# 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.

# This file is for testing purposes only. You SHOULD NOT include it
# or the PEM files when deploying your app.

import base64
import calendar
import datetime
import json
import os
import pytest

from google.auth import crypt
from google.auth import jwt
from google.oauth2 import id_token

import main


DATA_DIR = os.path.join(os.path.dirname(__file__), 'data')

with open(os.path.join(DATA_DIR, 'privatekey.pem'), 'rb') as fh:
    PRIVATE_KEY_BYTES = fh.read()

with open(os.path.join(DATA_DIR, 'public_cert.pem'), 'rb') as fh:
    PUBLIC_CERT_BYTES = fh.read()


@pytest.fixture
def client():
    main.app.testing = True
    return main.app.test_client()


@pytest.fixture
def signer():
    return crypt.RSASigner.from_string(PRIVATE_KEY_BYTES, '1')


@pytest.fixture
def fake_token(signer):
    now = calendar.timegm(datetime.datetime.utcnow().utctimetuple())
    payload = {
        'aud': 'example.com',
        'azp': '1234567890',
        'email': 'pubsub@example.iam.gserviceaccount.com',
        'email_verified': True,
        'iat': now,
        'exp': now + 3600,
        'iss': 'https://accounts.google.com',
        'sub': '1234567890'
    }
    header = {
        'alg': 'RS256',
        'kid': signer.key_id,
        'typ': 'JWT'
    }
    yield jwt.encode(signer, payload, header=header)


def _verify_mocked_oauth2_token(token, request, audience):
    claims = jwt.decode(token, certs=PUBLIC_CERT_BYTES, verify=True)
    return claims


def test_index(client):
    r = client.get('/')
    assert r.status_code == 200


def test_post_index(client):
    r = client.post('/', data={'payload': 'Test payload'})
    assert r.status_code == 200


def test_push_endpoint(monkeypatch, client, fake_token):
    monkeypatch.setattr(id_token, 'verify_oauth2_token',
                        _verify_mocked_oauth2_token)

    url = '/_ah/push-handlers/receive_messages?token=' + \
        os.environ['PUBSUB_VERIFICATION_TOKEN']

    r = client.post(
        url,
        data=json.dumps({
            "message": {
                "data": base64.b64encode(
                    u'Test message'.encode('utf-8')
                ).decode('utf-8')
            }
        }),
        headers=dict(
            Authorization="Bearer " + fake_token.decode('utf-8')
        )
    )
    assert r.status_code == 200

    # Make sure the message is visible on the home page.
    r = client.get('/')
    assert r.status_code == 200
    assert 'Test message' in r.data.decode('utf-8')


def test_push_endpoint_errors(client):
    # no token
    r = client.post('/_ah/push-handlers/receive_messages')
    assert r.status_code == 400

    # invalid token
    r = client.post('/_ah/push-handlers/receive_messages?token=bad')
    assert r.status_code == 400