# Buggy code
def ursula(
    click_config,
    action,
    dev,
    quiet,
    dry_run,
    force,
    lonely,
    network,
    teacher_uri,
    min_stake,
    rest_host,
    rest_port,
    db_filepath,
    checksum_address,
    withdraw_address,
    federated_only,
    poa,
    config_root,
    config_file,
    provider_uri,
    recompile_solidity,
    no_registry,
    registry_filepath,
    value,
    duration,
    index,
    list_,
    divide,
) -> None:
    """
    Manage and run an "Ursula" PRE node.

    \b
    Actions
    -------------------------------------------------
    \b
    init              Create a new Ursula node configuration.
    view              View the Ursula node's configuration.
    run               Run an "Ursula" node.
    save-metadata     Manually write node metadata to disk without running
    forget            Forget all known nodes.
    destroy           Delete Ursula node configuration.
    stake             Manage stakes for this node.
    confirm-activity  Manually confirm-activity for the current period.
    collect-reward    Withdraw staking reward.

    """

    #
    # Boring Setup Stuff
    #
    if not quiet:
        log = Logger("ursula.cli")

    if click_config.debug and quiet:
        raise click.BadOptionUsage(
            option_name="quiet",
            message="--debug and --quiet cannot be used at the same time.",
        )

    if not click_config.json_ipc and not click_config.quiet:
        click.secho(URSULA_BANNER.format(checksum_address or ""))

    #
    # Pre-Launch Warnings
    #
    if not click_config.quiet:
        if dev:
            click.secho("WARNING: Running in Development mode", fg="yellow")
        if force:
            click.secho("WARNING: Force is enabled", fg="yellow")

    #
    # Unauthenticated Configurations & Un-configured Ursula Control
    #
    if action == "init":
        """Create a brand-new persistent Ursula"""

        if not network:
            raise click.BadArgumentUsage(
                "--network is required to initialize a new configuration."
            )

        if dev:
            click_config.emitter(
                message="WARNING: Using temporary storage area", color="yellow"
            )

        if not config_root:  # Flag
            config_root = click_config.config_file  # Envvar

        if not rest_host:
            rest_host = click.prompt(
                "Enter Ursula's public-facing IPv4 address"
            )  # TODO: Remove this step

        ursula_config = UrsulaConfiguration.generate(
            password=click_config.get_password(confirm=True),
            config_root=config_root,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
            domains={network} if network else None,
            federated_only=federated_only,
            checksum_public_address=checksum_address,
            no_registry=federated_only or no_registry,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            poa=poa,
        )

        painting.paint_new_installation_help(
            new_configuration=ursula_config,
            config_root=config_root,
            config_file=config_file,
            federated_only=federated_only,
        )
        return

    #
    # Configured Ursulas
    #

    # Development Configuration
    if dev:
        ursula_config = UrsulaConfiguration(
            dev_mode=True,
            domains={TEMPORARY_DOMAIN},
            poa=poa,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            checksum_public_address=checksum_address,
            federated_only=federated_only,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
        )
    # Authenticated Configurations
    else:
        # Domains -> bytes | or default
        domains = [bytes(network, encoding="utf-8")] if network else None

        # Load Ursula from Configuration File
        ursula_config = UrsulaConfiguration.from_configuration_file(
            filepath=config_file,
            domains=domains,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
            poa=poa,
        )

        click_config.unlock_keyring(character_configuration=ursula_config)

    #
    # Connect to Blockchain (Non-Federated)
    #

    if not ursula_config.federated_only:
        click_config.connect_to_blockchain(
            character_configuration=ursula_config,
            recompile_contracts=recompile_solidity,
        )

    click_config.ursula_config = (
        ursula_config  # Pass Ursula's config onto staking sub-command
    )

    #
    # Launch Warnings
    #

    if ursula_config.federated_only:
        click_config.emitter(
            message="WARNING: Running in Federated mode", color="yellow"
        )

    # Seed - Step 1
    teacher_uris = [teacher_uri] if teacher_uri else list()
    teacher_nodes = actions.load_seednodes(
        teacher_uris=teacher_uris,
        min_stake=min_stake,
        federated_only=federated_only,
        network_middleware=click_config.middleware,
    )

    # Produce - Step 2
    URSULA = ursula_config(known_nodes=teacher_nodes, lonely=lonely)

    #
    # Action Switch
    #

    if action == "run":
        """Seed, Produce, Run!"""

