# Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2.0,
# as published by the Free Software Foundation.
#
# This program is also distributed with certain software (including
# but not limited to OpenSSL) that is licensed under separate terms,
# as designated in a particular file or component or in included license
# documentation.  The authors of MySQL hereby grant you an additional
# permission to link the program and your derivative works with the
# separately licensed software that they have included with MySQL.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License, version 2.0, for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

usage() {
  echo "usage: import-git-commit [-f] rev"
  echo
  echo "        [rev] must name a commit in the mysql-js tree."
  echo
  echo "        If automatic merge fails, use -f option to stage files"
  echo "        from mysql-js revision in current index."
  exit 1
}

fail() {
  echo $1
  exit 1
}

test -d "$GIT_WORK_TREES" || fail "Environment GIT_WORK_TREES must be set"
CUR_DIR=`pwd`
test `basename $CUR_DIR` = "nodejs" || fail "Must be run from storage/ndb/nodejs"
SOURCE_DIR=$GIT_WORK_TREES/mysql-js
test -d "$SOURCE_DIR" || fail "$SOURCE_DIR must exist"

if test "$1" = "-f"
  then
    copy_mode=1 ; REV=$2
  else
    copy_mode=0 ; REV=$1
fi

test -n "$REV" || usage

if ! git -C $SOURCE_DIR rev-parse --verify "$REV^{commit}"
 then
   fail "$REV must name a commit"
fi

stage_commit_message() {
  MSG=__staged-commit-message
  git -C $SOURCE_DIR show --no-patch --format=%B $REV > $MSG
  echo "Imported from mysql-js commit $REV" >> $MSG
  echo "To use staged commit message from $REV:"
  echo "    git commit -e -F $MSG"
}

run_copy_mode() {
  changed_files=`git -C $SOURCE_DIR diff --name-only --diff-filter=d $REV~1 $REV`
  deleted_files=`git -C $SOURCE_DIR diff --name-only --diff-filter=D $REV~1 $REV`
  # Apply changes to index
  for f in $changed_files
   do
    git -C $SOURCE_DIR show $REV:$f > $f
    echo $f ; git add $f
  done
  for f in $deleted_files
   do
    git rm $f
  done
  stage_commit_message
}

run_patch_mode() {
  PATCH_FILE=__import-git-commit.patch
  git -C $SOURCE_DIR diff --diff-algorithm=patience $REV~1..$REV > $PATCH_FILE
  if git apply --index --directory=storage/ndb/nodejs $PATCH_FILE
    then
      stage_commit_message
    else
      echo "Try again with -f option"
  fi
  rm $PATCH_FILE
}

if test $copy_mode -eq 1
  then
    run_copy_mode
  else
    run_patch_mode
fi