"""
"""
import struct

import logging

from oftest import config
import oftest.controller as controller
import ofp
import oftest.base_tests as base_tests

from oftest.testutils import *

NX_ROLE_OTHER = 0
NX_ROLE_MASTER = 1
NX_ROLE_SLAVE = 2

def set_role(test, role):
    request = ofp.message.nicira_controller_role_request(role=role)
    response, _ = test.controller.transact(request)
    test.assertTrue(isinstance(response, ofp.message.nicira_controller_role_reply), "Expected a role reply")
    test.assertEquals(response.role, role)

class AnyReply(base_tests.SimpleDataPlane):
    """
    Verify that a role request gets either a role reply or an error.

    This test should pass on any switch, no matter whether it implements
    the extension.
    """
    def runTest(self):
        request = ofp.message.nicira_controller_role_request(role=NX_ROLE_MASTER)
        response, pkt = self.controller.transact(request)
        self.assertTrue(response is not None, "No reply to Nicira role request")
        if isinstance(response, ofp.message.nicira_controller_role_reply):
            logging.info("Role reply received")
            logging.info(response.show())
            self.assertEquals(response.role, NX_ROLE_MASTER)
        elif isinstance(response, ofp.message.error_msg):
            logging.info("Error message received")
            logging.info(response.show())
            self.assertEquals(response.err_type, ofp.OFPET_BAD_REQUEST)
            self.assertEquals(response.code, ofp.OFPBRC_BAD_VENDOR)
        else:
            raise AssertionError("Unexpected reply type")

@nonstandard
class RolePermissions(base_tests.SimpleDataPlane):
    """
    Verify that a slave connection cannot modify switch state, but
    a master or equal can.
    """
    def runTest(self):
        self.features_reply, _ = self.controller.transact(ofp.message.features_request())
        delete_all_flows(self.controller)
        self.verify_permission(True)

        set_role(self, NX_ROLE_MASTER)
        self.verify_permission(True)

        set_role(self, NX_ROLE_SLAVE)
        self.verify_permission(False)

        set_role(self, NX_ROLE_OTHER)
        self.verify_permission(True)

    def verify_permission(self, perm):
        port = self.features_reply.ports[0]

        self.controller.message_send(ofp.message.port_mod(port_no=port.port_no, hw_addr=port.hw_addr))
        self.controller.message_send(ofp.message.packet_out(buffer_id=0xffffffff))
        self.controller.message_send(ofp.message.flow_add(buffer_id=0xffffffff))
        do_barrier(self.controller)

        err_count = 0
        while self.controller.packets:
            msg = self.controller.packets.pop(0)[0]
            if isinstance(msg, ofp.message.error_msg):
                self.assertEquals(msg.err_type, ofp.OFPET_BAD_REQUEST)
                self.assertEquals(msg.code, ofp.OFPBRC_EPERM)
                err_count += 1

        if perm:
            self.assertEquals(err_count, 0, "Expected no errors")
        else:
            self.assertEquals(err_count, 3, "Expected errors for each message")