neptune_backend_mock.py

#
# Copyright (c) 2022, Neptune Labs Sp. z o.o.
#
# 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 os
import uuid
from collections import defaultdict
from datetime import datetime
from shutil import copyfile
from typing import Any, Dict, Iterable, List, Optional, Tuple, Type, TypeVar, Union
from zipfile import ZipFile

from neptune.new.exceptions import (
    ContainerUUIDNotFound,
    InternalClientError,
    MetadataInconsistency,
    ModelVersionNotFound,
    NeptuneException,
    ProjectNotFound,
    RunNotFound,
)
from neptune.new.internal.artifacts.types import ArtifactFileData
from neptune.new.internal.backends.api_model import (
    ApiExperiment,
    ArtifactAttribute,
    Attribute,
    AttributeType,
    BoolAttribute,
    DatetimeAttribute,
    FileAttribute,
    FloatAttribute,
    FloatPointValue,
    FloatSeriesAttribute,
    FloatSeriesValues,
    ImageSeriesValues,
    IntAttribute,
    LeaderboardEntry,
    Project,
    StringAttribute,
    StringPointValue,
    StringSeriesAttribute,
    StringSeriesValues,
    StringSetAttribute,
    Workspace,
)
from neptune.new.internal.backends.hosted_file_operations import (
    get_unique_upload_entries,
)
from neptune.new.internal.backends.neptune_backend import NeptuneBackend
from neptune.new.internal.backends.nql import NQLQuery
from neptune.new.internal.container_structure import ContainerStructure
from neptune.new.internal.container_type import ContainerType
from neptune.new.internal.id_formats import QualifiedName, SysId, UniqueId
from neptune.new.internal.operation import (
    AddStrings,
    AssignArtifact,
    AssignBool,
    AssignDatetime,
    AssignFloat,
    AssignInt,
    AssignString,
    ClearArtifact,
    ClearFloatLog,
    ClearImageLog,
    ClearStringLog,
    ClearStringSet,
    ConfigFloatSeries,
    CopyAttribute,
    DeleteAttribute,
    DeleteFiles,
    LogFloats,
    LogImages,
    LogStrings,
    Operation,
    RemoveStrings,
    TrackFilesToArtifact,
    UploadFile,
    UploadFileContent,
    UploadFileSet,
)
from neptune.new.internal.operation_visitor import OperationVisitor
from neptune.new.internal.utils import base64_decode
from neptune.new.internal.utils.generic_attribute_mapper import NoValue
from neptune.new.internal.utils.paths import path_to_str
from neptune.new.metadata_containers import Model
from neptune.new.types import Boolean, Integer
from neptune.new.types.atoms import GitRef
from neptune.new.types.atoms.artifact import Artifact
from neptune.new.types.atoms.datetime import Datetime
from neptune.new.types.atoms.file import File
from neptune.new.types.atoms.float import Float
from neptune.new.types.atoms.string import String
from neptune.new.types.file_set import FileSet
from neptune.new.types.namespace import Namespace
from neptune.new.types.series.file_series import FileSeries
from neptune.new.types.series.float_series import FloatSeries
from neptune.new.types.series.string_series import StringSeries
from neptune.new.types.sets.string_set import StringSet
from neptune.new.types.value import Value
from neptune.new.types.value_visitor import ValueVisitor

Val = TypeVar("Val", bound=Value)


class NeptuneBackendMock(NeptuneBackend):
    WORKSPACE_NAME = "mock-workspace"
    PROJECT_NAME = "project-placeholder"
    PROJECT_KEY = SysId("OFFLINE")
    MODEL_SYS_ID = SysId("OFFLINE-MOD")

    def __init__(self, credentials=None, proxies=None):
        # pylint: disable=unused-argument
        self._project_id: UniqueId = UniqueId(str(uuid.uuid4()))
        self._containers: Dict[(UniqueId, ContainerType), ContainerStructure[Value, dict]] = dict()
        self._next_run = 1  # counter for runs
        self._next_model_version = defaultdict(lambda: 1)  # counter for model versions
        self._artifacts: Dict[Tuple[str, str], List[ArtifactFileData]] = dict()
        self._attribute_type_converter_value_visitor = self.AttributeTypeConverterValueVisitor()
        self._create_container(self._project_id, ContainerType.PROJECT, self.PROJECT_KEY)