        # GO!
        try:
            click_config.emitter(
                message="Starting Ursula on {}".format(URSULA.rest_interface),
                color="green",
                bold=True,
            )

            # Ursula Deploy Warnings
            click_config.emitter(
                message="Connecting to {}".format(
                    ",".join(str(d, encoding="utf-8") for d in ursula_config.domains)
                ),
                color="green",
                bold=True,
            )

            if not URSULA.federated_only and URSULA.stakes:
                click_config.emitter(
                    message=f"Staking {str(URSULA.total_staked)} ~ Keep Ursula Online!",
                    color="blue",
                    bold=True,
                )

            if not click_config.debug:
                stdio.StandardIO(UrsulaCommandProtocol(ursula=URSULA))

            if dry_run:
                return  # <-- ABORT -X (Last Chance)

            # Run - Step 3
            node_deployer = URSULA.get_deployer()
            node_deployer.addServices()
            node_deployer.catalogServers(node_deployer.hendrix)
            node_deployer.run()  # <--- Blocking Call (Reactor)

        # Handle Crash
        except Exception as e:
            ursula_config.log.critical(str(e))
            click_config.emitter(
                message="{} {}".format(e.__class__.__name__, str(e)),
                color="red",
                bold=True,
            )
            raise  # Crash :-(

        # Graceful Exit / Crash
        finally:
            click_config.emitter(message="Stopping Ursula", color="green")
            ursula_config.cleanup()
            click_config.emitter(message="Ursula Stopped", color="red")
        return

    elif action == "save-metadata":
        """Manually save a node self-metadata file"""
        metadata_path = ursula.write_node_metadata(node=URSULA)
        return click_config.emitter(
            message="Successfully saved node metadata to {}.".format(metadata_path),
            color="green",
        )

    elif action == "view":
        """Paint an existing configuration to the console"""
        response = UrsulaConfiguration._read_configuration_file(
            filepath=config_file or ursula_config.config_file_location
        )
        return click_config.emitter(response=response)

    elif action == "forget":
        actions.forget(configuration=ursula_config)
        return

    elif action == "destroy":
        """Delete all configuration files from the disk"""

        if dev:
            message = "'nucypher ursula destroy' cannot be used in --dev mode"
            raise click.BadOptionUsage(option_name="--dev", message=message)

        destroyed_filepath = destroy_system_configuration(
            config_class=UrsulaConfiguration,
            config_file=config_file,
            network=network,
            config_root=ursula_config.config_file_location,
            force=force,
        )

        return click_config.emitter(
            message=f"Destroyed {destroyed_filepath}", color="green"
        )

    elif action == "stake":
        # List Only
        if list_:
            if not URSULA.stakes:
                click.echo(
                    f"There are no existing stakes for {URSULA.checksum_public_address}"
                )
            painting.paint_stakes(stakes=URSULA.stakes)
            return

        # Divide Only
        if divide:
            """Divide an existing stake by specifying the new target value and end period"""

            # Validate
            if len(URSULA.stakes) == 0:
                click.secho(
                    "There are no active stakes for {}".format(
                        URSULA.checksum_public_address
                    )
                )
                return

            # Selection
            if index is None:
                painting.paint_stakes(stakes=URSULA.stakes)
                index = click.prompt(
                    "Select a stake to divide",
                    type=click.IntRange(min=0, max=len(URSULA.stakes) - 1),
                )

            # Lookup the stake
            current_stake = URSULA.stakes[index]

            # Value
            if not value:
                value = click.prompt(
                    f"Enter target value (must be less than {str(current_stake.value)})",
                    type=STAKE_VALUE,
                )
            value = NU(value, "NU")

