#!/bin/bash

# Copyright 2014 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.

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

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

kube::golang::verify_go_version

if ! which golint > /dev/null; then
  echo 'Can not find golint, install with:'
  echo 'go get -u github.com/golang/lint/golint'
  exit 1
fi

cd "${KUBE_ROOT}"

array_contains () {
    local seeking=$1; shift # shift will iterate through the array
    local in=1 # in holds the exit status for the function
    for element; do
        if [[ "$element" == "$seeking" ]]; then
            in=0 # set in to 0 since we found it
            break
        fi
    done
    return $in
}

# Check that the file is in alphabetical order
failure_file="${KUBE_ROOT}/hack/.golint_failures"
if ! diff -u "${failure_file}" <(LC_ALL=C sort "${failure_file}"); then
	{
		echo
		echo "hack/.golint_failures is not in alphabetical order. Please sort it:"
		echo
		echo "  LC_ALL=C sort -o hack/.golint_failures hack/.golint_failures"
		echo
	} >&2
	false
fi

export IFS=$'\n'
# NOTE: when "go list -e ./..." is run within GOPATH, it turns the k8s.io/kubernetes
# as the prefix, however if we run it outside it returns the full path of the file
# with a leading underscore. We'll need to support both scenarios for all_packages.
all_packages=(
	$(go list -e ./... | egrep -v "/(third_party|vendor|staging/src/k8s.io/client-go/pkg|generated|clientset_generated)" | sed -e 's|^k8s.io/kubernetes/||' -e "s|^_${KUBE_ROOT}/\?||")
)
failing_packages=(
	$(cat $failure_file)
)
unset IFS
errors=()
not_failing=()
for p in "${all_packages[@]}"; do
	# Run golint on package/*.go file explicitly to validate all go files
	# and not just the ones for the current platform.
	# Packages with a corresponding foo_test package will make golint fail
	# with a useless error. Just ignore that, see golang/lint#68.
	failedLint=$(golint "$p"/*.go 2>/dev/null)
	array_contains "$p" "${failing_packages[@]}" && in_failing=$? || in_failing=$?
	if [[ -n "${failedLint}" ]] && [[ "${in_failing}" -ne "0" ]]; then
		errors+=( "${failedLint}" )
	fi
	if [[ -z "${failedLint}" ]] && [[ "${in_failing}" -eq "0" ]]; then
		not_failing+=( $p )
	fi
done

# Check that all failing_packages actually still exist
gone=()
for p in "${failing_packages[@]}"; do
	array_contains "$p" "${all_packages[@]}" || gone+=( "$p" )
done

# Check to be sure all the packages that should pass lint are.
if [ ${#errors[@]} -eq 0 ]; then
	echo 'Congratulations!  All Go source files have been linted.'
else
	{
		echo "Errors from golint:"
		for err in "${errors[@]}"; do
			echo "$err"
		done
		echo
		echo 'Please review the above warnings. You can test via "golint" and commit the result.'
		echo 'If the above warnings do not make sense, you can exempt this package from golint'
		echo 'checking by adding it to hack/.golint_failures (if your reviewer is okay with it).'
		echo
	} >&2
	false
fi

if [[ ${#not_failing[@]} -gt 0 ]]; then
	{
		echo "Some packages in hack/.golint_failures are passing golint. Please remove them."
		echo
		for p in "${not_failing[@]}"; do
			echo "  $p"
		done
		echo
	} >&2
	false
fi

if [[ ${#gone[@]} -gt 0 ]]; then
	{
		echo "Some packages in hack/.golint_failures do not exist anymore. Please remove them."
		echo
		for p in "${gone[@]}"; do
			echo "  $p"
		done
		echo
	} >&2
	false
fi