#!/bin/sh

if test -z "${R_HOME}"; then
    echo "This command can be executed via R CMD only!"
    exit 1
fi

SED=sed

tools_classpath=${R_SHARE_DIR}/java

usage="
Usage: R CMD javareconf [options]

Detect current Java setup and update the corresponding configuration in R.

Options:
  -h, --help     print short help message and exit
  -n, --dry-run  perform Java detection, but don't touch any
                 configurations files
  xxx=yyy        evaluate the corresponding expression
                 (e.g. JAVA_HOME=/usr/lib/java)

Environment variables that can be used to influence the detection:
  JAVA           path to a Java interpreter executable
                 By default first 'java' command found on the PATH
                 is taken (unless JAVA_HOME is also specified).
  JAVA_HOME      home of the Java environment. If not specified,
                 it will be detected automatically from the Java
                 interpreter.

Report bugs to <r-bugs@r-project.org>."


dry_run=no
while test -n "${1}"; do
    case ${1} in
	-help | --help | -h) echo "${usage}"; exit 0 ;;
	-n | --dry-run) dry_run=yes ;;
	*=*) eval ${1} ;;
    esac
    shift
done

## find java compiler binaries
if test -z "${JAVA_HOME}" ; then
    JAVA_PATH=${PATH}
else
    if test ! -e "${JAVA_HOME}"; then
	echo "*** JAVA_HOME is not a valid path, ignoring"
	JAVA_HOME=
    fi

    ## try jre/bin first just in case we don't have full JDK
    JAVA_PATH=${JAVA_HOME}:${JAVA_HOME}/jre/bin:${JAVA_HOME}/bin:${PATH}
fi
## if 'java' is not on the PATH or JAVA_HOME, add some guesses as of
## where java could live
JAVA_PATH=${JAVA_PATH}:/usr/java/bin:/usr/jdk/bin:/usr/lib/java/bin:/usr/lib/jdk/bin:/usr/local/java/bin:/usr/local/jdk\
/bin:/usr/local/lib/java/bin:/usr/local/lib/jdk/bin

if test -z "$JAVA"; then
    save_IFS=$IFS; IFS=:
    for dir in ${JAVA_PATH}; do
	if test -f "$dir/java"; then
	    JAVA="$dir/java"
	    break
	fi
    done
    IFS=${save_IFS}
fi

if test -z "$JAVA"; then
    echo "~*** Cannot find any Java interpreter~*** Please make sure 'java' is on you PATH or set JAVA_HOME correspondingly"|${SED} -e 'y/~/\n/' >&2
    exit 1
fi

echo "Java interpreter : $JAVA"
jires=`$JAVA -classpath ${tools_classpath} getsp -test`
if test "$jires" != "Test1234OK"; then
    echo "$jires"
    echo "~*** Java interpreter doesn't work properly.~"|${SED} -e 'y/~/\n/' >&2
    exit 1
fi

if test -z "${JAVA_HOME}"; then
    JAVA_HOME=`$JAVA -classpath ${tools_classpath} getsp java.home`
fi

if test -z "${JAVA_HOME}"; then
    echo "~*** Cannot find Java environemnt.~*** Please set JAVA_HOME correspondingly.~"|${SED} -e 'y/~/\n/' >&2
    exit 1
fi

echo "Java version     : `$JAVA -classpath ${tools_classpath} getsp java.version 2>/dev/null`"
echo "Java home path   : ${JAVA_HOME}"

hostos=`uname 2>/dev/null`
case "$hostos" in
    Darwin*)
	JAVA_LD_LIBRARY_PATH=
	JAVA_LIBS="-framework JavaVM"
	;;
    *)
	## we need to reset LD_LIBRARY_PATH, because Java automatically
	## adds all LD_LIBRARY_PATH to Java path
	save_LDLP=${LD_LIBRARY_PATH}
	LD_LIBRARY_PATH=
	export LD_LIBRARY_PATH
	# remove trailing : (if any) and replace occurrences of JAVA_HOME
	# with $(JAVA_HOME)
	JAVA_LD_LIBRARY_PATH=`$JAVA -classpath ${tools_classpath} getsp java.library.path| ${SED} -e s:${JAVA_HOME}:\$\(JAVA_HOME\):g -e 's/:$//'`
	LD_LIBRARY_PATH=${save_LDLP}
	export LD_LIBRARY_PATH
	# build JAVA_LIBS from the detected path
	JAVA_LIBS=`echo ${JAVA_LD_LIBRARY_PATH}|${SED} -e 's|:| -L|g'`
	if test -n "${JAVA_LIBS}"; then JAVA_LIBS="-L${JAVA_LIBS}"; fi
	JAVA_LIBS="${JAVA_LIBS} -ljvm"
	# create shell-version to be used in scripts
	JAVA_LD_LIBRARY_PATH_SH=`echo ${JAVA_LD_LIBRARY_PATH}|${SED} -e 's:$(JAVA_HOME):\$\{JAVA_HOME\}:g'`
	;;
esac

echo "Java library path: ${JAVA_LD_LIBRARY_PATH}"
echo "JNI linker flags : ${JAVA_LIBS}"

echo ""

if test "${dry_run}" = yes; then exit 0; fi

echo "Updating Java configuration in ${R_HOME}"

files="${R_HOME}/etc${R_ARCH}/Makeconf ${R_HOME}/etc${R_ARCH}/ldpaths"
for file in $files; do
    ${SED} -e "s|JAVA =.\{0,\}|JAVA = $JAVA|" -e "s|JAVA_HOME =.\{0,\}|JAVA_HOME = ${JAVA_HOME}|" -e "s|: \${JAVA_HOME=.\{1,\}|: \${JAVA_HOME=${JAVA_HOME}}|" -e "s|: \${R_JAVA_LD_LIBRARY_PATH=.\{1,\}|: \${R_JAVA_LD_LIBRARY_PATH=${JAVA_LD_LIBRARY_PATH_SH}}|" -e "s|JAVA_LIBS =.\{0,\}|JAVA_LIBS = ${JAVA_LIBS}|g" -e "s|JAVA_LD_LIBRARY_PATH =.\{0,\}|JAVA_LD_LIBRARY_PATH = ${JAVA_LD_LIBRARY_PATH}|" "$file" > "${file}.new"
    if test -f "${file}.new"; then
	mv "${file}" "${file}.old"
	mv "${file}.new" "${file}"
    else
	echo "*** cannot create ${file}.new~*** Please run as root if required.~" | ${SED} -e 'y/~/\n/' >&2
	exit 1
    fi
done

echo "Done."
