# This file is part of Radicale Server - Calendar Server
# Copyright © 2017-2018 Unrud <unrud@outlook.com>
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This library 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Radicale.  If not, see <http://www.gnu.org/licenses/>.

"""
The web module for the website at ``/.web``.

Take a look at the class ``BaseWeb`` if you want to implement your own.

"""

from importlib import import_module

from radicale.log import logger

INTERNAL_TYPES = ("none", "internal")


def load(configuration):
    """Load the web module chosen in configuration."""
    web_type = configuration.get("web", "type")
    if web_type in INTERNAL_TYPES:
        module = "radicale.web.%s" % web_type
    else:
        module = web_type
    try:
        class_ = import_module(module).Web
    except Exception as e:
        raise RuntimeError("Failed to load web module %r: %s" %
                           (module, e)) from e
    logger.info("Web type is %r", web_type)
    return class_(configuration)


class BaseWeb:
    def __init__(self, configuration):
        """Initialize BaseWeb.

        ``configuration`` see ``radicale.config`` module.
        The ``configuration`` must not change during the lifetime of
        this object, it is kept as an internal reference.

        """
        self.configuration = configuration

    def get(self, environ, base_prefix, path, user):
        """GET request.

        ``base_prefix`` is sanitized and never ends with "/".

        ``path`` is sanitized and always starts with "/.web"

        ``user`` is empty for anonymous users.

        """
        raise NotImplementedError