#!/bin/sh
# Copyright (C) 2006-2007 G.P. Halkes
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Set zsh to emulate sh (otherwise all kinds of eval's wont work)
[ -n "${ZSH_VERSION}" ] && emulate sh

#==============================
# Functions
#==============================
error() {
	echo "$@"
	exit 1
}

not() {
	if "$@" ; then
		false
	else
		true
	fi
}

check() {
	if not "$@" ; then
		error "Error executing $@. Aborting."
	fi
}

check_message() {
	printf "$@"
	echo "----------------------------------">> config.log
	echo "$@" >> config.log
}

check_message_result() {
	echo "$@"
	echo "$@" >> config.log
}

clean() {
	rm -rf "$@" >/dev/null 2>&1
}

test_make() {
	echo "Running '${MAKE} -f .Makefile $@'" >> config.log
	"${MAKE}" -f .Makefile "$@"
}

test_compile() {
	clean .config.o
	check_message "Checking for $1... "
	shift

	if test_make "$@" .config.o >> config.log 2>&1 ; then
		check_message_result "yes"
		true
	else
		check_message_result "no"
		false
	fi
}

test_link() {
	clean .config
	check_message "Checking for $1... "
	shift

	if test_make "$@" .config >> config.log 2>&1 ; then
		check_message_result "yes"
		true
	else
		check_message_result "no"
		false
	fi
}

test_install() {
	clean .foo
	check_message "Checking for working install '$@'... "

	if  test_make "INSTALL=$@" "install" >> config.log 2>&1 ; then
		check_message_result "yes"
		true
	else
		check_message_result "no"
		false
	fi
}

add_replace_settings() {
	for SETTING
	do
		NAME=`echo "${SETTING}" | sed 's/=.*/=/g'`
		if grep -q "^${NAME}" Makefile.in ; then
			ESCAPED_SETTING=`echo "${SETTING}" | sed 's/\//\\\\\//g'`
			echo "s/^${NAME}.*/${ESCAPED_SETTING}/g"
		else
			echo "/^\\.POSIX:/a\\
${SETTING}"
		fi
	done
}

replace_default() {
	if [ -n "$2" ] ; then
		ESCAPED=`echo "$2" | sed 's/\//\\\\\//g'`
		echo "s/^$1=.*/$1=${ESCAPED}/g"
	fi
}

insert() {
	[ -n "$2" ] && echo "/^\\.POSIX:/a\\
$1=$2"
}

create_makefile() {
	if [ -n "${TEST_INSTALL}" ] ; then
		[ -n "${INSTALL}" ] && TEST_INSTALL="${INSTALL}"
		unset INSTALL
			
		for _INSTALL in ${TEST_INSTALL}
		do
			test_install "${_INSTALL}" && INSTALL="${_INSTALL}" && break
		done
		if [ -z "${INSTALL}" ] ; then
			check_message_result "!! No working install program found. The install target will not work."
		fi
	fi

	echo "----------------------------------">> config.log
	check_message_result "Creating Makefile"
	{
		replace_default prefix "${PREFIX}"
		replace_default mandir "${MANDIR}"
		replace_default CFLAGS "${CFLAGS}"


		[ -n "${TEST_INSTALL}" ] && replace_default INSTALL "${INSTALL}"

		echo '/^\.POSIX:/a\
# Inserted settings'

		insert CC "${CC}"
		insert LDFLAGS "${LDFLAGS}"
		insert LDLIBS "${LDLIBS}"

		sed_lines "$@"
	} > .sedscript
	cat Makefile.in | sed -f .sedscript > Makefile
	clean .sedscript .config.c .config.o .config .Makefile .foo
	exit 0
}

#==============================
# Setup
#==============================
unset LINKRULE COMPILERULE USERRULES TEST_INSTALL

. ./config.pkg

for _switch in ${SWITCHES}
do
	_name=`echo "${_switch}" | sed -e 's/^[+-]//' -e 's/-/_/g'`
	_pm=`echo "${_switch}" | sed 's/[^+-].*//'`
	if [ "${_pm}" = "+" ] ; then
		eval with_${_name}="yes"
	else
		eval with_${_name}="no"
	fi
done
_SWITCHES=`echo " ${SWITCHES}" | sed 's/[[:space:]][+-]/ /g'`

for PARAM
do
	case "${PARAM}" in
		-h|--help)
			cat <<EOF
Usage: configure [--prefix=<dir>] [<var>=<value>]

  --prefix=<dir>     Prefix for installation [/usr/local]
  --mandir=<dir>     Set manual page directory [prefix/share/man]

