#!/bin/sh

TARGET="$(cat Makefile.in | grep 'TARGET :=' | awk -F' ' '{ print $3; }')"
echo "configuring ${TARGET}"

which sed 2>/dev/null 1>/dev/null
if [ $? -ne 0 ]
then
	echo "cannot find sed!" 1>&2
fi

OPSYS=$(uname -s)

echo "Configuring for ${OPSYS}..."
if [ "x${OPSYS}" = "xLinux" ]
then
	OS_CFLAGS="-D_DEFAULT_SOURCE -D_XOPEN_SOURCE"
	OS_LIBS="-lbsd"
	if [ "x${CC}" = "xclang" ]; then
		OS_CFLAGS="${OS_CFLAGS} -fsanitize=memory"
	fi
	if [ -e "/usr/lib/libefence.a" ]
	then
		OS_LIBS="${OS_LIBS} -lefence"
	fi
else
	OS_CFLAGS=""
	OS_LIBS=""
fi

if [ -z "${OS_CFLAGS}" ]
then
	echo "${OPSYS} requires no extra build flags."
else
	echo "${OPSYS} requires build flags ${OS_CFLAGS}"
fi

if [ -z "${PREFIX}" ]; then
	PREFIX="/usr/local"
fi    

if [ "${PREFIX}" = "/usr" ]
then
	MANDIR="$(PREFIX)/share/man"
elif [ "${PREFIX}" = "/usr/local" ]
then
	if [ "${OPSYS}" = "Darwin" ]
	then
		MANDIR="${PREFIX}/share/man"
	else
		MANDIR="${PREFIX}/man"
	fi
else
	MANDIR="${PREFIX}/man"
fi

echo "prefix: ${PREFIX}"
echo "mandir: ${MANDIR}"

echo "writing new Makefile"
cat Makefile.in | sed -e "s|OS_CFLAGS|${OS_CFLAGS}|"	| \
		  sed -e "s|OS_LIBS|${OS_LIBS}|"	| \
		  sed -e "s|\$PREFIX|${PREFIX}|"	| \
		  sed -e "s|\$MANDIR|${MANDIR}|"	> Makefile

echo "done."