# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

####################################
# Staticdirect infrastructure.
# Borrowed largely from cc.engine
# by Chris Webber & Creative Commons
#
# This needs documentation!
####################################

import logging

_log = logging.getLogger(__name__)


class StaticDirect(object):
    """
    Direct to a static resource.

    This StaticDirect class can take a series of "domains" to
    staticdirect to.  In general, you should supply a None domain, as
    that's the "default" domain.

    Things work like this:
      >>> staticdirect = StaticDirect(
      ...     {None: "/static/",
      ...      "theme": "http://example.org/themestatic/"})
      >>> staticdirect("css/monkeys.css")
      "/static/css/monkeys.css"
      >>> staticdirect("images/lollerskate.png", "theme")
      "http://example.org/themestatic/images/lollerskate.png"
    """
    def __init__(self, domains):
        self.domains = dict(
            [(key, value.rstrip('/'))
             for key, value in domains.iteritems()])
        self.cache = {}

    def __call__(self, filepath, domain=None):
        if domain in self.cache and filepath in self.cache[domain]:
            return self.cache[domain][filepath]

        static_direction = self.cache.setdefault(
            domain, {})[filepath] = self.get(filepath, domain)
        return static_direction

    def get(self, filepath, domain=None):
        return '%s/%s' % (
            self.domains[domain], filepath.lstrip('/'))