#!/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.

# This script checks coding style for go language files in each
# Kubernetes package by golint.

usage () {
  cat <<EOF >&2
Usage: $0 [-- <golangci-lint run flags>] [packages]"
   -c <config|"none">: use the specified configuration or none instead of the default hack/golangci.yaml
   [packages]: check specific packages or directories instead of everything
EOF
  exit 1
}


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

KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
source "${KUBE_ROOT}/hack/lib/init.sh"
source "${KUBE_ROOT}/hack/lib/util.sh"

# Ensure that we find the binaries we build before anything else.
export GOBIN="${KUBE_OUTPUT_BINPATH}"
PATH="${GOBIN}:${PATH}"

invocation=(./hack/verify-golangci-lint.sh "$@")

# The logcheck plugin currently has to be configured via env variables
# (https://github.com/golangci/golangci-lint/issues/1512).
#
# Remember to clean the golangci-lint cache when changing
# the configuration and running this script multiple times,
# otherwise golangci-lint will report stale results:
# _output/local/bin/golangci-lint cache clean
golangci=(env LOGCHECK_CONFIG="${KUBE_ROOT}/hack/logcheck.conf" "${GOBIN}/golangci-lint" run)
golangci_config="${KUBE_ROOT}/hack/golangci.yaml"
while getopts "c:" o; do
  case "${o}" in
    c)
      if [ "${OPTARG}" = "none" ]; then
        golangci_config=""
      else
        golangci_config="${OPTARG}"
      fi
      ;;
   *)
     usage
     ;;
  esac
done

if [ "${golangci_config}" ]; then
    golangci+=(--config="${golangci_config}")
fi

# Filter out arguments that start with "-" and move them to the run flags.
shift $((OPTIND-1))
targets=()
for arg; do
  if [[ "${arg}" == -* ]]; then
    golangci+=("${arg}")
  else
    targets+=("${arg}")
  fi
done

kube::golang::verify_go_version

# Explicitly opt into go modules, even though we're inside a GOPATH directory
export GO111MODULE=on

# Install golangci-lint
echo "installing golangci-lint and logcheck plugin from hack/tools into ${GOBIN}"
pushd "${KUBE_ROOT}/hack/tools" >/dev/null
  go install github.com/golangci/golangci-lint/cmd/golangci-lint
  if [ "${golangci_config}" ]; then
    # This cannot be used without a config.
    go build -o "${GOBIN}/logcheck.so" -buildmode=plugin sigs.k8s.io/logtools/logcheck/plugin
  fi
popd >/dev/null

cd "${KUBE_ROOT}"

res=0
if [[ "${#targets[@]}" -gt 0 ]]; then
    echo "running ${golangci[*]} ${targets[*]}" >&2
    "${golangci[@]}" "${targets[@]}" >&2 || res=$?
else
    echo "running ${golangci[*]} ./..." >&2
    "${golangci[@]}" ./... >&2 || res=$?
    for d in staging/src/k8s.io/*; do
        MODPATH="staging/src/k8s.io/$(basename "${d}")"
        echo "running ( cd ${KUBE_ROOT}/${MODPATH}; ${golangci[*]} --path-prefix ${MODPATH} ./... )"
        pushd "${KUBE_ROOT}/${MODPATH}" >/dev/null
            "${golangci[@]}" --path-prefix "${MODPATH}" ./... >&2 || res=$?
        popd >/dev/null
    done
fi

# print a message based on the result
if [ "$res" -eq 0 ]; then
  echo 'Congratulations! All files are passing lint :-)'
else
  {
    echo
    echo "Please review the above warnings. You can test via \"${invocation[*]}\""
    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://golangci-lint.run/usage/false-positives/'
    echo
  } >&2
  exit 1
fi

# preserve the result
exit "$res"