"""Lambda test module."""

import json

import pytest
from src import config
from src import app
from constants import fields


@pytest.fixture
def dynamo_stream_event():
    """Get example event content."""
    with open('tests/event.json', 'r') as myfile:
        return json.loads(myfile.read())


@pytest.fixture
def mocked_invoke(mocker):
    """Mock boto3 lambda client."""
    mocked_boto_client = mocker.patch('boto3.client')
    mocked_lambda_client = mocker.Mock()
    mocked_invoke_func = mocker.Mock()
    mocked_lambda_client.invoke = mocked_invoke_func
    mocked_boto_client.return_value = mocked_lambda_client
    return mocked_invoke_func


def test_handler(mocked_invoke, dynamo_stream_event):
    """Test app.handler function, success case."""
    app.handler(dynamo_stream_event, None)

    assert mocked_invoke.call_count == 1
    assert mocked_invoke.call_args[1]['FunctionName'] == (
        config.VO_TO_DD_SYNC_LAMBDA_NAME)
    insert_record = dynamo_stream_event[fields.DDB_EVENT_RECORDS][0]
    ddb_record = insert_record[fields.DDB_EVENT_RECORD_MAIN]
    new_view = ddb_record[fields.DDB_EVENT_RECORD_NEW_VALUES]
    new_view_json_bytes = json.dumps(new_view).encode()
    assert mocked_invoke.call_args[1]['Payload'] == new_view_json_bytes


def test_handler_empty(mocked_invoke):
    """Test app.handler function, empty event."""
    app.handler({}, None)
    app.handler(None, None)

    assert mocked_invoke.call_count == 0