#!/bin/bash
# This script will attempt to load one of the NVIDIA driver version which
# present in this script, otherwise it will try to fallback to the Generic
# OpenGL driver (libgl1-mesa-glx)

# The list of Nvidia Supported Driver Version which present in this container
NSDV="361 340 304"

# Try to load the Generic OpenGL driver (libgl1-mesa-glx)
# Return 0 on success
function testGeneric {
    export LD_LIBRARY_PATH=/usr/lib/i386-linux-gnu/mesa
    glxinfo >/dev/null 2>&1
    return $?
}

# Try to load the NVIDIA driver
# Return 0 on success
function testNvidiaVer {
    export LD_LIBRARY_PATH=/usr/lib/nvidia-$1
    [ -e "$LD_LIBRARY_PATH/libGL.so.1" ] && glxinfo >/dev/null 2>&1
    return $?
}

#
# Go through all available in this container versions of the NVIDIA drivers and
# return the version which worked.
# If none of the NVIDIA drivers worked, then try to load the Generic OpenGL
# driver.
#
# Return 0 on success
# Return 1 if none of the graphic drivers worked, including the Generic OpenGL
#
function detectNvidiaDriver {
    echo "Attempting to load one of the supported NVIDIA drivers: "
    for ver in $NSDV; do
        echo -n "    Trying to load NVIDIA driver version: $ver ... "
        testNvidiaVer $ver
        RC=$?
        if [ $RC -eq 0 ]; then
            echo "SUCCESS"
            return $ver
        else
            echo "FAILURE"
        fi
    done

    echo "Attempting to load the Generic OpenGL driver ..."
    testGeneric
    RC=$?
    return $RC
}

#
# START
#
detectNvidiaDriver
RC=$?
if [ $RC -eq 0 ]; then
    echo "NVIDIA drivers could not be loaded."
    echo "Generic OpenGL driver will be used"
elif [ $RC -eq 1 ]; then
    echo "None of the supported NVIDIA drivers worked :/"
    echo "Please try installing one of the supported NVIDIA drivers"
    echo "Supported NVIDIA driver version are: $NSDV"
fi

export LD_LIBRARY_PATH
echo "LD_LIBRARY_PATH is set to: $LD_LIBRARY_PATH"

# This script understands the "glxdebug" argument
if [ "$1" == "glxdebug" ]; then
    linux32 glxgears -info
else
    linux32 steam $@
fi