# -*- coding: utf-8 -*-
from __future__ import absolute_import, unicode_literals

from decimal import Decimal

import pytest
from case import MagicMock, Mock, patch, sentinel, skip

from celery.backends import dynamodb as module
from celery.backends.dynamodb import DynamoDBBackend
from celery.exceptions import ImproperlyConfigured
from celery.five import string


@skip.unless_module('boto3')
class test_DynamoDBBackend:
    def setup(self):
        self._static_timestamp = Decimal(1483425566.52)  # noqa
        self.app.conf.result_backend = 'dynamodb://'

    @property
    def backend(self):
        """:rtype: DynamoDBBackend"""
        return self.app.backend

    def test_init_no_boto3(self):
        prev, module.boto3 = module.boto3, None
        try:
            with pytest.raises(ImproperlyConfigured):
                DynamoDBBackend(app=self.app)
        finally:
            module.boto3 = prev

    def test_init_aws_credentials(self):
        with pytest.raises(ImproperlyConfigured):
            DynamoDBBackend(
                app=self.app,
                url='dynamodb://a:@'
            )

    def test_get_client_explicit_endpoint(self):
        table_creation_path = \
            'celery.backends.dynamodb.DynamoDBBackend._get_or_create_table'
        with patch('boto3.client') as mock_boto_client, \
                patch(table_creation_path):

            self.app.conf.dynamodb_endpoint_url = 'http://my.domain.com:666'
            backend = DynamoDBBackend(
                app=self.app,
                url='dynamodb://@us-east-1'
            )
            client = backend._get_client()
            assert backend.client is client
            mock_boto_client.assert_called_once_with(
                'dynamodb',
                endpoint_url='http://my.domain.com:666',
                region_name='us-east-1'
            )
            assert backend.endpoint_url == 'http://my.domain.com:666'

    def test_get_client_local(self):
        table_creation_path = \
            'celery.backends.dynamodb.DynamoDBBackend._get_or_create_table'
        with patch('boto3.client') as mock_boto_client, \
                patch(table_creation_path):
            backend = DynamoDBBackend(
                app=self.app,
                url='dynamodb://@localhost:8000'
            )
            client = backend._get_client()
            assert backend.client is client
            mock_boto_client.assert_called_once_with(
                'dynamodb',
                endpoint_url='http://localhost:8000',
                region_name='us-east-1'
            )
            assert backend.endpoint_url == 'http://localhost:8000'

    def test_get_client_credentials(self):
        table_creation_path = \
            'celery.backends.dynamodb.DynamoDBBackend._get_or_create_table'
        with patch('boto3.client') as mock_boto_client, \
                patch(table_creation_path):
            backend = DynamoDBBackend(
                app=self.app,
                url='dynamodb://key:secret@test'
            )
            client = backend._get_client()
            assert client is backend.client
            mock_boto_client.assert_called_once_with(
                'dynamodb',
                aws_access_key_id='key',
                aws_secret_access_key='secret',
                region_name='test'
            )
            assert backend.aws_region == 'test'

    def test_get_or_create_table_not_exists(self):
        self.backend._client = MagicMock()
        mock_create_table = self.backend._client.create_table = MagicMock()
        mock_describe_table = self.backend._client.describe_table = \
            MagicMock()

        mock_describe_table.return_value = {
            'Table': {
                'TableStatus': 'ACTIVE'
            }
        }

        self.backend._get_or_create_table()
        mock_create_table.assert_called_once_with(
            **self.backend._get_table_schema()
        )

    def test_get_or_create_table_already_exists(self):
        from botocore.exceptions import ClientError

        self.backend._client = MagicMock()
        mock_create_table = self.backend._client.create_table = MagicMock()
        client_error = ClientError(
            {
                'Error': {
                    'Code': 'ResourceInUseException',
                    'Message': 'Table already exists: {}'.format(
                        self.backend.table_name
                    )
                }
            },
            'CreateTable'
        )
        mock_create_table.side_effect = client_error
        mock_describe_table = self.backend._client.describe_table = \
            MagicMock()

