#TODO test for pcre and a better test for lpthread? A better place for default CFLAGS?

AC_INIT(configure.in)

AM_CONFIG_HEADER(config.h)
AM_INIT_AUTOMAKE(eidps, 0.1)

AC_LANG_C
AC_PROG_CC
AM_PROG_LIBTOOL

AC_DEFUN([FAIL_MESSAGE],[
    echo
    echo
    echo "**********************************************"
    echo "  ERROR: unable to find" $1
    echo "  checked in the following places"
    for i in `echo $2`; do
        echo "        $i"
    done
    echo "**********************************************"
    echo
    exit 1
])

LIBS="-lpthread -lpcre"
CFLAGS="$CFLAGS -Wall -fno-strict-aliasing"

AC_ARG_WITH(libnfnetlink_includes,
    [  --with-libnfnetlink-includes=DIR  libnfnetlink include directory],
    [with_libnfnetlink_includes="$withval"],[with_libnfnetlink_includes=no])
AC_ARG_WITH(libnfnetlink_libraries,
    [  --with-libnfnetlink-libraries=DIR    libnfnetlink library directory],
    [with_libnfnetlink_libraries="$withval"],[with_libnfnetlink_libraries="no"])

if test "$with_libnfnetlink_includes" != "no"; then
    CPPFLAGS="${CPPFLAGS} -I${with_libnfnetlink_includes}"
fi

AC_CHECK_HEADER(libnfnetlink/libnfnetlink.h,,[AC_ERROR(libnfnetlink.h not found ...)])

if test "$with_libnfnetlink_libraries" != "no"; then
    LDFLAGS="${LDFLAGS}  -L${with_libnfnetlink_libraries}"
fi

NFNL=""
AC_CHECK_LIB(nfnetlink, nfnl_fd,, NFNL="no")

if test "$NFNL" = "no"; then
    echo
    echo "   ERROR!  nfnetlink library not found, go get it"
    echo "   from www.netfilter.org."
    echo "   we automatically append libnetfilter_queue/ when searching"
    echo "   for headers etc. when the --with-libnfnetlink-inlcudes directive"
    echo "   is used"
    echo
    exit 
fi

AC_ARG_WITH(libnetfilter_queue_includes,
    [  --with-libnetfilter_queue-includes=DIR  libnetfilter_queue include directory],
    [with_libnetfilter_queue_includes="$withval"],[with_libnetfilter_queue_includes=no])
AC_ARG_WITH(libnetfilter_queue_libraries,
    [  --with-libnetfilter_queue-libraries=DIR    libnetfilter_queue library directory],
    [with_libnetfilter_queue_libraries="$withval"],[with_libnetfilter_queue_libraries="no"])

if test "$with_libnetfilter_queue_includes" != "no"; then
    CPPFLAGS="${CPPFLAGS} -I${with_libnetfilter_queue_includes}"
fi

AC_CHECK_HEADER(libnetfilter_queue/libnetfilter_queue.h,,[AC_ERROR(libnetfilter_queue/libnetfilter_queue.h not found ...)])

if test "$with_libnetfilter_queue_libraries" != "no"; then
    LDFLAGS="${LDFLAGS}  -L${with_libnetfilter_queue_libraries}"
fi

#LDFLAGS="${LDFLAGS} -lnetfilter_queue"

NFQ=""
AC_CHECK_LIB(netfilter_queue, nfq_open,, NFQ="no",)

if test "$NFQ" = "no"; then
    echo
    echo "   ERROR!  libnetfilter_queue library not found, go get it"
    echo "   from www.netfilter.org."
    echo "   we automatically append libnetfilter_queue/ when searching"
    echo "   for headers etc. when the --with-libnfq-inlcudes directive"
    echo "   is used"
    echo
    exit 1 
fi

AC_ARG_WITH(libnet_includes,
    [  --with-libnet-includes=DIR     libnet include directory],
    [with_libnet_includes="$withval"],[with_libnet_includes="no"])
    
AC_ARG_WITH(libnet_libraries,
    [  --with-libnet-libraries=DIR    libnet library directory],
    [with_libnet_libraries="$withval"],[with_libnet_libraries="no"])
    
if test "x$with_libnet_includes" != "xno"; then
    CPPFLAGS="${CPPFLAGS} -I${with_libnet_includes}"
fi  

if test "x$with_libnet_libraries" != "xno"; then
    LDFLAGS="${LDFLAGS} -L${with_libnet_libraries}"
fi

LIBNET_INC_DIR=""
AC_MSG_CHECKING("for libnet.h version 1.1.x")
libnet_dir="/usr/include /usr/local/include"
for i in $libnet_dir; do
     if test -r "$i/libnet.h"; then
         LIBNET_INC_DIR="$i"
     fi
done

if test "$LIBNET_INC_DIR" != ""; then
    if eval "grep LIBNET_VERSION $LIBNET_INC_DIR/libnet.h | grep -v 1.1 >/dev/null"; then
        FAIL_MESSAGE("libnet 1.1.x (libnet.h)", $tmp)
    fi
    CFLAGS="${CFLAGS} `libnet-config --defines` `libnet-config --cflags`"
    LIBS="${LIBS} `libnet-config --libs`"
    CPPFLAGS="${CPPFLAGS} -I${LIBNET_INC_DIR}"
    AC_MSG_RESULT($i)
else
    AC_MSG_RESULT(no)
    AC_MSG_ERROR("libnet 1.1.x could not be found.  please download and install the library from http://www.packetfactory.net/libnet/")
fi

# see if we have the patched libnet 1.1
# http://www.inliniac.net/blog/2007/10/16/libnet-11-ipv6-fixes-and-additions.html
LLIBNET=""
AC_CHECK_LIB(net, libnet_build_icmpv6_unreach,, LLIBNET="no")
    if test "$LLIBNET" != "no"; then
        CFLAGS="$CFLAGS -DHAVE_LIBNET_ICMPV6_UNREACH"
    fi

# libpcap
CFLAGS="${CFLAGS} `pcap-config --defines` `pcap-config --cflags`"
LIBS="${LIBS} -lpcap"

AC_SUBST(CFLAGS)
AC_SUBST(LDFLAGS)
AC_SUBST(CPPFLAGS)

AC_OUTPUT(Makefile src/Makefile)