dataclasses.py

from inspect import isclass
from typing import List, Tuple

from .base import GenericModelCodeGenerator, KWAGRS_TEMPLATE, METADATA_FIELD_NAME, sort_kwargs, template
from ..dynamic_typing import (DDict, DList, DOptional, ImportPathList, MetaData, ModelMeta, StringSerializable)

DEFAULT_ORDER = (
    ("default", "default_factory"),
    "*",
    ("metadata",)
)


class DataclassModelCodeGenerator(GenericModelCodeGenerator):
    DC_DECORATOR = template(f"dataclass{{% if kwargs %}}({KWAGRS_TEMPLATE}){{% endif %}}")
    DC_FIELD = template(f"field({KWAGRS_TEMPLATE})")

    def __init__(self, model: ModelMeta, meta=False, dataclass_kwargs: dict = None, **kwargs):
        """
        :param model: ModelMeta instance
        :param meta: Enable generation of metadata as attrib argument
        :param dataclass_kwargs: kwargs for @dataclass() decorators
        :param kwargs:
        """
        super().__init__(model, **kwargs)
        self.no_meta = not meta
        self.dataclass_kwargs = dataclass_kwargs or {}

    @property
    def decorators(self) -> Tuple[ImportPathList, List[str]]:
        imports, decorators = super().decorators
        imports.append(('dataclasses', ['dataclass', 'field']))
        decorators.insert(0, self.DC_DECORATOR.render(kwargs=self.dataclass_kwargs))
        return imports, decorators

    def field_data(self, name: str, meta: MetaData, optional: bool) -> Tuple[ImportPathList, dict]:
        """
        Form field data for template

        :param name: Original field name
        :param meta: Field metadata
        :param optional: Is field optional
        :return: imports, field data
        """
        imports, data = super().field_data(name, meta, optional)
        body_kwargs = {}
        if optional:
            meta: DOptional
            if isinstance(meta.type, DList):
                body_kwargs["default_factory"] = "list"
            elif isinstance(meta.type, DDict):
                body_kwargs["default_factory"] = "dict"
            else:
                body_kwargs["default"] = "None"
                if isclass(meta.type) and issubclass(meta.type, StringSerializable):
                    pass
        elif isclass(meta) and issubclass(meta, StringSerializable):
            pass

        if not self.no_meta and name != data["name"]:
            body_kwargs["metadata"] = {METADATA_FIELD_NAME: name}
        if len(body_kwargs) == 1 and next(iter(body_kwargs.keys())) == "default":
            data["body"] = body_kwargs["default"]
        elif body_kwargs:
            data["body"] = self.DC_FIELD.render(kwargs=sort_kwargs(body_kwargs, DEFAULT_ORDER))
        return imports, data

    @property
    def convert_strings_kwargs(self) -> Tuple[ImportPathList, dict]:
        """
        :return: Imports and Dict with kw-arguments for `json_to_models.models.string_converters.convert_strings` decorator.
        """
        imports, kwargs = super().convert_strings_kwargs
        imports.append(('json_to_models.models', ['ClassType']))
        kwargs["class_type"] = 'ClassType.Dataclass'
        return imports, kwargs