# -*- coding: utf-8 -*- #
# Copyright 2022 Google LLC. All Rights Reserved.
#
# 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.
"""Utilities shared between local and cloud code dev implementations."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import glob
import os

from googlecloudsdk.core import exceptions


def ChooseExistingServiceYaml(context, arg):
  """Rules for choosing a service.yaml or app.yaml file.

  The rules are meant to discover common filename variants like
  'service.dev.yml' or 'staging-service.yaml'.

  Args:
    context: Build context dir. Could be '.'.
    arg: User's path (relative to context or absolute) to a yaml file with
      service config, or None. The service config could be a knative Service
      description or an appengine app.yaml.

  Returns:
    Absolute path to a yaml file, or None.
  """
  if arg is not None:
    complete_abs_path = os.path.abspath(os.path.join(context, arg))
    if os.path.exists(complete_abs_path):
      return complete_abs_path
    raise exceptions.Error("File '{}' not found.".format(complete_abs_path))
  for pattern in [
      '*service.dev.yaml',
      '*service.dev.yml',
      '*service.yaml',
      '*service.yml',
  ]:
    matches = glob.glob(os.path.join(context, pattern))
    if matches:
      return sorted(matches)[0]
  return None