#!/usr/bin/env python
# -*- coding: utf-8 -*-
""" Bunch is a subclass of dict with attribute-style access.
    >>> b = Bunch()
    >>> b.hello = 'world'
    >>> b.hello
    'world'
    >>> b['hello'] += "!"
    >>> b.hello
    'world!'
    >>> b.foo = Bunch(lol=True)
    >>> b.foo.lol
    True
    >>> b.foo is b['foo']
    True

    It is safe to import * from this module:

        __all__ = ('Bunch', 'bunchify','unbunchify')

    un/bunchify provide dictionary conversion; Bunches can also be
    converted via Bunch.to/fromDict().
"""

__all__ = ('Bunch', 'bunchify', 'unbunchify',)


class Bunch(dict):
    """ A dictionary that provides attribute-style access.

        >>> b = Bunch()
        >>> b.hello = 'world'
        >>> b.hello
        'world'
        >>> b['hello'] += "!"
        >>> b.hello
        'world!'
        >>> b.foo = Bunch(lol=True)
        >>> b.foo.lol
        True
        >>> b.foo is b['foo']
        True

        A Bunch is a subclass of dict; it supports all the methods a dict does...

        >>> b.keys()
        dict_keys(['hello', 'foo'])

        Including update()...

        >>> b.update({ 'ponies': 'are pretty!' }, hello=42)
        >>> print(repr(b))
        Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')

        As well as iteration...

        >>> [ (k,b[k]) for k in b ]
        [('hello', 42), ('foo', Bunch(lol=True)), ('ponies', 'are pretty!')]

        And "splats".

        >>> "The {knights} who say {ni}!".format(**Bunch(knights='lolcats', ni='can haz'))
        'The lolcats who say can haz!'

        See unbunchify/Bunch.toDict, bunchify/Bunch.fromDict for notes about conversion.
    """

    def __contains__(self, k):
        """ >>> b = Bunch(ponies='are pretty!')
            >>> 'ponies' in b
            True
            >>> 'foo' in b
            False
            >>> b['foo'] = 42
            >>> 'foo' in b
            True
            >>> b.hello = 'hai'
            >>> 'hello' in b
            True
        """
        try:
            return hasattr(self, k) or dict.__contains__(self, k)
        except:
            return False

    # only called if k not found in normal places
    def __getattr__(self, k):
        """ Gets key if it exists, otherwise throws AttributeError.

            nb. __getattr__ is only called if key is not found in normal places.

            >>> b = Bunch(bar='baz', lol={})
            >>> b.bar
            'baz'
            >>> getattr(b, 'bar')
            'baz'
            >>> b['bar']
            'baz'

            >>> b.lol is b['lol']
            True
            >>> b.lol is getattr(b, 'lol')
            True
        """
        try:
            # Throws exception if not in prototype chain
            return object.__getattribute__(self, k)
        except AttributeError:
            try:
                return self[k]
            except KeyError:
                raise AttributeError(k)

    def __setattr__(self, k, v):
        """ Sets attribute k if it exists, otherwise sets key k. A KeyError
            raised by set-item (only likely if you subclass Bunch) will
            propagate as an AttributeError instead.

            >>> b = Bunch(foo='bar', this_is='useful when subclassing')
            >>> b.values                            #doctest: +ELLIPSIS
            <built-in method values of Bunch object at 0x...>
            >>> b.values = 'uh oh'
            >>> b.values
            'uh oh'
            >>> b['values']
            Traceback (most recent call last):
              File "<stdin>", line 1, in <module>
            KeyError: 'values'
        """
        try:
            # Throws exception if not in prototype chain
            object.__getattribute__(self, k)
        except AttributeError:
            try:
                self[k] = v
            except:
                raise AttributeError(k)
        else:
            object.__setattr__(self, k, v)

    def __delattr__(self, k):
        """ Deletes attribute k if it exists, otherwise deletes key k. A KeyError
            raised by deleting the key--such as when the key is missing--will
            propagate as an AttributeError instead.

