#!/usr/bin/python3
#
# This file is based on Bazel plugin for IntelliJ by The Bazel Authors, licensed under Apache-2.0;
# It was modified by JetBrains s.r.o. and contributors
#
# Copyright 2019 Google LLC
#
# 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.

"""Merges multiple xml files with the same top element tags into a single file.
"""

import argparse
import sys
from xml.dom.minidom import parse  # pylint: disable=g-importing-member

parser = argparse.ArgumentParser()

parser.add_argument(
    "--output",
    help="The file to output to. If none, prints to stdout.",
    required=False,)

parser.add_argument(
    "xmls",
    nargs="+",
    help="The xml files to merge",)


def AppendFileToTree(filepath, tree):
  """Reads XML from a file and appends XML content to the tree.

  Root elements for both trees must have the same tag.

  Args:
    filepath: Path to the file containing XML specification.
    tree: Tree to add content to.

  Raises:
    RuntimeError: The top-level XML tags are incompatible
  """

  file_dom = parse(filepath)

  if file_dom.documentElement.tagName != tree.documentElement.tagName:
    raise RuntimeError("Incompatible top-level tags: '%s' vs. '%s'" %
                       (file_dom.documentElement.tagName,
                        tree.documentElement.tagName))

  for node in file_dom.documentElement.childNodes:
    tree.documentElement.appendChild(tree.importNode(node, True))


if __name__ == "__main__":
  args = parser.parse_args()
  if not args.xmls:
    sys.exit(2)

  dom = parse(args.xmls[0])
  for filename in args.xmls[1:]:
    AppendFileToTree(filename, dom)

  if args.output:
    with open(args.output, "wb") as f:
      f.write(dom.toprettyxml(encoding="utf-8"))
  else:
    sys.stdout.buffer.write(dom.toprettyxml(encoding="utf-8"))