            # Duration
            if not duration:
                extension = click.prompt(
                    "Enter number of periods to extend", type=STAKE_EXTENSION
                )
            else:
                extension = duration

            if not force:
                painting.paint_staged_stake_division(
                    ursula=URSULA,
                    original_index=index,
                    original_stake=current_stake,
                    target_value=value,
                    extension=extension,
                )

                click.confirm("Is this correct?", abort=True)

            txhash_bytes = URSULA.divide_stake(
                stake_index=index, target_value=value, additional_periods=extension
            )

            if not quiet:
                click.secho("Successfully divided stake", fg="green")
                click.secho(f"Transaction Hash ........... {txhash_bytes.hex()}")

            # Show the resulting stake list
            painting.paint_stakes(stakes=URSULA.stakes)

            return

        # Confirm new stake init
        if not force:
            click.confirm("Stage a new stake?", abort=True)

        # Validate balance
        balance = URSULA.token_balance
        if balance == 0:
            click.secho(f"{ursula.checksum_public_address} has 0 NU.")
            raise click.Abort
        if not quiet:
            click.echo(f"Current balance: {balance}")

        # Gather stake value
        if not value:
            value = click.prompt(
                f"Enter stake value",
                type=STAKE_VALUE,
                default=NU(MIN_ALLOWED_LOCKED, "NuNit"),
            )
        else:
            value = NU(int(value), "NU")

        # Duration
        if not quiet:
            message = "Minimum duration: {} | Maximum Duration: {}".format(
                MIN_LOCKED_PERIODS, MAX_MINTING_PERIODS
            )
            click.echo(message)
        if not duration:
            duration = click.prompt(
                "Enter stake duration in periods (1 Period = 24 Hours)",
                type=STAKE_DURATION,
            )
        start_period = URSULA.miner_agent.get_current_period()
        end_period = start_period + duration

        # Review
        if not force:
            painting.paint_staged_stake(
                ursula=URSULA,
                stake_value=value,
                duration=duration,
                start_period=start_period,
                end_period=end_period,
            )

            if not dev:
                actions.confirm_staged_stake(
                    ursula=URSULA, value=value, duration=duration
                )

        # Last chance to bail
        if not force:
            click.confirm("Publish staged stake to the blockchain?", abort=True)

        staking_transactions = URSULA.initialize_stake(
            amount=int(value), lock_periods=duration
        )
        painting.paint_staking_confirmation(
            ursula=URSULA, transactions=staking_transactions
        )
        return

    elif action == "confirm-activity":
        if not URSULA.stakes:
            click.secho(
                "There are no active stakes for {}".format(
                    URSULA.checksum_public_address
                )
            )
            return
        URSULA.miner_agent.confirm_activity(node_address=URSULA.checksum_public_address)
        return

    elif action == "collect-reward":
        """Withdraw staking reward to the specified wallet address"""
        if not force:
            click.confirm(
                f"Send {URSULA.calculate_reward()} to {URSULA.checksum_public_address}?"
            )

        URSULA.collect_policy_reward(
            collector_address=withdraw_address or checksum_address
        )
        URSULA.collect_staking_reward()

    else:
        raise click.BadArgumentUsage("No such argument {}".format(action))


# Traceback (builtins.AttributeError)
2019-04-04T17:31:25-0700 [learning-loop#warn] Unhandled error during node learning: Traceback (most recent call last):
File "/home/kieran/.local/share/virtualenvs/nucypher-9CH2v_st/lib/python3.7/site-packages/twisted/internet/base.py", line 1272, in run
self.mainLoop()
File "/home/kieran/.local/share/virtualenvs/nucypher-9CH2v_st/lib/python3.7/site-packages/twisted/internet/base.py", line 1281, in mainLoop
self.runUntilCurrent()
File "/home/kieran/.local/share/virtualenvs/nucypher-9CH2v_st/lib/python3.7/site-packages/twisted/internet/base.py", line 902, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/home/kieran/.local/share/virtualenvs/nucypher-9CH2v_st/lib/python3.7/site-packages/twisted/internet/task.py", line 239, in __call__
d = defer.maybeDeferred(self.f, *self.a, **self.kw)
--- <exception caught here> ---
File "/home/kieran/.local/share/virtualenvs/nucypher-9CH2v_st/lib/python3.7/site-packages/twisted/internet/defer.py", line 151, in maybeDeferred
result = f(*args, **kw)
File "/home/kieran/Git/nucypher/nucypher/network/nodes.py", line 534, in keep_learning_about_nodes
self.learn_from_teacher_node(eager=False)
File "/home/kieran/Git/nucypher/nucypher/network/nodes.py", line 746, in learn_from_teacher_node
if not self.learning_domains.intersection(node.serving_domains):
builtins.AttributeError: 'list' object has no attribute 'intersection'