            >>> b = Bunch(lol=42)
            >>> del b.lol
            >>> b.lol
            Traceback (most recent call last):
            ......
            AttributeError: lol
        """
        try:
            # Throws exception if not in prototype chain
            object.__getattribute__(self, k)
        except AttributeError:
            try:
                del self[k]
            except KeyError:
                raise AttributeError(k)
        else:
            object.__delattr__(self, k)

    def toDict(self):
        """ Recursively converts a bunch back into a dictionary.

            >>> b = Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
            >>> b.toDict()
            {'foo': {'lol': True}, 'hello': 42, 'ponies': 'are pretty!'}

            See unbunchify for more info.
        """
        return unbunchify(self)

    def __repr__(self):
        """ Invertible* string-form of a Bunch.

            >>> b = Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
            >>> print(repr(b))
            Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
            >>> eval(repr(b))
            Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')

            (*) Invertible so long as collection contents are each repr-invertible.
        """
        keys = list(self.keys())
        keys.sort()
        args = ', '.join(['%s=%r' % (key, self[key]) for key in keys])
        return '%s(%s)' % (self.__class__.__name__, args)

    @staticmethod
    def fromDict(d):
        """ Recursively transforms a dictionary into a Bunch via copy.

            >>> b = Bunch.fromDict({'urmom': {'sez': {'what': 'what'}}})
            >>> b.urmom.sez.what
            'what'

            See bunchify for more info.
        """
        return bunchify(d)


# While we could convert abstract types like Mapping or Iterable, I think
# bunchify is more likely to "do what you mean" if it is conservative about
# casting (ex: isinstance(str,Iterable) == True ).
#
# Should you disagree, it is not difficult to duplicate this function with
# more aggressive coercion to suit your own purposes.

def bunchify(x):
    """ Recursively transforms a dictionary into a Bunch via copy.

        >>> b = bunchify({'urmom': {'sez': {'what': 'what'}}})
        >>> b.urmom.sez.what
        'what'

        bunchify can handle intermediary dicts, lists and tuples (as well as
        their subclasses), but ymmv on custom datatypes.

        >>> b = bunchify({ 'lol': ('cats', {'hah':'i win again'}),
        ...         'hello': [{'french':'salut', 'german':'hallo'}] })
        >>> b.hello[0].french
        'salut'
        >>> b.lol[1].hah
        'i win again'

        nb. As dicts are not hashable, they cannot be nested in sets/frozensets.
    """
    if isinstance(x, dict):
        return Bunch((k, bunchify(v)) for k, v in x.items())
    elif isinstance(x, (list, tuple)):
        return type(x)(bunchify(v) for v in x)
    else:
        return x


def unbunchify(x):
    """ Recursively converts a Bunch into a dictionary.

        >>> b = Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
        >>> unbunchify(b)
        {'foo': {'lol': True}, 'hello': 42, 'ponies': 'are pretty!'}

        unbunchify will handle intermediary dicts, lists and tuples (as well as
        their subclasses), but ymmv on custom datatypes.

        >>> b = Bunch(foo=['bar', Bunch(lol=True)], hello=42,
        ...         ponies=('are pretty!', Bunch(lies='are trouble!')))
        >>> unbunchify(b) #doctest: +NORMALIZE_WHITESPACE
        {'foo': ['bar', {'lol': True}], 'hello': 42, 'ponies': ('are pretty!', {'lies': 'are trouble!'})}

        nb. As dicts are not hashable, they cannot be nested in sets/frozensets.
    """
    if isinstance(x, dict):
        return dict((k, unbunchify(v)) for k, v in x.items())
    elif isinstance(x, (list, tuple)):
        return type(x)(unbunchify(v) for v in x)
    else:
        return x


#   Serialization

try:
    try:
        import json
    except ImportError:
        import simplejson as json


    def toJSON(self, **options):
        """ Serializes this Bunch to JSON. Accepts the same keyword options as `json.dumps()`.

