# Copyright 2015 - Mirantis, Inc.
#
# 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.

from oslo_config import cfg
from oslo_log import log as logging
import testtools

from mistral.actions import base as actions_base
from mistral.db.v2 import api as db_api
from mistral import exceptions as exc
from mistral.services import workflows as wf_service
from mistral.tests import base as test_base
from mistral.tests.unit.engine import base
from mistral.workflow import utils as wf_utils

LOG = logging.getLogger(__name__)

# Use the set_default method to set value otherwise in certain test cases
# the change in value is not permanent.
cfg.CONF.set_default('auth_enable', False, group='pecan')

WF = """
---
version: '2.0'

wf:
  input:
    - workflow_input: '__WORKFLOW_INPUT__'
    - action_output_length: 0
  tasks:
    task1:
      action: my_action
      input:
        action_input: '__ACTION_INPUT__'
        action_output_length: <% $.action_output_length %>
      publish:
        p_var: '__TASK_PUBLISHED__'
"""


class MyAction(actions_base.Action):
    def __init__(self, action_input, action_output_length):
        self.action_input = action_input
        self.action_output_length = action_output_length

    def run(self):
        return wf_utils.Result(
            data=''.join('A' for _ in range(self.action_output_length))
        )

    def test(self):
        raise NotImplementedError


def expect_size_limit_exception(field_name):
    def logger(test_func):
        def wrapped(*args, **kwargs):
            with testtools.ExpectedException(exc.SizeLimitExceededException,
                                             value_re="Size of '%s' is 1KB "
                                                      "which exceeds the limit"
                                                      " of 0KB" % field_name):
                return test_func(*args, **kwargs)

        return wrapped

    return logger


def generate_workflow(tokens):
    new_wf = WF
    long_string = ''.join('A' for _ in range(1024))
    for token in tokens:
        new_wf = new_wf.replace(token, long_string)
    return new_wf


class ExecutionFieldsSizeLimitTest(base.EngineTestCase):
    def setUp(self):
        """Resets the size limit config between tests"""
        super(ExecutionFieldsSizeLimitTest, self).setUp()
        cfg.CONF.set_default('execution_field_size_limit_kb', 0,
                             group='engine')
        test_base.register_action_class('my_action', MyAction)

    def test_default_limit(self):
        cfg.CONF.set_default('execution_field_size_limit_kb', -1,
                             group='engine')

        new_wf = generate_workflow(
            ['__ACTION_INPUT_', '__WORKFLOW_INPUT__',
             '__TASK_PUBLISHED__'])

        wf_service.create_workflows(new_wf)

        # Start workflow.
        wf_ex = self.engine.start_workflow('wf', {})

        self._await(lambda: self.is_execution_success(wf_ex.id))

    @expect_size_limit_exception('input')
    def test_workflow_input_default_value_limit(self):
        new_wf = generate_workflow(['__WORKFLOW_INPUT__'])

        wf_service.create_workflows(new_wf)

        # Start workflow.
        self.engine.start_workflow('wf', {})

    @expect_size_limit_exception('input')
    def test_workflow_input_limit(self):
        wf_service.create_workflows(WF)

        # Start workflow.
        self.engine.start_workflow(
            'wf',
            {
                'workflow_input': ''.join('A' for _ in range(1024))
            }
        )

    @expect_size_limit_exception('input')
    def test_action_input_limit(self):
        new_wf = generate_workflow(['__ACTION_INPUT__'])

        wf_service.create_workflows(new_wf)

        # Start workflow.
        self.engine.start_workflow('wf', {})

    def test_action_output_limit(self):
        wf_service.create_workflows(WF)

        # Start workflow.
        wf_ex = self.engine.start_workflow('wf', {
            'action_output_length': 1024
        })

        self._await(lambda: self.is_execution_error(wf_ex.id))

        # Note: We need to reread execution to access related tasks.
        wf_ex = db_api.get_workflow_execution(wf_ex.id)

        self.assertEqual("Size of 'output' is 1KB which exceeds "
                         "the limit of 0KB",
                         wf_ex.state_info)

    def test_task_published_limit(self):
        new_wf = generate_workflow(['__TASK_PUBLISHED__'])

        wf_service.create_workflows(new_wf)

        # Start workflow.
        wf_ex = self.engine.start_workflow('wf', {})

        self._await(lambda: self.is_execution_error(wf_ex.id))

        # Note: We need to reread execution to access related tasks.
        wf_ex = db_api.get_workflow_execution(wf_ex.id)

        self.assertEqual("Size of 'published' is 1KB which exceeds "
                         "the limit of 0KB",
                         wf_ex.state_info)

    @expect_size_limit_exception('params')
    def test_workflow_params_limit(self):
        wf_service.create_workflows(WF)

        # Start workflow.
        long_string = ''.join('A' for _ in range(1024))
        self.engine.start_workflow('wf', {}, '', env={'param': long_string})

    def tearDown(self):
        """Restores the size limit config to default"""
        super(ExecutionFieldsSizeLimitTest, self).tearDown()
        cfg.CONF.set_default('execution_field_size_limit_kb', 1024,
                             group='engine')
