#
#    Copyright (c) 2022 Project CHIP Authors
#
#    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.

import copy
from dataclasses import dataclass, field
from enum import Enum, auto

from . import fixes
from .constraints import get_constraints, is_typed_constraint
from .definitions import SpecDefinitions
from .errors import TestStepError, TestStepKeyError, TestStepValueNameError
from .pics_checker import PICSChecker
from .yaml_loader import YamlLoader


class UnknownPathQualifierError(TestStepError):
    """Raise when an attribute/command/event name is not found in the definitions."""

    def __init__(self, content, target_type, target_name, candidate_names=[]):
        if candidate_names:
            message = f'Unknown {target_type}: "{target_name}". Candidates are: "{candidate_names}"'

            for candidate_name in candidate_names:
                if candidate_name.lower() == target_name.lower():
                    message = f'Unknown {target_type}: "{target_name}". Did you mean "{candidate_name}" ?'
                    break
        else:
            message = f'The cluster does not have any {target_type}s.'

        super().__init__(message)
        self.tag_key_with_error(content, target_type)


class TestStepAttributeKeyError(UnknownPathQualifierError):
    """Raise when an attribute name is not found in the definitions."""

    def __init__(self, content, target_name, candidate_names=[]):
        super().__init__(content, 'attribute', target_name, candidate_names)


class TestStepCommandKeyError(UnknownPathQualifierError):
    """Raise when a command name is not found in the definitions."""

    def __init__(self, content, target_name, candidate_names=[]):
        super().__init__(content, 'command', target_name, candidate_names)


class TestStepEventKeyError(UnknownPathQualifierError):
    """Raise when an event name is not found in the definitions."""

    def __init__(self, content, target_name, candidate_names=[]):
        super().__init__(content, 'event', target_name, candidate_names)


class PostProcessCheckStatus(Enum):
    '''Indicates the post processing check step status.'''
    SUCCESS = 'success',
    WARNING = 'warning',
    ERROR = 'error'


class PostProcessCheckType(Enum):
    '''Indicates the post processing check step type.'''
    IM_STATUS = auto()
    CLUSTER_STATUS = auto()
    RESPONSE_VALIDATION = auto()
    CONSTRAINT_VALIDATION = auto()
    SAVE_AS_VARIABLE = auto()
    WAIT_VALIDATION = auto()


class PostProcessCheck:
    '''Information about a single post processing operation that was performed.

    Each check has a helpful message, indicating what the post processing operation did and whether
    it was successful or not.
    '''

    def __init__(self, state: PostProcessCheckStatus, category: PostProcessCheckType, message: str, exception=None):
        self.state = state
        self.category = category
        self.message = message
        self.exception = exception

    def is_success(self) -> bool:
        return self.state == PostProcessCheckStatus.SUCCESS

    def is_warning(self) -> bool:
        return self.state == PostProcessCheckStatus.WARNING

    def is_error(self) -> bool:
        return self.state == PostProcessCheckStatus.ERROR


class PostProcessResponseResult:
    '''Post processing response result information.

    There are multiple operations that occur when post processing a response. This contains all the
    results for each operation performed. Note that the number and types of steps performed is
    dependant on test step itself.
    '''

    def __init__(self):
        self.entries = []
        self.successes = 0
        self.warnings = 0
        self.errors = 0

    def success(self, category: PostProcessCheckType, message: str):
        '''Adds a success entry that occured when post processing response to results.'''
        self._insert(PostProcessCheckStatus.SUCCESS, category, message)
        self.successes += 1

    def warning(self, category: PostProcessCheckType, message: str):
        '''Adds a warning entry that occured when post processing response to results.'''
        self._insert(PostProcessCheckStatus.WARNING, category, message)
        self.warnings += 1

    def error(self, category: PostProcessCheckType, message: str, exception: TestStepError = None):
        '''Adds an error entry that occured when post processing response to results.'''
        self._insert(PostProcessCheckStatus.ERROR,
                     category, message, exception)
        self.errors += 1

