utils

class PendingCollection(UserList):
    """An iterable implementation of parsed values.

    The values are parsed individually in the end we
    need to convert it to a tuple or a list based on
    the mutability setting of the data class.

    Args:
        initlist: An initial list of values or None
        factory: A callable factory for the values
            when the node parse has finished.

    """

    def __init__(self, initlist: Optional[Iterable], factory: Optional[Callable]):
        super().__init__(initlist)
        self.factory = factory or list

    def evaluate(self) -> Iterable[Any]:
        """Evaluate the values factory and return the result.

        Returns:
            A list or tuple or set of values
        """
        return self.factory(self.data)

class ParserUtils:
    """Random parser util functions."""

    @classmethod
    def xsi_type(cls, attrs: Dict, ns_map: Dict) -> Optional[str]:
        """Parse the xsi:type attribute value if present.

        Args:
            attrs: The element attributes
            ns_map: The element namespace prefix-URI map

        Returns:
            The xsi:type attribute value or None
        """
        xsi_type = attrs.get(QNames.XSI_TYPE)
        if not xsi_type:
            return None

        namespace, name = QNameConverter.resolve(xsi_type, ns_map)
        return build_qname(namespace, name)

    @classmethod
    def xsi_nil(cls, attrs: Dict) -> Optional[bool]:
        """Return whether xsi:nil attribute value.

        Args:
            attrs: The element attributes

        Returns:
            The bool value or None if it doesn't exist.
        """
        xsi_nil = attrs.get(QNames.XSI_NIL)
        return xsi_nil == constants.XML_TRUE if xsi_nil else None

    @classmethod
    def parse_var(
        cls,
        meta: XmlMeta,
        var: XmlVar,
        value: Any,
        ns_map: Optional[Dict] = None,
        default: Any = None,
        types: Optional[Sequence[Type]] = None,
        tokens_factory: Optional[Callable] = None,
        format: Optional[str] = None,
    ) -> Any:
        """Convert a value to a python primitive type.

        Args:
            meta: The xml meta instance
            var: The xml var instance
            value: A primitive value or a list of primitive values
            ns_map: The element namespace prefix-URI map
            default: Override the var default value
            types: Override the var types
            tokens_factory: Override the var tokens factory
            format: Override the var format

        Returns:
            The converted value or values.
        """
        try:
            value = cls.parse_value(
                value=value,
                types=types or var.types,
                default=default or var.default,
                ns_map=ns_map,
                tokens_factory=tokens_factory or var.tokens_factory,
                format=format or var.format,
            )
        except ConverterError as ex:
            message = f"  {ex}"
            warnings.warn(
                f"Failed to convert value for `{meta.clazz.__qualname__}.{var.name}`\n{message}",
                ConverterWarning,
            )

        return value

    @classmethod
    def parse_value(
        cls,
        value: Any,
        types: Sequence[Type],
        default: Optional[Any] = None,
        ns_map: Optional[Dict] = None,
        tokens_factory: Optional[Callable] = None,
        format: Optional[str] = None,
    ) -> Any:
        """Convert a value to a python primitive type.

        Args:
            value: A primitive value or a list of primitive values
            types: An iterable of types to try to convert the value
            default: The default value/factory if the given is None
            ns_map: The element namespace prefix-URI map
            tokens_factory: A callable factory for the converted values
                if the element is derived from xs:NMTOKENS
            format: The format argument for base64/hex values or dates.

        Returns:
            The converted value or values.
        """
        if value is None:
            if callable(default):
                return default() if tokens_factory else None

            return default

        if tokens_factory:
            value = value if collections.is_array(value) else value.split()
            return tokens_factory(
                converter.deserialize(val, types, ns_map=ns_map, format=format)
                for val in value
            )

        return converter.deserialize(value, types, ns_map=ns_map, format=format)

    @classmethod
    def normalize_content(cls, value: Optional[str]) -> Optional[str]:
        """Normalize element text or tail content.

        If content is just whitespace return None, otherwise preserve
        the original content.

        Args:
            value: The element content

        Returns:
            The normalized content
        """
        if value and value.strip():
            return value

        return None

    @classmethod
    def parse_any_attributes(
        cls, attrs: Dict[str, str], ns_map: Dict[Optional[str], str]
    ) -> Dict[str, str]:
        """Parse attributes with qname support.

        Example:
            {"foo": "bar", "xsi:type": "my:type"} ->
            {"foo": "bar", "xsi:type" "{http://someuri.com}type"}

        Args:
            attrs: The element attributes
            ns_map: The element namespace prefix-URI map

        Returns:
            The parsed attributes with expanded namespace prefixes
        """
        return {
            key: cls.parse_any_attribute(value, ns_map) for key, value in attrs.items()
        }

    @classmethod
    def parse_any_attribute(cls, value: str, ns_map: Dict) -> str:
        """Expand the value with the full namespace if it has a prefix.

        Args:
            value: The attr value
            ns_map: The element namespace prefix-URI map

        Returns:
            The expanded value.
        """
        prefix, suffix = text.split(value)
        if prefix and prefix in ns_map and not suffix.startswith("//"):
            value = build_qname(ns_map[prefix], suffix)

        return value

    @classmethod
    def validate_fixed_value(cls, meta: XmlMeta, var: XmlVar, value: Any):
        """Validate if the parsed value matches the fixed value.

        Special cases
            - float nans are never equal in python
            - strings with whitespaces, need trimming

        """

        default_value = var.default() if callable(var.default) else var.default
        if (
            isinstance(default_value, float)
            and isinstance(value, float)
            and math.isnan(default_value)
            and math.isnan(value)
        ) or (
            isinstance(default_value, str)
            and isinstance(value, str)
            and default_value.strip() == value.strip()
        ):
            return

        if default_value != value:
            raise ParserError(
                f"Fixed value mismatch {meta.qname}:{var.qname}, `{default_value} != {value}`"
            )