#!/usr/bin/env bash
#
# Release script for Akka.
#
# To run this script you need a user account on akka.io and contributor access
# to github.com/akka/akka.
#
# If your username on akka.io is different from your local username then you can
# configure ssh to always associate a particular username with akka.io by adding
# the following to .ssh/config:
#   Host akka.io
#   User <username on akka.io>

# defaults
declare -r default_server="akka.io"
declare -r default_path="/akka/www"

# settings
declare -r release_dir="target/release"
declare release_server=${default_server}
declare release_path=${default_path}
declare -r unzipped_dir="target/dist/unzipped"

# flags
unset run_tests dry_run

# get the source location for this script; handles symlinks
function get_script_path {
  local source="${BASH_SOURCE[0]}"
  while [ -h "${source}" ] ; do
    source="$(readlink "${source}")";
  done
  echo ${source}
}

# path, name, and dir for this script
declare -r script_path=$(get_script_path)
declare -r script_name=$(basename "${script_path}")
declare -r script_dir="$(cd -P "$(dirname "${script_path}")" && pwd)"

# print usage info
function usage {
  cat <<EOM
Usage: ${script_name} [options] VERSION
  -h | --help            Print this usage message
  -t | --run-tests       Run all tests before releasing
  -s | --server SERVER   Set the release server (default ${default_server})
  -p | --path PATH       Set the path on the release server (default ${default_path})
  -n | --dry-run         Build everything but do not push the release
EOM
}

# echo a log message
function echolog {
  echo "[${script_name}] $@"
}

# echo an error message
function echoerr {
  echo "[${script_name}] $@" 1>&2
}

# echo a dry run log message
function echodry {
  echolog "(dry run) $@"
}

# fail the script with an error message
function fail {
  echoerr "$@"
  exit 1
}

# process options and set flags
while true; do
  case "$1" in
    -h | --help ) usage; exit 1 ;;
    -t | --run-tests ) run_tests=true; shift ;;
    -s | --server ) release_server=$2; shift 2 ;;
    -p | --path ) release_path=$2; shift 2 ;;
    -n | --dry-run) dry_run=true; shift ;;
    * ) break ;;
  esac
done

if [ $# != "1" ]; then
  usage
  fail "A release version must be specified"
fi

declare -r version=$1
declare -r publish_path="${release_server}:${release_path}"

# check for a git command
type -P git &> /dev/null || fail "git command not found"

# check for an sbt command
type -P sbt &> /dev/null || fail "sbt command not found"

# check for an rsync command
type -P rsync &> /dev/null || fail "rsync command not found"

# check for a tar command
type -P tar &> /dev/null || fail "tar command not found"

# get the current git branch
function get_current_branch {
  local ref=$(git symbolic-ref HEAD 2> /dev/null)
  local branch=${ref#refs/heads/}
  echo "${branch}"
}

# get the current project version from sbt
# a little messy as the ansi escape codes are included
function get_current_version {
  local result=$(sbt version | tail -1 | cut -f2)
  # remove ansi escape code from end
  local code0=$(echo -e "\033[0m")
  echo ${result%$code0}
}

# store the current git branch for cleaning up
declare -r initial_branch=$(get_current_branch)

# check we have an initial branch
[[ "${initial_branch}" ]] || fail "Not on a git branch"

# check that we have a clean status
[[ -z "$(git status --porcelain)" ]] || {
  git status
  fail "There are uncommitted changes - please commit before releasing"
}

# the branch we'll release on
declare -r release_branch="releasing-${version}"

# try to run a cleanup command - these shouldn't actually fail
function safely {
  "$@" || fail "Failed to clean up release - please check current state"
}

# perform a clean up when a failure has occurred
function git_cleanup {
  echoerr "Cleaning up..."
  local branch=$(get_current_branch)
  safely git reset --hard
  safely git clean -f
  if [ "${branch}" == "${release_branch}" ]; then
    safely git checkout ${initial_branch}
    safely git branch -D ${release_branch}
    local tags=$(git tag -l)
    [[ "${tags}" == *v${version}* ]] && safely git tag -d v${version}
  fi
}

# clean up and fail the script with an error message
function bail_out {
  echoerr "Bailing out!"
  git_cleanup
  echoerr "Cleaned up failed release"
  fail "$@"
}

# bail out for signals
function signal_bail_out {
  echoerr "Interrupted by signal"
  bail_out "Received signal to stop release"
}

# bail out on signals
trap signal_bail_out SIGHUP SIGINT SIGTERM

# try to run a command or otherwise bail out
function try {
  "$@" || bail_out "Failed to create release"
}

echolog "Creating release ${version} ..."

if [ $dry_run ]; then
  echodry "Building everything but not pushing release"
else
  echolog "Publishing to ${publish_path}"
fi

[[ $run_tests ]] && echolog "All tests will be run"

# try ssh'ing to the release server
echolog "Checking ssh connection to ${release_server}"
try ssh -t ${release_server} echo "Successfully contacted release server."

echolog "Getting current project version from sbt..."
declare -r current_version=$(get_current_version)
echolog "Current version is ${current_version}"

# check out a release branch
try git checkout -b ${release_branch}

# find and replace the version
try ${script_dir}/find-replace ${current_version} ${version}

# start clean
try sbt clean

# run the tests if specified
if [ $run_tests ]; then
  echolog "Running all tests..."
  try sbt test
  echolog "All tests are green"
fi

# build the release
echolog "Building the release..."
try sbt build-release
try cp akka-spring/src/main/resources/akka/spring/akka-*.xsd ${release_dir}
echolog "Creating gzipped tar download..."
try tar -cz -C ${unzipped_dir} -f ${release_dir}/downloads/akka-${version}.tgz akka-${version}
echolog "Successfully created local release"

# commit and tag this release
echolog "Committing and tagging..."
try git add .
try git commit -am "Update version for release ${version}"
try git tag -m "Version ${version}" v${version}

# the point of no return... we're now pushing out to servers

# use a special failure from now on
function arrgh {
  cat 1>&2 <<EOM
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

  Release failed while pushing to servers!

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
EOM
  fail "Could not complete release - please check current state"
}

# try running a pushing command or otherwise fail
function important {
  "$@" || arrgh
}

# new interrupted bail out for signals
function arrgh_interrupt {
  echoerr "Interrupted by signal"
  arrgh
}

# new exit on signals
trap arrgh_interrupt SIGHUP SIGINT SIGTERM

# push the commits and tags to git origin
echolog "Pushing to git origin..."
if [ $dry_run ]; then
  echodry "Not actually pushing to git origin. Commands:"
  echodry "  git push origin ${release_branch}"
  echodry "  git push origin --tags"
else
  important git push origin ${release_branch}
  important git push origin --tags
fi

# push the release to the server
echolog "Pushing ${release_dir} to ${publish_path} ..."
if [ $dry_run ]; then
  echodry "Not actually pushing to server. Command:"
  echodry "  rsync -rlpvz --chmod=Dg+ws,Fg+w ${release_dir}/ ${publish_path}/"
else
  important rsync -rlpvz --chmod=Dg+ws,Fg+w ${release_dir}/ ${publish_path}/
fi

if [ $dry_run ]; then
  git_cleanup
  echodry "Successfully created release ${version}"
  echodry "See ${release_dir}"
else
  echolog "Switching back to initial branch"
  git checkout ${initial_branch}
  echolog "Successfully created release ${version}"
fi