#!/bin/sh

# [1] Manage missing parameter
if [ $# -lt 1 ]; then
	echo "missing argument {interface_path}" && exit;
fi;

# variables
path=`realpath $1`;
CONFIG="";

# [2] create current config backup (safe)
cp $path $path.save \
	&& echo "config backup created" \
	|| ( echo "cannot create config backup" && exit );

# [3] Data / Option choice 
echo "\n== REQUIRED ==";

	# (1) Manage interface choice
	read -p "Interface name: " iface_name;
	
	test -z "$iface_name" && echo "empty interface name !\naborting" && exit;

	CONFIG="auto $iface_name";





	read -p "Use dhcp or static config (d/s) [d]" config_type;

	test -z "$config_type" && config_type="d";

	## (1) STATIC IP ##
	if [ $config_type = "s" ]; then

		CONFIG="$CONFIG\niface $iface_name inet static";
		
		echo "\nNetwork configuration (leave blank not to mention a field)";
		read -p "ip address: " s_address;
		read -p "network mask: " s_netmask;
		read -p "network address: " s_network;
		read -p "gateway address: " s_gateway;
		read -p "broadcast address: " s_broadcast;

		test -n "$s_address"   && CONFIG="$CONFIG\n\taddress\t$s_address";
		test -n "$s_netmask"   && CONFIG="$CONFIG\n\tnetmask\t$s_netmask";
		test -n "$s_network"   && CONFIG="$CONFIG\n\tnetwork\t$s_network";
		test -n "$s_gateway"   && CONFIG="$CONFIG\n\tgateway\t$s_gateway";
		test -n "$s_broadcast" && CONFIG="$CONFIG\n\tbroadcast\t$s_broadcast";

	## (2) DHCP ##
	else
		CONFIG="$CONFIG\niface $iface_name inet dhcp";
	fi;






	# (3) Set wpa if wanted
	read -p "is it a wireless interface ? (y/n) [n]" is_wireless;

	test -z "$is_wireless" && is_wireless="n";

	## Set Wireless credentials
	if [ -n "$is_wireless" -a $is_wireless = "y" ]; then
		read -p "Wifi SSID:" w_ssid;
		read -p "Wifi PASSWORD:" w_pass;

		w_psk=$( wpa_passphrase "$w_ssid" "$w_pass" | grep -E "^\spsk" | sed 's/^\spsk=//' );

		# add ssid/psk to config
		CONFIG="$CONFIG\n\twpa-ssid\t$w_ssid\n\twpa-psk\t$w_psk";
	fi;




echo "\n== OPTIONAL ==";

	# (4) Add pre/post scripts
	read -p "add 'pre-up' script:" pre_up;
	test -n "$pre_up" && test -a $pre_up && CONFIG="$CONFIG\n\tpre-up\t$pre_up";

	read -p "add 'up' script:" up;
	test -n "$up" && test -a $up && CONFIG="$CONFIG\n\tup\t$up";

	read -p "add 'down' script:" up;
	test -n "$down" && test -a $down && CONFIG="$CONFIG\n\tdown\t$down";

	read -p "add 'post-down' script:" up;
	test -n "$post_down" && test -a $post_down && CONFIG="$CONFIG\n\tpost-down\t$post_down";




echo $CONFIG > $path;
echo "\n== WRITTEN TO FILE ==";