# -*- coding: utf-8 -*-
'''
    :codeauthor: :email:`Pedro Algarvio (pedro@algarvio.me)`
    :copyright: © 2013 by the SaltStack Team, see AUTHORS for more details.
    :license: Apache 2.0, see LICENSE for more details.


    salt.utils.odict
    ~~~~~~~~~~~~~~~~

    This is a compatibility/"importability" layer for an ordered dictionary.
    Tries to import from the standard library if python >= 2.7, then from the
    ``ordereddict`` package available from PyPi, and, as a last resort,
    provides an ``OrderedDict`` implementation based on::

        http://code.activestate.com/recipes/576669/
'''

try:
    from collections import OrderedDict  # pylint: disable=E0611
except ImportError:
    try:
        from ordereddict import OrderedDict
    except ImportError:
        ## {{{ http://code.activestate.com/recipes/576693/ (r9)
        # Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pypy.
        # Passes Python2.7's test suite and incorporates all the latest updates.

        try:
            from thread import get_ident as _get_ident
        except ImportError:
            from dummy_thread import get_ident as _get_ident

#        try:
#            from _abcoll import KeysView, ValuesView, ItemsView
#        except ImportError:
#            pass

        class OrderedDict(dict):
            'Dictionary that remembers insertion order'
            # An inherited dict maps keys to values.
            # The inherited dict provides __getitem__, __len__, __contains__, and get.
            # The remaining methods are order-aware.
            # Big-O running times for all methods are the same as for regular dictionaries.

            # The internal self.__map dictionary maps keys to links in a doubly linked list.
            # The circular doubly linked list starts and ends with a sentinel element.
            # The sentinel element never gets deleted (this simplifies the algorithm).
            # Each link is stored as a list of length three:  [PREV, NEXT, KEY].

            def __init__(self, *args, **kwds):  # pylint: disable=E1003
                '''Initialize an ordered dictionary.  Signature is the same as for
                regular dictionaries, but keyword arguments are not recommended
                because their insertion order is arbitrary.

                '''
                super(OrderedDict, self).__init__()  # pylint: disable=E1003
                if len(args) > 1:
                    raise TypeError('expected at most 1 arguments, got %d' % len(args))
                try:
                    self.__root
                except AttributeError:
                    self.__root = root = []                     # sentinel node
                    root[:] = [root, root, None]
                    self.__map = {}
                self.__update(*args, **kwds)

            def __setitem__(self, key, value, dict_setitem=dict.__setitem__):
                'od.__setitem__(i, y) <==> od[i]=y'
                # Setting a new item creates a new link which goes at the end of the linked
                # list, and the inherited dictionary is updated with the new key/value pair.
                if key not in self:
                    root = self.__root
                    last = root[0]
                    last[1] = root[0] = self.__map[key] = [last, root, key]
                dict_setitem(self, key, value)

            def __delitem__(self, key, dict_delitem=dict.__delitem__):
                'od.__delitem__(y) <==> del od[y]'
                # Deleting an existing item uses self.__map to find the link which is
                # then removed by updating the links in the predecessor and successor nodes.
                dict_delitem(self, key)
                link_prev, link_next, key = self.__map.pop(key)
                link_prev[1] = link_next
                link_next[0] = link_prev

            def __iter__(self):
                'od.__iter__() <==> iter(od)'
                root = self.__root
                curr = root[1]
                while curr is not root:
                    yield curr[2]
                    curr = curr[1]

            def __reversed__(self):
                'od.__reversed__() <==> reversed(od)'
                root = self.__root
                curr = root[0]
                while curr is not root:
                    yield curr[2]
                    curr = curr[0]

            def clear(self):
                'od.clear() -> None.  Remove all items from od.'
                try:
                    for node in self.__map.itervalues():
                        del node[:]
                    root = self.__root
                    root[:] = [root, root, None]
                    self.__map.clear()
                except AttributeError:
                    pass
                dict.clear(self)

            def popitem(self, last=True):
                '''od.popitem() -> (k, v), return and remove a (key, value) pair.
                Pairs are returned in LIFO order if last is true or FIFO order if false.

