#!/usr/bin/env bash

# Copyright 2018 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.

# This script lints each shell script by `shellcheck`.
# Usage: `hack/verify-shellcheck.sh`.
# Taken from - https://github.com/kubernetes/kubernetes/blob/master/hack/verify-shellcheck.sh
# modified according to use.

set -o errexit
set -o nounset
set -o pipefail

CAPZ_ROOT=$( cd "$(dirname "${BASH_SOURCE[0]}")/.." &> /dev/null && pwd )

# allow overriding docker cli, which should work fine for this script
DOCKER="${DOCKER:-docker}"
SHELLCHECK_COLORIZED_OUTPUT="${SHELLCHECK_COLORIZED_OUTPUT:-auto}"

# required version for this script, if not installed on the host we will
# use the official docker image instead. keep this in sync with SHELLCHECK_IMAGE
SHELLCHECK_VERSION="0.9.0"
# upstream shellcheck latest stable image as of August 23, 2023.
SHELLCHECK_IMAGE="docker.io/koalaman/shellcheck:v0.9.0@sha256:f35e8987b02760d4e76fc99a68ad5c42cc10bb32f3dd2143a3cf92f1e5446a45"

# disabled lints
disabled=(
  # this lint disallows non-constant source, which we use extensively without
  # any known bugs
  1090
  # this lint prefers command -v to which, they are not the same
  2230
)

# comma separate for passing to shellcheck
join_by() {
  local IFS="$1";
  shift;
  echo "$*";
}
SHELLCHECK_DISABLED="$(join_by , "${disabled[@]}")"
readonly SHELLCHECK_DISABLED

# Ensure we're linting the correct source tree
cd "${CAPZ_ROOT}"

# Find all shell scripts excluding:
# - Anything git-ignored - No need to lint untracked files.
# - ./_* - No need to lint output directories.
# - ./.git/* - Ignore anything in the git object store.
# - ./vendor* - Vendored code should be fixed upstream instead.
# - ./third_party/*, but re-include ./third_party/forked/*  - only code we
#    forked should be linted and fixed.
all_shell_scripts=()
while IFS=$'\n' read -r script;
  do git check-ignore -q "$script" || all_shell_scripts+=("$script");
done < <(find . -name "*.sh" \
  -not \( \
    -path ./_\*      -o \
    -path ./.git\*   -o \
    -path ./vendor\* -o \
    \( -path ./third_party\* -a -not -path ./third_party/forked\* \) \
  \))

# Detect if the host machine has the required shellcheck version installed
# if so, we will use that instead.
HAVE_SHELLCHECK=false
if which shellcheck &>/dev/null; then
  detected_version="$(shellcheck --version | grep 'version: .*')"
  if [[ "${detected_version}" = "version: ${SHELLCHECK_VERSION}" ]]; then
    HAVE_SHELLCHECK=true
  fi
fi

# common arguments we'll pass to shellcheck
SHELLCHECK_OPTIONS=(
  # allow following sourced files that are not specified in the command,
  # we need this because we specify one file at a time in order to trivially
  # detect which files are failing
  "--external-sources"
  # include our disabled lints
  "--exclude=${SHELLCHECK_DISABLED}"
  # set colorized output
  "--color=${SHELLCHECK_COLORIZED_OUTPUT}"
)

# tell the user which we've selected and lint all scripts
res=0
if ${HAVE_SHELLCHECK}; then
  echo "Using host shellcheck ${SHELLCHECK_VERSION} binary."
  shellcheck "${SHELLCHECK_OPTIONS[@]}" "${all_shell_scripts[@]}" || res=$?
else
  echo "Using shellcheck ${SHELLCHECK_VERSION} docker image."
  "${DOCKER}" run \
    --rm -v "${CAPZ_ROOT}:${CAPZ_ROOT}" -w "${CAPZ_ROOT}" \
    "${SHELLCHECK_IMAGE}" \
  "${SHELLCHECK_OPTIONS[@]}" "${all_shell_scripts[@]}" || res=$?
fi

# print a message based on the result
if [ $res -eq 0 ]; then
  echo 'Congratulations! All shell files are passing lint :-)'
else
  {
    echo
    echo 'Please review the above warnings. You can test via "./hack/verify-shellcheck.sh"'
    echo 'If the above warnings do not make sense, you can exempt this warning with a comment'
    echo ' (if your reviewer is okay with it).'
    echo 'In general please prefer to fix the error, we have already disabled specific lints'
    echo ' that the project chooses to ignore.'
    echo 'See: https://github.com/koalaman/shellcheck/wiki/Ignore#ignoring-one-specific-instance-in-a-file'
    echo
  } >&2
  exit 1
fi

# preserve the result
exit $res