    def get_display_address(self) -> str:
        return "OFFLINE"

    def get_available_projects(
        self, workspace_id: Optional[str] = None, search_term: Optional[str] = None
    ) -> List[Project]:
        return [
            Project(
                id=UniqueId(str(uuid.uuid4())),
                name=self.PROJECT_NAME,
                workspace=self.WORKSPACE_NAME,
                sys_id=self.PROJECT_KEY,
            )
        ]

    def get_available_workspaces(self) -> List[Workspace]:
        return [Workspace(id=UniqueId(str(uuid.uuid4())), name=self.WORKSPACE_NAME)]

    def _create_container(
        self, container_id: UniqueId, container_type: ContainerType, sys_id: SysId
    ):
        container = self._containers.setdefault(
            (container_id, container_type), ContainerStructure[Value, dict]()
        )
        container.set(["sys", "id"], String(sys_id))
        container.set(["sys", "state"], String("running"))
        container.set(["sys", "owner"], String("offline_user"))
        container.set(["sys", "size"], Float(0))
        container.set(["sys", "tags"], StringSet(set()))
        container.set(["sys", "creation_time"], Datetime(datetime.now()))
        container.set(["sys", "modification_time"], Datetime(datetime.now()))
        container.set(["sys", "failed"], Boolean(False))
        if container_type == ContainerType.MODEL_VERSION:
            container.set(["sys", "model_id"], String(self.MODEL_SYS_ID))
            container.set(["sys", "stage"], String("none"))
        return container

    def _get_container(self, container_id: UniqueId, container_type: ContainerType):
        key = (container_id, container_type)
        if key not in self._containers:
            raise ContainerUUIDNotFound(container_id, container_type)
        container = self._containers[(container_id, container_type)]
        return container

    def create_run(
        self,
        project_id: UniqueId,
        git_ref: Optional[GitRef] = None,
        custom_run_id: Optional[str] = None,
        notebook_id: Optional[str] = None,
        checkpoint_id: Optional[str] = None,
    ) -> ApiExperiment:
        sys_id = SysId(f"{self.PROJECT_KEY}-{self._next_run}")
        self._next_run += 1
        new_run_id = UniqueId(str(uuid.uuid4()))
        container = self._create_container(new_run_id, ContainerType.RUN, sys_id=sys_id)
        if git_ref:
            container.set(["source_code", "git"], git_ref)
        return ApiExperiment(
            id=new_run_id,
            type=ContainerType.RUN,
            sys_id=sys_id,
            workspace=self.WORKSPACE_NAME,
            project_name=self.PROJECT_NAME,
            trashed=False,
        )

    def create_model(self, project_id: str, key: str) -> ApiExperiment:
        sys_id = SysId(f"{self.PROJECT_KEY}-{key}")
        new_run_id = UniqueId(str(uuid.uuid4()))
        self._create_container(new_run_id, ContainerType.MODEL, sys_id=sys_id)
        return ApiExperiment(
            id=new_run_id,
            type=ContainerType.MODEL,
            sys_id=sys_id,
            workspace=self.WORKSPACE_NAME,
            project_name=self.PROJECT_NAME,
            trashed=False,
        )

    def create_model_version(self, project_id: str, model_id: UniqueId) -> ApiExperiment:
        try:
            model_key = self._get_container(
                container_id=model_id, container_type=ContainerType.MODEL
            ).get("sys/id")
        except ContainerUUIDNotFound:
            model_key = "MOD"

        sys_id = SysId(f"{self.PROJECT_KEY}-{model_key}-{self._next_model_version[model_id]}")
        self._next_model_version[model_id] += 1
        new_run_id = UniqueId(str(uuid.uuid4()))
        self._create_container(new_run_id, ContainerType.MODEL_VERSION, sys_id=sys_id)
        return ApiExperiment(
            id=new_run_id,
            type=ContainerType.MODEL,
            sys_id=sys_id,
            workspace=self.WORKSPACE_NAME,
            project_name=self.PROJECT_NAME,
            trashed=False,
        )

    def create_checkpoint(self, notebook_id: str, jupyter_path: str) -> Optional[str]:
        return None

    def get_project(self, project_id: QualifiedName) -> Project:
        return Project(
            id=self._project_id,
            name=self.PROJECT_NAME,
            workspace=self.WORKSPACE_NAME,
            sys_id=self.PROJECT_KEY,
        )

