#!/bin/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.

# Workflow
# 1. [master branch] update existing snapshot (include API change for a new alpha/beta/GA
# release)
#   - add a new snapshot or reuse the existing snapshot, the latter means either
#     API change happened in a k8s patch release, or we want to include some new
#     python / python-base change in the release note
#   - API change w/ release notes
#   - master change w/ release notes
#   - submodule change w/ release notes
# 2. [master branch] create new snapshot (include API change for a new alpha release)
#   - add a new snapshot or reuse the existing snapshot, the latter means either
#     API change happened in a k8s patch release, or we want to include some new
#     python / python-base change in the release note
#   - API change w/ release notes
#   - master change w/ release notes
#   - submodule change w/ release notes
# 3. [release branch] create a new release
#   - pull master
#     - it's possible that master has new changes after the latest snaphost,
#       update CHANGELOG accordingly
#   - for generated file, resolve conflict by committing the master version
#   - abort if a snapshot doesn't exist
#   - generate client change, abort if API change is detected
#   - CHANGELOG: latest snapshot becomes the release, create a new snapshot
#     section that reflect the master branch state
#   - README: add the release to README
#   - an extra PR to update CHANGELOG and README in master in sync with this new
#     release
#
# Difference between 1&2: API change release notes
#
# TODO(roycaihw):
# - add user input validation
# - add function input validaiton (release/version strings start with 'v' or not)
# - automatically send a PR; provide useful links for review
#   - master branch diff: https://github.com/kubernetes-client/python/compare/commit1..commit2
#   - python base diff: https://github.com/kubernetes-client/python-base/compare/commit1..commit2
#   - Kubernetes changelog, e.g. https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md
# - add debug log
# - add a sentence about "changes since {last release}". In most cases our
#   releases should be sequential. This script (the workflow above) is based on
#   this assumption, and we should make the release note clear about that.
# - update readme; if it's a real release (instead of a snapshot in master
#   branch), also create a PR to update changelog and readme in the master
#   branch
#
# Usage:
#   $ KUBERNETES_BRANCH=release-1.19 CLIENT_VERSION=19.0.0-snapshot DEVELOPMENT_STATUS="3 - Alpha" scripts/release.sh

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

# Verify git status
if git_status=$(git status --porcelain --untracked=no 2>/dev/null) && [[ -n "${git_status}" ]]; then
  echo "!!! Dirty tree. Clean up and try again."
  exit 1
fi

REPO_ROOT="$(git rev-parse --show-toplevel)"
declare -r REPO_ROOT
cd "${REPO_ROOT}"
declare -r REBASEMAGIC="${REPO_ROOT}/.git/rebase-apply"
if [[ -e "${REBASEMAGIC}" ]]; then
  echo "!!! 'git rebase' or 'git am' in progress. Clean up and try again."
  exit 1
fi

# Set constants used by the client generator.
export USERNAME=kubernetes

# Set up utilities.
source scripts/util/changelog.sh
source scripts/util/kube_changelog.sh

# Read user inputs or values locally.
KUBERNETES_BRANCH=${KUBERNETES_BRANCH:-$(python3 "scripts/constants.py" KUBERNETES_BRANCH)}
CLIENT_VERSION=${CLIENT_VERSION:-$(python3 "scripts/constants.py" CLIENT_VERSION)}
DEVELOPMENT_STATUS=${DEVELOPMENT_STATUS:-$(python3 "scripts/constants.py" DEVELOPMENT_STATUS)}

# Create a local branch
STARTINGBRANCH=$(git symbolic-ref --short HEAD)
declare -r STARTINGBRANCH
gitamcleanup=false
function return_to_kansas {
  if [[ "${gitamcleanup}" == "true" ]]; then
    echo
    echo "+++ Aborting in-progress git am."
    git am --abort >/dev/null 2>&1 || true
  fi

  echo "+++ Returning you to the ${STARTINGBRANCH} branch and cleaning up."
  git checkout -f "${STARTINGBRANCH}" >/dev/null 2>&1 || true
}
trap return_to_kansas EXIT

remote_branch=upstream/master
if [[ $CLIENT_VERSION != *"snapshot"* ]]; then
  remote_branch=upstream/release-"${CLIENT_VERSION%%.*}".0
fi
echo "+++ Updating remotes..."
git remote update upstream origin
if ! git log -n1 --format=%H "${remote_branch}" >/dev/null 2>&1; then
  echo "!!! '${remote_branch}' not found."
  echo "    (In particular, it needs to be a valid, existing remote branch that I can 'git checkout'.)"
  exit 1
fi

newbranch="$(echo "automated-release-of-${CLIENT_VERSION}-${remote_branch}" | sed 's/\//-/g')"
newbranchuniq="${newbranch}-$(date +%s)"
declare -r newbranchuniq
echo "+++ Creating local branch ${newbranchuniq}"
git checkout -b "${newbranchuniq}" "${remote_branch}"

