#!/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.

# This script automates the release processes for all pre-releases and official
# releases for Kubernetes.  See docs/devel/releasing.md for more info.

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

# Sets DIR, INSTRUCTIONS
function main() {
  # Parse arguments
  if [[ "$#" -ne 2 && "$#" -ne 3 ]]; then
    usage
    exit 1
  fi
  local -r new_version=${1-}
  local -r build_version=${2-}
  DRY_RUN=true
  if [[ "${3-}" == "--no-dry-run" ]]; then
    echo "!!! This NOT is a dry run."
    DRY_RUN=false
  else
    echo "This is a dry run."
  fi

  check-prereqs

  # Get and verify version info
  local -r alpha_version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.0-alpha\\.([1-9][0-9]*)$"
  local -r beta_version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)-beta\\.([1-9][0-9]*)$"
  local -r official_version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)$"
  local -r series_version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)$"
  if [[ "${new_version}" =~ $alpha_version_regex ]]; then
    local -r release_type='alpha'
    local -r version_major="${BASH_REMATCH[1]}"
    local -r version_minor="${BASH_REMATCH[2]}"
    local -r version_alpha_rev="${BASH_REMATCH[3]}"
  elif [[ "${new_version}" =~ $beta_version_regex ]]; then
    local -r release_type='beta'
    local -r version_major="${BASH_REMATCH[1]}"
    local -r version_minor="${BASH_REMATCH[2]}"
    local -r version_patch="${BASH_REMATCH[3]}"
    local -r version_beta_rev="${BASH_REMATCH[4]}"
  elif [[ "${new_version}" =~ $official_version_regex ]]; then
    local -r release_type='official'
    local -r version_major="${BASH_REMATCH[1]}"
    local -r version_minor="${BASH_REMATCH[2]}"
    local -r version_patch="${BASH_REMATCH[3]}"
  elif [[ "${new_version}" =~ $series_version_regex ]]; then
    local -r release_type='series'
    local -r version_major="${BASH_REMATCH[1]}"
    local -r version_minor="${BASH_REMATCH[2]}"
  else
    usage
    echo
    echo "!!! You specified an invalid version '${new_version}'."
    exit 1
  fi

  # Get the git commit from the build_version and verify it
  local -r git_commit_regex="^[0-9a-f]{7}$"
  local -r git_commit=$(echo "${build_version}" | awk -F'+' '{print $2}' | head -c7)
  if ! [[ "${git_commit}" =~ $git_commit_regex ]]; then
    usage
    echo
    echo "!!! You specified an invalid build_version '${build_version}'."
    echo "!!! Tried to extract commit, got ${git_commit}."
    exit 1
  fi
  echo "Doing ${release_type} release '${new_version}'."

  # Set the default umask for the release. This ensures consistency
  # across our release builds.
  #
  # TODO(ihmccreery): This should be in our build process, not our release
  # process.
  local -r release_umask=${release_umask:-022}
  umask "${release_umask}"

  local -r github="https://github.com/kubernetes/kubernetes.git"
  declare -r DIR=$(mktemp -d "/tmp/kubernetes-${release_type}-release-${new_version}-XXXXXXX")

  # Start a tmp file that will hold instructions for the user.
  declare -r INSTRUCTIONS=$(mktemp "/tmp/kubernetes-${release_type}-release-${new_version}-instructions-XXXXXXX")
  if $DRY_RUN; then
    cat > "${INSTRUCTIONS}" <<- EOM
Success on dry run!  Do

  pushd ${DIR}

to see what happened.

You would now do the following, if not a dry run:

EOM
  else
    cat > "${INSTRUCTIONS}" <<- EOM
Success!  You must now do the following (you may want to cut and paste these
instructions elsewhere):

EOM
  fi

  echo "Cloning from '${github}'..."
  git clone "${github}" "${DIR}"

  # !!! REMINDER !!!
  #
  # Past this point, you are dealing with a different clone of the repo at some
  # version. Don't assume you're executing code from the same repo as this script
  # is running in. This is a version agnostic process.
  pushd "${DIR}"

  if [[ "${release_type}" == 'alpha' ]]; then
    local -r ancestor="v${version_major}.${version_minor}.0-alpha.$((${version_alpha_rev}-1))"

    git checkout "${git_commit}"
    verify-at-git-commit "${git_commit}"
    verify-ancestor "${ancestor}"

    alpha-release "${new_version}"
  elif [[ "${release_type}" == 'beta' ]]; then
    local -r release_branch="release-${version_major}.${version_minor}"
    local -r ancestor="v${version_major}.${version_minor}.${version_patch}-beta.$((${version_beta_rev}-1))"

    git checkout "${release_branch}"
    verify-at-git-commit "${git_commit}"
    verify-ancestor "${ancestor}"

    beta-release "${new_version}"

    git-push ${release_branch}
  elif [[ "${release_type}" == 'official' ]]; then
    local -r release_branch="release-${version_major}.${version_minor}"
    local -r beta_version="v${version_major}.${version_minor}.$((${version_patch}+1))-beta.0"
    local -r ancestor="${new_version}-beta.0"

    git checkout "${release_branch}"
    verify-at-git-commit "${git_commit}"
    verify-ancestor "${ancestor}"

    official-release "${new_version}"
    beta-release "${beta_version}"

    git-push ${release_branch}
  else # [[ "${release_type}" == 'series' ]]
    local -r release_branch="release-${version_major}.${version_minor}"
    local -r alpha_version="v${version_major}.$((${version_minor}+1)).0-alpha.0"
    local -r beta_version="v${version_major}.${version_minor}.0-beta.0"
    # NOTE: We check the second alpha version, ...-alpha.1, because ...-alpha.0
    # is the branch point for the previous release cycle, so could provide a
    # false positive if we accidentally try to release off of the old release
    # branch.
    local -r ancestor="v${version_major}.${version_minor}.0-alpha.1"