    def get_metadata_container(
        self,
        container_id: Union[UniqueId, QualifiedName],
        expected_container_type: ContainerType,
    ) -> ApiExperiment:
        if "/" not in container_id:
            raise ValueError("Backend mock expect container_id as QualifiedName only")

        if expected_container_type == ContainerType.RUN:
            raise RunNotFound(container_id)
        elif expected_container_type == ContainerType.MODEL:
            return ApiExperiment(
                id=UniqueId(str(uuid.uuid4())),
                type=Model.container_type,
                sys_id=SysId(container_id.rsplit("/", 1)[-1]),
                workspace=self.WORKSPACE_NAME,
                project_name=self.PROJECT_NAME,
            )
        elif expected_container_type == ContainerType.MODEL_VERSION:
            raise ModelVersionNotFound(container_id)
        else:
            raise ProjectNotFound(container_id)

    def execute_operations(
        self,
        container_id: UniqueId,
        container_type: ContainerType,
        operations: List[Operation],
    ) -> Tuple[int, List[NeptuneException]]:
        result = []
        for op in operations:
            try:
                self._execute_operation(container_id, container_type, op)
            except NeptuneException as e:
                result.append(e)
        return len(operations), result

    def _execute_operation(
        self, container_id: UniqueId, container_type: ContainerType, op: Operation
    ) -> None:
        run = self._get_container(container_id, container_type)
        val = run.get(op.path)
        if val is not None and not isinstance(val, Value):
            if isinstance(val, dict):
                raise MetadataInconsistency("{} is a namespace, not an attribute".format(op.path))
            else:
                raise InternalClientError("{} is a {}".format(op.path, type(val)))
        visitor = NeptuneBackendMock.NewValueOpVisitor(self, op.path, val)
        new_val = visitor.visit(op)
        if new_val is not None:
            run.set(op.path, new_val)
        else:
            run.pop(op.path)

    def get_attributes(self, container_id: str, container_type: ContainerType) -> List[Attribute]:
        run = self._get_container(container_id, container_type)
        return list(self._generate_attributes(None, run.get_structure()))

    def _generate_attributes(self, base_path: Optional[str], values: dict):
        for key, value_or_dict in values.items():
            new_path = base_path + "/" + key if base_path is not None else key
            if isinstance(value_or_dict, dict):
                yield from self._generate_attributes(new_path, value_or_dict)
            else:
                yield Attribute(
                    new_path,
                    value_or_dict.accept(self._attribute_type_converter_value_visitor),
                )

    def download_file(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        destination: Optional[str] = None,
    ):
        run = self._get_container(container_id, container_type)
        value: File = run.get(path)
        target_path = os.path.abspath(
            destination or (path[-1] + ("." + value.extension if value.extension else ""))
        )
        if value.content is not None:
            with open(target_path, "wb") as target_file:
                target_file.write(value.content)
        elif value.path != target_path:
            copyfile(value.path, target_path)

    def download_file_set(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        destination: Optional[str] = None,
    ):
        run = self._get_container(container_id, container_type)
        source_file_set_value: FileSet = run.get(path)

        if destination is None:
            target_file = path[-1] + ".zip"
        elif os.path.isdir(destination):
            target_file = os.path.join(destination, path[-1] + ".zip")
        else:
            target_file = destination

        upload_entries = get_unique_upload_entries(source_file_set_value.file_globs)

        with ZipFile(target_file, "w") as zipObj:
            for upload_entry in upload_entries:
                zipObj.write(upload_entry.source, upload_entry.target_path)

    def get_float_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> FloatAttribute:
        val = self._get_attribute(container_id, container_type, path, Float)
        return FloatAttribute(val.value)

    def get_int_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> IntAttribute:
        val = self._get_attribute(container_id, container_type, path, Integer)
        return IntAttribute(val.value)

    def get_bool_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> BoolAttribute:
        val = self._get_attribute(container_id, container_type, path, Boolean)
        return BoolAttribute(val.value)

    def get_file_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> FileAttribute:
        val = self._get_attribute(container_id, container_type, path, File)
        return FileAttribute(
            name=os.path.basename(val.path) if val.path else "",
            ext=val.extension or "",
            size=0,
        )

    def get_string_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> StringAttribute:
        val = self._get_attribute(container_id, container_type, path, String)
        return StringAttribute(val.value)

