# Copyright 2022 Google Inc.
#
# 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.
from typing import Any
import google.auth
from google.auth.transport.requests import AuthorizedSession
import requests
import json
import logging

# Following GCP best practices, these credentials should be
# constructed at start-up time and used throughout
# https://cloud.google.com/apis/docs/client-libraries-best-practices
AUTH_SCOPE = "https://www.googleapis.com/auth/cloud-platform"
CREDENTIALS, _ = google.auth.default(scopes=[AUTH_SCOPE])


def make_composer2_web_server_request(
        url: str,
        method: str = "GET",
        **kwargs: Any) -> google.auth.transport.Response:
    """
    Make a request to Cloud Composer 2 environment's web server.
    Args:
      url: The URL to fetch.
      method: The request method to use ('GET', 'OPTIONS', 'HEAD', 'POST', 'PUT',
        'PATCH', 'DELETE')
      **kwargs: Any of the parameters defined for the request function:
                https://github.com/requests/requests/blob/master/requests/api.py
                  If no timeout is provided, it is set to 90 by default.
    """

    authed_session = AuthorizedSession(CREDENTIALS)

    # Set the default timeout, if missing
    if "timeout" not in kwargs:
        kwargs["timeout"] = 90

    return authed_session.request(method, url, **kwargs)


def trigger_dag(web_server_url: str, dag_id: str, data: dict) -> str:
    """
    Make a request to trigger a dag using the stable Airflow 2 REST API.
    https://airflow.apache.org/docs/apache-airflow/stable/stable-rest-api-ref.html

    Args:
      web_server_url: The URL of the Airflow 2 web server.
      dag_id: The DAG ID.
      data: Additional configuration parameters for the DAG run (json).
    """

    endpoint = f"api/v1/dags/{dag_id}/dagRuns"
    request_url = f"{web_server_url}/{endpoint}"
    json_data = {"conf": data}

    logging.info('request_url: %s', request_url)
    json_formatted_str = json.dumps(json_data, indent=2)
    logging.info('json_request_dagrun: %s', json_formatted_str)

    response = make_composer2_web_server_request(request_url,
                                                 method="POST",
                                                 json=json_data)

    if response.status_code == 403:
        raise requests.HTTPError(
            "You do not have a permission to perform this operation. "
            "Check Airflow RBAC roles for your account."
            f"{response.headers} / {response.text}")
    elif response.status_code != 200:
        response.raise_for_status()
    else:
        return response.text
