#!/bin/sh

# The checksums below must correspond to the downloads for this version.

GO_VERSION=go1.9.2

if [ $(uname -s) = "Darwin" ]; then

GO_PKG=${GO_VERSION}.darwin-amd64.tar.gz

GO_PKG_SHA=8b4f6ae6deae1150d2e341d02c247fd18a99af387516540eeb84702ffd76d3a1

elif [ $(uname -s) = "Linux" ]; then

GO_PKG=${GO_VERSION}.linux-amd64.tar.gz

GO_PKG_SHA=de874549d9a8d8d8062be05808509c09a88a248e77ec14eb77453530829ac02b

else

echo 1>&2 "I don't know how to install Go on your platform."

echo 1>&2 "Please install $GO_VERSION or later and add it to your PATH."

exit 1

fi

archivesum() {

shasum -a256 "$ARCHIVE"

}

archiveok() {

test -f "$ARCHIVE" && archivesum | grep -q $GO_PKG_SHA

}

if go version 2>/dev/null | grep -q $GO_VERSION; then

go version

exit 0

fi

ROOTDIR="$( cd "$( dirname "$0" )/.." && pwd )"

VENDORDIR="$ROOTDIR/vendor"

DOWNLOAD_URL=https://storage.googleapis.com/golang/$GO_PKG

ARCHIVE="$VENDORDIR/$GO_PKG"

INSTALLDIR="$VENDORDIR/$GO_VERSION"

export GOROOT="$INSTALLDIR/go"

INSTALLEDGO="$GOROOT/bin/go"

if [ -x $INSTALLEDGO ]; then

"$INSTALLEDGO" version

exit 0

fi

if ! archiveok; then

echo "Downloading $DOWNLOAD_URL"

mkdir -p "$VENDORDIR"

if ! curl -L -o "$ARCHIVE" $DOWNLOAD_URL; then

rm -f "$ARCHIVE"

echo 1>&2 "download failed"

fi

if ! archiveok; then

archivesum 1>&2

echo 1>&2 "expected checksum $GO_PKG_SHA"

exit 1

fi

fi

rm -rf "$INSTALLDIR"

mkdir -p "$INSTALLDIR"

tar xf "$ARCHIVE" -C "$INSTALLDIR"

"$INSTALLEDGO" version