# Copyright 2019 ScyllaDB
#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Scylla.  If not, see <http://www.gnu.org/licenses/>.

# This file contains "test fixtures", a pytest concept described in
# https://docs.pytest.org/en/latest/fixture.html.
# A "fixture" is some sort of setup which an invididual test requires to run.
# The fixture has setup code and teardown code, and if multiple tests
# require the same fixture, it can be set up only once - while still allowing
# the user to run individual tests and automatically set up the fixtures they need.

import pytest
import boto3
from util import create_test_table

# When tests are run with HTTPS, the server often won't have its SSL
# certificate signed by a known authority. So we will disable certificate
# verification with the "verify=False" request option. However, once we do
# that, we start getting scary-looking warning messages, saying that this
# makes HTTPS insecure. The following silences those warnings:
import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

# Test that the Boto libraries are new enough. These tests want to test a
# large variety of DynamoDB API features, and to do this we need a new-enough
# version of the the Boto libraries (boto3 and botocore) so that they can
# access all these API features.
# In particular, the BillingMode feature was added in botocore 1.12.54.
import botocore
import sys
from distutils.version import LooseVersion
if (LooseVersion(botocore.__version__) < LooseVersion('1.12.54')):
    pytest.exit("Your Boto library is too old. Please upgrade it,\ne.g. using:\n    sudo pip{} install --upgrade boto3".format(sys.version_info[0]))

# By default, tests run against a local Scylla installation on localhost:8080/.
# The "--aws" option can be used to run against Amazon DynamoDB in the us-east-1
# region.
def pytest_addoption(parser):
    parser.addoption("--aws", action="store_true",
        help="run against AWS instead of a local Scylla installation")
    parser.addoption("--https", action="store_true",
        help="communicate via HTTPS protocol on port 8043 instead of HTTP when"
            " running against a local Scylla installation")
    parser.addoption("--url", action="store",
        help="communicate with given URL instead of defaults")

# "dynamodb" fixture: set up client object for communicating with the DynamoDB
# API. Currently this chooses either Amazon's DynamoDB in the default region
# or a local Alternator installation on http://localhost:8080 - depending on the
# existence of the "--aws" option. In the future we should provide options
# for choosing other Amazon regions or local installations.
# We use scope="session" so that all tests will reuse the same client object.
@pytest.fixture(scope="session")
def dynamodb(request):
    if request.config.getoption('aws'):
        return boto3.resource('dynamodb')
    else:
        # Even though we connect to the local installation, Boto3 still
        # requires us to specify dummy region and credential parameters,
        # otherwise the user is forced to properly configure ~/.aws even
        # for local runs.
        if request.config.getoption('url') != None:
            local_url = request.config.getoption('url')
        else:
            local_url = 'https://localhost:8043' if request.config.getoption('https') else 'http://localhost:8000'
        # Disable verifying in order to be able to use self-signed TLS certificates
        verify = not request.config.getoption('https')
        return boto3.resource('dynamodb', endpoint_url=local_url, verify=verify,
            region_name='us-east-1', aws_access_key_id='alternator', aws_secret_access_key='secret_pass',
            config=botocore.client.Config(retries={"max_attempts": 0}, read_timeout=300))

@pytest.fixture(scope="session")
def dynamodbstreams(request):
    if request.config.getoption('aws'):
        return boto3.client('dynamodbstreams')
    else:
        # Even though we connect to the local installation, Boto3 still
        # requires us to specify dummy region and credential parameters,
        # otherwise the user is forced to properly configure ~/.aws even
        # for local runs.
        if request.config.getoption('url') != None:
            local_url = request.config.getoption('url')
        else:
            local_url = 'https://localhost:8043' if request.config.getoption('https') else 'http://localhost:8000'
        # Disable verifying in order to be able to use self-signed TLS certificates
        verify = not request.config.getoption('https')
        return boto3.client('dynamodbstreams', endpoint_url=local_url, verify=verify,
            region_name='us-east-1', aws_access_key_id='alternator', aws_secret_access_key='secret_pass',
            config=botocore.client.Config(retries={"max_attempts": 3}))

