import logging
from ast import literal_eval

from tfw.components import MessageSender
from tfw.builtins import TFWServerUplinkConnector
from tfw.builtins import EventHandler, FSMAwareEventHandler, TerminalCommandsEventHandler

LOG = logging.getLogger(__name__)


class CenatorEventHandler(EventHandler):
    """
    Logs commands executed in terminal to messages and invokes an
    additional callback function to handle special commands.
    !! Please remove from production code. !!
    """
    def __init__(self, key):
        super().__init__(key)

    def handle_event(self, message):
        command = message['value']
        LOG.debug('User executed command: "%s"', command)
        MessageSender(self.server_connector).send('JOHN CENA', f'You\'ve executed "{command}"')


class TestCommandsEventHandler(TerminalCommandsEventHandler):
    """
    Some example commands useful for debugging.
    !! Please remove from production code !! and inherit your own
    class from TerminalCommands if you need to define custom
    commands in your challenge.
    """
    # pylint: disable=unused-argument, attribute-defined-outside-init, no-self-use
    def command_sendmessage(self, *args):
        """
        Insert TFW message template as first argument if executed without args.

        Evaluate first argumen as a dict and send it to the frontend.
        This is useful for playing around with frontend APIs.
        """
        if not args:
            message_template = """'{"key": "", "data": {"command": ""}}'"""
            TFWServerUplinkConnector().send_message({
                'key': 'shell',
                'data': {
                    'command': 'write',
                    'value': f'sendmessage {message_template}'
                }
            })
        else:
            TFWServerUplinkConnector().send_message(literal_eval(args[0]))


class MessageFSMStepsEventHandler(FSMAwareEventHandler):
    """
    This example EventHandler is capable of detecting FSM state.
    !! Please remove from production code !!
    """
    def handle_event(self, message):
        pass

    def handle_fsm_step(self, **kwargs):
        """
        When the FSM steps this method is invoked.
        Receives a 'data' field from an fsm_update message as kwargs.
        """
        MessageSender(self.server_connector).send(
            'FSM info',
            f'FSM has stepped from state "{kwargs["last_event"]["from_state"]}" '
            f'to state "{kwargs["current_state"]}" in response to trigger "{kwargs["last_event"]["trigger"]}"'
        )