        mock_describe_table.return_value = {
            'Table': {
                'TableStatus': 'ACTIVE'
            }
        }

        self.backend._get_or_create_table()
        mock_describe_table.assert_called_once_with(
            TableName=self.backend.table_name
        )

    def test_wait_for_table_status(self):
        self.backend._client = MagicMock()
        mock_describe_table = self.backend._client.describe_table = \
            MagicMock()
        mock_describe_table.side_effect = [
            {'Table': {
                'TableStatus': 'CREATING'
            }},
            {'Table': {
                'TableStatus': 'SOME_STATE'
            }}
        ]
        self.backend._wait_for_table_status(expected='SOME_STATE')
        assert mock_describe_table.call_count == 2

    def test_prepare_get_request(self):
        expected = {
            'TableName': u'celery',
            'Key': {u'id': {u'S': u'abcdef'}}
        }
        assert self.backend._prepare_get_request('abcdef') == expected

    def test_prepare_put_request(self):
        expected = {
            'TableName': u'celery',
            'Item': {
                u'id': {u'S': u'abcdef'},
                u'result': {u'B': u'val'},
                u'timestamp': {
                    u'N': str(Decimal(self._static_timestamp))
                }
            }
        }
        with patch('celery.backends.dynamodb.time', self._mock_time):
            result = self.backend._prepare_put_request('abcdef', 'val')
        assert result == expected

    def test_item_to_dict(self):
        boto_response = {
            'Item': {
                'id': {
                    'S': sentinel.key
                },
                'result': {
                    'B': sentinel.value
                },
                'timestamp': {
                    'N': Decimal(1)
                }
            }
        }
        converted = self.backend._item_to_dict(boto_response)
        assert converted == {
            'id': sentinel.key,
            'result': sentinel.value,
            'timestamp': Decimal(1)
        }

    def test_get(self):
        self.backend._client = Mock(name='_client')
        self.backend._client.get_item = MagicMock()

        assert self.backend.get('1f3fab') is None
        self.backend.client.get_item.assert_called_once_with(
            Key={u'id': {u'S': u'1f3fab'}},
            TableName='celery'
        )

    def _mock_time(self):
        return self._static_timestamp

    def test_set(self):

        self.backend._client = MagicMock()
        self.backend._client.put_item = MagicMock()

        # should return None
        with patch('celery.backends.dynamodb.time', self._mock_time):
            assert self.backend.set(sentinel.key, sentinel.value) is None

        assert self.backend._client.put_item.call_count == 1
        _, call_kwargs = self.backend._client.put_item.call_args
        expected_kwargs = {
            'Item': {
                u'timestamp': {u'N': str(self._static_timestamp)},
                u'id': {u'S': string(sentinel.key)},
                u'result': {u'B': sentinel.value}
            },
            'TableName': 'celery'
        }
        assert call_kwargs['Item'] == expected_kwargs['Item']
        assert call_kwargs['TableName'] == 'celery'

    def test_delete(self):
        self.backend._client = Mock(name='_client')
        mocked_delete = self.backend._client.delete = Mock('client.delete')
        mocked_delete.return_value = None
        # should return None
        assert self.backend.delete('1f3fab') is None
        self.backend.client.delete_item.assert_called_once_with(
            Key={u'id': {u'S': u'1f3fab'}},
            TableName='celery'
        )

    def test_backend_by_url(self, url='dynamodb://'):
        from celery.app import backends
        from celery.backends.dynamodb import DynamoDBBackend
        backend, url_ = backends.by_url(url, self.app.loader)
        assert backend is DynamoDBBackend
        assert url_ == url

    def test_backend_params_by_url(self):
        self.app.conf.result_backend = \
            'dynamodb://@us-east-1/celery_results?read=10&write=20'
        assert self.backend.aws_region == 'us-east-1'
        assert self.backend.table_name == 'celery_results'
        assert self.backend.read_capacity_units == 10
        assert self.backend.write_capacity_units == 20
        assert self.backend.endpoint_url is None