'''

auth.py: authorization functions for client

Copyright (C) 2017-2018 The Board of Trustees of the Leland Stanford Junior
University.
Copyright (C) 2017-2018 Vanessa Sochat.

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 <https://www.gnu.org/licenses/>.

'''

from sregistry.main.registry.utils import (
    generate_signature,
    generate_credential,
    generate_timestamp
)

def authorize(self, names, payload=None, request_type="push"):
    '''Authorize a client based on encrypting the payload with the client
       token, which should be matched on the receiving server'''

    if self.secrets is not None:

        if "registry" in self.secrets:

            # Use the payload to generate a digest   push|collection|name|tag|user
            timestamp = generate_timestamp()
            credential = generate_credential(self.secrets['registry']['username'])
            credential = "%s/%s/%s" %(request_type,credential,timestamp)

            if payload is None:
                payload = "%s|%s|%s|%s|%s|" %(request_type,
                                              names['collection'],
                                              timestamp,
                                              names['image'],
                                              names['tag'])

            signature = generate_signature(payload,self.secrets['registry']['token'])
            return "SREGISTRY-HMAC-SHA256 Credential=%s,Signature=%s" %(credential,signature)
