from router import Router, Resource
from router import JSONRenderer, HTMLRenderer, XMLRenderer, AtomRenderer


router = Router()

# Add Renderers
router.add_renderer(JSONRenderer, default=True)
router.add_renderer(HTMLRenderer)
router.add_renderer(AtomRenderer)

router.add_auth_source(DbAuthenticator('users.db'))
router.add_authenz_source(DbAuthorizor('users.db'))

revision_spec = FragmentSpec(required=False, default='tip',
                             regex='(tip|[0-9a-zA-Z]+)')

# Add Resource Mappings
Route('/{project_name}', ProjectSummaryResource, [
    Route('/summary', ProjectSummaryResource),
    Route('/shortlog/{revision}', ShortLogResource,
            uri_spec={ 'revision': revision_spec }),
    Route('/graph/{revision}', GraphResource,
            uri_spec={ 'revision': revision_spec }),
    Route('/raw-rev/{revision}', RawRevisionResource,
            uri_spec={ 'revision': revision_spec }),
    Route('/tags', TagsResource),
    Route('/annotate/{revision}/{filename}', AnnotateResource,
            uri_spec={ 'revision': revision_spec,
                       'filename': FragmentSpec(required=False) }),
    Route(('/diff/{revision}/{filename}', '/filediff/{revision}/{filename}'),
            DiffResource,
            uri_spec={ 'revision': revision_spec,
                       'filename': FragmentSpec(required=False) }),
    Route('/raw-file/{revision}/{filename}', RawFileResource,
            uri_spec={ 'revision': revision_spec,
                       'filename': FragmentSpec(required=False) }),
    Route('/branches', BranchesResource),
    Route('/archive/{revision}.tar.{format}', ArchiveResource,
            uri_spec={ 'revision': FragmentSpec(regex='(tip|[0-9a-zA-Z]+)'),
                       'format': FragmentSpec(value_list=('gz', 'bz2') }),
    Route(('/rev/{revision}','/changeset/{revision}'), RevisionResource,
            uri_spec={ 'revision': revision_spec }),
    Route(('/log/{revision}', '/changelog/{revision}', '/filelog/{revision}'),
            LogResource,
            uri_spec={ 'revision': revision_spec }),
    Route('/file/{revision}/{filename}', FileResource,
            uri_spec={ 'revision': revision_spec,
                       'filename': FragmentSpec(required=False) }),
    ])


class constant(object):
    """
    Constant descriptor to provide a level of protection against
    changes to constants in class instances. Does not prevent
    changes directly to constants in non-instances.
    """

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

    def __get__(self, instance, owner):
        return self.value

    def __set__(self, instance, value):
        raise ValueError('Can not assign to constant.')

    def __delete__(self, instance):
        raise ValueError('Can not delete constant.')


class Route(object):

    # ----------------------------------------------------------------
    # Constants
    # ----------------------------------------------------------------
    REDIRECT = constant('redirect')
    FAILURE = constant('failure')

    # ----------------------------------------------------------------
    # Required Parameters
    # ----------------------------------------------------------------

    #: Part of the URI that will map to this route
    uri_part = None

    #: Resource existing at this route
    resource = None

    #: Resource requires that the user is using an HTTPS connection
    #: can be True, False, REDIRECT or FAILRE. If True and no HTTPS
    #: the route will fail to match. If REDIRECT and no HTTPS the
    #: client will be redirect to the secure version of the resouce.
    #: If FAILURE a 403 (Forbidden) error will be returned to the
    #: client.
    https = False

    #: Route requires authentication
    requires_authentication = True

    # ----------------------------------------------------------------
    # Optional, if unspecified these will not be used
    # ----------------------------------------------------------------

    #: Dictionary of uri fragment names to FragmentSpec objects used
    #: to validate the individual uri fragments
    uri_spec = None

    #: Callable or list of callables to which the matching resouce
    #: and context will be passed, the first failure will cause the
    #: route to not match.
    conditions = None

    #: Type of permission required. The router doesn't care what
    #: this object is as long as the security system understands it
    permissions_required = None

    # ----------------------------------------------------------------
    # Optional, if unspecified these will use the router defaults
    # ----------------------------------------------------------------
    #: List of content-types supported by this route
    content_types = None

    #: Source for authentication
    auth_source = None

    #: Source for authorization
    authz_source = None


class FragmentSpec(object):

    #: Indicates if the framgent is required
    required = True

    #: Regex used to check if the fragment is valid if specified
    #: value_list may not be specified.
    regex = r'.*'

    #: Optional list of acceptable values. May not be specified
    #: with regex
    value_list = None

    #: Default value if the user provides no value
    default = None


class NotSupported(object):
    pass


class Resource(object):

    GET = NotSupported()
    POST = NotSupported()
    HEAD = NotSupported()
    PUT = NotSupported()
    DELETE = NotSupported()