taipy/taipy/core/data/json.py

# Copyright 2021-2024 Avaiga Private Limited
#
# 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 dataclasses
import json
from datetime import date, datetime, timedelta
from enum import Enum
from pydoc import locate
from typing import Any, Dict, List, Optional, Set

from taipy.config.common.scope import Scope

from .._entity._reload import _Reloader, _self_reload
from .._version._version_manager_factory import _VersionManagerFactory
from ._file_datanode_mixin import _FileDataNodeMixin
from .data_node import DataNode
from .data_node_id import DataNodeId, Edit


class JSONDataNode(DataNode, _FileDataNodeMixin):
    """Data Node stored as a JSON file.

    Attributes:
        config_id (str): Identifier of the data node configuration. This string must be a valid
            Python identifier.
        scope (Scope^): The scope of this data node.
        id (str): The unique identifier of this data node.
        owner_id (str): The identifier of the owner (sequence_id, scenario_id, cycle_id) or `None`.
        parent_ids (Optional[Set[str]]): The identifiers of the parent tasks or `None`.
        last_edit_date (datetime): The date and time of the last modification.
        edits (List[Edit^]): The ordered list of edits for that job.
        version (str): The string indicates the application version of the data node to instantiate. If not provided,
            the current version is used.
        validity_period (Optional[timedelta]): The duration implemented as a timedelta since the last edit date for
            which the data node can be considered up-to-date. Once the validity period has passed, the data node is
            considered stale and relevant tasks will run even if they are skippable (see the
            [Task management page](../core/entities/task-mgt.md) for more details).
            If _validity_period_ is set to `None`, the data node is always up-to-date.
        edit_in_progress (bool): True if a task computing the data node has been submitted
            and not completed yet. False otherwise.
        editor_id (Optional[str]): The identifier of the user who is currently editing the data node.
        editor_expiration_date (Optional[datetime]): The expiration date of the editor lock.
        path (str): The path to the JSON file.
        encoder (json.JSONEncoder): The JSON encoder that is used to write into the JSON file.
        decoder (json.JSONDecoder): The JSON decoder that is used to read from the JSON file.
        properties (dict[str, Any]): A dictionary of additional properties. The _properties_
            must have a _"default_path"_ or _"path"_ entry with the path of the JSON file:

            - _"default_path"_ `(str)`: The default path of the CSV file.\n
            - _"encoding"_ `(str)`: The encoding of the CSV file. The default value is `utf-8`.\n
            - _"default_data"_: The default data of the data nodes instantiated from this json data node.\n
    """

    __STORAGE_TYPE = "json"
    __ENCODING_KEY = "encoding"
    _ENCODER_KEY = "encoder"
    _DECODER_KEY = "decoder"
    _REQUIRED_PROPERTIES: List[str] = []

    def __init__(
        self,
        config_id: str,
        scope: Scope,
        id: Optional[DataNodeId] = None,
        owner_id: Optional[str] = None,
        parent_ids: Optional[Set[str]] = None,
        last_edit_date: Optional[datetime] = None,
        edits: Optional[List[Edit]] = None,
        version: Optional[str] = None,
        validity_period: Optional[timedelta] = None,
        edit_in_progress: bool = False,
        editor_id: Optional[str] = None,
        editor_expiration_date: Optional[datetime] = None,
        properties: Optional[Dict] = None,
    ) -> None:
        self.id = id or self._new_id(config_id)

        if properties is None:
            properties = {}

        if self.__ENCODING_KEY not in properties.keys():
            properties[self.__ENCODING_KEY] = "utf-8"

        default_value = properties.pop(self._DEFAULT_DATA_KEY, None)
        _FileDataNodeMixin.__init__(self, properties)

        DataNode.__init__(
            self,
            config_id,
            scope,
            self.id,
            owner_id,
            parent_ids,
            last_edit_date,
            edits,
            version or _VersionManagerFactory._build_manager()._get_latest_version(),
            validity_period,
            edit_in_progress,
            editor_id,
            editor_expiration_date,
            **properties,
        )

        self._decoder = self._properties.get(self._DECODER_KEY, _DefaultJSONDecoder)
        self._encoder = self._properties.get(self._ENCODER_KEY, _DefaultJSONEncoder)

        with _Reloader():
            self._write_default_data(default_value)

        self._TAIPY_PROPERTIES.update(
            {
                self._PATH_KEY,
                self._DEFAULT_PATH_KEY,
                self._DEFAULT_DATA_KEY,
                self._IS_GENERATED_KEY,
                self.__ENCODING_KEY,
                self._ENCODER_KEY,
                self._DECODER_KEY,
            }
        )

    @classmethod
    def storage_type(cls) -> str:
        return cls.__STORAGE_TYPE

    @property  # type: ignore
    @_self_reload(DataNode._MANAGER_NAME)
    def encoder(self):
        return self._encoder

    @encoder.setter
    def encoder(self, encoder: json.JSONEncoder):
        self.properties[self._ENCODER_KEY] = encoder

    @property  # type: ignore
    @_self_reload(DataNode._MANAGER_NAME)
    def decoder(self):
        return self._decoder

    @decoder.setter
    def decoder(self, decoder: json.JSONDecoder):
        self.properties[self._DECODER_KEY] = decoder

    def _read(self):
        return self._read_from_path()

    def _read_from_path(self, path: Optional[str] = None, **read_kwargs) -> Any:
        if path is None:
            path = self._path

        with open(path, "r", encoding=self.properties[self.__ENCODING_KEY]) as f:
            return json.load(f, cls=self._decoder)

    def _append(self, data: Any):
        with open(self._path, "r+", encoding=self.properties[self.__ENCODING_KEY]) as f:
            file_data = json.load(f, cls=self._decoder)
            if isinstance(file_data, List):
                if isinstance(data, List):
                    file_data.extend(data)
                else:
                    file_data.append(data)
            elif isinstance(data, Dict):
                file_data.update(data)

            f.seek(0)
            json.dump(file_data, f, indent=4, cls=self._encoder)

    def _write(self, data: Any):
        with open(self._path, "w", encoding=self.properties[self.__ENCODING_KEY]) as f:  # type: ignore
            json.dump(data, f, indent=4, cls=self._encoder)


class _DefaultJSONEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, Enum):
            return {
                "__type__": f"Enum-{o.__class__.__module__}-{o.__class__.__qualname__}-{o.name}",
                "__value__": o.value,
            }

        if isinstance(o, (datetime, date)):
            return {"__type__": "Datetime", "__value__": o.isoformat()}

        if dataclasses.is_dataclass(o):
            return {
                "__type__": f"dataclass-{o.__class__.__module__}-{o.__class__.__qualname__}",
                "__value__": dataclasses.asdict(o),
            }

        return super().default(o)


class _DefaultJSONDecoder(json.JSONDecoder):
    def __init__(self, *args, **kwargs):
        json.JSONDecoder.__init__(self, *args, **kwargs, object_hook=self.object_hook)

    def object_hook(self, source):
        if _type := source.get("__type__"):
            if _type.startswith("Enum"):
                _, module, classname, name = _type.split("-")
                _enum_class = locate(f"{module}.{classname}")
                return _enum_class[name]

            if _type == "Datetime":
                return datetime.fromisoformat(source.get("__value__"))

            if _type.startswith("dataclass"):
                _, module, classname = _type.split("-")
                _data_class = locate(f"{module}.{classname}")
                return _data_class(**source.get("__value__"))

        return source