#!/bin/bash
# select a java version
#
# Notes:
# - JDK's and JRE's are installed into /usr/lib/java/$name-$version
# - java-config creates a symlink called /usr/lib/java/home to the sdk/re you
#   select
#
# Example:
# $ java-config -l
# jdk-1.3
# jdk-1.4
# jdk-1.4.2
# $ java-config -s jdk-1.4.2
# $ java-config -l
# jdk-1.3
# jdk-1.4
# jdk-1.4.2 *


# JAVA_BASE=/usr/lib/java
JAVA_BASE=/tmp/java # temporary
JAVA_HOME=$JAVA_BASE/home

usage() {
    name=$(basename $0)
    echo "Usage: "
    echo "    $name -l:        list available sdk/re's"
    echo "    $name -s <sdk>:  select <sdk>"
    exit -2
}


if [ -e $JAVA_HOME ] && [ ! -L $JAVA_HOME ]; then
    echo "$JAVA_HOME is not a symbolic link; exiting"
    exit -1
fi

case $1 in
    "-l")
    	if [ -L $JAVA_HOME ]; then
	    selected=$(ls -l $JAVA_HOME|sed -e 's|.*/||g')
	fi
        find $JAVA_BASE -maxdepth 1 -mindepth 1 -type d| sed -e 's|.*/||g'|\
		sed -e "s|^$selected$|$selected \*|g"
	;;
   "-s")
        if [ "$2" = "" ]; then
	   usage
	fi
	if [ ! -d $JAVA_BASE/$2 ]; then
            echo "$JAVA_BASE/$2 does not exist; exiting"
	    exit -3
	fi 
	rm -f $JAVA_HOME	
	ln -s $JAVA_BASE/$2 $JAVA_HOME
	;;
   *)
	usage
	;;
esac