Environment variables that tune build:
  MAKE        Make program to use [make]
  CC          C-compiler to use (default determined by make)
  CFLAGS      C-compiler flags to use [-O2]
  LDFLAGS     Linker flags to use (default determined by make)
  LDLIBS      Extra libraries to link
  PREFIX      See --prefix=<dir>
EOF
			[ -n "${TEST_INSTALL}" ] && echo "  INSTALL     The install program to use"

			[ -n "${USER_HELP}" ] && { echo ; echo "Package specific settings" ; echo "${USER_HELP}" ; }

			cat <<EOF
			
Note: Environment variables may also be specified as parameters.
EOF
		exit 0
		;;
		--prefix=*)
			PREFIX=`echo "${PARAM}" | sed 's/--prefix=//g'`
		;;
		--mandir=*)
			MANDIR=`echo "${PARAM}" | sed 's/--mandir=//g'`
		;;
		--*=*)
			unset _match
			for _option in ${OPTIONS}
			do
				case "${PARAM}" in
					--${_option}=*)
						_name=`echo "${_option}" | sed 's/-/_/g'`
						_value=`echo "${PARAM}" | sed 's/--[^=]*=//'`
						eval option_${_name}="\"${_value}\""
						_match="1"
						break
					;;
				esac
			done
			[ -z "${_match}" ] && error "Error on commandline: ${PARAM}"
		;;
		--*)
			unset _match
			for _switch in ${_SWITCHES}
			do
				case "${PARAM}" in
					--with-${_switch})
						_name=`echo "${_switch}" | sed 's/-/_/g'`
						eval with_${_name}="yes"
						_match="1"
						break
					;;
					--without-${_switch})
						_name=`echo "${_switch}" | sed 's/-/_/g'`
						eval with_${_name}="no"
						_match="1"
						break
					;;
				esac
			done
			[ -z "${_match}" ] && error "Error on commandline: ${PARAM}"
		;;
		*=*)
			name=`echo "${PARAM}" | sed 's/=.*//g'`
			value=`echo "${PARAM}" | sed 's/^[^=]*=//g'`
			eval "${name}"="\"${value}\""
		;;
		*)
			error "Error on commandline: ${PARAM}"
		;;
	esac
done

echo "Configuration test log created at `date`" > config.log
echo "-- configure called with $0 $@" >> config.log


[ -z "${LINKRULE}" ] && LINKRULE='$(CC) $(CFLAGS) $(LDFLAGS) -o .config .config.o $(LDLIBS) $(TESTLIBS)'
[ -z "${COMPILERULE}" ] && COMPILERULE='$(CC) $(CFLAGS) $(TESTFLAGS) -c -o .config.o .config.c'

unset SETTINGS 
[ -z "${LDLIBS}" ] || SETTINGS="LDLIBS=${LDLIBS} ${SETTINGS}"
[ -z "${LDFLAGS}" ] || SETTINGS="LDFLAGS=${LDFLAGS} ${SETTINGS}"
[ -z "${CFLAGS}" ] || SETTINGS="CFLAGS=${CFLAGS} ${SETTINGS}"
[ -z "${CC}" ] || SETTINGS="CC=${CC} ${SETTINGS}"

[ -n "${SETTINGS}" ] && check_message_result "Using settings ${SETTINGS}"

clean .config .config.o .config.c config.log .Makefile .sedscript

{
	echo ".POSIX:"
	[ -z "${CC}" ] || echo "CC=${CC}"
	[ -z "${LDFLAGS}" ] || echo "LDFLAGS=${LDFLAGS}"
	[ -z "${LDLIBS}" ] || echo "LDLIBS=${LDLIBS}"

	if 	[ -n "${CFLAGS}" ] ; then
		echo "CFLAGS=${CFLAGS}"
	else
		echo "CFLAGS=-O2"
	fi

	echo "${USERRULES}"

	if [ -n "${TEST_INSTALL}" ] ; then
		cat <<EOF
install:
	\$(INSTALL) -d .foo/bar
	\$(INSTALL) -m 755 configure .foo/bar
	test -x .foo/bar/configure

EOF
	fi

	cat <<EOF
.config: .config.o
	${LINKRULE}

.c.o:
	${COMPILERULE}
EOF
} > .Makefile

if [ -z "${MAKE}" ] ; then
	MAKE=make
fi

cat > .config.c <<EOF
int main() {
	return 0;
}
EOF


test_link "working make (${MAKE})" || error "${MAKE} failed on sanity check. See config.log."

config
error "Error in config.pkg. Cannot continue."