#!/bin/sh
# $Id$
# @Id.

TOP=`pwd`
PREFIX="/usr/local"
EXEC=""

EXPORTS="TOP PREFIX EXEC"

if [ ! -e ./configure.script ]; then
	echo "configure.script is missing, aborted"
	exit 1
fi

for arg in $@; do
	case "$arg" in
		--help|-h)
			echo "$0 configures stuffs for you"
			echo ""
			echo "Usage: $0 [options]"
			exit 0
			;;
		--prefix=*)
			PREFIX=`echo $arg | sed "s/--prefix=//g"`
			;;
		--config=*)
			. `echo $arg | sed "s/--config=//g"`
			;;
		*)
			echo "Invalid option: $arg"
			exit 1
			;;
	esac
done

echo "$0 is generating config.mk/config.h/Makefile"

DEBUG () {
	if ${DODEBUG:-false}; then
		echo "DEBUG: $1" > /dev/stderr
	fi
}

PARSE () {
	i=1
	OPTIONAL=false
	LABEL=""
	FAILLABEL=""
	RUNIF=true
	_JOB=""
	OPLEN=`echo -n "$OP" | wc -m`
	DEBUG "--- BEGIN Parsing operator: $OP ---"
	while [ $i -le $OPLEN ]; do
		if [ $i -gt 1 ]; then
			_CHAR=`echo $OP | cut -c $i`
			_EXEC=false

			# Arguments required
			if [ "x$_JOB" = "x" ]; then
				:
			elif [ "$_JOB" = ":" ]; then
				DEBUG "Will define label: $_CHAR"
				LABEL="$_CHAR"
				_EXEC=true
			elif [ "$_JOB" = ";" ]; then
				DEBUG "Will define label if failed: $_CHAR"
				FAILLABEL="$_CHAR"
				_EXEC=true
			elif [ "$_JOB" = "@" ]; then
				DEBUG "Will run if label $_CHAR is defined"
				RUNIF=`GET_LABEL $_CHAR`
				if $RUNIF; then
					DEBUG "Running, label $_CHAR is defined"
				else
					DEBUG "Not running, label $_CHAR is not defined"
				fi
				_EXEC=true
			fi
			if [ "x$_JOB" = "x" ]; then
				_JOB="$_CHAR"
				DEBUG "Job token: $_JOB"
			fi

			# No arguments required
			if [ "$_JOB" = "?" ]; then
				DEBUG "Optional job specified"
				OPTIONAL=true
				_JOB=""
			fi

			if $_EXEC; then
				_JOB=""
			fi
		fi
		i=`expr $i +  1`
	done
	DEBUG "--- END Parsing operator: $OP ---"
}

SET_LABEL () {
	eval LABEL_$1=$2
}

GET_LABEL () {
	RESULT=`eval echo \\\$LABEL_$1`
	if [ "x$RESULT" = "x" ]; then
		echo "false"
	else
		echo $RESULT
	fi
}

TEST_C () {
	OLDPWD=`pwd`
	cd /tmp
	DEBUG "--- BEGIN C compiler check: $1 ---"
	echo "int main(int argc, char** argv){return 0;}" >> $$.c
	$1 -c -o $$.o $$.c >/dev/null 2>&1
	RET=$?
	if [ "$RET" = "0" ]; then
		rm -f $$.o
		DEBUG "Seems to compile fine"
	else
		DEBUG "Compilation failure"
	fi
	rm -f $$.c
	cd $OLDPWD
	DEBUG "--- END C compiler check: $1 ---"
	return $RET
}

COMPILE_C () {
	OLDPWD=`pwd`
	cd /tmp
	DEBUG "--- BEGIN C program check ---"
	printf "$1" > $$.c
	$CC $2 -c -o $$.o $$.c >/dev/null 2>&1
	RET=$?
	if [ "$RET" = "0" ]; then
		rm -f $$.o
		DEBUG "Seems to compile fine"
	else
		DEBUG "Compilation failure"
	fi
	rm -f $$.c
	cd $OLDPWD
	DEBUG "--- END C program check ---"
	return $RET
}