                '''
                if not self:
                    raise KeyError('dictionary is empty')
                root = self.__root
                if last:
                    link = root[0]
                    link_prev = link[0]
                    link_prev[1] = root
                    root[0] = link_prev
                else:
                    link = root[1]
                    link_next = link[1]
                    root[1] = link_next
                    link_next[0] = root
                key = link[2]
                del self.__map[key]
                value = dict.pop(self, key)
                return key, value

            # -- the following methods do not depend on the internal structure --

            def keys(self):
                'od.keys() -> list of keys in od'
                return list(self)

            def values(self):
                'od.values() -> list of values in od'
                return [self[key] for key in self]

            def items(self):
                'od.items() -> list of (key, value) pairs in od'
                return [(key, self[key]) for key in self]

            def iterkeys(self):
                'od.iterkeys() -> an iterator over the keys in od'
                return iter(self)

            def itervalues(self):
                'od.itervalues -> an iterator over the values in od'
                for k in self:
                    yield self[k]

            def iteritems(self):
                'od.iteritems -> an iterator over the (key, value) items in od'
                for k in self:
                    yield (k, self[k])

            def update(*args, **kwds):  # pylint: disable=E0211
                '''od.update(E, **F) -> None.  Update od from dict/iterable E and F.

                If E is a dict instance, does:           for k in E: od[k] = E[k]
                If E has a .keys() method, does:         for k in E.keys(): od[k] = E[k]
                Or if E is an iterable of items, does:   for k, v in E: od[k] = v
                In either case, this is followed by:     for k, v in F.items(): od[k] = v

                '''
                if len(args) > 2:
                    raise TypeError('update() takes at most 2 positional '
                                    'arguments (%d given)' % (len(args),))
                elif not args:
                    raise TypeError('update() takes at least 1 argument (0 given)')
                self = args[0]
                # Make progressively weaker assumptions about "other"
                other = ()
                if len(args) == 2:
                    other = args[1]
                if isinstance(other, dict):
                    for key in other:
                        self[key] = other[key]
                elif hasattr(other, 'keys'):
                    for key in other.keys():
                        self[key] = other[key]
                else:
                    for key, value in other:
                        self[key] = value
                for key, value in kwds.items():
                    self[key] = value

            __update = update  # let subclasses override update without breaking __init__

            __marker = object()

            def pop(self, key, default=__marker):
                '''od.pop(k[,d]) -> v, remove specified key and return the corresponding value.
                If key is not found, d is returned if given, otherwise KeyError is raised.

                '''
                if key in self:
                    result = self[key]
                    del self[key]
                    return result
                if default is self.__marker:
                    raise KeyError(key)
                return default

            def setdefault(self, key, default=None):
                'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'
                if key in self:
                    return self[key]
                self[key] = default
                return default

            def __repr__(self, _repr_running={}):  # pylint: disable=W0102
                'od.__repr__() <==> repr(od)'
                call_key = id(self), _get_ident()
                if call_key in _repr_running:
                    return '...'
                _repr_running[call_key] = 1
                try:
                    if not self:
                        return '%s()' % (self.__class__.__name__,)
                    return '%s(%r)' % (self.__class__.__name__, self.items())
                finally:
                    del _repr_running[call_key]

            def __reduce__(self):
                'Return state information for pickling'
                items = [[k, self[k]] for k in self]
                inst_dict = vars(self).copy()
                for k in vars(OrderedDict()):
                    inst_dict.pop(k, None)
                if inst_dict:
                    return (self.__class__, (items,), inst_dict)
                return self.__class__, (items,)

            def copy(self):
                'od.copy() -> a shallow copy of od'
                return self.__class__(self)

            @classmethod
            def fromkeys(cls, iterable, value=None):
                '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S
                and values equal to v (which defaults to None).

                '''
                d = cls()
                for key in iterable:
                    d[key] = value
                return d

            def __eq__(self, other):
                '''od.__eq__(y) <==> od==y.  Comparison to another OD is order-sensitive
                while comparison to a regular mapping is order-insensitive.

                '''
                if isinstance(other, OrderedDict):
                    return len(self) == len(other) and self.items() == other.items()
                return dict.__eq__(self, other)

            def __ne__(self, other):
                return not self == other

#            # -- the following methods are only used in Python 2.7 --
#
#            def viewkeys(self):
#                "od.viewkeys() -> a set-like object providing a view on od's keys"
#                return KeysView(self)
#
#            def viewvalues(self):
#                "od.viewvalues() -> an object providing a view on od's values"
#                return ValuesView(self)
#
#            def viewitems(self):
#                "od.viewitems() -> a set-like object providing a view on od's items"
#                return ItemsView(self)
#        ## end of http://code.activestate.com/recipes/576693/ }}}