# Get Kubernetes API versions
old_client_version=$(python3 "scripts/constants.py" CLIENT_VERSION)
old_k8s_api_version=$(util::changelog::get_k8s_api_version "v$old_client_version")
new_k8s_api_version=$(util::kube_changelog::find_latest_patch_version $KUBERNETES_BRANCH)
echo "Old Kubernetes API Version: $old_k8s_api_version"
echo "New Kubernetes API Version: $new_k8s_api_version"

# If it's an actual release, pull master branch
if [[ $CLIENT_VERSION != *"snapshot"* ]]; then
  git pull -X theirs upstream master --no-edit

  # Collect release notes from master branch
  start_sha=$(git log ${remote_branch}..upstream/master | grep ^commit | tail -n1 | sed 's/commit //g')
  end_sha=$(git log ${remote_branch}..upstream/master | grep ^commit | head -n1 | sed 's/commit //g')
  output="/tmp/python-master-relnote.md"
  release-notes --dependencies=false --org kubernetes-client --repo python --start-sha $start_sha --end-sha $end_sha --output $output
  sed -i 's/(\[\#/(\[kubernetes-client\/python\#/g' $output

  IFS_backup=$IFS
  IFS=$'\n'
  sections=($(grep "^### " $output))
  IFS=$IFS_backup
  for section in "${sections[@]}"; do
    # ignore section titles and empty lines; replace newline with liternal "\n"
    master_release_notes=$(sed -n "/$section/,/###/{/###/!p}" $output | sed -n "{/^$/!p}" | sed ':a;N;$!ba;s/\n/\\n/g')
    util::changelog::write_changelog v$CLIENT_VERSION "$section" "$master_release_notes"
  done
  git add .
  if ! git diff-index --quiet --cached HEAD; then
    util::changelog::update_release_api_version $CLIENT_VERSION $CLIENT_VERSION $new_k8s_api_version
    git add .
    git commit -m "update changelog with release notes from master branch"
  fi
fi

# Update version constants
sed -i "s/^KUBERNETES_BRANCH =.*$/KUBERNETES_BRANCH = \"$KUBERNETES_BRANCH\"/g" scripts/constants.py
sed -i "s/^CLIENT_VERSION =.*$/CLIENT_VERSION = \"$CLIENT_VERSION\"/g" scripts/constants.py
sed -i "s:^DEVELOPMENT_STATUS =.*$:DEVELOPMENT_STATUS = \"$DEVELOPMENT_STATUS\":g" scripts/constants.py
git commit -am "update version constants for $CLIENT_VERSION release"

# Update CHANGELOG with API change release notes since $old_k8s_api_version.
# NOTE: $old_k8s_api_version may be one-minor-version behind $KUBERNETES_BRANCH, e.g.
#   KUBERNETES_BRANCH=release-1.19
#   old_k8s_api_version=1.18.17
# when we bump the minor version for the snapshot in the master branch. We
# don't need to collect release notes in release-1.18, because any API
# change in 1.18.x (x > 17) must be a cherrypick that is already included in
# release-1.19.
# TODO(roycaihw): not all Kubernetes API changes modify the OpenAPI spec.
# Download the patch and skip if the spec is not modified. Also we want to
# look at other k/k sections like "deprecation"
release_notes=$(util::kube_changelog::get_api_changelog "$KUBERNETES_BRANCH" "$old_k8s_api_version")
if [[ -n "$release_notes" ]]; then
  util::changelog::write_changelog v$CLIENT_VERSION "### API Change" "$release_notes"
fi
git add .
git diff-index --quiet --cached HEAD || git commit -am "update changelog"

# Re-generate the client
scripts/update-client.sh

# Apply hotfixes
rm -r kubernetes/test/
git add .
git commit -m "temporary generated commit"
scripts/apply-hotfixes.sh
git reset HEAD~2

# Custom object API is hosted in gen repo. Commit custom object API change
# separately for easier review
if [[ -n "$(git diff kubernetes/client/api/custom_objects_api.py)" ]]; then
  git add kubernetes/client/api/custom_objects_api.py
  git commit -m "generated client change for custom_objects"
fi
# Check if there is any API change, then commit
git add kubernetes/docs kubernetes/client/api/ kubernetes/client/models/ kubernetes/swagger.json.unprocessed scripts/swagger.json
git diff-index --quiet --cached HEAD || git commit -m "generated API change"
# Commit everything else
git add .
git commit -m "generated client change"

echo "Release finished successfully. Please create a PR from branch ${newbranchuniq}."