    def is_success(self):
        # It is possible that post processing a response doesn't have any success entires added
        # that is why we explicitly only search for if an error occurred.
        return self.errors == 0

    def is_failure(self):
        return self.errors != 0

    def _insert(self, state: PostProcessCheckStatus, category: PostProcessCheckType, message: str, exception: Exception = None):
        log = PostProcessCheck(state, category, message, exception)
        self.entries.append(log)


def _value_or_none(data, key):
    return data[key] if key in data else None


def _value_or_config(data, key, config):
    return data[key] if key in data else config.get(key)


class _TestStepWithPlaceholders:
    '''A single YAML test parsed, as is, from YAML.

    Some YAML test steps contain placeholders for variable subsitution. The value of the variable
    is only known after an earlier test step's has executed and the result successfully post
    processed.
    '''

    def __init__(self, test: dict, config: dict, definitions: SpecDefinitions, pics_checker: PICSChecker):
        # Disabled tests are not parsed in order to allow the test to be added to the test
        # suite even if the feature is not implemented yet.
        self.is_enabled = not ('disabled' in test and test['disabled'])
        if not self.is_enabled:
            return

        self._parsing_config_variable_storage = config

        self.label = _value_or_none(test, 'label')
        self.node_id = _value_or_config(test, 'nodeId', config)
        self.group_id = _value_or_config(test, 'groupId', config)
        self.cluster = _value_or_config(test, 'cluster', config)
        self.command = _value_or_config(test, 'command', config)
        self.attribute = _value_or_none(test, 'attribute')
        self.event = _value_or_none(test, 'event')
        self.endpoint = _value_or_config(test, 'endpoint', config)
        self.pics = _value_or_none(test, 'PICS')
        self.is_pics_enabled = pics_checker.check(_value_or_none(test, 'PICS'))

        self.identity = _value_or_none(test, 'identity')
        self.fabric_filtered = _value_or_none(test, 'fabricFiltered')
        self.min_interval = _value_or_none(test, 'minInterval')
        self.max_interval = _value_or_none(test, 'maxInterval')
        self.timed_interaction_timeout_ms = _value_or_none(
            test, 'timedInteractionTimeoutMs')
        self.busy_wait_ms = _value_or_none(test, 'busyWaitMs')
        self.wait_for = _value_or_none(test, 'wait')
        self.event_number = _value_or_none(test, 'eventNumber')

        self.is_attribute = self.__is_attribute_command()
        self.is_event = self.__is_event_command()

        arguments = _value_or_none(test, 'arguments')
        self._convert_single_value_to_values(arguments)
        self.arguments_with_placeholders = arguments

        responses = _value_or_none(test, 'response')
        # Test may expect multiple responses. For example reading events may
        # trigger multiple event responses. Or reading multiple attributes
        # at the same time, may trigger multiple responses too.
        if responses is None:
            # If no response is specified at all, it implies that the step expect
            # a success with any associatied value(s). So the empty response is effectively
            # replace by an array that contains an empty object to represent that.
            responses = [{}]
        elif not isinstance(responses, list):
            # If a single response is specified, it is converted to a list of responses.
            responses = [responses]

        for response in responses:
            self._convert_single_value_to_values(response)
        self.responses_with_placeholders = responses

        self._update_mappings(test, definitions)
        self.update_arguments(self.arguments_with_placeholders)
        self.update_responses(self.responses_with_placeholders)

        # This performs a very basic sanity parse time check of constraints. This parsing happens
        # again inside post processing response since at that time we will have required variables
        # to substitute in. This parsing check here has value since some test can take a really
        # long time to run so knowing earlier on that the test step would have failed at parsing
        # time before the test step run occurs save developer time that building yaml tests.
        for response in self.responses_with_placeholders:
            for value in response:
                if 'constraints' not in value:
                    continue
                get_constraints(value['constraints'])

    def _update_mappings(self, test: dict, definitions: SpecDefinitions):
        cluster_name = self.cluster
        if definitions is None or not definitions.has_cluster_by_name(cluster_name):
            self.argument_mapping = None
            self.response_mapping = None
            self.response_mapping_name = None
            return

