#!/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().
"""

__version__ = '1.0.1'
VERSION = tuple(map(int, __version__.split('.')))

__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()
        ['foo', 'hello']
        
        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 ]
        [('ponies', 'are pretty!'), ('foo', Bunch(lol=True)), ('hello', 42)]
        
        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.foo
            Traceback (most recent call last):
                ...
            AttributeError: foo
            
            >>> 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):
                ...
            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.values
            Traceback (most recent call last):
                ...
            AttributeError: 'Bunch' object attribute 'values' is read-only
            >>> 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()
            {'ponies': 'are pretty!', 'foo': {'lol': True}, 'hello': 42}
            
            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 = 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.iteritems() )
    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)
        {'ponies': 'are pretty!', 'foo': {'lol': True}, 'hello': 42}
        
        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
        {'ponies': ('are pretty!', {'lies': 'are trouble!'}), 
         'foo': ['bar', {'lol': True}], 'hello': 42}
        
        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.iteritems() )
    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)
            '{"ponies": "are pretty!", "foo": {"lol": true}, "hello": 42}'
            >>> b.toJSON()
            '{"ponies": "are pretty!", "foo": {"lol": true}, "hello": 42}'
        """
        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()

