#------------------------------------------------------------------------------
# Copyright (c) 2013-2019, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#------------------------------------------------------------------------------
from .catom import Member, DefaultValue, Validate
from .instance import Instance


class Tuple(Member):
    """ A member which allows tuple values.

    If item validation is used, then assignment will create a copy of
    the original tuple before validating the items, since validation
    may change the item values.

    """
    __slots__ = ('item',)

    def __init__(self, item=None, default=()):
        """ Initialize a Tuple.

        Parameters
        ----------
        item : Member, type, or tuple of types, optional
            A member to use for validating the types of items allowed in
            the tuple. This can also be a type object or a tuple of types,
            in which case it will be wrapped with an Instance member. If
            this is not given, no item validation is performed.

        default : tuple, optional
            The default tuple of values.

        """
        if item is not None and not isinstance(item, Member):
            item = Instance(item)
        self.item = item
        self.set_default_value_mode(DefaultValue.Static, default)
        self.set_validate_mode(Validate.Tuple, item)

    def set_name(self, name):
        """ Set the name of the member.

        This method ensures that the item member name is also updated.

        """
        super(Tuple, self).set_name(name)
        if self.item is not None:
            self.item.set_name(name + "|item")

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

        This method ensures that the item member index is also updated.

        """
        super(Tuple, self).set_index(index)
        if self.item is not None:
            self.item.set_index(index)

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

        This will clone the internal tuple item if one is in use.

        """
        clone = super(Tuple, self).clone()
        item = self.item
        if item is not None:
            clone.item = item_clone = item.clone()
            mode, ctxt = self.validate_mode
            clone.set_validate_mode(mode, item_clone)
        else:
            clone.item = None
        return clone