        argument_mapping = None
        response_mapping = None
        response_mapping_name = None

        if self.is_attribute:
            attribute_name = self.attribute
            attribute = definitions.get_attribute_by_name(
                cluster_name,
                attribute_name
            )

            if not attribute:
                targets = definitions.get_attribute_names(cluster_name)
                raise TestStepAttributeKeyError(test, attribute_name, targets)

            attribute_mapping = self._as_mapping(
                definitions,
                cluster_name,
                attribute.definition.data_type.name
            )

            argument_mapping = attribute_mapping
            response_mapping = attribute_mapping
            response_mapping_name = attribute.definition.data_type.name
        elif self.is_event:
            event_name = self.event
            event = definitions.get_event_by_name(
                cluster_name,
                event_name
            )

            if not event:
                targets = definitions.get_event_names(cluster_name)
                raise TestStepEventKeyError(test, event_name, targets)

            event_mapping = self._as_mapping(
                definitions,
                cluster_name,
                event_name
            )

            argument_mapping = event_mapping
            response_mapping = event_mapping
            response_mapping_name = event.name
        else:
            command_name = self.command
            command = definitions.get_command_by_name(
                cluster_name,
                command_name
            )

            if not command:
                targets = definitions.get_command_names(cluster_name)
                raise TestStepCommandKeyError(test, command_name, targets)

            if command.input_param is None:
                argument_mapping = {}
            else:
                argument_mapping = self._as_mapping(
                    definitions,
                    cluster_name,
                    command.input_param
                )

            response_mapping = self._as_mapping(
                definitions,
                cluster_name,
                command.output_param
            )
            response_mapping_name = command.output_param

        self.argument_mapping = argument_mapping
        self.response_mapping = response_mapping
        self.response_mapping_name = response_mapping_name

    def _convert_single_value_to_values(self, container):
        if container is None or 'values' in container:
            return

        # Attribute tests pass a single value argument that does not carry a name but
        # instead uses a generic 'value' keyword. Convert to keyword to be the single
        # members of the 'values' array which is what is used for other tests.
        value = {}

        known_keys_to_copy = ['value', 'constraints', 'saveAs']
        known_keys_to_allow = ['error', 'clusterError']

        for key, item in list(container.items()):
            if key in known_keys_to_copy:
                value[key] = item
                del container[key]
            elif key in known_keys_to_allow:
                # Nothing to do for those keys.
                pass
            else:
                raise TestStepKeyError(item, key)

        container['values'] = [value]

    def _as_mapping(self, definitions, cluster_name, target_name):
        element = definitions.get_type_by_name(cluster_name, target_name)

        if hasattr(element, 'base_type'):
            target_name = element.base_type.lower()
        elif hasattr(element, 'fields'):
            target_name = {f.name: self._as_mapping(
                definitions, cluster_name, f.data_type.name) for f in element.fields}
        elif target_name:
            target_name = target_name.lower()

        return target_name

    def update_arguments(self, arguments_with_placeholders):
        self._update_with_definition(
            arguments_with_placeholders, self.argument_mapping)

    def update_responses(self, responses_with_placeholders):
        for response in responses_with_placeholders:
            self._update_with_definition(
                response, self.response_mapping)

    def _update_with_definition(self, container: dict, mapping_type):
        if not container or mapping_type is None:
            return

        values = container['values']
        if values is None:
            return

        for value in list(values):
            for key, item_value in list(value.items()):
                if self.is_attribute or self.is_event:
                    mapping = mapping_type
                else:
                    target_key = value['name']
                    if mapping_type.get(target_key) is None:
                        raise TestStepValueNameError(
                            value, target_key, [key for key in mapping_type])
                    mapping = mapping_type[target_key]

