#!/bin/sh

usage() {
	prog=$1
	cat << _EOF
${prog} [<options>]

<options> can be one of the following:

--prefix=<val>		The installation prefix (default: /usr).
--enable-debug		Enable debug mode compilation (default: disabled).
--disable-allocator	Disable use of internal memory allocator mechanism (default: enabled).
--enable-debug-stats	Enable printing of some verbose debug info (default: disabled).
--with-libbsc=<path to libbsc source>
			Enable support for libbsc (See: libbsc.com). Full path to the libbsc
                        source tree must be provided. It links the library statically.
--with-openssl=<path to OpenSSL installation tree> (Default: System)
                        This defaults to the system's OpenSSL library. You can use this option
                        if you want to use an alternate OpenSSL installation.
--use-key256		Use 256-bit encryption keys. Default key length is 128-bit.
--help			Display this help message.

_EOF
}

arg1=$1
debug=0
allocator=1
debug_stats=0
prefix=/usr
libbsc_dir=
libbsc_lib=
libbsclflags=
libbscwrapobj=
libbscgenopt=
libbsccppflags=
openssl_prefix=
openssl_libdir=
openssl_incdir=
libbz2_libdir=
libz_libdir=
sha256asmobjs=
sha256objs=
keylen=
yasm=yasm
keccak_srcs=
keccak_hdrs=
keccak_srcs_asm=
lto_flag=

# Try a simple compilation
cat << _EOF > tst.c
#include <stdio.h>

int
main(void)
{
	long l;
	printf("%d\n", sizeof (l));
	return (0);
}
_EOF

gcc tst.c -o tst
if [ $? -ne 0 ]
then
	echo "ERROR:"
	echo "Cannot compile a simple program. GCC 4.1 and above is required"
	echo "to build this program. Please include installation bindir of GCC in the PATH."
	echo ""
	rm -f tst.c
	exit 1
fi

# Check GCC version and enable LTO flags if possible
gcc -v 2>&1 | grep lto > /dev/null
[ $? -eq 0 ] && lto_flag="-flto"

# Check bitness of system
bitness=`./tst`
rm -f tst tst.c
if [ $bitness -lt 8 ]
then
	echo "ERROR:"
	echo "Only 64-bit platforms are supported."
	echo ""
	exit 1
fi

while [ "${arg1}" != "" ]
do
	case "$arg1" in
	--enable-debug) debug=1;;
	--disable-allocator) allocator=0;;
	--enable-debug-stats) debug_stats=1;;
	--prefix=*)
		pval=`echo ${arg1} | cut -f2 -d"="`
		prefix=$pval
	;;
	--with-libbsc=*)
		path=`echo ${arg1} | cut -f2 -d"="`
		if [ -f ${path}/bsc.cpp -a -f ${path}/libbsc/libbsc.h ]
		then
			libbsc_dir="${path}"
			libbsc_lib="${path}/libbsc.a"
			libbsclflags='\$\(LIBBSCLFLAGS\)'
			libbscwrapobj='\$\(LIBBSCWRAPOBJ\)'
			libbscgenopt='\$\(LIBBSCGEN_OPT\)'
			libbsccppflags='\$\(LIBBSCCPPFLAGS\)'
		else
			echo "Libbsc not found in ${path}, not enabling libbsc support.\n"
		fi
	;;
	--with-openssl=*)
		openssl_prefix=`echo ${arg1} | cut -f2 -d"="`
	;;
	--use-key256)
		keylen='-DKEYLEN=32'
	;;
	--help) usage $0;;
	*)
		echo "Unrecognized option: ${arg1}"
		exit 1
	;;
	esac
	shift
	arg1=$1
done

if [ $debug -eq 1 ]
then
	typ="DEBUG"
else
	typ="RELEASE"
fi

OS=$(uname)
skeinblock='\$\(SKEIN_BLOCK_C\)'
if [ "$OS" = "Linux" ]
then
	plat=$(uname -m)
elif [ "$OS" = "SunOS" ]
then
	plat=$(isainfo -v)
else
	echo "Unsupported OS: $OS"
	exit 1
fi

# Check GCC version
vers=`gcc -dumpversion`
OIFS="$IFS"
IFS=.
set -- ${vers}
IFS="$OIFS"

if [ $1 -lt 4 -o $2 -lt 1 ]
then
	echo "ERROR:"
	echo "GCC version 4.1 or above is required."
	echo ""
	exit 1
fi

echo $plat | egrep 'x86_64|amd64' > /dev/null
if [ $? -eq 0 ]
then
	skeinblock='\$\(SKEIN_BLOCK_ASM\)'
	yasm=

