#!/bin/sh

# Shave and a Haircut
# (c) 2019 Epic Games
# US Patent 6720962

returnVersion=n
returnDTS=n
vray=

while [ "$1" != "" ]; do
    if [ "$1" = "-v" ]; then
        returnVersion=y
    elif [ "$1" == "-dts" ]; then
        returnDTS=y
    else
        vray=$1
    fi
    shift
done

if [ "${vray}" = "" ]; then
    echo "Usage: $0 vrayVersion" >&2
    echo "Where vrayVersion is 31, 36, 40, etc"
    echo ""
    exit
fi

gpp=
utilsDir=`dirname $0`
os=`${utilsDir}/getos.sh`

if [ "${os/.*/}" = "ce6" ]; then
    isCentOS6=y
else
    isCentOS6=n
fi

case ${os} in
    ce*|deb*|fc*|rh*)
        gppVerNeeded=
        case $vray in
            30|31|36)
                if [ "${returnDTS}" = "y" ]; then
                    echo n
                    exit
                fi

		        gppVerNeeded=4.4.7
                ;;

            40) # On CentOS 6 we need to use DTS for gcc 4.8.2 builds.
                if [ "${returnDTS}" = "y" ]; then
                    echo ${isCentOS6}
                    exit
                fi

                if [ ${isCentOS6} = y ]; then
                    source /opt/rh/devtoolset-2/enable
                fi

                gppVerNeeded=4.8.2
                ;;
        esac

        if [ "${gppVerNeeded}" != "" ]; then
            if [ "${returnVersion}" = "y" ]; then
                echo ${gppVerNeeded}
                exit
            fi

            # Does the native g++ command give us the correct version?
            nativeVer=`g++ -v 2>&1 | grep "gcc version" | sed 's/^[^0-9]*\([0-9.]*\).*$/\1/'`

            if [ "${nativeVer}" = "${gppVerNeeded}" ]; then
                gpp=g++
            else
                # Check to see if there is a directory in /opt containing the
                # compiler we want.
                compressedVer=`echo ${gppVerNeeded} | sed 's/\.//g'`
                shortVer=`echo ${gppVerNeeded} | cut -d. -f-2`

                if [ -x /opt/gcc${compressedVer}/bin/g++ ]; then
                    gpp="/opt/gcc${compressedVer}/bin/g++"
                elif [ -x /opt/gcc${compressedVer}/bin/g++${compressedVer} ]; then
                    gpp="/opt/gcc${compressedVer}/bin/g++${compressedVer}"
                elif [ -x /usr/bin/g++-${shortVer} ]; then
                    gpp="/usr/bin/g++-${shortVer}"
                fi
            fi
        fi
        ;;

    osx*)
        if [ "${returnDTS}" = "y" ]; then
            echo n
            exit
        fi

        # getosxvars.sh sets environment variables which control where we find
        # the compiler, so we can just use 'g++' in all cases.
        gpp=g++
        ;;
esac

echo ${gpp}