#!/usr/bin/env bash
# Copyright 2021 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# script to setup go version with gimme as needed
# Ensure running from root dir
REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd -P)"
trap "popd >/dev/null 2>&1" EXIT
pushd "${REPO_ROOT}" >/dev/null 2>&1

# read go-version file unless GO_VERSION is set
GO_VERSION="${GO_VERSION:-"$(cat .go-version)"}"

# we don't actually care where the .env files are
# however, GIMME_SILENT_ENV doesn't trigger re-generating a .env if it
# already exists and isn't "silent" (no `go version` command in it)
# so we fix that by changing where the .env is written, ensuring ours
# is generated from this repo and silent.
export GIMME_ENV_PREFIX=./_bin/.gimme/
export GIMME_SILENT_ENV=y

# only setup go if we haven't set FORCE_HOST_GO, or `go version` doesn't match
if [ -n "${FORCE_HOST_GO:-}" ]; then
  GOTOOLCHAIN="${GOTOOLCHAIN:-local}"
  export GOTOOLCHAIN
else
  GOTOOLCHAIN="go${GO_VERSION}"
  export GOTOOLCHAIN
  # go version output looks like:
  # go version go1.14.5 darwin/amd64
  if ! (command -v go >/dev/null && [ "$(go version | cut -d' ' -f3)" = "go${GO_VERSION}" ]); then
      # eval because the output of this is shell to set PATH etc.
      eval "$(hack/third_party/gimme/gimme "${GO_VERSION}")"
  fi
fi
# debug go version
go version

# force go modules
export GO111MODULE=on
