import logging
from ast import literal_eval
from functools import partial
from signal import signal, SIGTERM, SIGINT

from tornado.ioloop import IOLoop

from tfw.fsm import YamlFSM
from tfw.event_handlers import EventHandlerBase, FSMAwareEventHandler, TFWServerUplinkConnector
from tfw.components import IdeEventHandler, TerminalEventHandler
from tfw.components import ProcessManagingEventHandler, BashMonitor
from tfw.components import TerminalCommands, LogMonitoringEventHandler
from tfw.components import FSMManagingEventHandler, DirectorySnapshottingEventHandler
from tfw.components import FrontendEventHandler, MessageSender
from tfw.config import TFWENV
from tao.config import TAOENV
from tfw.config.log import TFWLog

LOG = logging.getLogger(__name__)


class TerminalCallbackEventHandler(EventHandlerBase):
    """
    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, callback):
        self.callback = callback
        super().__init__(key)

    def handle_event(self, message):
        command = message['value']
        self.cenator(command)
        self.callback(command)

    @staticmethod
    def cenator(command):
        LOG.debug('User executed command: "%s"', command)
        MessageSender().send('JOHN CENA', f'You\'ve executed "{command}"')


class TestCommands(TerminalCommands):
    """
    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]))

    def command_seppuku_tfw(self, *args):
        """
        Restart tfw_server.py and event_handler_main.py.
        This can speed up development when combined with mounting
        volumes from host to container.
        """
        seppuku = (
            'nohup sh -c "supervisorctl restart tfwserver event_handler_main" &> /dev/null & '
            'clear && echo "Committed seppuku! :)" && sleep infinity'
        )
        uplink = TFWServerUplinkConnector()
        uplink.send_message({
            'key': 'shell',
            'data': {
                'command': 'write',
                'value': f'{seppuku}\n'
            }
        })
        uplink.send_message({
            'key': 'dashboard',
            'data': {
                'command': 'reloadFrontend'
            }
        })


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().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"]}"'
        )


def main():
    # pylint: disable=unused-variable
    TFWLog().start()

    # TFW component EventHandlers (builtins, required for their respective functionalities)
    fsm = FSMManagingEventHandler(  # TFW FSM
        key='fsm',
        fsm_type=partial(
            YamlFSM,
            'test_fsm.yml',
            {}  # jinja2 variables, use empty dict to enable jinja2 parsing without any variables
        )
    )
    ide = IdeEventHandler(  # Web IDE backend
        key='ide',
        allowed_directories=[TFWENV.IDE_WD, TFWENV.WEBSERVICE_DIR],
        directory=TFWENV.IDE_WD,
        exclude=['*.pyc']
    )
    terminal = TerminalEventHandler(  # Web shell backend
        key='shell',
        monitor=BashMonitor(TFWENV.HISTFILE)
    )
    commands = TerminalCallbackEventHandler( # Reacts to terminal commands
        'history.bash',
        TestCommands(bashrc=f'/home/{TAOENV.USER}/.bashrc').callback
    )
    processmanager = ProcessManagingEventHandler(  # Handles 'deploy' button clicks
        key='processmanager',
        dirmonitor=ide.monitor,
        log_tail=2000
    )
    logmonitor = LogMonitoringEventHandler(  # Sends live logs of webservice process to frontend
        key='logmonitor',
        process_name='webservice',
        log_tail=2000
    )
    snapshot = DirectorySnapshottingEventHandler(  # Manages filesystem snapshots of directories
        key='snapshot',
        directories=[
            TFWENV.IDE_WD,
            TFWENV.WEBSERVICE_DIR
        ]
    )
    frontend = FrontendEventHandler()  # Proxies frontend API calls to frontend

    # Your custom event handlers
    message_fsm_steps_eh = MessageFSMStepsEventHandler(
        key='test'
    )

    event_handlers = EventHandlerBase.get_local_instances()
    def stop(sig, frame):
        for eh in event_handlers:
            eh.stop()
        exit(0)
    signal(SIGTERM, stop)
    signal(SIGINT, stop)

    IOLoop.instance().start()


if __name__ == '__main__':
    main()