#!/bin/bash

# Copyright 2019 The Bazel Authors. All rights reserved.

#

# 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.

set -eu

# This is a script which can be installed as your "bazel" binary instead of the

# real Bazel binary. When called, it tries to determine and run the correct

# Bazel version for a given project and forwards all arguments to it.

#

# You can specify which Bazel version to use using these methods:

# 1. Set $USE_BAZEL_VERSION to a version number

# (e.g. export USE_BAZEL_VERSION=1.0.0).

# 2. Add a .bazelversion file that contains a version number next to your

# WORKSPACE[.bazel] file.

# 3. Otherwise, the latest Bazel version will be used.

#

# This wrapper only recognizes Bazel versions installed next to itself, thus

# if you install this wrapper as /usr/bin/bazel, you'll have to install binaries

# for individual Bazel binaries as e.g. /usr/bin/bazel-1.0.0.

#

# In addition, if an executable called "tools/bazel" is found in the current

# workspace, this script will not directly execute Bazel, but instead store

# the path to the real Bazel executable in the environment variable BAZEL_REAL

# and then execute the "tools/bazel" wrapper script. The location of the wrapper

# script relative to the workspace can be changed with the $BAZEL_WRAPPER

# environment variable.

#

# In contrast to Bazelisk, this script does not download anything from the

# internet and instead relies on the local system to provide Bazel binaries.

function color() {

}

# `readlink -f` that works on OSX too.

function get_realpath() {

}

function get_workspace_root() {

}

get_workspace_root

readonly wrapper_dir="$(dirname "$(get_realpath "${BASH_SOURCE[0]}")")"

readonly os_arch_suffix="$(uname -s | tr '[:upper:]' '[:lower:]')-$(uname -m)"

function get_bazel_version() {

}

get_bazel_version

BAZEL_REAL="${wrapper_dir}/bazel-${bazel_version}-${os_arch_suffix}"

# Try without the architecture suffix.

if [[ ! -x ${BAZEL_REAL} ]]; then

BAZEL_REAL="${wrapper_dir}/bazel-${bazel_version}"

fi

# Last try: Maybe `bazel-real` is actually the requested correct version?

readonly bazel_real_path="${wrapper_dir}/bazel-real"

if [[ ! -x ${BAZEL_REAL} && -x ${bazel_real_path} ]]; then

# Note that "bazel --version" is very fast and doesn't start the Bazel server,

# as opposed to "bazel version".

readonly bazel_real_version="$("${bazel_real_path}" --version | grep '^bazel ' | cut -d' ' -f2)"

if [[ $bazel_real_version == $bazel_version ]]; then

BAZEL_REAL="${bazel_real_path}"

fi

fi

# If the repository contains a checked-in executable set by $BAZEL_WRAPPER

# (defaults to tools/bazel), we assume that they know what they're doing and

# have their own way of versioning Bazel. Thus, we don't have to print our

# helpful messages or error out in case we couldn't find a binary.

BAZEL_WRAPPER=${BAZEL_WRAPPER:-"tools/bazel"}

readonly wrapper="${workspace_dir}/${BAZEL_WRAPPER}"

if [[ -x "$wrapper" && -f "$wrapper" ]]; then

export BAZEL_REAL

exec -a "$0" "${wrapper}" "$@"

fi

if [[ -z $bazel_version ]]; then

color "31" "ERROR: No installed Bazel version found, cannot continue."

(echo ""

echo "Bazel binaries have to be installed in ${wrapper_dir}, but none were found.") 2>&1

exit 1

fi

if [[ ! -x $BAZEL_REAL ]]; then

color "31" "ERROR: The project you're trying to build requires Bazel ${bazel_version} (${reason}), but it wasn't found in ${wrapper_dir}."

long_binary_name="bazel-${bazel_version}-${os_arch_suffix}"

if [[ -x $(command -v apt-get) && $wrapper_dir == "/usr/bin" ]]; then

(echo ""

echo "You can install the required Bazel version via apt:"

echo " sudo apt update && sudo apt install bazel-${bazel_version}"

echo ""

echo "If this doesn't work, check Bazel's installation instructions for help:"

echo " https://bazel.build/install/ubuntu") 2>&1

else

(echo ""

echo "Bazel binaries for all official releases can be downloaded from here:"

echo " https://github.com/bazelbuild/bazel/releases") 2>&1

if [[ -x $(command -v curl) && -w $wrapper_dir ]]; then

(echo ""

echo "You can download the required version directly using this command:"

echo " (cd \"${wrapper_dir}\" && curl -fLO https://releases.bazel.build/${bazel_version}/release/${long_binary_name} && chmod +x ${long_binary_name})") 2>&1

elif [[ -x $(command -v wget) && -w $wrapper_dir ]]; then

(echo ""

echo "You can download the required version directly using this command:"

echo " (cd \"${wrapper_dir}\" && wget https://releases.bazel.build/${bazel_version}/release/${long_binary_name} && chmod +x ${long_binary_name})") 2>&1

else

(echo ""

echo "Please put the downloaded Bazel binary into this location:"

echo " ${wrapper_dir}/${long_binary_name}") 2>&1

fi

fi

exit 1

fi

exec -a "$0" "${BAZEL_REAL}" "$@"