	#
	# Detect Yasm
	#
	for bindir in /bin /usr/bin /usr/local/bin
	do
		if [ -x ${bindir}/yasm ]
		then
			# Get yasm version
			yver=`${bindir}/yasm --version | head -1 | awk '{print $2}'`
			_OIFS=$IFS; IFS="."; set -- ${yver}; IFS="$_OIFS"
			major=$1
			minor=$2

			# Minimum yasm version 1.1
			[ $major -lt 1 -o $minor -lt 1 ] && continue
			yasm=${bindir}/yasm
			sha256asmobjs='\$\(SHA256ASM_OBJS\)'
			sha256objs='\$\(SHA256_OBJS\)'
		fi
	done
	if [ "x${yasm}" = "x" ]
	then
		echo "Yasm version 1.1 or later is required to build on x64 platforms"
		exit 1
	fi

	if [ $debug -eq 1 ]
	then
		keccak_srcs='\$\(KECCAK_SRC_OPT64\)'
		keccak_hdrs='\$\(KECCAK_HDRS_OPT64\)'
	else
		keccak_srcs='\$\(KECCAK_SRC_OPT64_ASM1\)'
		keccak_srcs_asm='\$\(KECCAK_SRC_OPT64_ASM2\)'
		keccak_hdrs='\$\(KECCAK_HDRS_OPT64_ASM\)'
	fi
else
	keccak_srcs='\$\(KECCAK_SRC_OPT64\)'
fi

# Detect OpenSSL library
for lib in "${openssl_prefix}/lib64" "${openssl_prefix}/usr/lib64" \
	"${openssl_prefix}/lib" "${openssl_prefix}/usr/lib" \
	"${openssl_prefix}/ssl/lib64" "${openssl_prefix}/ssl/lib" \
	"${openssl_prefix}/lib/x86_64-linux-gnu" \
	"${openssl_prefix}/usr/lib/x86_64-linux-gnu"
do
	if [ -d ${lib} ]
	then
		if [ -f "${lib}/libcrypto.so" -o -h "${lib}/libcrypto.so" ]
		then
			openssl_libdir=${lib}
			break
		else
			if [ -f "${lib}/libcrypto.a" ]
			then
				openssl_libdir=${lib}
				break
			fi
		fi
	fi
done

if [ "x${openssl_libdir}" = "x" ]
then
	echo "ERROR: OpenSSL libraries not detected."
	exit 1
fi

# Detect OpenSSL headers
for inc in "${openssl_prefix}/include" \
	"${openssl_prefix}/usr/include" \
	"${openssl_prefix}/ssl/include"
do
	if [ -d ${inc} ]
	then
		if [ -f "${inc}/openssl/sha.h" ]
		then
			openssl_incdir=${inc}
			break
		fi
	fi
done

if [ "x${openssl_incdir}" = "x" ]
then
	echo "ERROR: OpenSSL header files not detected."
	if [ "x${openssl_prefix}" = "x" ]
	then
		echo "Depending on your system you may need to install the openssl-devel or openssl-dev package."
	fi
	exit 1
fi


# Detect other library packages
for libname in "libbz2" "libz"
do
	for lib in "/lib64" "/usr/lib64" "/lib" "/usr/lib" "/lib/x86_64-linux-gnu" \
		"/usr/lib/x86_64-linux-gnu" \
		"${prefix}/lib64" "${prefix}/lib" "${prefix}/lib/x86_64-linux-gnu"
	do
		if [ -d ${lib} ]
		then
			if [ -f "${lib}/${libname}.so" -o -h "${lib}/${libname}.so" ]
			then
				eval "${libname}_libdir=${lib}"
				break
			else
				if [ -f "${lib}/${libname}.a" ]
				then
					eval "${libname}_libdir=${lib}"
					break
				fi
			fi
		fi
	done
done

if [ "x${libbz2_libdir}" = "x" ]
then
	echo "ERROR: Libbz2 not detected."
	echo "       You may have to install libbz2-devel or libbz2-dev"
	exit 1
fi

if [ "x${libz_libdir}" = "x" ]
then
	echo "ERROR: Zlib not detected."
	echo "       You may have to install libz-devel or libz-dev"
	exit 1
fi

libbz2_inc=
libz_inc=
# Detect other library headers
for hdr in "libbz2_inc:bzlib.h" "libz_inc:zlib.h"
do
	_OIFS="$IFS"
	IFS=":"
	set -- ${hdr}
	var=$1
	hdrf=$2
	IFS="$_OIFS"

	for inc in "${prefix}/include" "/usr/include"
	do
		if [ -d ${inc} ]
		then
			if [ -f "${inc}/${hdrf}" ]
			then
				eval "${var}=\"-I${inc}\""
				break
			fi
		fi
	done
done