                if key == 'value':
                    value[key] = self._update_value_with_definition(
                        item_value, mapping)
                elif key == 'saveAs' and type(item_value) is str and item_value not in self._parsing_config_variable_storage:
                    self._parsing_config_variable_storage[item_value] = None
                elif key == 'constraints':
                    for constraint, constraint_value in item_value.items():
                        # Only apply update_value_with_definition to constraints that have a value that depends on
                        # the the value type for the target field.
                        if is_typed_constraint(constraint):
                            value[key][constraint] = self._update_value_with_definition(
                                constraint_value, mapping_type)
                else:
                    # This key, value pair does not rely on cluster specifications.
                    pass

    def _update_value_with_definition(self, value, mapping_type):
        if not mapping_type:
            return value

        if type(value) is dict:
            rv = {}
            for key in value:
                # FabricIndex is a special case where the framework requires it to be passed even
                # if it is not part of the requested arguments per spec and not part of the XML
                # definition.
                if key == 'FabricIndex' or key == 'fabricIndex':
                    rv[key] = value[key]  # int64u
                else:
                    if not mapping_type.get(key):
                        raise TestStepKeyError(value, key)
                    mapping = mapping_type[key]
                    rv[key] = self._update_value_with_definition(
                        value[key], mapping)
            return rv
        if type(value) is list:
            return [self._update_value_with_definition(entry, mapping_type) for entry in value]
        # TODO currently unsure if the check of `value not in config` is sufficant. For
        # example let's say value = 'foo + 1' and map type is 'int64u', we would arguably do
        # the wrong thing below.
        if value is not None and value not in self._parsing_config_variable_storage:
            if mapping_type == 'int64u' or mapping_type == 'int64s' or mapping_type == 'bitmap64' or mapping_type == 'epoch_us':
                value = fixes.try_apply_float_to_integer_fix(value)
                value = fixes.try_apply_yaml_cpp_longlong_limitation_fix(value)
                value = fixes.try_apply_yaml_unrepresentable_integer_for_javascript_fixes(
                    value)
            elif mapping_type == 'single' or mapping_type == 'double':
                value = fixes.try_apply_yaml_float_written_as_strings(value)
            elif isinstance(value, float) and mapping_type != 'single' and mapping_type != 'double':
                value = fixes.try_apply_float_to_integer_fix(value)
            elif mapping_type == 'octet_string' or mapping_type == 'long_octet_string':
                value = fixes.convert_yaml_octet_string_to_bytes(value)
            elif mapping_type == 'boolean':
                value = bool(value)

        return value

    def __is_attribute_command(self) -> bool:
        commands = {
            'readAttribute',
            'writeAttribute',
            'subscribeAttribute',
            'waitForReport',
        }

        return self.attribute and (self.command in commands or self.wait_for in commands)

    def __is_event_command(self) -> bool:
        commands = {
            'readEvent',
            'subscribeEvent',
            'waitForReport',
        }

        return self.event and (self.command in commands or self.wait_for in commands)


class TestStep:
    '''A single YAML test action parsed from YAML.

    This object contains all the information required for a test runner to execute the test step.
    It also provide a function that is expected to be called by the test runner to post process
    the recieved response from the accessory. Post processing both validates recieved response
    and saves any variables that might be required but test step that have yet to be executed.
    '''

    def __init__(self, test: _TestStepWithPlaceholders, step_index: int, runtime_config_variable_storage: dict):
        self._test = test
        self._step_index = step_index
        self._runtime_config_variable_storage = runtime_config_variable_storage
        self.arguments = copy.deepcopy(test.arguments_with_placeholders)
        self.responses = copy.deepcopy(test.responses_with_placeholders)
        if test.is_pics_enabled:
            self._update_placeholder_values(self.arguments)
            self._update_placeholder_values(self.responses)
            self._test.node_id = self._config_variable_substitution(
                self._test.node_id)
            self._test.event_number = self._config_variable_substitution(
                self._test.event_number)
            test.update_arguments(self.arguments)
            test.update_responses(self.responses)

    @property
    def step_index(self):
        return self._step_index

    @property
    def is_enabled(self):
        return self._test.is_enabled

    @property
    def is_pics_enabled(self):
        return self._test.is_pics_enabled

