#!/bin/bash

# exit on first error
set -e

usage_string="\
Usage: $0 VERSION
"

function usage() {
  echo "$usage_string"
  exit
}

function raise_error() {
  echo "*** $1" 1>&2
  exit
}

function file_ending() {
  echo $(basename "$1" | awk -F '.' '{if (NF > 1) print $NF}')
}

function assert_exists() {
  while [ $# -gt 0 ]; do
    if [ -z "$(file_ending "$1")" ]; then
      # assume directory for paths without file ending
      if [ ! -d "$1" ] ; then
        raise_error "directory $1 missing"
      fi
    else
      if [ ! -f "$1" ]; then
        raise_error "file $1 missing"
      fi
    fi
    shift
  done
}

function assert_exists_not() {
  while [ $# -gt 0 ]; do
    if [ -e "$1" ]; then
        raise_error "file $1 already exists"
    fi
    shift
  done
}

function assert_git_status_clean() {
  # save current directory
  anchor="$PWD"
  cd "$1"
  # check for untracked files
  untracked_files=$(git ls-files --others --exclude-standard)
  if [ -n "$untracked_files" ]; then
    raise_error "$1 contains untracked files"
  fi
  # check Git status
  if [ -n "$(git status --porcelain)" ] ; then
    raise_error "$1 is not in a clean state (see git status)"
  fi
  # restore directory
  cd "$anchor"
}

function ask_permission() {
  yes_or_no=""
  while [ "$yes_or_no" != "n" ] && [ "$yes_or_no" != "y" ]; do
    echo ">>> $1"
    read yes_or_no
  done
  if [ "$yes_or_no" = "n" ]; then
    raise_error "aborted"
  fi
}

if [ $# -ne 1  ] ; then
  usage
fi

echo "\

                         ____    _    _____
                        / ___|  / \  |  ___|    C++
                       | |     / _ \ | |_       Actor
                       | |___ / ___ \|  _|      Framework
                        \____/_/   \_|_|

This script expects to run at the root directory of a Git clone of CAF.
The current repository must be master. There must be no untracked file
and the working tree status must be equal to the current HEAD commit.
Further, the script expects a relase_note.md file in the current directory
with the developer blog checked out one level above, i.e.:

\$HOME
├── .github-oauth-token

.
├── libcaf_io
├── blog_release_note.md [optional]
├── github_release_note.md

..
├── blog
│   ├── _posts

"

if [ $(git rev-parse --abbrev-ref HEAD) != "master" ]; then
  raise_error "not in master branch"
fi

# assumed files
token_path="$HOME/.github-oauth-token"
blog_msg="blog_release_note.md"
github_msg="github_release_note.md"
config_hpp_path="libcaf_core/caf/config.hpp"

# assumed directories
blog_posts_path="../blog/_posts"

# check whether all expected files and directories exist
assert_exists "$token_path" "$config_hpp_path" "$github_msg"

# check for a clean state
assert_exists_not .make-release-steps.bash
assert_git_status_clean "."

if [ ! -f "$blog_msg"  ]; then
  ask_permission "$blog_msg missing, continue without blog post [y] or abort [n]?"
else
  # target files
  assert_exists "$blog_posts_path"
  blog_target_file="$blog_posts_path/$(date +%F)-version-$1-released.md"
  assert_exists_not "$blog_target_file"
  assert_git_status_clean "../blog/"
fi

# convert major.minor.patch version given as first argument into JJIIPP with:
#   JJ: two-digit (zero padded) major version
#   II: two-digit (zero padded) minor version
#   PP: two-digit (zero padded) patch version
# but omit leading zeros
version_str=$(echo "$1" | awk -F. '{ if ($1 > 0) printf("%d%02d%02d\n", $1, $2, $3); else printf("%02d%02d\n", $2, $3)  }')

echo ">>> patching config.hpp"
sed "s/#define CAF_VERSION [0-9]*/#define CAF_VERSION ${version_str}/g" < "$config_hpp_path" > .tmp_conf_hpp
mv .tmp_conf_hpp "$config_hpp_path"

echo ; echo
echo ">>> please review the diff reported by Git for patching config.hpp:"
git diff
echo ; echo
ask_permission "type [n] to abort or [y] to proceed"

# piping through AWK/printf makes sure 0.15 is expanded to 0.15.0
tag_version=$(echo "$1" | awk -F. '{ printf("%d.%d.%d", $1, $2, $3)  }')

token=$(cat "$token_path")
tag_descr=$(awk 1 ORS='\\r\\n' "$github_msg")
github_json=$(printf '{"tag_name": "%s","name": "%s","body": "%s","draft": false,"prerelease": false}' "$tag_version" "$tag_version" "$tag_descr")

# for returning to this directory after pushing blog
anchor="$PWD"

echo "\
#!/bin/bash
set -e
git commit -a -m \"Change version to $1\"
git push
git tag $tag_version
git push origin --tags
curl --data '$github_json' https://api.github.com/repos/actor-framework/actor-framework/releases?access_token=$token
" > .make-release-steps.bash

if which brew &>/dev/null ; then
  file_url="https://github.com/actor-framework/actor-framework/archive/$tag_version.tar.gz"
  echo "\
export HOMEBREW_GITHUB_API_TOKEN=\$(cat "$token_path")
brew bump-formula-pr --message=\"Update CAF to version $tag_version\" --url=\"$file_url\" caf
" >> .make-release-steps.bash
fi

if [ -f "$blog_msg"  ]; then
  echo "\
  cp "$blog_msg" "$blog_target_file"
  cd ../blog
  git add _posts
  git commit -m \"$1 announcement\"
  git push
  cd "$anchor"
  " >> .make-release-steps.bash
fi

echo ; echo
echo ">>> please review the final steps for releasing $1"
cat .make-release-steps.bash
echo ; echo
ask_permission "type [y] to execute the steps above or [n] to abort"

chmod +x .make-release-steps.bash
./.make-release-steps.bash

echo ; echo
echo ">>> cleaning up"
rm "$github_msg" .make-release-steps.bash
if [ -f "$blog_msg" ]; then
  rm "$blog_msg"
fi

echo ; echo
echo ">>> done"