# --------------------------------------------------------------------------------------
# Copyright (c) 2013-2024, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file LICENSE, distributed with this software.
# --------------------------------------------------------------------------------------
from collections import defaultdict

from .catom import DefaultValue, Member, Validate
from .instance import Instance
from .typing_utils import extract_types, is_optional


class Dict(Member):
    """A value of type `dict`."""

    __slots__ = ()

    def __init__(self, key=None, value=None, default=None):
        """Initialize a Dict.

        Parameters
        ----------
        key : Member, type, tuple of types, or None, optional
            A member to use for validating the types of keys allowed in
            the dict. This can also be a type or a tuple of types, which
            will be wrapped with an Instance member. If this is not
            given, no key validation is performed.

        value : Member, type, tuple of types, or None, optional
            A member to use for validating the types of values allowed
            in the dict. This can also be a type or a tuple of types,
            which will be wrapped with an Instance member. If this is
            not given, no value validation is performed.

        default : dict, optional
            The default dict of items. A new copy of this dict will be
            created for each atom instance.

        """
        self.set_default_value_mode(DefaultValue.Dict, default)
        if key is not None and not isinstance(key, Member):
            opt, types = is_optional(extract_types(key))
            key = Instance(types, optional=opt)
        if value is not None and not isinstance(value, Member):
            opt, types = is_optional(extract_types(value))
            value = Instance(types, optional=opt)
        self.set_validate_mode(Validate.Dict, (key, value))

    def set_name(self, name):
        """Assign the name to this member.

        This method is called by the Atom metaclass when a class is
        created. This makes sure the name of the internal members are
        also updated.

        """
        super(Dict, self).set_name(name)
        key, value = self.validate_mode[1]
        if key is not None:
            key.set_name(name + "|key")
        if value is not None:
            value.set_name(name + "|value")

    def set_index(self, index):
        """Assign the index to this member.

        This method is called by the Atom metaclass when a class is
        created. This makes sure the index of the internal members are
        also updated.

        """
        super(Dict, self).set_index(index)
        key, value = self.validate_mode[1]
        if key is not None:
            key.set_index(index)
        if value is not None:
            value.set_index(index)

    def clone(self):
        """Create a clone of the member.

        This will clone the internal dict key and value members if they exist.

        """
        clone = super(Dict, self).clone()
        key, value = self.validate_mode[1]
        if key is not None or value is not None:
            key_clone = key.clone() if key is not None else None
            value_clone = value.clone() if value is not None else None
            mode, _ = self.validate_mode
            clone.set_validate_mode(mode, (key_clone, value_clone))
        return clone


class _DefaultWrapper:
    __slots__ = ("wrapped",)

    def __init__(self, wrapped):
        self.wrapped = wrapped

    def __call__(self, atom):
        return self.wrapped()

    def __repr__(self):
        return repr(self.wrapped)


class DefaultDict(Member):
    """A value of type `dict` implementing __missing__"""

    __slots__ = ()

    def __init__(self, key=None, value=None, default=None, *, missing=None):
        """Initialize a DefaultDict.

        Parameters
        ----------
        key : Member, type, tuple of types, or None, optional
            A member to use for validating the types of keys allowed in
            the dict. This can also be a type or a tuple of types, which
            will be wrapped with an Instance member. If this is not
            given, no key validation is performed.

        value : Member, type, tuple of types, or None, optional
            A member to use for validating the types of values allowed
            in the dict. This can also be a type or a tuple of types,
            which will be wrapped with an Instance member. If this is
            not given, no value validation is performed.

        default : dict or None, optional
            The default dict of items. A new copy of this dict will be
            created for each atom instance.

        missing : Callable[[], Any] or None, optional
            Factory to build a default value for a missing key in the dictionary.

        """
        self.set_default_value_mode(DefaultValue.DefaultDict, default)
        if key is not None and not isinstance(key, Member):
            opt, types = is_optional(extract_types(key))
            key = Instance(types, optional=opt)
        if value is not None and not isinstance(value, Member):
            opt, types = is_optional(extract_types(value))
            # Assume a default value can be created to avoid the need to specify a
            # missing factory in simple case even for custom types.
            value = Instance(types, optional=opt, args=())

        if missing is not None:
            if not callable(missing):
                raise ValueError(
                    f"The missing argument expect a callable, got {missing}"
                )
            try:
                missing()
            except Exception as e:
                raise ValueError(
                    "The missing argument expect a callable taking no argument. "
                    "Trying to call it with not argument failed with the chained "
                    "exception."
                ) from e
            missing = _DefaultWrapper(missing)

        if isinstance(default, defaultdict):
            if missing is not None:
                raise ValueError(
                    "Both a missing factory and a default value which is a default "
                    "dictionary were specified. When using a default dict as default "
                    "value missing should be omitted."
                )
            missing = _DefaultWrapper(default.default_factory)

        if (
            missing is None
            and value is not None
            and value.default_value_mode[0]
            not in (DefaultValue.NoOp, DefaultValue.NonOptional)
        ):
            missing = value.do_default_value

        if missing is None:
            raise ValueError(
                "No missing value factory was specified and none could be "
                "deduced from the value member."
            )

        self.set_validate_mode(Validate.DefaultDict, (key, value, missing))

    def set_name(self, name):
        """Assign the name to this member.

        This method is called by the Atom metaclass when a class is
        created. This makes sure the name of the internal members are
        also updated.

        """
        super().set_name(name)
        key, value, _ = self.validate_mode[1]
        if key is not None:
            key.set_name(name + "|key")
        if value is not None:
            value.set_name(name + "|value")

    def set_index(self, index):
        """Assign the index to this member.

        This method is called by the Atom metaclass when a class is
        created. This makes sure the index of the internal members are
        also updated.

        """
        super().set_index(index)
        key, value, _ = self.validate_mode[1]
        if key is not None:
            key.set_index(index)
        if value is not None:
            value.set_index(index)

    def clone(self):
        """Create a clone of the member.

        This will clone the internal dict key and value members if they exist.

        """
        clone = super().clone()
        mode, (key, value, missing) = self.validate_mode
        key_clone = key.clone() if key is not None else None
        value_clone = value.clone() if value is not None else None
        clone.set_validate_mode(mode, (key_clone, value_clone, missing))
        return clone