    @property
    def is_attribute(self):
        return self._test.is_attribute

    @property
    def is_event(self):
        return self._test.is_event

    @property
    def label(self):
        return self._test.label

    @property
    def node_id(self):
        return self._test.node_id

    @property
    def group_id(self):
        return self._test.group_id

    @property
    def cluster(self):
        return self._test.cluster

    @property
    def command(self):
        return self._test.command

    @property
    def attribute(self):
        return self._test.attribute

    @property
    def event(self):
        return self._test.event

    @property
    def endpoint(self):
        return self._test.endpoint

    @property
    def identity(self):
        return self._test.identity

    @property
    def fabric_filtered(self):
        return self._test.fabric_filtered

    @property
    def min_interval(self):
        return self._test.min_interval

    @property
    def max_interval(self):
        return self._test.max_interval

    @property
    def timed_interaction_timeout_ms(self):
        return self._test.timed_interaction_timeout_ms

    @property
    def busy_wait_ms(self):
        return self._test.busy_wait_ms

    @property
    def wait_for(self):
        return self._test.wait_for

    @property
    def event_number(self):
        return self._test.event_number

    @property
    def pics(self):
        return self._test.pics

    def post_process_response(self, received_responses):
        result = PostProcessResponseResult()

        # A list of responses is what is expected, but for legacy, if the response
        # does not comes up as a list, it is converted here.
        # TODO It should be removed once all decoders returns a list.
        if not isinstance(received_responses, list):
            received_responses = [received_responses]

        if self.wait_for is not None:
            self._response_cluster_wait_validation(received_responses, result)
            return result

        check_type = PostProcessCheckType.RESPONSE_VALIDATION
        error_failure_wrong_response_number = f'The test expects {len(self.responses)} responses but got {len(received_responses)} responses.'

        received_responses_copy = copy.deepcopy(received_responses)
        for expected_response in self.responses:
            if len(received_responses_copy) == 0:
                result.error(check_type, error_failure_wrong_response_number)
                return result
            received_response = received_responses_copy.pop(0)
            self._response_error_validation(
                expected_response, received_response, result)
            self._response_cluster_error_validation(
                expected_response, received_response, result)
            self._response_values_validation(
                expected_response, received_response, result)
            self._response_constraints_validation(
                expected_response, received_response, result)
            self._maybe_save_as(expected_response, received_response, result)

        # An empty response array in a test step (responses: []) implies that the test step does expect a response
        # but without any associated value.
        if self.responses == [] and received_responses_copy == [{}]:
            # if the received responses is a simple success ([{}]), that is valid.
            return result
        # This is different from the case where no response is specified at all, which implies that the step expect
        # a success with any associatied value(s).
        elif self.responses == [{'values': [{}]}] and len(received_responses_copy):
            # if there are multiple responses and the test specifies that it does not really care
            # about which values are returned, that is valid too.
            return result
        # Anything more complex where the response field as been defined with some values and the number
        # of expected responses differs from the number of received responses is an error.
        elif len(received_responses_copy) != 0:
            result.error(check_type, error_failure_wrong_response_number)

        return result

    def _response_cluster_wait_validation(self, received_responses, result):
        """Check if the response concrete path matches the configuration of the test step
           and validate that the response type (e.g readAttribute/writeAttribute/...) matches
           the expectation from the test step."""
        check_type = PostProcessCheckType.WAIT_VALIDATION
        error_success = 'The test expectation "{wait_for}" for "{cluster}.{wait_type}" on endpoint {endpoint} is true'
        error_failure = 'The test expectation "{expected} == {received}" is false'
        error_failure_multiple_responses = 'The test expects a single response but got {len(received_responses)} responses.'

