resp
		case "$resp" in
		'?')	ipaddr_help;;
		"abort") return;;
		"dhcp")
			HAS_DHCP=yes
			echo "type=dhcp" >> $conf
			unconfigured_del $iface
			return ;;
		br[0-9]*|bridge[0-9]*)
			case "$iface" in
				# we dont allow bridge bridges
				br[0-9]*|bridge[0-9]*) continue;;
			esac
			bridge_add_iface $resp $iface
			return ;;
		esac
	done

	# extract netmask if entered together with address
	if [ "$address" != "${address%%/*}" ]; then
		netmask=$(ipcalc -s -m $address | cut -d= -f2)
	fi

	# use ipcalc -m to validate netmask. we dont accept <addr>/mask suffix
	# so we pass on a dummy mask to ipcalc.
	while ! ipcalc -s -m $netmask/0 >/dev/null 2>&1; do
		netmask=`get_default_mask $address`
		ask "Netmask?" $netmask
		netmask=$resp
		[ "$netmask" = "abort" ] && return
	done

	# use ipcalc -m to validate netmask. we dont accept <addr>/mask suffix
	# so we pass on a dummy mask to ipcalc.
	while ! ipcalc -s -m $gateway/0 >/dev/null 2>&1; do
		gateway=`get_default_gateway $iface`
		[ -z "$gateway" ] && gateway=none
		ask "Gateway? (or 'none')" $gateway
		gateway=$resp
		[ "$gateway" = "abort" ] && return
		[ "$gateway" = "none" ] && gateway=""
		[ -z "$gateway" ] && break
	done
	
	echo "type=static" >> $conf
	if [ -n "$bridge_ports" ]; then
		echo "bridge_ports=$bridge_ports" >> $conf
	fi
	echo "address=${address%%/*}" >> $conf  #strip off /mask if there
	echo "netmask=$netmask" >> $conf
	echo "gateway=$gateway" >> $conf


	# print summary
	echo "Configuration for $iface:"
	sed 's/^/  /' $conf
	
	unconfigured_del $iface
}

usage() {
        cat <<__EOF__
usage: setup-interfaces [-bhi] [-p ROOT]

Setup network interfaces

options:
 -b  Ask for bridging of interfaces
 -h  Show this help
 -i  Read new contents of /etc/network/interfaces from stdin
 -p  Use ROOT as system prefix
__EOF__
        exit 1
}

prompt_for_interfaces() {
	init_tmpdir TMP
	
	cd $TMP
	unconfigured_detect
	
	index=1
	while ! unconfigured_all_done; do
		echo "Available interfaces are: $(unconfigured_list)."
		ask "Which one do you want to initialize? (or 'done')" \
			$(unconfigured_get_first)
		iface=$resp
	
		[ "$iface" = "done" ] && break
		unconfigured_isin $iface || continue
		config_iface $iface $(printf "%.3d~" $index)
		index=$(( $index + 1 ))
	done
	
	echo "type=loopback" > 000~lo.conf
	echo "" > interface
	hostname=$(cat $ROOT/etc/hostname 2>/dev/null)
	
	for i in *.conf ; do
		iface=`basename $i .conf`
		iface=${iface#[0-9]*~}
		bridge_ports=
		address=
		type=
		gateway=
		. ./$i
		echo "auto $iface" >> interfaces
		echo "iface $iface inet $type" >> interfaces
		if [ -n "$bridge_ports" ]; then
			echo -e "\tbridge-ports $bridge_ports" >> interfaces
		fi
		case $type in
		dhcp)
			[ -n "$hostname" ] \
				&& echo -e "\thostname $hostname" >> interfaces
			;;
		static)
			echo -e "\taddress $address" >> interfaces
			echo -e "\tnetmask $netmask" >> interfaces
			[ "$gateway" ] \
				&& echo -e "\tgateway $gateway" >> interfaces
			;;
		esac
		if [ -n "$bridge" ]; then
			echo -e "\tpost-down brctl delif $bridge $iface" >> interfaces
			echo -e "\tpost-down brctl delbr $bridge" >> interfaces
		fi
		echo "" >> interfaces
		bridge=""
	done
	
	while [ "$answer" != "yes" ] && [ "$answer" != "no" ] ; do
		ask "Do you want to do any manual network configuration?" no
		case $resp in
			y) answer=yes;;
			n) answer=no;;
			*) answer=$resp;;
		esac
	done

	if yesno "$answer"; then
		case "$EDITOR" in
			nano)	apk add nano;;
			vim)	apk add vim;;
		esac
		${EDITOR:-vi} interfaces
	fi
		
	mkdir -p $ROOT/etc/network
	cp interfaces $ROOT/etc/network/
}

ask_bridge=
is_xen_dom0 && ask_bridge=1

while getopts "bhip:" opt; do
        case $opt in
		b) ask_bridge=1;;
                h) usage;;
		i) STDINPUT=1;;
		p) ROOT=$OPTARG;;
        esac
done

mkdir -p $ROOT/etc/network
if [ "$STDINPUT" = "1" ]; then
	cat > $ROOT/etc/network/interfaces
else
	prompt_for_interfaces
fi