"""A WSGI app for serving CAS.
"""
import os
import tempfile
from webob import exc, Response
from webob.dec import wsgify

template_dir = os.path.join(os.path.dirname(__file__), 'templates')


class CASServer(object):
    """A WSGI CAS server.

    This CAS server stores credential data (tickets, etc.) in a local
    sqlite3 database file.

    `db_path` -
       The filesystem path to the database to use. If none is given
       CAS server will create a new one in some new, temporary
       directory. Please note that credentials will be lost after a
       CAS server restart.

       If the path is given and the file exists already, it will be
       used.

       If the database file does not exist, it will be created.
    """
    def __init__(self, db_path=None):
        if db_path is None:
            db_path = os.path.join(tempfile.mkdtemp(), 'cas.db')
        self.db_path = db_path

    @wsgify
    def __call__(self, req):
        if req.path in ['/login', '/validate', '/logout']:
            return getattr(self, req.path[1:])(req)
        return exc.HTTPNotFound()

    def login(self, req):
        return Response(
            open(os.path.join(template_dir, 'login.html'), 'r').read())

    def validate(self, req):
        return exc.HTTPNotImplemented()

    def logout(self, req):
        return exc.HTTPNotImplemented()

cas_server = CASServer


def make_cas_server(global_conf, **local_conf):
    return CASServer(**local_conf)