PROBE () {
	DEBUG "--- BEGIN Probing ---"
	for i in $@; do
		OLDIFS="$IFS"
		IFS=":"
		for p in $PATH; do
			if [ -f $p/$i ]; then
				DEBUG "$p/$i exists"
				IFS="$OLDIFS"
				echo $p/$i
				DEBUG "--- END Probing ---"
				return 0
			else
				DEBUG "$p/$i does not exist"
			fi
		done
		IFS="$OLDIFS"
	done
	DEBUG "--- END Probing ---"
	return 1
}

PROBE_C () {
	DEBUG "--- BEGIN Probing C ---"
	for i in $@; do
		OLDIFS="$IFS"
		IFS=":"
		for p in $PATH; do
			if [ -f $p/$i ]; then
				DEBUG "$p/$i exists"
				IFS="$OLDIFS"
				if TEST_C $p/$i; then
					IFS=":"
					echo $p/$i
					DEBUG "--- END Probing ---"
					return 0
				fi
				IFS=":"
			else
				DEBUG "$p/$i does not exist"
			fi
		done
		IFS="$OLDIFS"
	done
	DEBUG "--- END Probing C ---"
	return 1
}

AFTER () {
	if [ ! "x$LABEL" = "x" ]; then
		if [ "$1" = "0" ]; then
			SET_LABEL $LABEL true
		else
			SET_LABEL $LABEL false
		fi
	fi
	if [ ! "x$FAILLABEL" = "x" ]; then
		if [ "$1" = "0" ]; then
			SET_LABEL $FAILLABEL false
		else
			SET_LABEL $FAILLABEL true
		fi
	fi
}

echo "# This file was auto-generated" > config.mk
echo "/* This file was auto-generated */" > config.h