            >>> b = Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
            >>> json.dumps(b)
            '{"foo": {"lol": true}, "hello": 42, "ponies": "are pretty!"}'
            >>> b.toJSON()
            '{"foo": {"lol": true}, "hello": 42, "ponies": "are pretty!"}'
        """
        return json.dumps(self, **options)


    Bunch.toJSON = toJSON

except ImportError:
    pass

try:
    # Attempt to register ourself with PyYAML as a representer
    import yaml
    from yaml.representer import Representer, SafeRepresenter


    def from_yaml(loader, node):
        """ PyYAML support for Bunches using the tag `!bunch` and `!bunch.Bunch`.

            >>> import yaml
            >>> yaml.load('''
            ... Flow style: !bunch.Bunch { Clark: Evans, Brian: Ingerson, Oren: Ben-Kiki }
            ... Block style: !bunch
            ...   Clark : Evans
            ...   Brian : Ingerson
            ...   Oren  : Ben-Kiki
            ... ''') #doctest: +NORMALIZE_WHITESPACE
            {'Flow style': Bunch(Brian='Ingerson', Clark='Evans', Oren='Ben-Kiki'),
             'Block style': Bunch(Brian='Ingerson', Clark='Evans', Oren='Ben-Kiki')}

            This module registers itself automatically to cover both Bunch and any
            subclasses. Should you want to customize the representation of a subclass,
            simply register it with PyYAML yourself.
        """
        data = Bunch()
        yield data
        value = loader.construct_mapping(node)
        data.update(value)


    def to_yaml_safe(dumper, data):
        """ Converts Bunch to a normal mapping node, making it appear as a
            dict in the YAML output.

            >>> b = Bunch(foo=['bar', Bunch(lol=True)], hello=42)
            >>> import yaml
            >>> yaml.safe_dump(b, default_flow_style=True)
            '{foo: [bar, {lol: true}], hello: 42}\\n'
        """
        return dumper.represent_dict(data)


    def to_yaml(dumper, data):
        """ Converts Bunch to a representation node.

            >>> b = Bunch(foo=['bar', Bunch(lol=True)], hello=42)
            >>> import yaml
            >>> yaml.dump(b, default_flow_style=True)
            '!bunch.Bunch {foo: [bar, !bunch.Bunch {lol: true}], hello: 42}\\n'
        """
        return dumper.represent_mapping(u'!bunch.Bunch', data)


    yaml.add_constructor(u'!bunch', from_yaml)
    yaml.add_constructor(u'!bunch.Bunch', from_yaml)

    SafeRepresenter.add_representer(Bunch, to_yaml_safe)
    SafeRepresenter.add_multi_representer(Bunch, to_yaml_safe)

    Representer.add_representer(Bunch, to_yaml)
    Representer.add_multi_representer(Bunch, to_yaml)


    # Instance methods for YAML conversion
    def toYAML(self, **options):
        """ Serializes this Bunch to YAML, using `yaml.safe_dump()` if
            no `Dumper` is provided. See the PyYAML documentation for more info.

            >>> b = Bunch(foo=['bar', Bunch(lol=True)], hello=42)
            >>> import yaml
            >>> yaml.safe_dump(b, default_flow_style=True)
            '{foo: [bar, {lol: true}], hello: 42}\\n'
            >>> b.toYAML(default_flow_style=True)
            '{foo: [bar, {lol: true}], hello: 42}\\n'
            >>> yaml.dump(b, default_flow_style=True)
            '!bunch.Bunch {foo: [bar, !bunch.Bunch {lol: true}], hello: 42}\\n'
            >>> b.toYAML(Dumper=yaml.Dumper, default_flow_style=True)
            '!bunch.Bunch {foo: [bar, !bunch.Bunch {lol: true}], hello: 42}\\n'
        """
        opts = dict(indent=4, default_flow_style=False)
        opts.update(options)
        if 'Dumper' not in opts:
            return yaml.safe_dump(self, **opts)
        else:
            return yaml.dump(self, **opts)


    def fromYAML(*args, **kwargs):
        return bunchify(yaml.load(*args, **kwargs))


    Bunch.toYAML = Bunch.__str__ = toYAML
    Bunch.fromYAML = staticmethod(fromYAML)

except ImportError:
    pass

if __name__ == "__main__":
    import doctest

    doctest.testmod()

