import flask
import gssapi
import requests
from requests_gssapi import HTTPSPNEGOAuth
from zope import component
from zope.interface import implementer

from ceo_common.interfaces import IConfig, IHTTPClient


@implementer(IHTTPClient)
class HTTPClient:
    def __init__(self):
        # Determine how to connect to other ceod instances
        cfg = component.getUtility(IConfig)
        if cfg.get('ceod_use_https'):
            self.scheme = 'https'
        else:
            self.scheme = 'http'
        self.ceod_port = cfg.get('ceod_port')
        self.base_domain = cfg.get('base_domain')

    def request(self, host: str, api_path: str, method: str, delegate: bool, **kwargs):
        # always use the FQDN
        if '.' not in host:
            host = host + '.' + self.base_domain

        # SPNEGO
        spnego_kwargs = {
            'opportunistic_auth': True,
            'target_name': gssapi.Name('ceod/' + host),
        }
        if flask.has_request_context() and 'client_token' in flask.g:
            # This is reached when we are the server and the client has forwarded
            # their credentials to us.
            spnego_kwargs['creds'] = gssapi.Credentials(token=flask.g.client_token)
        if delegate:
            # This is reached when we are the client and we want to forward our
            # credentials to the server.
            spnego_kwargs['delegate'] = True
        auth = HTTPSPNEGOAuth(**spnego_kwargs)

        return requests.request(
            method,
            f'{self.scheme}://{host}:{self.ceod_port}{api_path}',
            auth=auth, **kwargs,
        )

    def get(self, host: str, api_path: str, delegate: bool = True, **kwargs):
        return self.request(host, api_path, 'GET', delegate, **kwargs)

    def post(self, host: str, api_path: str, delegate: bool = True, **kwargs):
        return self.request(host, api_path, 'POST', delegate, **kwargs)

    def patch(self, host: str, api_path: str, delegate: bool = True, **kwargs):
        return self.request(host, api_path, 'PATCH', delegate, **kwargs)

    def delete(self, host: str, api_path: str, delegate: bool = True, **kwargs):
        return self.request(host, api_path, 'DELETE', delegate, **kwargs)