# Fixed code
def ursula(
    click_config,
    action,
    dev,
    quiet,
    dry_run,
    force,
    lonely,
    network,
    teacher_uri,
    min_stake,
    rest_host,
    rest_port,
    db_filepath,
    checksum_address,
    withdraw_address,
    federated_only,
    poa,
    config_root,
    config_file,
    provider_uri,
    recompile_solidity,
    no_registry,
    registry_filepath,
    value,
    duration,
    index,
    list_,
    divide,
) -> None:
    """
    Manage and run an "Ursula" PRE node.

    \b
    Actions
    -------------------------------------------------
    \b
    init              Create a new Ursula node configuration.
    view              View the Ursula node's configuration.
    run               Run an "Ursula" node.
    save-metadata     Manually write node metadata to disk without running
    forget            Forget all known nodes.
    destroy           Delete Ursula node configuration.
    stake             Manage stakes for this node.
    confirm-activity  Manually confirm-activity for the current period.
    collect-reward    Withdraw staking reward.

    """

    #
    # Boring Setup Stuff
    #
    if not quiet:
        log = Logger("ursula.cli")

    if click_config.debug and quiet:
        raise click.BadOptionUsage(
            option_name="quiet",
            message="--debug and --quiet cannot be used at the same time.",
        )

    if not click_config.json_ipc and not click_config.quiet:
        click.secho(URSULA_BANNER.format(checksum_address or ""))

    #
    # Pre-Launch Warnings
    #
    if not click_config.quiet:
        if dev:
            click.secho("WARNING: Running in Development mode", fg="yellow")
        if force:
            click.secho("WARNING: Force is enabled", fg="yellow")

    #
    # Unauthenticated Configurations & Un-configured Ursula Control
    #
    if action == "init":
        """Create a brand-new persistent Ursula"""

        if not network:
            raise click.BadArgumentUsage(
                "--network is required to initialize a new configuration."
            )

        if dev:
            click_config.emitter(
                message="WARNING: Using temporary storage area", color="yellow"
            )

        if not config_root:  # Flag
            config_root = click_config.config_file  # Envvar

        if not rest_host:
            rest_host = click.prompt(
                "Enter Ursula's public-facing IPv4 address"
            )  # TODO: Remove this step

        ursula_config = UrsulaConfiguration.generate(
            password=click_config.get_password(confirm=True),
            config_root=config_root,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
            domains={network} if network else None,
            federated_only=federated_only,
            checksum_public_address=checksum_address,
            no_registry=federated_only or no_registry,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            poa=poa,
        )

        painting.paint_new_installation_help(
            new_configuration=ursula_config,
            config_root=config_root,
            config_file=config_file,
            federated_only=federated_only,
        )
        return

    #
    # Configured Ursulas
    #

    # Development Configuration
    if dev:
        ursula_config = UrsulaConfiguration(
            dev_mode=True,
            domains={TEMPORARY_DOMAIN},
            poa=poa,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            checksum_public_address=checksum_address,
            federated_only=federated_only,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
        )
    # Authenticated Configurations
    else:
        # Domains -> bytes | or default
        domains = [bytes(network, encoding="utf-8")] if network else None

