#!/bin/bash

#/**
#         setserveraddr {str_ipaddress | str_netiface}
#@file    setserveraddr
#@brief   Command the modifies configuration files to assign the default network interface.
#@param   str_ipaddress  IP address assigned to a network interface
#@param   str_netiface   network interface name defined by the operating system.
#@version Initial version.
#@author  Ramón M. Gómez - ETSII Univ. Sevilla
#@date    2011-01-25
#@version 1.0.5 - Regenerate configuration files.
#@author  Ramón M. Gómez - ETSII Univ. Sevilla
#@date    2014-06-06
#@version 1.1.1 - Updating menu URLs, PXE files, and repository API key.
#@author  Ramón M. Gómez - ETSII Univ. Sevilla
#@date    2018-11-15
#*/ ##


# Variables.
PROG="$(basename "$0")"
OPENGNSYS=/opt/opengnsys
PXEDIR=$OPENGNSYS/tftpboot/menu.lst
DEFAULTFILE=/etc/default/opengnsys

# Checking parameters.
if [ $# -ne 1 ]; then
	echo "$PROG: Incorrect operand. Format: $PROG ipaddress|netiface" >&2
	exit 1
fi
if [ "$USER" != "root" ]; then
	echo "$PROG: Need to be root." >&2
	exit 1
fi

# Showing warning to inform that initiated clients may hang.
read -rp "WARNING: initiated clients can hang. Continue? (y/n): " ANSWER
if [ "${ANSWER,,}" != "y" ]; then
	echo "Operation canceled."
	exit 0
fi

# Detecting network interfaces.
DEVICES=$(ip -o link show up | awk -F: '$2!~/lo/ {print $2}')
for DEV in $DEVICES; do
	# If the network interface is found, get its IP address.
	IP=$(ip -o addr show dev "$DEV" | awk '$3~/inet$/ {sub (/\/.*/, ""); print ($4)}')
	if [ "$DEV" == "$1" ] || [ "$IP" == "$1" ]; then
		SERVERIP="$IP"
		SERVERDEV="$DEV"
	fi
done

# Checking if IP address has been detected.
if [ -n "$SERVERIP" ]; then
	# Temporary files.
	tmpfile=$(mktemp /tmp/og.XXXXX)
	MYCNF=$(mktemp /tmp/.my.cnf.XXXXX)
	trap "rm -f $tmpfile $MYCNF" 1 2 3 6 9 15

	# Checking whether the DHCP settings need to be changed.
	CHANGE=0
	for f in /etc/{dhcp,hcp3}/dhcpd.conf; do
		if [ -f $f ]; then
			# Changing DHCP "next-server" parameter.
			file="${f/./-$SERVERDEV.}"
			sed -e "s/next-server.*/next-server $SERVERIP;/" \
			    -e "s/option routers ;/option routers ${SERVERIP%.*}.1;/" $file >$tmpfile
			# Copying and linking file if there are changes.
			if [ ! $f -ef $file ] || ! diff -q $tmpfile $file &>/dev/null; then
				mv $tmpfile $file
				chmod 644 $file
				ln -f $file $f
				CHANGE=1
			fi
		fi
	done
	# Restarting DHCP service if its configuration has changed.
	if [ $CHANGE == 1 ]; then
		for f in /etc/init.d/{isc-dhcp-server,dhcp3-server,dhcpd}; do
			[ -x $f ] && $f restart
		done
	else
		echo "DHCP configuration has not changed."
	fi

	# Saving old IP address.
	source $OPENGNSYS/etc/ogAdmRepo.cfg
	OLDSERVERIP=$IPlocal

	# Checking if configuration files need to be modified.
	CHANGE=0
	for f in $OPENGNSYS/{etc/{ogAdmServer,ogAdmRepo,ogAdmAgent}.cfg,www/controlacceso.php,client/etc/ogAdmClient.cfg}; do
		# Error if configuration file cannot be found.
		if [ ! -f $f ]; then
			echo "$PROG: File $file does not exist." >&2
			exit 2
		fi
		# Updating configuration variables (if URLs does not contain "localhost").
		sed -e "s,ServidorAdm=.*,ServidorAdm=$SERVERIP," \
		    -e "s,IPlocal=.*,IPlocal=$SERVERIP," \
		    -e "s,UrlMenu=https?://\([^/]*\)/\(.*\),UrlMenu=https://$SERVERIP/\2," \
		    -e '/localhost/!s,https\?://[^/]*/\(.*\),https://'$SERVERIP'/\1,' $f >$tmpfile
		file="${f/./-$SERVERDEV.}"
		# Copying updated file, if needed.
		if [ ! $f -ef $file ] || ! diff -q $tmpfile $file &>/dev/null; then
			cp $tmpfile $file
			ln -f $file $f
			CHANGE=1
		fi
	done

	# Processing when something has changed.
	if [ $CHANGE == 1 ]; then
		# Restart OpenGnsys services.
		/etc/init.d/opengnsys restart
		# If Repository is active, generating a new API token.
		source $DEFAULTFILE
		if [ "$RUN_OGADMREPO" == "yes" ]; then
			REPOKEY=$(php -r 'echo md5(uniqid(rand(), true));')
			sed -i -e "s/ApiToken=.*/ApiToken=$REPOKEY/" $OPENGNSYS/etc/ogAdmRepo.cfg
			sed -i -e "s/APITOKEN=.*/APITOKEN=$REPOKEY/" $OPENGNSYS/etc/ogAdmServer.cfg
		fi
		# If OpenGnsys Server is active, updating the database.
		if [ "$RUN_OGADMSERVER" == "yes" ]; then
			source $OPENGNSYS/etc/ogAdmServer.cfg
			# Creating credentials file.
			cat << EOT > $MYCNF
[client]
user=$USUARIO
password=$PASSWORD
EOT
			# Updating OpenGnsys Server IP address.
			mysql --defaults-extra-file=$MYCNF -D "$CATALOG" -e \
				 "UPDATE entornos
				     SET ipserveradm='$SERVERIP'
				   WHERE identorno=1"
			# If OpenGnsys Repository is active, updating IP address and API token.
			if [ "$RUN_OGADMREPO" == "yes" ]; then
				mysql --defaults-extra-file=$MYCNF -D "$CATALOG" -e \
					 "UPDATE repositorios
					     SET ip='$SERVERIP', apikey='$REPOKEY'
					   WHERE ip='$OLDSERVERIP'"
				unset REPOKEY
			fi
			# Updating all menu URLs.
			mysql --defaults-extra-file=$MYCNF -D "$CATALOG" -e \
				 "UPDATE menus
				     SET htmlmenupub = REPLACE(htmlmenupub, '$OLDSERVERIP', '$SERVERIP'),
				         htmlmenupri = REPLACE(htmlmenupri, '$OLDSERVERIP', '$SERVERIP');"
			# Updating all PXE files.
			find $PXEDIR -name "01-*" -exec sed -i -e "s/$OLDSERVERIP/$SERVERIP/g" {} \;
		fi

		# Showing manual task to do after execution.
		cat << EOT
Default server interface set to: $SERVERDEV ($SERVERIP)

Manual tasks:
- Check DHCP configuration file and restart service, if needed.
- Check PXE files.
- Log-in as Web Console user: 
  - Check menu URLs.
${REPOKEY:+"  - Update repository API token"}
EOT
	else
		# Showing message if nothing changes.
		echo "Default interface has not changed: $1"
	fi
else
	# Error if network interface is not found.
	echo "$PROG: Network device not found. Format: $PROG ipaddress|netiface" >&2
	exit 1
fi

# Removing temporary files.
rm -f $tmpfile $MYCNF