#!/bin/bash

# Copyright 2015 The Kubernetes 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 -o errexit
set -o nounset
set -o pipefail

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

branch="${1:-master}"
# notice this uses ... to find the first shared ancestor
if ! git diff origin/"${branch}"...HEAD | grep 'Godeps/' > /dev/null; then
  exit 0
fi

# create a nice clean place to put our new godeps
_tmpdir="$(mktemp -d -t gopath.XXXXXX)"
function cleanup {
  echo "Removing ${_tmpdir}"
  rm -rf "${_tmpdir}"
}
trap cleanup EXIT

# build the godep tool
export GOPATH="${_tmpdir}"
go get -u github.com/tools/godep 2>/dev/null
go install github.com/tools/godep 2>/dev/null
GODEP="${_tmpdir}/bin/godep"

# fill out that nice clean place with the kube godeps
echo "Starting to download all kubernetes godeps. This takes a while"
"${GODEP}" restore
echo "Download finished"

# copy the contents of your kube directory into the nice clean place
_kubetmp="${_tmpdir}/src/k8s.io/"
mkdir -p "${_kubetmp}"
#should create ${_kubectmp}/kubernetes
git archive --format=tar --prefix=kubernetes/ $(git write-tree) | (cd "${_kubetmp}" && tar xf -)
_kubetmp="${_kubetmp}/kubernetes"

# destroy godeps in our COPY of the kube tree
pushd "${_kubetmp}" > /dev/null
rm -rf ./Godeps

# for some reason the kube tree needs to be a git repo for the godep tool to run. Doesn't make sense
git init > /dev/null 2>&1

# recreate the Godeps using the nice clean set we just downloaded
"${GODEP}" save ./...
popd > /dev/null

# Check for any (meaninful) differences between the godeps in the tree and this nice clean one we just built
if ! _out="$(diff -NIaupr --ignore-matching-lines='^\s*\"GoVersion\":' --ignore-matching-lines='^\s*\"Comment\":' ${KUBE_ROOT}/Godeps/ ${_kubetmp}/Godeps/)"; then
  echo "Your godeps changes are not reproducable"
  echo "${_out}"
  exit 1
fi

# ex: ts=2 sw=2 et filetype=sh