#!/usr/bin/env bash

# Copyright 2016 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.

# Constants. Enter relevant repo information here.
UPSTREAM_REPO="kubernetes-incubator"
CLI="kompose"

usage() {
  echo "This will prepare $CLI for release!"
  echo ""
  echo "Requirements:"
  echo " git"
  echo " tar - you should already have this on your system"
  echo " hub"
  echo " github-release"
  echo " GITHUB_TOKEN in your env variable"
  echo " "
  echo "Not only that, but you must have permission for:"
  echo " Tagging releases within Github"
  echo ""
}

requirements() {
  if [ ! -f /usr/bin/git ] && [ ! -f /usr/local/bin/git ]; then
    echo "No git."
    return 1
  fi

  if [ ! -f $GOPATH/bin/github-release ]; then
    echo "No $GOPATH/bin/github-release. Please run 'go get -v github.com/aktau/github-release'"
    return 1
  fi

  if [ ! -f /usr/bin/hub ]; then
    echo "Hub needed in order to create the relevant PR's. Please install hub @ https://github.com/github/hub"
    return 1
  fi

  if [[ -z "$GITHUB_TOKEN" ]]; then
    echo "export GITHUB_TOKEN=yourtoken needed for using github-release"
  fi
}

# Clone and then change to user's upstream repo for pushing to master / opening PR's :)
clone() {
  git clone ssh://git@github.com/$UPSTREAM_REPO/$CLI.git
  if [ $? -eq 0 ]; then
        echo OK
  else
        echo FAIL
        exit
  fi
  cd $CLI
  git remote remove origin
  git remote add origin git@github.com:$ORIGIN_REPO/$CLI.git
  git checkout -b release-$1
  cd ..
}

replaceversion() {
  cd $CLI

  echo "1. Replaced version in version.go"
  find . -name 'version.go' -maxdepth 3 -type f -exec sed -i "s/$1/$2/g" {} \;

  echo "2. Replaced README.md versioning"
  sed -i "s/$1/$2/g" README.md
  
  cd ..
}

changelog() {
  cd $CLI
  echo "Getting commit changes. Writing to ../changes.txt"
  LOG=`git shortlog --email --no-merges --pretty=%s v${1}..`
  echo -e "\`\`\`\n$LOG\n\`\`\`" > ../changes.txt
  echo "Changelog has been written to changes.txt"
  echo "!!PLEASE REVIEW BEFORE CONTINUING!!"
  echo "Open changes.txt and add the release information"
  echo "to the beginning of the file before the git shortlog"
  cd ..
}

changelog_md() {
  echo "Generating CHANGELOG.md"
  CHANGES=$(cat changes.txt)
  cd $CLI
  DATE=$(date +"%m-%d-%Y")
  CHANGELOG=$(cat CHANGELOG.md)
  HEADER="## $CLI $1 ($DATE)"
  echo -e "$HEADER\n\n$CHANGES\n\n$CHANGELOG" >CHANGELOG.md
  echo "Changes have been written to CHANGELOG.md"
  cd ..
}

git_commit() {
  cd $CLI 

  BRANCH=`git symbolic-ref --short HEAD`
  if [ -z "$BRANCH" ]; then
    echo "Unable to get branch name, is this even a git repo?"
    return 1
  fi
  echo "Branch: " $BRANCH

  git add .
  git commit -m "$1 Release"
  git push origin $BRANCH
  hub pull-request -b $UPSTREAM_REPO/$CLI:master -h $ORIGIN_REPO/$CLI:$BRANCH

  cd ..
  echo ""
  echo "PR opened against master to update version"
  echo "MERGE THIS BEFORE CONTINUING"
  echo ""
}

git_pull() {
  cd $CLI
  git pull
  cd ..
}

push() {
  CHANGES=$(cat changes.txt)
  # Release it!
  github-release release \
      --user $UPSTREAM_REPO \
      --repo $CLI \
      --tag v$1 \
      --name "v$1" \
      --description "$CHANGES"
  if [ $? -eq 0 ]; then
        echo RELEASE UPLOAD OK 
  else 
        echo RELEASE UPLOAD FAIL
        exit
  fi

  github-release upload \
      --user $UPSTREAM_REPO \
      --repo $CLI \
      --tag $1 \
      --name "$CLI-$1.tar.gz" \
      --file $CLI-$1.tar.gz
  if [ $? -eq 0 ]; then
        echo TARBALL UPLOAD OK 
  else 
        echo TARBALL UPLOAD FAIL
        exit
  fi

  echo "DONE"
  echo "DOUBLE CHECK IT:"
  echo "!!!"
  echo "https://github.com/$UPSTREAM_REPO/$CLI/releases/edit/$1"
  echo "!!!"
}

clean() {
  rm -rf $CLI $CLI-$1 $CLI-$1.tar.gz changes.txt
}

main() {
  local cmd=$1
  usage

  echo "What is your Github username? (location of your $CLI fork)"
  read ORIGIN_REPO 
  echo "You entered: $ORIGIN_REPO"
  echo ""
  
  echo ""
  echo "First, please enter the version of the NEW release: "
  read VERSION
  echo "You entered: $VERSION"
  echo ""

  echo ""
  echo "Second, please enter the version of the LAST release: "
  read PREV_VERSION
  echo "You entered: $PREV_VERSION"
  echo ""

  clear

  echo "Now! It's time to go through each step of releasing $CLI!"
  echo "If one of these steps fails / does not work, simply re-run ./release.sh"
  echo "Re-enter the information at the beginning and continue on the failed step"
  echo ""

  PS3='Please enter your choice: '
  options=(
  "Git clone master"
  "Replace version number"
  "Generate changelog"
  "Generate changelog for release"
  "Create PR"
  "Git pull most recent changes"
  "Upload the tarball and push to Github release page"
  "Clean"
  "Quit")
  select opt in "${options[@]}"
  do
      echo ""
      case $opt in
          "Git clone master")
              clone $VERSION
              ;;
          "Replace version number")
              replaceversion $PREV_VERSION $VERSION
              ;;
          "Generate changelog")
              changelog $PREV_VERSION
              ;;
          "Generate changelog for release")
              changelog_md $VERSION
              ;;
          "Create PR")
              git_commit $VERSION
              ;;
          "Git pull most recent changes")
              git_pull
              ;;
          "Upload the tarball and push to Github release page")
              push $VERSION
              ;;
          "Clean")
              clean $VERSION
              ;;
          "Quit")
              clear
              break
              ;;
          *) echo invalid option;;
      esac
      echo ""
  done
}

main "$@"