        if len(received_responses) > 1:
            result.error(check_type, error_failure.multiple_responses)
            return
        received_response = received_responses[0]

        if self.is_attribute:
            expected_wait_type = self.attribute
            received_wait_type = received_response.get('attribute')
        elif self.is_event:
            expected_wait_type = self.event
            received_wait_type = received_response.get('event')
        else:
            expected_wait_type = self.command
            received_wait_type = receive_response.get('command')

        expected_values = [
            self.wait_for,
            self.endpoint,
            # TODO The name in tests does not always use spaces
            self.cluster.replace(' ', ''),
            expected_wait_type
        ]

        received_values = [
            received_response.get('wait_for'),
            received_response.get('endpoint'),
            received_response.get('cluster'),
            received_wait_type
        ]

        success = True
        for expected_value in expected_values:
            received_value = received_values.pop(0)

            if expected_value != received_value:
                result.error(check_type, error_failure.format(
                    expected=expected_value, received=received_value))
                success = False

        if success:
            result.success(check_type, error_success.format(
                wait_for=self.wait_for, cluster=self.cluster, wait_type=expected_wait_type, endpoint=self.endpoint))

    def _response_error_validation(self, expected_response, received_response, result):
        check_type = PostProcessCheckType.IM_STATUS
        error_success = 'The test expects the "{error}" error which occured successfully.'
        error_success_no_error = 'The test expects no error and no error occurred.'
        error_wrong_error = 'The test expects the "{error}" error but the "{value}" error occured.'
        error_unexpected_error = 'The test expects no error but the "{error}" error occured.'
        error_unexpected_success = 'The test expects the "{error}" error but no error occured.'

        expected_error = expected_response.get(
            'error') if expected_response else None
        received_error = received_response.get('error')

        if expected_error and received_error and expected_error == received_error:
            result.success(check_type, error_success.format(
                error=expected_error))
        elif expected_error and received_error:
            result.error(check_type, error_wrong_error.format(
                error=expected_error, value=received_error))
        elif expected_error and not received_error:
            result.error(check_type, error_unexpected_success.format(
                error=expected_error))
        elif not expected_error and received_error:
            result.error(check_type, error_unexpected_error.format(
                error=received_error))
        elif not expected_error and not received_error:
            result.success(check_type, error_success_no_error)
        else:
            # This should not happens
            raise AssertionError('This should not happens.')

    def _response_cluster_error_validation(self, expected_response, received_response, result):
        check_type = PostProcessCheckType.CLUSTER_STATUS
        error_success = 'The test expects the "{error}" error which occured successfully.'
        error_unexpected_success = 'The test expects the "{error}" error but no error occured.'
        error_wrong_error = 'The test expects the "{error}" error but the "{value}" error occured.'

        expected_error = expected_response.get('clusterError')
        received_error = received_response.get('clusterError')

        if expected_error:
            if received_error and expected_error == received_error:
                result.success(check_type, error_success.format(
                    error=expected_error))
            elif received_error:
                result.error(check_type, error_wrong_error.format(
                    error=expected_error, value=received_error))
            else:
                result.error(check_type, error_unexpected_success.format(
                    error=expected_error))
        else:
            # Nothing is logged here to not be redundant with the generic error checking code.
            pass

    def _response_values_validation(self, expected_response, received_response, result):
        check_type = PostProcessCheckType.RESPONSE_VALIDATION
        error_success = 'The test expectation "{name} == {value}" is true'
        error_failure = 'The test expectation "{name} == {value}" is false'
        error_name_does_not_exist = 'The test expects a value named "{name}" but it does not exists in the response."'
        error_value_does_not_exist = 'The test expects a value but it does not exists in the response."'

        for value in expected_response['values']:
            if 'value' not in value:
                continue

            expected_name = 'value'
            if expected_name not in received_response:
                result.error(
                    check_type, error_value_does_not_exist)
                break

            received_value = received_response.get('value')
            if not self.is_attribute and not self.is_event:
                expected_name = value.get('name')
                if expected_name not in received_value:
                    result.error(check_type, error_name_does_not_exist.format(
                        name=expected_name))
                    continue

                received_value = received_value.get(
                    expected_name) if received_value else None

            expected_value = value.get('value')
            if self._response_value_validation(expected_value, received_value):
                result.success(check_type, error_success.format(
                    name=expected_name, value=expected_value))
            else:
                result.error(check_type, error_failure.format(
                    name=expected_name, value=expected_value))