        # Load Ursula from Configuration File
        ursula_config = UrsulaConfiguration.from_configuration_file(
            filepath=config_file,
            domains=domains,
            registry_filepath=registry_filepath,
            provider_uri=provider_uri,
            rest_host=rest_host,
            rest_port=rest_port,
            db_filepath=db_filepath,
            poa=poa,
            federated_only=federated_only,
        )

        click_config.unlock_keyring(character_configuration=ursula_config)

    #
    # Connect to Blockchain (Non-Federated)
    #

    if not ursula_config.federated_only:
        click_config.connect_to_blockchain(
            character_configuration=ursula_config,
            recompile_contracts=recompile_solidity,
        )

    click_config.ursula_config = (
        ursula_config  # Pass Ursula's config onto staking sub-command
    )

    #
    # Launch Warnings
    #

    if ursula_config.federated_only:
        click_config.emitter(
            message="WARNING: Running in Federated mode", color="yellow"
        )

    # Seed - Step 1
    teacher_uris = [teacher_uri] if teacher_uri else list()
    teacher_nodes = actions.load_seednodes(
        teacher_uris=teacher_uris,
        min_stake=min_stake,
        federated_only=ursula_config.federated_only,
        network_middleware=click_config.middleware,
    )

    # Produce - Step 2
    URSULA = ursula_config(known_nodes=teacher_nodes, lonely=lonely)

    #
    # Action Switch
    #

    if action == "run":
        """Seed, Produce, Run!"""

        # GO!
        try:
            click_config.emitter(
                message="Starting Ursula on {}".format(URSULA.rest_interface),
                color="green",
                bold=True,
            )

            # Ursula Deploy Warnings
            click_config.emitter(
                message="Connecting to {}".format(
                    ",".join(str(d, encoding="utf-8") for d in ursula_config.domains)
                ),
                color="green",
                bold=True,
            )

            if not URSULA.federated_only and URSULA.stakes:
                click_config.emitter(
                    message=f"Staking {str(URSULA.total_staked)} ~ Keep Ursula Online!",
                    color="blue",
                    bold=True,
                )

            if not click_config.debug:
                stdio.StandardIO(UrsulaCommandProtocol(ursula=URSULA))

            if dry_run:
                return  # <-- ABORT -X (Last Chance)

            # Run - Step 3
            node_deployer = URSULA.get_deployer()
            node_deployer.addServices()
            node_deployer.catalogServers(node_deployer.hendrix)
            node_deployer.run()  # <--- Blocking Call (Reactor)

        # Handle Crash
        except Exception as e:
            ursula_config.log.critical(str(e))
            click_config.emitter(
                message="{} {}".format(e.__class__.__name__, str(e)),
                color="red",
                bold=True,
            )
            raise  # Crash :-(

        # Graceful Exit / Crash
        finally:
            click_config.emitter(message="Stopping Ursula", color="green")
            ursula_config.cleanup()
            click_config.emitter(message="Ursula Stopped", color="red")
        return

    elif action == "save-metadata":
        """Manually save a node self-metadata file"""
        metadata_path = ursula.write_node_metadata(node=URSULA)
        return click_config.emitter(
            message="Successfully saved node metadata to {}.".format(metadata_path),
            color="green",
        )

    elif action == "view":
        """Paint an existing configuration to the console"""
        response = UrsulaConfiguration._read_configuration_file(
            filepath=config_file or ursula_config.config_file_location
        )
        return click_config.emitter(response=response)

    elif action == "forget":
        actions.forget(configuration=ursula_config)
        return

    elif action == "destroy":
        """Delete all configuration files from the disk"""

        if dev:
            message = "'nucypher ursula destroy' cannot be used in --dev mode"
            raise click.BadOptionUsage(option_name="--dev", message=message)

        destroyed_filepath = destroy_system_configuration(
            config_class=UrsulaConfiguration,
            config_file=config_file,
            network=network,
            config_root=ursula_config.config_file_location,
            force=force,
        )

        return click_config.emitter(
            message=f"Destroyed {destroyed_filepath}", color="green"
        )

    elif action == "stake":
        # List Only
        if list_:
            if not URSULA.stakes:
                click.echo(
                    f"There are no existing stakes for {URSULA.checksum_public_address}"
                )
            painting.paint_stakes(stakes=URSULA.stakes)
            return