linkvar="LINK"
compilevar="COMPILE"
compilecppvar="COMPILE_cpp"
vecflagsvar="VEC_FLAGS"
loopoptflagsvar="LOOP_OPTFLAGS"
cppflagsvar="CPPFLAGS"
genoptvar="GEN_OPT"
rabinoptvar="RABIN_OPT"
noslabcppflagsvar="NO_SLAB_CPPFLAGS"
debugstatscppflagsvar="DEBUG_STATS_CPPFLAGS"
prefixvar="PREFIX"
skeinblockvar="SKEIN_BLOCK"
keylenvar="KEYLEN"

libbscdirvar="LIBBSCDIR"
libbsclibvar="LIBBSCLIB"
libbsclflagsvar="LIBBSCLFLAGS"
libbscwrapobjvar="LIBBSCWRAPOBJ"
libbscgenoptvar="LIBBSCGEN_OPT"
libbsccppflagsvar="LIBBSCCPPFLAGS"
sha256asmobjsvar="SHA256ASM_OBJS"
sha256objsvar="SHA256_OBJS"
yasmvar="YASM"
fptr_flag_var="FPTR_FLAG"
lto_flag_var="LTO_FLAG"

openssllibdirvar="OPENSSL_LIBDIR"
opensslincdirvar="OPENSSL_INCDIR"
libbz2libdirvar="LIBBZ2_DIR"
libzlibdirvar="LIBZ_DIR"
libbz2incvar="LIBBZ2_INC"
libzincvar="LIBZ_INC"

keccak_srcs_var="KECCAK_SRCS"
keccak_hdrs_var="KECCAK_HDRS"
keccak_srcs_asm_var="KECCAK_SRCS_ASM"

noslabcppflagsval=
debugstatscppflagsval=

[ $allocator -eq 0 ] && noslabcppflagsval='\$\(NO_SLAB_CPPFLAGS\)'
[ $debug_stats -eq 1 ] && debugstatscppflagsval='\$\(DEBUG_STATS_CPPFLAGS\)'

cat Makefile.in | sed "
s#@${linkvar}@#\\\$\\(${typ}_${linkvar}\\)#g
s#@${compilevar}@#\\\$\\(${typ}_${compilevar}\\)#g
s#@${compilecppvar}@#\\\$\\(${typ}_${compilecppvar}\\)#g
s#@${vecflagsvar}@#\\\$\\(${typ}_${vecflagsvar}\\)#g
s#@${loopoptflagsvar}@#\\\$\\(${typ}_${loopoptflagsvar}\\)#g
s#@${cppflagsvar}@#\\\$\\(${typ}_${cppflagsvar}\\)#g
s#@${genoptvar}@#\\\$\\(${typ}_${genoptvar}\\)#g
s#@${rabinoptvar}@#\\\$\\(${typ}_${rabinoptvar}\\)#g
s#@${fptr_flag_var}@#\\\$\\(${typ}_${fptr_flag_var}\\)#g
s#@${noslabcppflagsvar}@#${noslabcppflagsval}#g
s#@${debugstatscppflagsvar}@#${debugstatscppflagsval}#g
s#@${prefixvar}@#${prefix}#g
s#@${libbscdirvar}@#${libbsc_dir}#g
s#@${libbsclibvar}@#${libbsc_lib}#g
s#@${libbsclflagsvar}@#${libbsclflags}#g
s#@${libbscwrapobjvar}@#${libbscwrapobj}#g
s#@${libbscgenoptvar}@#${libbscgenopt}#g
s#@${libbsccppflagsvar}@#${libbsccppflags}#g
s#@${skeinblockvar}@#${skeinblock}#g
s#@${openssllibdirvar}@#${openssl_libdir}#g
s#@${opensslincdirvar}@#${openssl_incdir}#g
s#@${sha256asmobjsvar}@#${sha256asmobjs}#g
s#@${sha256objsvar}@#${sha256objs}#g
s#@${yasmvar}@#${yasm}#g
s#@${keylenvar}@#${keylen}#g
s#@${libbz2libdirvar}@#${libbz2_libdir}#g
s#@${libzlibdirvar}@#${libz_libdir}#g
s#@${libbz2incvar}@#${libbz2_inc}#g
s#@${libzincvar}@#${libz_inc}#g
s#@${keccak_srcs_var}@#${keccak_srcs}#g
s#@${keccak_hdrs_var}@#${keccak_hdrs}#g
s#@${keccak_srcs_var}@#${keccak_srcs}#g
s#@${keccak_srcs_asm_var}@#${keccak_srcs_asm}#g
s#@${lto_flag_var}@#${lto_flag}#g
" > Makefile