configure

#!/usr/bin/env bash

MAKEFILE_CFG=Makefile.config
REQUIRE_RUNTIME=1

### for error reporting on failures
FAILURE_MSG=

### for the Makefile.config
SUBDIRS=(extern assign)
PREFIX=$PWD



usage() {
	cat <<EOF
$0 [OPTIONS]

OPTIONS:
  --prefix PATH           Set the install PREFIX
  --require-runtime       Make the configure step fail if the runtime dependencies cannot be found
EOF
}

fail() {
	FAILURE_MSG="$@"
	return 1
}

die() {
	local ecode=$1
	shift
	local msg="$@ $FAILURE_MSG"
	FAILURE_MSG=
	echo $msg
	exit $ecode
}

set-args() {

	local args=($@)
	local opt=
	local val=

	while [ ! -z $1 ]; do
		opt="$1"
		shift

		case $opt in
			--prefix)
				val="$1"; shift
				test ! -z "$val" || return 1
				PREFIX="$val";;
			--require-runtime)
				REQUIRE_RUNTIME=0
				;;
			*)
				usage; exit 1;;
		esac
	done

}


makefile-cfg-array() {
	local name=$1
	local array="${name}[@]"
	echo "$name = ${!array}"
}

makefile-cfg-var() {
	local name=$1
	local val=
	eval val=\$$name
	echo "$name = $val"
}


check-clib() {
	local desc="$1"; shift
	local include="$1"; shift
	local libs="$@"
	local tmpfile=$(mktemp /tmp/awe-configure.XXX)
	trap "rm -f '$tmpfile'" RETURN EXIT

	local include_stmt=

	test -z "$include" || include_stmt="#include \"$include\""

	printf "Checking for $libs..."
	build="gcc -xc $libs -o $tmpfile -"
	prog=$(cat <<EOF
$include_stmt
int main (void) { return 0; }
EOF
)

	printf "$prog" | $build >/dev/null 2>&1

	ecode=$?

	if test ! $ecode -eq 0; then
		echo cannot find $desc FAIL
		# echo "PROGRAM"
		# echo "========================================"
		# echo "$prog"
		# echo "========================================"
		# echo "Build command: $build"
		return 1
	else
		echo OK
		return 0
	fi
}


get-python-version() {
	python -c 'import sys;v=sys.version_info;major=v[0];minor=v[1];print("%s.%s" % (major,minor))'
}

check-python-version() {
	printf "Checking for compatible python installation..."
	pv=$(get-python-version)
	for v in 2.6 2.7 3.4; do
		test  $pv == $v && echo OK && return 0
	done
	echo FAIL
	return 1
}

check-build-depends() {
	echo "=================================================="
	echo "Checking build dependencies"
	check-clib xdrfile xdrfile/xdrfile.h -lxdrfile
	check-clib gsl gsl/gsl_matrix.h  -lgsl -lgslcblas
	check-python-version
}


set-args $@ || die 1

rm -f $MAKEFILE_CFG
check-build-depends || die 2
makefile-cfg-array SUBDIRS >>$MAKEFILE_CFG
makefile-cfg-var PREFIX    >>$MAKEFILE_CFG