#!/usr/bin/python

# Copyright (c) 2013 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Requires the following command to be run:
#   setsebool -P httpd_can_network_connect 1
#   setsebool -P httpd_can_network_memcache 1

import os
import cgi
from swift.common.memcached import MemcacheRing
from time import time, ctime
from swiftkerbauth import MEMCACHE_SERVERS, TOKEN_LIFE, DEBUG_HEADERS
from swiftkerbauth.kerbauth_utils import get_remote_user, get_auth_data, \
    generate_token, set_auth_data, get_groups_from_username


def main():
    try:
        username = get_remote_user(os.environ)
    except RuntimeError:
        print "Status: 401 Unauthorized\n"
        print "Malformed REMOTE_USER"
        return

    if not MEMCACHE_SERVERS:
        print "Status: 500 Internal Server Error\n"
        print "Memcache not configured in /etc/swift/proxy-server.conf"
        return

    mc_servers = [s.strip() for s in MEMCACHE_SERVERS.split(',') if s.strip()]
    mc = MemcacheRing(mc_servers)

    token, expires, groups = get_auth_data(mc, username)

    if not token:
        token = generate_token()
        expires = time() + TOKEN_LIFE
        groups = get_groups_from_username(username)
        set_auth_data(mc, username, token, expires, groups)

    print "X-Auth-Token: %s" % token
    print "X-Storage-Token: %s" % token

    # For debugging.
    if DEBUG_HEADERS:
        print "X-Debug-Remote-User: %s" % username
        print "X-Debug-Groups: %s" % groups
        print "X-Debug-Token-Life: %ss" % TOKEN_LIFE
        print "X-Debug-Token-Expires: %s" % ctime(expires)

    print ""

try:
    print("Content-Type: text/html")
    main()
except:
    cgi.print_exception()