while read a; do
	OP=`echo $a | cut -d" " -f1`
	LEN=`echo -n $OP | wc -m`
	LEN=`expr $LEN + 2`
	ARG=`echo $a | cut -c$LEN-`
	DEBUG "--- BEGIN Line $a ---"
	DEBUG "Operator: $OP"
	DEBUG "Argument: $ARG"
	case "$OP" in
		"#")
			;;
		f*)
			PARSE
			if $RUNIF; then
				if [ "$ARG" = "ansi" ]; then
					echo -n "Checking the flag for ANSI... "
					COMPILE_C "int main(int argc, char** argv){}" "-std=c89"
					if [ "$RET" = "0" ]; then
						ANSI="-std=c89"
					else
						COMPILE_C "int main(int argc, char** argv){}" "-ansi"
						if [ "$RET" = "0" ]; then
							ANSI="-ansi"
						fi
					fi
					if [ "x$ANSI" = "x" ]; then
						echo "(none?)"
						if $OPTIONAL; then
							:
						else
							echo "Cannot find a flag for C89!" > /dev/stderr
							exit 1
						fi
					else
						echo "$ANSI"
					fi
				else
					echo "Not supported" > /dev/stderr
					exit 1
				fi
			fi
			;;
		s*)
			PARSE
			if $RUNIF; then
				SYMBOL=`echo $ARG | cut -d"@" -f1`
				HEADER=`echo $ARG | cut -d"@" -f2`
				echo -n "Checking if $SYMBOL exists in $HEADER... "
				COMPILE_C "#include <$HEADER>\nint main(int argc, char** argv){(void)$SYMBOL;return 0;}"
				RET=$?
				if [ "$RET" = "0" ]; then
					echo "yes"
				else
					echo "no"
					if $OPTIONAL; then
						:
					else
						echo "Symbol not found!" > /dev/stderr
						exit 1
					fi
				fi
				AFTER $RET
			fi
			;;
		d*)
			PARSE
			if $RUNIF; then
				echo "#define $ARG 1" >> config.h
			fi
			;;
		h*)
			PARSE
			if $RUNIF; then
				echo -n "Checking if $ARG exists... "
				COMPILE_C "#include <$ARG>"
				RET=$?
				if [ "$RET" = "0" ]; then
					echo "yes"
				else
					echo "no"
					if $OPTIONAL; then
						:
					else
						echo "Header not found!" > /dev/stderr
						exit 1
					fi
				fi
				AFTER $RET
			fi
			;;
		p*)
			PARSE
			if $RUNIF; then
				if [ "x$ARG" = "xc" ]; then
					echo -n "Probing C compiler... "
					if [ "x$CC" = "x" ]; then
						CC=`PROBE_C gcc clang cc`
					fi
					if [ "x$CC" = "x" ]; then
						echo "not found"
						if $OPTIONAL; then
							:
						else
							echo "C compiler not found!" > /dev/stderr
							exit 1
						fi
						AFTER 1
					else
						echo "$CC"
						AFTER 0
					fi
					EXPORTS="$EXPORTS CC"
				elif [ "x$ARG" = "xar" ]; then
					echo -n "Probing archiver... "
					if [ "x$AR" = "x" ]; then
						AR=`PROBE gar ar`
					fi
					if [ "x$AR" = "x" ]; then
						echo "not found"
						if $OPTIONAL; then
							:
						else
							echo "Archiver not found!" > /dev/stderr
							exit 1
						fi
						AFTER 1
					else
						echo "$AR"
						AFTER 0
					fi
					EXPORTS="$EXPORTS AR"
				elif [ "x$ARG" = "xp" ]; then
					echo -n "Probing Pascal compiler... "
					if [ "x$PC" = "x" ]; then
						PC=`PROBE fpc`
					fi
					if [ "x$PC" = "x" ]; then
						echo "not found"
						if $OPTIONAL; then
							:
						else
							echo "Pascal compiler not found!" > /dev/stderr
							exit 1
						fi
						AFTER 1
					else
						echo "$PC"
						AFTER 0
					fi
					EXPORTS="$EXPORTS PC PCFLAGS"
				elif [ "x$ARG" = "xr" ]; then
					echo -n "Probing ranlib... "
					if [ "x$RANLIB" = "x" ]; then
						RANLIB=`PROBE granlib ranlib`
					fi
					if [ "x$RANLIB" = "x" ]; then
						echo "not found"
						if $OPTIONAL; then
							:
						else
							echo "Ranlib not found!" > /dev/stderr
							exit 1
						fi
						AFTER 1
					else
						echo "$RANLIB"
						AFTER 0
					fi
					EXPORTS="$EXPORTS RANLIB"
				else
					echo "Not supported" > /dev/stderr
					exit 1
				fi
			fi
			;;
		m*)
			PARSE
			if $RUNIF; then
				echo "$ARG"
			fi
			AFTER 0
			;;
		o*)
			PARSE
			if $RUNIF; then
				echo "Creating $ARG"
				if [ -f $ARG.in ]; then
					cp $ARG.in /tmp/$$.1
					for i in $EXPORTS; do
						eval "data=\$$i"
						data="`echo "$data" | sed -E "s/%/\\\\\%/g"`"
						sed "s%@$i@%$data%g" /tmp/$$.1 > /tmp/$$.2
						mv /tmp/$$.2 /tmp/$$.1
					done
					mv /tmp/$$.1 $ARG
					AFTER 0
				else
					if $OPTIONAL; then
						AFTER 1
					else
						echo "Cannot find $ARG.in!" > /dev/stderr
						exit 1
					fi
				fi
			fi
			;;
		r*)
			PARSE
			if $RUNIF; then
				eval $ARG
				AFTER $?
			fi
			;;
	esac
	DEBUG "--- END Line $a ---"
done < configure.script

for i in $EXPORTS; do
	eval "data=\$$i"
	echo "$i=$data" >> config.mk
done