#!/bin/bash
# Copyright [1999-2015] Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute
# Copyright [2016-2022] EMBL-European Bioinformatics Institute
# 
# 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 is called by 'git commit' just before doing the actual commit
# If the user has a config 'user.shared' as true, this script prevents commits
# via the shared user and forces user to provide an actual git identity.
# The provided git identity is saved (see git ensconfig) and reused within the
# same session.
# If the user is not shared, this script forces user to set his user.name and
# user.email config

# if user is not shared, enforce setting user.name and user.email
if [ "$(git config user.shared)" != 'true' ] ; then

  # get configured name and email
  default_name=$(git config --get user.name)
  default_email=$(git config --get user.email)

  # Ask the user the fix this first
  if [ -z "$default_name" ] || [ -z "$default_email" ] ; then
    echo "Your name and email address have not been configured. Please configure them with the following command before continuing:
    git config [--global] user.name \"Your Name\"
    git config [--global] user.email you@example.com"
    echo "If the user account is shared among multiple users, please add a configuration with the following command:
    git config [--global] user.shared true"
    exit 1
  fi
  exit 0
fi

# if git-ensconfig is not present
ensconfig=$(git ensconfig --test 2> /dev/null)
if [ -z "$ensconfig" ] ; then
  echo 'Error: git-ensconfig is not available. Please contact your paladin.'
  exit 1
fi

# get the previously used identity
identity=$(git ensconfig --get)

# if identity not configured yet
if [ -z "$identity" ] ; then

  # Ask for user identity
  echo -n "Type in your git committer identity (eg. if your email registered with GitHub is foobar@ebi.ac.uk, type in 'foo' or 'foobar'): "
  read shortname < /dev/tty

  # Confirm with user, the full identity for the matching users
  while read match ; do
    match_found="yes"
    while $(true) ; do
      echo -n "Confirm details \"$match\" (y/n):"
      read yn < /dev/tty
      case $yn in
        [Yy]* ) identity="$match" ; break ;;
        [Nn]* ) break ;;
        * ) echo "Please type 'y' for Yes or 'n' for No." ;;
      esac
    done
    [ -n "$identity" ] && break
  done < <(git rev-list --all -n100 -i --author="$shortname" --format="%aN <%aE>" | grep -v ^commit | grep -v '@users.noreply.github.com' | sort | uniq)

  # if git rev-list didn't return any user name
  if [ -z "$match_found" ] ; then
    echo "Sorry, there is no history for author with pattern '$shortname'. If you think this is not correct, please contact your paladin."
    echo "[Note: This might be true if you have never worked in this repository before. Please use 'git ensconfig' to add your details (run the command for details)]"
    exit 1
  fi

  # If none of the found users were valid
  if [ -z "$identity" ] ; then
    echo "Sorry, none of the found users for pattern '$shortname' could be confirmed. If you think this is not correct, please contact your paladin."
    exit 1
  fi

  # save the user details to the config file
  git ensconfig --set "$identity"

fi

# modify the commit message file if no inline message was provided
if [ -z "$2" ] ; then

  # give precedence to the command line --author if provided
  author=$(grep '# Author: ' "$1" | sed -r "s/^# Author:\s+//")
  [ -z "$author" ] && author="$identity" || sed -i '4d' "$1" && sed -i '5d' "$1"

  sed -i -r '/^# (Author|Committer):/d' "$1"
  sed -i "4i #\n# The following committer and author identity will be forced on the\n# commit.\n#   (use \"git ensconfig --unset\" to remove identity)\n#\n# Author:    $author\n# Committer: $identity\n#" "$1"

fi

exit 0