    def get_datetime_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> DatetimeAttribute:
        val = self._get_attribute(container_id, container_type, path, Datetime)
        return DatetimeAttribute(val.value)

    def get_artifact_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> ArtifactAttribute:
        val = self._get_attribute(container_id, container_type, path, Artifact)
        return ArtifactAttribute(val.hash)

    def list_artifact_files(self, project_id: str, artifact_hash: str) -> List[ArtifactFileData]:
        return self._artifacts[(project_id, artifact_hash)]

    def get_float_series_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> FloatSeriesAttribute:
        val = self._get_attribute(container_id, container_type, path, FloatSeries)
        return FloatSeriesAttribute(val.values[-1] if val.values else None)

    def get_string_series_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> StringSeriesAttribute:
        val = self._get_attribute(container_id, container_type, path, StringSeries)
        return StringSeriesAttribute(val.values[-1] if val.values else None)

    def get_string_set_attribute(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> StringSetAttribute:
        val = self._get_attribute(container_id, container_type, path, StringSet)
        return StringSetAttribute(set(val.values))

    def _get_attribute(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        expected_type: Type[Val],
    ) -> Val:
        run = self._get_container(container_id, container_type)
        value: Optional[Value] = run.get(path)
        str_path = path_to_str(path)
        if value is None:
            raise MetadataInconsistency("Attribute {} not found".format(str_path))
        if isinstance(value, expected_type):
            return value
        raise MetadataInconsistency("Attribute {} is not {}".format(str_path, type.__name__))

    def get_string_series_values(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        offset: int,
        limit: int,
    ) -> StringSeriesValues:
        val = self._get_attribute(container_id, container_type, path, StringSeries)
        return StringSeriesValues(
            len(val.values),
            [
                StringPointValue(timestampMillis=42342, step=idx, value=v)
                for idx, v in enumerate(val.values)
            ],
        )

    def get_float_series_values(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        offset: int,
        limit: int,
    ) -> FloatSeriesValues:
        val = self._get_attribute(container_id, container_type, path, FloatSeries)
        return FloatSeriesValues(
            len(val.values),
            [
                FloatPointValue(timestampMillis=42342, step=idx, value=v)
                for idx, v in enumerate(val.values)
            ],
        )

    def get_image_series_values(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        offset: int,
        limit: int,
    ) -> ImageSeriesValues:
        return ImageSeriesValues(0)

    def download_file_series_by_index(
        self,
        container_id: str,
        container_type: ContainerType,
        path: List[str],
        index: int,
        destination: str,
    ):
        """Non relevant for backend"""

    def get_run_url(self, run_id: str, workspace: str, project_name: str, sys_id: str) -> str:
        return f"offline/{run_id}"

    def get_project_url(self, project_id: str, workspace: str, project_name: str) -> str:
        return f"offline/{project_id}"

    def get_model_url(self, model_id: str, workspace: str, project_name: str, sys_id: str) -> str:
        return f"offline/{model_id}"

    def get_model_version_url(
        self,
        model_version_id: str,
        model_id: str,
        workspace: str,
        project_name: str,
        sys_id: str,
    ) -> str:
        return f"offline/{model_version_id}"

    def _get_attribute_values(self, value_dict, path_prefix: List[str]):
        assert isinstance(value_dict, dict)
        for k, value in value_dict.items():
            if isinstance(value, dict):
                yield from self._get_attribute_values(value, path_prefix + [k])
            else:
                attr_type = value.accept(self._attribute_type_converter_value_visitor).value
                attr_path = "/".join(path_prefix + [k])
                if hasattr(value, "value"):
                    yield attr_path, attr_type, value.value
                else:
                    return attr_path, attr_type, NoValue

    def fetch_atom_attribute_values(
        self, container_id: str, container_type: ContainerType, path: List[str]
    ) -> List[Tuple[str, AttributeType, Any]]:
        run = self._get_container(container_id, container_type)
        values = self._get_attribute_values(run.get(path), path)
        namespace_prefix = path_to_str(path)
        if namespace_prefix:
            # don't want to catch "ns/attribute/other" while looking for "ns/attr"
            namespace_prefix += "/"
        return [
            (full_path, attr_type, attr_value)
            for (full_path, attr_type, attr_value) in values
            if full_path.startswith(namespace_prefix)
        ]

