configure

#!/bin/sh

# Determine the directory in which the user is running configure,
# and the source directory where it lives
WORKING_DIR=$(pwd)
cd $(dirname $0)
SOURCE_DIR=$(pwd)
cd "${WORKING_DIR}"

find_libcurl(){
	PKG=libcurl
	echo "Looking for $PKG..."
	VAR_PREFIX=`echo $PKG | tr [:lower:] [:upper:]`
	TMP_FOUND=`eval echo "$"${VAR_PREFIX}_FOUND`
	if [ "$TMP_FOUND" ]; then return; fi
	
	which "$CURL_CONFIG" 2>&1 > /dev/null
	if [ "$?" -ne 0 ]; then 
		echo "$CURL_CONFIG not found; unable to locate $PKG" >&2
		return; 
	fi

	LIBCURL_CFLAGS=`"$CURL_CONFIG" --cflags`" -I"`curl-config --prefix`"/include"
	LIBCURL_LDFLAGS=`"$CURL_CONFIG" --libs`
	LIBCURL_FOUND=1
	echo " Found $PKG"
}

find_libxml2(){
	PKG=libxml2
	echo "Looking for $PKG..."
	VAR_PREFIX=`echo $PKG | tr [:lower:] [:upper:]`
	TMP_FOUND=`eval echo "$"${VAR_PREFIX}_FOUND`
	if [ "$TMP_FOUND" ]; then return; fi
	
	which "$XML2_CONFIG" 2>&1 > /dev/null
	if [ "$?" -ne 0 ]; then 
		echo "$XML2_CONFIG not found; unable to locate $PKG" >&2
		return; 
	fi

	LIBXML2_CFLAGS=`"$XML2_CONFIG" --cflags`
	LIBXML2_LDFLAGS=`"$XML2_CONFIG" --libs`
	LIBXML2_FOUND=1
	echo " Found $PKG"
}

find_cryptopp(){
	# We have no actual way to do this. Try compiling a trivial program to see if
	# it works. 
	echo "Checking for cryptopp..."
	TEST_FLAGS="$CXXFLAGS $CRYPTOPP_CFLAGS $LDFLAGS $CRYPTOPP_LDFLAGS"
	$CXX "${SOURCE_DIR}/src/cryptopp_test.cpp" $TEST_FLAGS -o "${WORKING_DIR}/bin/cryptopp_test" >/dev/null 2>&1
	RESULT=$?
	if [ "$RESULT" -ne 0 ];
	then
		echo "Unable to compile a basic program using the Crypto++ library" >&2
		echo "There is either a problem with the compiler or the flags " >&2
		echo " associated with cryptopp. Please specify --with-cryptopp=..." >&2
		echo " as necessary. " >&2
		return
	fi
	rm -f bin/cryptopp_test
	CRYPTOPP_FOUND=1
	echo " cryptopp available"
}

PREFIX=/usr/local
VERSION_NUM=000100
VERSION=`echo $VERSION_NUM | awk '{
	major = int($1/100000);
	minor = ($1/100)%1000;
	patch = $1%100;
	print major"."minor"."patch;
}'`
OS_NAME=`uname -s`

GUESS_CXX=g++
GUESS_AR=ar
GUESS_LD=ld
if [ "$OS_NAME" = Darwin ]; then
	GUESS_CXX=clang++
	GUESS_LD=clang++
	DYN_SUFFIX=.dylib
	DYN_OPT='-dynamiclib -compatibility_version $(VERSION) -current_version $(VERSION)'
elif [ "$OS_NAME" = FreeBSD ]; then
	DYN_SUFFIX=.so
	DYN_OPT='-shared'
else
	DYN_SUFFIX=.so
	DYN_OPT='-shared -Wl,-soname,$(shell basename $(DYN_PRODUCT))'
fi

CXX=${CXX-$GUESS_CXX}
AR=${AR-$GUESS_AR}
LD=${LD-$GUESS_LD}

CURL_CONFIG="curl-config"
XML2_CONFIG="xml2-config"
CRYPTOPP_CFLAGS=${CRYPTOPP_CFLAGS-""}
CRYPTOPP_LDFLAGS=${CRYPTOPP_LDFLAGS-"-lcryptopp"}

CXXFLAGS="$CXXFLAGS -std=c++11 -O2 -I${SOURCE_DIR}/include"

if [ ! -d ./bin/ ]; then
    mkdir bin;
fi
if [ ! -d ./lib/ ]; then
	mkdir lib;
fi

# define help
HELP="Usage: ./config.sh [OPTION]... 

Installation directories:
  --prefix=PREFIX         install files in PREFIX
                          [$PREFIX]

By default, \`make install' will install all the files in
\`$PREFIX/bin', \`$PREFIX/lib' etc.  You can specify
an installation prefix other than \`$PREFIX' using \`--prefix',
for instance \`--prefix=\$HOME'.

