#!/bin/bash
# Copyright 2019 The gRPC 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.


# Keeping up with Bazel's breaking changes is currently difficult.
# This script wraps calling bazel by downloading the currently
# supported version, and then calling it. This way, we can make sure
# that running bazel will always get meaningful results, at least
# until Bazel 1.0 is released.
# NOTE: This script relies on bazel's feature where //tools/bazel
# script can be used to hijack "bazel" invocations in given workspace.

set -e

# First of all, if DISABLE_BAZEL_WRAPPER is set, just use BAZEL_REAL as set by
# https://github.com/bazelbuild/bazel/blob/master/scripts/packages/bazel.sh
# that originally invoked this script.
if [ "${BAZEL_REAL}" != "" ] && [ "${DISABLE_BAZEL_WRAPPER}" != "" ]
then
  exec -a "$0" "${BAZEL_REAL}" "$@"
fi

VERSION=1.0.0
echo "INFO: Running bazel wrapper (see //tools/bazel for details), bazel version $VERSION will be used instead of system-wide bazel installation." >&2

BASEURL=https://github.com/bazelbuild/bazel/releases/download/
pushd "$(dirname "$0")" >/dev/null
TOOLDIR=$(pwd)

case $(uname -sm) in
  "Linux x86_64")
    suffix=linux-x86_64
    ;;
  "Darwin x86_64")
    suffix=darwin-x86_64
    ;;
  *)
    echo "Unsupported architecture: $(uname -sm)" >&2
    exit 1
    ;;
esac

filename="bazel-$VERSION-$suffix"

if [ ! -x "$filename" ] ; then
  curl -L "$BASEURL/$VERSION/$filename" > "$filename"
  chmod a+x "$filename"
fi

popd >/dev/null
exec "$TOOLDIR/$filename" "$@"