    def search_leaderboard_entries(
        self,
        project_id: UniqueId,
        types: Optional[Iterable[ContainerType]] = None,
        query: Optional[NQLQuery] = None,
        columns: Optional[Iterable[str]] = None,
    ) -> List[LeaderboardEntry]:
        """Non relevant for mock"""

    class AttributeTypeConverterValueVisitor(ValueVisitor[AttributeType]):
        def visit_float(self, _: Float) -> AttributeType:
            return AttributeType.FLOAT

        def visit_integer(self, _: Integer) -> AttributeType:
            return AttributeType.INT

        def visit_boolean(self, _: Boolean) -> AttributeType:
            return AttributeType.BOOL

        def visit_string(self, _: String) -> AttributeType:
            return AttributeType.STRING

        def visit_datetime(self, _: Datetime) -> AttributeType:
            return AttributeType.DATETIME

        def visit_file(self, _: File) -> AttributeType:
            return AttributeType.FILE

        def visit_file_set(self, _: FileSet) -> AttributeType:
            return AttributeType.FILE_SET

        def visit_float_series(self, _: FloatSeries) -> AttributeType:
            return AttributeType.FLOAT_SERIES

        def visit_string_series(self, _: StringSeries) -> AttributeType:
            return AttributeType.STRING_SERIES

        def visit_image_series(self, _: FileSeries) -> AttributeType:
            return AttributeType.IMAGE_SERIES

        def visit_string_set(self, _: StringSet) -> AttributeType:
            return AttributeType.STRING_SET

        def visit_git_ref(self, _: GitRef) -> AttributeType:
            return AttributeType.GIT_REF

        def visit_artifact(self, _: Artifact) -> AttributeType:
            return AttributeType.ARTIFACT

        def visit_namespace(self, _: Namespace) -> AttributeType:
            raise NotImplementedError

        def copy_value(self, source_type: Type[Attribute], source_path: List[str]) -> AttributeType:
            raise NotImplementedError

    class NewValueOpVisitor(OperationVisitor[Optional[Value]]):
        def __init__(self, backend, path: List[str], current_value: Optional[Value]):
            self._backend = backend
            self._path = path
            self._current_value = current_value
            self._artifact_hash = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"

        def visit_assign_float(self, op: AssignFloat) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Float):
                raise self._create_type_error("assign", Float.__name__)
            return Float(op.value)

        def visit_assign_int(self, op: AssignInt) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Integer):
                raise self._create_type_error("assign", Integer.__name__)
            return Integer(op.value)

        def visit_assign_bool(self, op: AssignBool) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Boolean):
                raise self._create_type_error("assign", Boolean.__name__)
            return Boolean(op.value)

        def visit_assign_string(self, op: AssignString) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, String):
                raise self._create_type_error("assign", String.__name__)
            return String(op.value)

        def visit_assign_datetime(self, op: AssignDatetime) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Datetime):
                raise self._create_type_error("assign", Datetime.__name__)
            return Datetime(op.value)

        def visit_assign_artifact(self, op: AssignArtifact) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Artifact):
                raise self._create_type_error("assign", Artifact.__name__)
            return Artifact(op.hash)

        def visit_track_files_to_artifact(self, _: TrackFilesToArtifact) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, Artifact):
                raise self._create_type_error("save", Artifact.__name__)
            return Artifact(self._artifact_hash)

        def visit_clear_artifact(self, _: ClearArtifact) -> Optional[Value]:
            if self._current_value is None:
                return Artifact()
            if not isinstance(self._current_value, Artifact):
                raise self._create_type_error("clear", Artifact.__name__)
            return Artifact()

        def visit_upload_file(self, op: UploadFile) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, File):
                raise self._create_type_error("save", File.__name__)
            return File(path=op.file_path, extension=op.ext)

        def visit_upload_file_content(self, op: UploadFileContent) -> Optional[Value]:
            if self._current_value is not None and not isinstance(self._current_value, File):
                raise self._create_type_error("upload_files", File.__name__)
            return File(content=base64_decode(op.file_content), extension=op.ext)

        def visit_upload_file_set(self, op: UploadFileSet) -> Optional[Value]:
            if self._current_value is None or op.reset:
                return FileSet(op.file_globs)
            if not isinstance(self._current_value, FileSet):
                raise self._create_type_error("save", FileSet.__name__)
            return FileSet(self._current_value.file_globs + op.file_globs)