    def _response_value_validation(self, expected_value, received_value):
        if isinstance(expected_value, list):
            if len(expected_value) != len(received_value):
                return False

            for index, expected_item in enumerate(expected_value):
                received_item = received_value[index]
                if not self._response_value_validation(expected_item, received_item):
                    return False
            return True
        elif isinstance(expected_value, dict):
            for key, expected_item in expected_value.items():
                received_item = received_value.get(key)
                if not self._response_value_validation(expected_item, received_item):
                    return False
            return True
        else:
            return expected_value == received_value

    def _response_constraints_validation(self, expected_response, received_response, result):
        check_type = PostProcessCheckType.CONSTRAINT_VALIDATION
        error_success = 'Constraints check passed'
        error_failure = 'Constraints check failed'

        response_type_name = self._test.response_mapping_name
        for value in expected_response['values']:
            if 'constraints' not in value:
                continue

            received_value = received_response.get('value')
            if not self.is_attribute and not self.is_event:
                expected_name = value.get('name')
                if received_value is None or expected_name not in received_value:
                    received_value = None
                else:
                    received_value = received_value.get(
                        expected_name) if received_value else None

                if self._test.response_mapping:
                    response_type_name = self._test.response_mapping.get(
                        expected_name)
                else:
                    # We don't have a mapping for this type. This happens for pseudo clusters.
                    # If there is a constraint check for the type it is likely an incorrect
                    # constraint check by the test writter.
                    response_type_name = None

            constraints = get_constraints(value['constraints'])

            for constraint in constraints:
                try:
                    constraint.validate(received_value, response_type_name)
                    result.success(check_type, error_success)
                except TestStepError as e:
                    e.update_context(expected_response, self.step_index)
                    result.error(check_type, error_failure, e)

    def _maybe_save_as(self, expected_response, received_response, result):
        check_type = PostProcessCheckType.SAVE_AS_VARIABLE
        error_success = 'The test save the value "{value}" as {name}.'
        error_name_does_not_exist = 'The test expects a value named "{name}" but it does not exists in the response."'

        for value in expected_response['values']:
            if 'saveAs' not in value:
                continue

            received_value = received_response.get('value')
            if not self.is_attribute and not self.is_event:
                expected_name = value.get('name')
                if received_value is None or expected_name not in received_value:
                    result.error(check_type, error_name_does_not_exist.format(
                        name=expected_name))
                    continue

                received_value = received_value.get(
                    expected_name) if received_value else None

            save_as = value.get('saveAs')
            self._runtime_config_variable_storage[save_as] = received_value
            result.success(check_type, error_success.format(
                value=received_value, name=save_as))

    def _update_placeholder_values(self, containers):
        if not containers:
            return

        if not isinstance(containers, list):
            containers = [containers]

        for container in containers:
            values = container['values']
            for idx, item in enumerate(values):
                if 'value' in item:
                    values[idx]['value'] = self._config_variable_substitution(
                        item['value'])

                if 'constraints' in item:
                    for constraint, constraint_value in item['constraints'].items():
                        values[idx]['constraints'][constraint] = self._config_variable_substitution(
                            constraint_value)

            container['values'] = values

    def _config_variable_substitution(self, value):
        if type(value) is list:
            return [self._config_variable_substitution(entry) for entry in value]
        elif type(value) is dict:
            mapped_value = {}
            for key in value:
                mapped_value[key] = self._config_variable_substitution(
                    value[key])
            return mapped_value
        elif type(value) is str:
            # For most tests, a single config variable is used and it can be replaced as in.
            # But some other tests were relying on the fact that the expression was put 'as if' in
            # the generated code and was resolved before being sent over the wire. For such
            # expressions (e.g 'myVar + 1') we need to compute it before sending it over the wire.
            tokens = value.split()
            if len(tokens) == 0:
                return value