        # Divide Only
        if divide:
            """Divide an existing stake by specifying the new target value and end period"""

            # Validate
            if len(URSULA.stakes) == 0:
                click.secho(
                    "There are no active stakes for {}".format(
                        URSULA.checksum_public_address
                    )
                )
                return

            # Selection
            if index is None:
                painting.paint_stakes(stakes=URSULA.stakes)
                index = click.prompt(
                    "Select a stake to divide",
                    type=click.IntRange(min=0, max=len(URSULA.stakes) - 1),
                )

            # Lookup the stake
            current_stake = URSULA.stakes[index]

            # Value
            if not value:
                value = click.prompt(
                    f"Enter target value (must be less than {str(current_stake.value)})",
                    type=STAKE_VALUE,
                )
            value = NU(value, "NU")

            # Duration
            if not duration:
                extension = click.prompt(
                    "Enter number of periods to extend", type=STAKE_EXTENSION
                )
            else:
                extension = duration

            if not force:
                painting.paint_staged_stake_division(
                    ursula=URSULA,
                    original_index=index,
                    original_stake=current_stake,
                    target_value=value,
                    extension=extension,
                )

                click.confirm("Is this correct?", abort=True)

            txhash_bytes = URSULA.divide_stake(
                stake_index=index, target_value=value, additional_periods=extension
            )

            if not quiet:
                click.secho("Successfully divided stake", fg="green")
                click.secho(f"Transaction Hash ........... {txhash_bytes.hex()}")

            # Show the resulting stake list
            painting.paint_stakes(stakes=URSULA.stakes)

            return

        # Confirm new stake init
        if not force:
            click.confirm("Stage a new stake?", abort=True)

        # Validate balance
        balance = URSULA.token_balance
        if balance == 0:
            click.secho(f"{ursula.checksum_public_address} has 0 NU.")
            raise click.Abort
        if not quiet:
            click.echo(f"Current balance: {balance}")

        # Gather stake value
        if not value:
            value = click.prompt(
                f"Enter stake value",
                type=STAKE_VALUE,
                default=NU(MIN_ALLOWED_LOCKED, "NuNit"),
            )
        else:
            value = NU(int(value), "NU")

        # Duration
        if not quiet:
            message = "Minimum duration: {} | Maximum Duration: {}".format(
                MIN_LOCKED_PERIODS, MAX_MINTING_PERIODS
            )
            click.echo(message)
        if not duration:
            duration = click.prompt(
                "Enter stake duration in periods (1 Period = 24 Hours)",
                type=STAKE_DURATION,
            )
        start_period = URSULA.miner_agent.get_current_period()
        end_period = start_period + duration

        # Review
        if not force:
            painting.paint_staged_stake(
                ursula=URSULA,
                stake_value=value,
                duration=duration,
                start_period=start_period,
                end_period=end_period,
            )

            if not dev:
                actions.confirm_staged_stake(
                    ursula=URSULA, value=value, duration=duration
                )

        # Last chance to bail
        if not force:
            click.confirm("Publish staged stake to the blockchain?", abort=True)

        staking_transactions = URSULA.initialize_stake(
            amount=int(value), lock_periods=duration
        )
        painting.paint_staking_confirmation(
            ursula=URSULA, transactions=staking_transactions
        )
        return

    elif action == "confirm-activity":
        if not URSULA.stakes:
            click.secho(
                "There are no active stakes for {}".format(
                    URSULA.checksum_public_address
                )
            )
            return
        URSULA.miner_agent.confirm_activity(node_address=URSULA.checksum_public_address)
        return

    elif action == "collect-reward":
        """Withdraw staking reward to the specified wallet address"""
        if not force:
            click.confirm(
                f"Send {URSULA.calculate_reward()} to {URSULA.checksum_public_address}?"
            )

        URSULA.collect_policy_reward(
            collector_address=withdraw_address or checksum_address
        )
        URSULA.collect_staking_reward()

    else:
        raise click.BadArgumentUsage("No such argument {}".format(action))