The following options can be used to maunally specify the 
locations of dependencies:
  --with-cryptopp=DIR        use the copy of Crypto++ in DIR
                             assuming headers are in DIR/include
                             and libraries in DIR/lib
  --with-cryptopp-incdir=DIR use the Crypto++ headers in DIR
  --with-cryptopp-libdir=DIR use the Crypto++ library in DIR
  --with-curl-config=PROG    use PROG as curl-config to obtain
                             suitable libcurl flags
  --with-xml2-config=PROG    use PROG as xml2-config to obtain
                             suitable libxml2 flags

Some influential environment variables:
CXX         C++ compiler command
AR          Static linker command
LD          Dynamic linker command
CXXFLAGS    C++ compiler flags
LDFLAGS     Linker flags
" #`

# parse arguments

for var in "$@"
do
	if [ "$var" = "--help" -o "$var" = "-h" ]; then
		echo "$HELP"
		exit 0
	fi

	TMP=`echo "$var" | sed -n 's/^--prefix=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then PREFIX="$TMP"; continue; fi

	TMP=`echo "$var" | sed -n 's/^--with-cryptopp=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then
		CRYPTOPP_INCDIR="${TMP}/include";
		CRYPTOPP_LIBDIR="${TMP}/lib";
	continue; fi

	TMP=`echo "$var" | sed -n 's/^--with-cryptopp-incdir=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then CRYPTOPP_INCDIR="$TMP"; continue; fi

	TMP=`echo "$var" | sed -n 's/^--with-cryptopp-libdir=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then CRYPTOPP_LIBDIR="$TMP"; continue; fi

	TMP=`echo "$var" | sed -n 's/^--with-curl-config=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then CURL_CONFIG="${TMP}"; continue; fi

	TMP=`echo "$var" | sed -n 's/^--with-xml2-config=\(.*\)$/\1/p'`
	if [ "$TMP" ]; then XML2_CONFIG="${TMP}"; continue; fi

	echo "config.sh: Unknown or malformed option '$var'" 1>&2
	exit 1
done

find_libcurl
find_libxml2

if [ "$CRYPTOPP_INCDIR" -o "$CRYPTOPP_LIBDIR" ]; then
	echo "Checking manually specified cryptopp..."
	if [ -d "$CRYPTOPP_INCDIR/cryptopp" \
         -a -e "$CRYPTOPP_INCDIR/cryptopp/sha.h" \
         -a -d "$CRYPTOPP_LIBDIR" \
         -a -e "$CRYPTOPP_LIBDIR/libcryptopp.a" ]; then
		CRYPTOPP_FOUND=1
		CRYPTOPP_CFLAGS="-I$CRYPTOPP_INCDIR"
		CRYPTOPP_LDFLAGS="-L$CRYPTOPP_LIBDIR -lcryptopp"
	else
		echo "Warning: manually specifed crypto++ not found"
	fi
fi
find_cryptopp

if [ ! "$LIBCURL_FOUND" -o ! "$LIBXML2_FOUND" -o ! "$CRYPTOPP_FOUND" ]; then
	echo >&2
	if [ ! "$LIBCURL_FOUND" ]; then
		echo "configure: Error: libcurl not found" >&2
	fi
	if [ ! "$LIBXML2_FOUND" ]; then
		echo "configure: Error: libxml2 not found" >&2
	fi
	if [ ! "$CRYPTOPP_FOUND" ]; then
		echo "configure: Error: cryptopp not found" >&2
	fi
	exit 1
fi

# git and git-like things are too dumb to know about directories, so any 
# directories which are initially empty need to be re-created on demand.
mkdir -p bin
mkdir -p build
mkdir -p lib

if [ ! -e "${WORKING_DIR}/makefile" -o "${SOURCE_DIR}/makefile" -nt "${WORKING_DIR}/makefile" ]; then
	echo "Copying makefile"
	cp "${SOURCE_DIR}/makefile" "${WORKING_DIR}/makefile"
fi

CRYPTOPP_SRC_URL="https://cryptopp.com/cryptopp870.zip"

echo "Generating settings.mk"
echo "
# Directories
SOURCE_DIR:=$SOURCE_DIR
WORKING_DIR:=$WORKING_DIR

# Compiler
CXX:=$CXX
AR:=$AR
LD:=$LD

# Dependencies
LIBCURL_CFLAGS=$LIBCURL_CFLAGS
LIBCURL_LDFLAGS=$LIBCURL_LDFLAGS
LIBXML2_CFLAGS=$LIBXML2_CFLAGS
LIBXML2_LDFLAGS=$LIBXML2_LDFLAGS
CRYPTOPP_CFLAGS=$CRYPTOPP_CFLAGS
CRYPTOPP_LDFLAGS=$CRYPTOPP_LDFLAGS

# Installation
PREFIX:=$PREFIX

# Other
VERSION:=$VERSION
CXXFLAGS:=$CXXFLAGS
LDFLAGS:=$LDFLAGS

CRYPTOPP_SRC_URL:=$CRYPTOPP_SRC_URL

DYN_SUFFIX:=$DYN_SUFFIX
DYN_OPT=$DYN_OPT
"> settings.mk
echo "Generation done. Now ready to run 'make'."