#
# Copyright 2017-2018 Amazon.com, Inc. and its affiliates. All Rights Reserved.
#
# Licensed under the MIT License. See the LICENSE accompanying this file
# for the specific language governing permissions and limitations under
# the License.
#

import mount_efs
import json

import pytest

from .. import utils

try:
    import ConfigParser
except ImportError:
    from configparser import ConfigParser

try:
    from urllib2 import URLError, HTTPError
except ImportError:
    from urllib.error import URLError, HTTPError

INSTANCE_DATA = {
  'devpayProductCodes': None,
  'privateIp': '192.168.1.1',
  'availabilityZone': 'us-east-1a',
  'version': '2010-08-31',
  'instanceId': 'i-deadbeefdeadbeef0',
  'billingProducts': None,
  'pendingTime': '2017-06-20T18:32:00Z',
  'instanceType': 'm3.xlarge',
  'accountId': '123412341234',
  'architecture': 'x86_64',
  'kernelId': None,
  'ramdiskId': None,
  'imageId': 'ami-deadbeef',
  'region': 'us-east-1'
}

TARGET_REGION = 'us-east-1'
INSTANCE_DOCUMENT = json.dumps(INSTANCE_DATA)
DNS_NAME_SUFFIX = 'amazonaws.com'


class MockHeaders(object):
    def __init__(self, content_charset=None):
        self.content_charset = content_charset

    def get_content_charset(self):
        return self.content_charset


class MockUrlLibResponse(object):
    def __init__(self, code=200, data=INSTANCE_DOCUMENT, headers=MockHeaders()):
        self.code = code
        self.data = data
        self.headers = headers

    def getcode(self):
        return self.code

    def read(self):
        return self.data


def get_config(dns_name_format, region=None):
    try:
        config = ConfigParser.SafeConfigParser()
    except AttributeError:
        config = ConfigParser()
    config.add_section(mount_efs.CONFIG_SECTION)
    config.set(mount_efs.CONFIG_SECTION, 'dns_name_format', dns_name_format)
    if region:
        config.set(mount_efs.CONFIG_SECTION, 'region', region)
    return config


def get_target_region_helper():
    config = get_config('{az}.{fs_id}.efs.{region}.{dns_name_suffix}')
    return mount_efs.get_target_region(config)


"""
Get target region from ec2 instance metadata
"""
def test_get_target_region_with_token(mocker):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value='ABCDEFG==')
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse())
    assert 'us-east-1' == get_target_region_helper()


def test_get_target_region_without_token(mocker):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse())
    assert 'us-east-1' == get_target_region_helper()


def test_get_target_region_metadata_endpoint_unauthorized(mocker):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value='ABCDEFG==')
    mocker.patch('mount_efs.urlopen', side_effect=[HTTPError('url', 401, 'Unauthorized', None, None), MockUrlLibResponse()])
    assert 'us-east-1' == get_target_region_helper()


# Reproduce https://github.com/aws/efs-utils/issues/46
def test_get_target_region_token_endpoint_not_allowed(mocker):
    get_aws_ec2_metadata_token_mock = mocker.patch('mount_efs.get_aws_ec2_metadata_token',
                                                   side_effect=HTTPError('url', 405, 'Not allowed', None, None))
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse())
    assert 'us-east-1' == get_target_region_helper()
    utils.assert_not_called(get_aws_ec2_metadata_token_mock)


def test_get_target_region_py3_no_charset(mocker):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse(data=bytearray(INSTANCE_DOCUMENT, 'us-ascii')))
    assert 'us-east-1' == get_target_region_helper()


def test_get_target_region_py3_utf8_charset(mocker):
    charset = 'utf-8'
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse(data=bytearray(INSTANCE_DOCUMENT, charset)),
                 headers=MockHeaders(content_charset=charset))
    assert 'us-east-1' == get_target_region_helper()


def test_get_target_region_from_metadata(mocker):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', return_value=MockUrlLibResponse())
    config = get_config('{fs_id}.efs.{region}.{dns_name_suffix}', None)
    assert TARGET_REGION == mount_efs.get_target_region(config)


def test_get_target_region_config_metadata_unavailable(mocker, capsys):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', side_effect=URLError('test error'))
    config = get_config('{fs_id}.efs.{region}.{dns_name_suffix}')
    with pytest.raises(SystemExit) as ex:
      mount_efs.get_target_region(config)

    assert 0 != ex.value.code
    out, err = capsys.readouterr()
    assert 'Error retrieving region' in err


def _test_get_target_region_error(mocker, capsys, response=None, error=None):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    if (response and error) or (not response and not error):
        raise ValueError('Invalid arguments')
    elif response:
        mocker.patch('mount_efs.urlopen', return_value=response)
    elif error:
        mocker.patch('mount_efs.urlopen', side_effect=error)

    with pytest.raises(SystemExit) as ex:
        get_target_region_helper()

    assert 0 != ex.value.code

    out, err = capsys.readouterr()
    assert 'Error retrieving region' in err


def test_get_target_region_bad_response(mocker, capsys):
    _test_get_target_region_error(mocker, capsys, error=HTTPError('url', 400, 'Bad Request Error', None, None))


def test_get_target_region_error_response(mocker, capsys):
    _test_get_target_region_error(mocker, capsys, error=URLError('test error'))


def test_get_target_region_bad_json(mocker, capsys):
    _test_get_target_region_error(mocker, capsys, response=MockUrlLibResponse(data='not json'))


def test_get_target_region_missing_region(mocker, capsys):
    _test_get_target_region_error(mocker, capsys, response=MockUrlLibResponse(data=json.dumps({})))


"""
Get target region from configuration file
"""
def test_get_target_region_from_config_variable(mocker):
    config = get_config('{az}.{fs_id}.efs.us-east-2.{dns_name_suffix}', TARGET_REGION)
    assert TARGET_REGION == mount_efs.get_target_region(config)


def _test_get_target_region_from_dns_format(mocker, config):
    mocker.patch('mount_efs.get_aws_ec2_metadata_token', return_value=None)
    mocker.patch('mount_efs.urlopen', side_effect=URLError('test error'))
    assert TARGET_REGION == mount_efs.get_target_region(config)


def test_get_target_region_from_legacy_dns_name_format(mocker):
    config = get_config('{az}.{fs_id}.efs.us-east-1.amazonaws.com')
    _test_get_target_region_from_dns_format(mocker, config)


def test_get_target_region_from_suffixed_dns_name_format(mocker):
    config = get_config('{az}.{fs_id}.efs.us-east-1.{dns_name_suffix}')
    config.set(mount_efs.CONFIG_SECTION, 'dns_name_suffix', DNS_NAME_SUFFIX)
    _test_get_target_region_from_dns_format(mocker, config)