# "test_table" fixture: Create and return a temporary table to be used in tests
# that need a table to work on. The table is automatically deleted at the end.
# We use scope="session" so that all tests will reuse the same client object.
# This "test_table" creates a table which has a specific key schema: both a
# partition key and a sort key, and both are strings. Other fixtures (below)
# can be used to create different types of tables.
#
# TODO: Although we are careful about deleting temporary tables when the
# fixture is torn down, in some cases (e.g., interrupted tests) we can be left
# with some tables not deleted, and they will never be deleted. Because all
# our temporary tables have the same test_table_prefix, we can actually find
# and remove these old tables with this prefix. We can have a fixture, which
# test_table will require, which on teardown will delete all remaining tables
# (possibly from an older run). Because the table's name includes the current
# time, we can also remove just tables older than a particular age. Such
# mechanism will allow running tests in parallel, without the risk of deleting
# a parallel run's temporary tables.
@pytest.fixture(scope="session")
def test_table(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' },
                    { 'AttributeName': 'c', 'KeyType': 'RANGE' }
        ],
        AttributeDefinitions=[
                    { 'AttributeName': 'p', 'AttributeType': 'S' },
                    { 'AttributeName': 'c', 'AttributeType': 'S' },
        ])
    yield table
    # We get back here when this fixture is torn down. We ask Dynamo to delete
    # this table, but not wait for the deletion to complete. The next time
    # we create a test_table fixture, we'll choose a different table name
    # anyway.
    table.delete()

# The following fixtures test_table_* are similar to test_table but create
# tables with different key schemas.
@pytest.fixture(scope="session")
def test_table_s(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' } ])
    yield table
    table.delete()
# test_table_s_2 has exactly the same schema as test_table_s, and is useful
# for tests which need two different tables with the same schema.
@pytest.fixture(scope="session")
def test_table_s_2(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' } ])
    yield table
    table.delete()
@pytest.fixture(scope="session")
def test_table_b(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'B' } ])
    yield table
    table.delete()
@pytest.fixture(scope="session")
def test_table_sb(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, { 'AttributeName': 'c', 'KeyType': 'RANGE' } ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' }, { 'AttributeName': 'c', 'AttributeType': 'B' } ])
    yield table
    table.delete()
@pytest.fixture(scope="session")
def test_table_sn(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, { 'AttributeName': 'c', 'KeyType': 'RANGE' } ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' }, { 'AttributeName': 'c', 'AttributeType': 'N' } ])
    yield table
    table.delete()
@pytest.fixture(scope="session")
def test_table_ss(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, { 'AttributeName': 'c', 'KeyType': 'RANGE' } ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' }, { 'AttributeName': 'c', 'AttributeType': 'S' } ])
    yield table
    table.delete()

# "filled_test_table" fixture:  Create a temporary table to be used in tests
# that involve reading data - GetItem, Scan, etc. The table is filled with
# 328 items - each consisting of a partition key, clustering key and two
# string attributes. 164 of the items are in a single partition (with the
# partition key 'long') and the 164 other items are each in a separate
# partition. Finally, a 329th item is added with different attributes.
# This table is supposed to be read from, not updated nor overwritten.
# This fixture returns both a table object and the description of all items
# inserted into it.
@pytest.fixture(scope="session")
def filled_test_table(dynamodb):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' },
                    { 'AttributeName': 'c', 'KeyType': 'RANGE' }
        ],
        AttributeDefinitions=[
                    { 'AttributeName': 'p', 'AttributeType': 'S' },
                    { 'AttributeName': 'c', 'AttributeType': 'S' },
        ])
    count = 164
    items = [{
        'p': str(i),
        'c': str(i),
        'attribute': "x" * 7,
        'another': "y" * 16
    } for i in range(count)]
    items = items + [{
        'p': 'long',
        'c': str(i),
        'attribute': "x" * (1 + i % 7),
        'another': "y" * (1 + i % 16)
    } for i in range(count)]
    items.append({'p': 'hello', 'c': 'world', 'str': 'and now for something completely different'})

    with table.batch_writer() as batch:
        for item in items:
            batch.put_item(item)

    yield table, items
    table.delete()

# The "scylla_only" fixture can be used by tests for Scylla-only features,
# which do not exist on AWS DynamoDB. A test using this fixture will be
# skipped if running with "--aws".
@pytest.fixture(scope="session")
def scylla_only(dynamodb):
    if dynamodb.meta.client._endpoint.host.endswith('.amazonaws.com'):
        pytest.skip('Scylla-only feature not supported by AWS')

# The "test_table_s_forbid_rmw" fixture is the same as test_table_s, except
# with the "forbid_rmw" write isolation mode. This is useful for verifying
# that writes that we think should not need a read-before-write in fact do
# not need it.
# Because forbid_rmw is a Scylla-only feature, this test is skipped when not
# running against Scylla.
@pytest.fixture(scope="session")
def test_table_s_forbid_rmw(dynamodb, scylla_only):
    table = create_test_table(dynamodb,
        KeySchema=[ { 'AttributeName': 'p', 'KeyType': 'HASH' }, ],
        AttributeDefinitions=[ { 'AttributeName': 'p', 'AttributeType': 'S' } ])
    arn = table.meta.client.describe_table(TableName=table.name)['Table']['TableArn']
    table.meta.client.tag_resource(ResourceArn=arn, Tags=[{'Key': 'system:write_isolation', 'Value': 'forbid_rmw'}])
    yield table
    table.delete()