            substitution_occured = False
            for idx, token in enumerate(tokens):
                if token in self._runtime_config_variable_storage:
                    variable_info = self._runtime_config_variable_storage[token]
                    if type(variable_info) is dict and 'defaultValue' in variable_info:
                        variable_info = variable_info['defaultValue']
                    if variable_info is not None:
                        tokens[idx] = variable_info
                        substitution_occured = True

            if len(tokens) == 1:
                return tokens[0]

            tokens = [str(token) for token in tokens]
            value = ' '.join(tokens)
            # TODO we should move away from eval. That will mean that we will need to do extra
            # parsing, but it would be safer then just blindly running eval.
            return value if not substitution_occured else eval(value)
        else:
            return value


class YamlTests:
    '''Parses YAML tests and becomes an iterator to provide 'TestStep's

    The provided TestStep is expected to be used by a runner/adapter to run the test step and
    provide the response from the device to the TestStep object.

    Currently this is a one time use object. Eventually this should be refactored to take a
    runner/adapter as an argument and run through all test steps and should be reusable for
    multiple runs.
    '''

    def __init__(self, parsing_config_variable_storage: dict, definitions: SpecDefinitions, pics_checker: PICSChecker, tests: dict):
        self._parsing_config_variable_storage = parsing_config_variable_storage
        enabled_tests = []
        try:
            for step_index, step in enumerate(tests):
                test_with_placeholders = _TestStepWithPlaceholders(
                    step, self._parsing_config_variable_storage, definitions, pics_checker)
                if test_with_placeholders.is_enabled:
                    enabled_tests.append(test_with_placeholders)
        except TestStepError as e:
            e.update_context(step, step_index)
            raise

        fixes.try_update_yaml_node_id_test_runner_state(
            enabled_tests, self._parsing_config_variable_storage)
        self._runtime_config_variable_storage = copy.deepcopy(
            parsing_config_variable_storage)
        self._tests = enabled_tests
        self._index = 0
        self.count = len(self._tests)

    def __iter__(self):
        return self

    def __next__(self) -> TestStep:
        if self._index < self.count:
            test = self._tests[self._index]
            test_step = TestStep(test, self._index + 1,
                                 self._runtime_config_variable_storage)
            self._index += 1
            return test_step

        raise StopIteration


@dataclass
class TestParserConfig:
    pics: str = None
    definitions: SpecDefinitions = None
    config_override: dict = field(default_factory=dict)


class TestParser:
    def __init__(self, test_file: str, parser_config: TestParserConfig = TestParserConfig()):
        yaml_loader = YamlLoader()
        filename, name, pics, config, tests = yaml_loader.load(test_file)

        self.__apply_legacy_config(config)
        self.__apply_config_override(config, parser_config.config_override)

        self.filename = filename
        self.name = name
        self.PICS = pics
        self.tests = YamlTests(
            config,
            parser_config.definitions,
            PICSChecker(parser_config.pics),
            tests
        )
        self.timeout = config['timeout']

    def __apply_config_override(self, config, config_override):
        for key, value in config_override.items():
            if value is None or not key in config:
                continue

            if type(value) is str:
                if key == 'timeout' or key == 'endpoint':
                    value = int(value)
                elif key == 'nodeId' and value.startswith('0x'):
                    value = int(value, 16)
                elif key == 'nodeId':
                    value = int(value)

            if isinstance(config[key], dict) and 'defaultValue' in config[key]:
                config[key]['defaultValue'] = value
            else:
                config[key] = value

    def __apply_legacy_config(self, config):
        # These are a list of "KnownVariables". These are defaults the codegen used to use. This
        # is added for legacy support of tests that expect to uses these "defaults".
        self.__apply_legacy_config_if_missing(config, 'nodeId', 0x12345)
        self.__apply_legacy_config_if_missing(config, 'endpoint', '')
        self.__apply_legacy_config_if_missing(config, 'cluster', '')
        self.__apply_legacy_config_if_missing(config, 'timeout', 90)

    def __apply_legacy_config_if_missing(self, config, key, value):
        if key not in config:
            config[key] = value