#!/usr/bin/env bash

JAVA_HOME=/usr/lib/jvm/openjdk-10.0.2
JDK_FILENAME=openjdk-10.0.2_linux-x64_bin.tar.gz
JDK_URL=https://download.java.net/java/GA/jdk10/10.0.2/19aef61b38124481863b1413dce1855f/13/openjdk-10.0.2_linux-x64_bin.tar.gz

# Determine which package manager to use depending on the distribution
declare -A osInfo;
osInfo[/etc/redhat-release]=yum
osInfo[/etc/arch-release]=pacman
osInfo[/etc/gentoo-release]=emerge
osInfo[/etc/SuSE-release]=zypp
osInfo[/etc/debian_version]=apt-get
for f in ${!osInfo[@]}
do
    if [[ -f $f ]]; then
        PACKAGE_MANAGER=${osInfo[$f]}
        break
    fi
done

if [ ! -d "$JAVA_HOME" ]; then
    # Ensure curl is installed since it may not be
    $PACKAGE_MANAGER -y install curl

    curl -L -O $JDK_URL
    mkdir -p $JAVA_HOME
    tar -zxf $JDK_FILENAME -C $JAVA_HOME --strip 1
    rm $JDK_FILENAME

    update-alternatives --install /usr/bin/java java $JAVA_HOME/bin/java 2000
    update-alternatives --install /usr/bin/javac javac $JAVA_HOME/bin/javac 2000
fi