        def visit_log_floats(self, op: LogFloats) -> Optional[Value]:
            raw_values = [x.value for x in op.values]
            if self._current_value is None:
                return FloatSeries(raw_values)
            if not isinstance(self._current_value, FloatSeries):
                raise self._create_type_error("log", FloatSeries.__name__)
            return FloatSeries(
                self._current_value.values + raw_values,
                min=self._current_value.min,
                max=self._current_value.max,
                unit=self._current_value.unit,
            )

        def visit_log_strings(self, op: LogStrings) -> Optional[Value]:
            raw_values = [x.value for x in op.values]
            if self._current_value is None:
                return StringSeries(raw_values)
            if not isinstance(self._current_value, StringSeries):
                raise self._create_type_error("log", StringSeries.__name__)
            return StringSeries(self._current_value.values + raw_values)

        def visit_log_images(self, op: LogImages) -> Optional[Value]:
            raw_values = [File.from_content(base64_decode(x.value.data)) for x in op.values]
            if self._current_value is None:
                return FileSeries(raw_values)
            if not isinstance(self._current_value, FileSeries):
                raise self._create_type_error("log", FileSeries.__name__)
            return FileSeries(self._current_value.values + raw_values)

        def visit_clear_float_log(self, op: ClearFloatLog) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                return FloatSeries([])
            if not isinstance(self._current_value, FloatSeries):
                raise self._create_type_error("clear", FloatSeries.__name__)
            return FloatSeries(
                [],
                min=self._current_value.min,
                max=self._current_value.max,
                unit=self._current_value.unit,
            )

        def visit_clear_string_log(self, op: ClearStringLog) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                return StringSeries([])
            if not isinstance(self._current_value, StringSeries):
                raise self._create_type_error("clear", StringSeries.__name__)
            return StringSeries([])

        def visit_clear_image_log(self, op: ClearImageLog) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                return FileSeries([])
            if not isinstance(self._current_value, FileSeries):
                raise self._create_type_error("clear", FileSeries.__name__)
            return FileSeries([])

        def visit_config_float_series(self, op: ConfigFloatSeries) -> Optional[Value]:
            if self._current_value is None:
                return FloatSeries([], min=op.min, max=op.max, unit=op.unit)
            if not isinstance(self._current_value, FloatSeries):
                raise self._create_type_error("log", FloatSeries.__name__)
            return FloatSeries(self._current_value.values, min=op.min, max=op.max, unit=op.unit)

        def visit_add_strings(self, op: AddStrings) -> Optional[Value]:
            if self._current_value is None:
                return StringSet(op.values)
            if not isinstance(self._current_value, StringSet):
                raise self._create_type_error("add", StringSet.__name__)
            return StringSet(self._current_value.values.union(op.values))

        def visit_remove_strings(self, op: RemoveStrings) -> Optional[Value]:
            if self._current_value is None:
                return StringSet(set())
            if not isinstance(self._current_value, StringSet):
                raise self._create_type_error("remove", StringSet.__name__)
            return StringSet(self._current_value.values.difference(op.values))

        def visit_clear_string_set(self, op: ClearStringSet) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                return StringSet(set())
            if not isinstance(self._current_value, StringSet):
                raise self._create_type_error("clear", StringSet.__name__)
            return StringSet(set())

        def visit_delete_files(self, op: DeleteFiles) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                return FileSet([])
            if not isinstance(self._current_value, FileSet):
                raise self._create_type_error("delete_files", FileSet.__name__)
            # It is not important to support deleting properly in debug mode, let's just ignore this operation
            return self._current_value

        def visit_delete_attribute(self, op: DeleteAttribute) -> Optional[Value]:
            # pylint: disable=unused-argument
            if self._current_value is None:
                raise MetadataInconsistency(
                    "Cannot perform delete operation on {}. Attribute is undefined.".format(
                        self._path
                    )
                )
            return None

        def visit_copy_attribute(self, op: CopyAttribute) -> Optional[Value]:
            return op.resolve(self._backend).accept(self)

        def _create_type_error(self, op_name, expected):
            return MetadataInconsistency(
                "Cannot perform {} operation on {}. Expected {}, {} found.".format(
                    op_name, self._path, expected, type(self._current_value)
                )
            )