code

@dataclass
class PycodeSerializer:
    """Pycode serializer for data class instances.

    Generate python pretty representation code from a model instance.

    Args:
        context: The models context instance
    """

    context: XmlContext = field(default_factory=XmlContext)

    def render(self, obj: object, var_name: str = "obj") -> str:
        """Serialize the input model instance to python representation string.

        Args:
            obj: The input model instance to serialize
            var_name: The var name to assign the model instance

        Returns:
            The serialized representation string.
        """
        output = StringIO()
        self.write(output, obj, var_name)
        return output.getvalue()

    def write(self, out: TextIO, obj: Any, var_name: str):
        """Write the given object to the output text stream.

        Args:
            out: The output text stream
            obj: The input model instance to serialize
            var_name: The var name to assign the model instance
        """
        types: Set[Type] = set()

        tmp = StringIO()
        for chunk in self.repr_object(obj, 0, types):
            tmp.write(chunk)

        imports = self.build_imports(types)
        out.write(imports)
        out.write("\n\n")
        out.write(f"{var_name} = ")
        out.write(tmp.getvalue())
        out.write("\n")

    @classmethod
    def build_imports(cls, types: Set[Type]) -> str:
        """Build a list of imports from the given types.

        Args:
            types: A set of types

        Returns:
            The `from x import y` statements as string.
        """
        imports = set()
        for tp in types:
            module = tp.__module__
            name = tp.__qualname__
            if module != "builtins":
                if "." in name:
                    name = name.split(".")[0]

                imports.add(f"from {module} import {name}\n")

        return "".join(sorted(set(imports)))

    def repr_object(self, obj: Any, level: int, types: Set[Type]) -> Iterator[str]:
        """Write the given object as repr code.

        Args:
            obj: The input object to serialize
            level: The current object level
            types: The parent object types

        Yields:
            An iterator of the representation strings.
        """
        types.add(type(obj))
        if collections.is_array(obj):
            yield from self.repr_array(obj, level, types)
        elif isinstance(obj, dict):
            yield from self.repr_mapping(obj, level, types)
        elif self.context.class_type.is_model(obj):
            yield from self.repr_model(obj, level, types)
        elif isinstance(obj, Enum):
            yield str(obj)
        else:
            yield literal_value(obj)

    def repr_array(
        self,
        obj: Union[List, Set, Tuple],
        level: int,
        types: Set[Type],
    ) -> Iterator[str]:
        """Convert an iterable object to repr code.

        Args:
            obj: A list, set, tuple instance
            level: The current object level
            types: The parent object types

        Yields:
            An iterator of the representation strings.
        """
        if not obj:
            yield str(obj)
            return

        next_level = level + 1
        yield "[\n"
        for val in obj:
            yield spaces * next_level
            yield from self.repr_object(val, next_level, types)
            yield ",\n"

        yield f"{spaces * level}]"

    def repr_mapping(self, obj: Mapping, level: int, types: Set[Type]) -> Iterator[str]:
        """Convert a map object to repr code.

        Args:
            obj: A map instance
            level: The current object level
            types: The parent object types

        Yields:
            An iterator of the representation strings.
        """
        if not obj:
            yield str(obj)
            return

        next_level = level + 1
        yield "{\n"
        for key, value in obj.items():
            yield spaces * next_level
            yield from self.repr_object(key, next_level, types)
            yield ": "
            yield from self.repr_object(value, next_level, types)
            yield ",\n"

        yield f"{spaces * level}}}"

    def repr_model(self, obj: Any, level: int, types: Set[Type]) -> Iterator[str]:
        """Convert a data model instance to repr code.

        Args:
            obj: A map instance
            level: The current object level
            types: The parent object types

        Yields:
            An iterator of the representation strings.
        """
        yield f"{obj.__class__.__qualname__}(\n"

        next_level = level + 1
        index = 0
        for f in self.context.class_type.get_fields(obj):
            if not f.init:
                continue

            value = getattr(obj, f.name, types)
            default = self.context.class_type.default_value(f, default=unset)
            if default is not unset and (
                (callable(default) and default() == value) or default == value
            ):
                continue

            if index:
                yield f",\n{spaces * next_level}{f.name}="
            else:
                yield f"{spaces * next_level}{f.name}="

            yield from self.repr_object(value, next_level, types)

            index += 1

        yield f"\n{spaces * level})"