    git checkout "${git_commit}"
    verify-at-git-commit "${git_commit}"
    verify-ancestor "${ancestor}"

    alpha-release "${alpha_version}"

    echo "Branching ${release_branch}."
    git checkout -b "${release_branch}"
    versionize-docs-and-commit "${release_branch}"

    beta-release "${beta_version}"

    git-push ${release_branch}
  fi

  echo
  cat "${INSTRUCTIONS}"
}

function usage() {
  echo "Usage: ${0} <release_version> <build_version> [--no-dry-run]"
  echo
  echo "<release_version> is the version you want to release,"
  echo "<build_version> is the version of the build you want to mark as <release-version>."
  echo "Please see docs/devel/releasing.md for more info."
}

function check-prereqs() {
  SED=sed
  if which gsed &>/dev/null; then
    SED=gsed
  fi
  if ! ($SED --version 2>&1 | grep -q GNU); then
    echo "!!! GNU sed is required.  If on OS X, use 'brew install gnu-sed'."
    exit 1
  fi
}

function alpha-release() {
  local -r alpha_version="${1}"

  echo "Doing an alpha release of ${alpha_version}."

  echo "Tagging ${alpha_version} at $(current-git-commit)."
  git tag -a -m "Kubernetes pre-release ${alpha_version}" "${alpha_version}"
  git-push "${alpha_version}"

  cat >> "${INSTRUCTIONS}" <<- EOM
- Finish the ${alpha_version} release build: from this directory (clone of
  upstream/master),
    ./release/build-official-release.sh ${alpha_version}
EOM
}

function beta-release() {
  local -r beta_version="${1}"

  echo "Doing a beta release of ${beta_version}."

  rev-version-and-commit "${beta_version}"

  echo "Tagging ${beta_version} at $(current-git-commit)."
  git tag -a -m "Kubernetes pre-release ${beta_version}" "${beta_version}"
  git-push "${beta_version}"

  cat >> "${INSTRUCTIONS}" <<- EOM
- Finish the ${beta_version} release build: from this directory (clone of
  upstream/master),
    ./release/build-official-release.sh ${beta_version}
EOM
}

function official-release() {
  local -r official_version="${1}"

  echo "Doing an official release of ${official_version}."

  rev-version-and-commit "${official_version}"

  echo "Tagging ${official_version} at $(current-git-commit)."
  git tag -a -m "Kubernetes release ${official_version}" "${official_version}"
  git-push "${official_version}"

  cat >> "${INSTRUCTIONS}" <<- EOM
- Finish the ${official_version} release build: from this directory (clone of
  upstream/master),
    ./release/build-official-release.sh ${official_version}
EOM
}

function verify-at-git-commit() {
  local -r git_commit="${1}"
  echo "Verifying we are at ${git_commit}."
  if [[ $(current-git-commit) != ${git_commit} ]]; then
    cat <<- EOM
!!! We are not at commit ${git_commit}! (If you're cutting a beta or official
release, that probably means your release branch isn't frozen, so the commit
you want to release isn't at HEAD of the release branch.)"
EOM
    exit 1
  fi
}

function current-git-commit() {
  git rev-parse --short HEAD
}

function verify-ancestor() {
  local -r ancestor="${1}"
  # Check to make sure the previous version is an ancestor.
  echo "Checking that previous version '${ancestor}' is an ancestor."
  if ! git merge-base --is-ancestor "${ancestor}" HEAD; then
    echo "!!! Previous version '${ancestor}' is not an ancestor!"
    exit 1
  fi
}

function versionize-docs-and-commit() {
  local -r release_branch="${1}"
  echo "Versionizing docs for ${release_branch} and committing."
  # NOTE: This is using versionize-docs.sh at the release point.
  ./build/versionize-docs.sh ${release_branch}
  git commit -am "Versioning docs and examples for ${release_branch}."
}

function rev-version-and-commit() {
  local -r version="${1}"
  local -r version_file="pkg/version/base.go"

  local -r version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(-beta\\.(0|[1-9][0-9]*))?$"
  if [[ "${version}" =~ $version_regex ]]; then
    local -r version_major="${BASH_REMATCH[1]}"
    # We append a '+' to the minor version on a beta build per hack/lib/version.sh's logic.
    if [[ -z "${BASH_REMATCH[4]}" ]]; then
      local -r version_minor="${BASH_REMATCH[2]}"
    else
      local -r version_minor="${BASH_REMATCH[2]}+"
    fi
  else
    echo "!!! Something went wrong.  Tried to rev version to invalid version; should not have gotten to this point."
    exit 1
  fi

  echo "Updating ${version_file} to ${version}"
  $SED -ri -e "s/gitMajor\s+string = \"[^\"]*\"/gitMajor string = \"${version_major}\"/" "${version_file}"
  $SED -ri -e "s/gitMinor\s+string = \"[^\"]*\"/gitMinor string = \"${version_minor}\"/" "${version_file}"
  $SED -ri -e "s/gitVersion\s+string = \"[^\"]*\"/gitVersion string = \"${version}+\$Format:%h\$\"/" "${version_file}"
  gofmt -s -w "${version_file}"

  echo "Committing version change ${version}"
  git add "${version_file}"
  git commit -m "Kubernetes version ${version}"
}

function git-push() {
  local -r object="${1}"
  if $DRY_RUN; then
    echo "Dry run: would have done git push origin ${object}"
  else
    git push origin "${object}"
  fi
}

main "$@"