import logging
import time

from .messaging import RollbotResponse, RollbotFailure
from .plugins import as_plugin


def lift_response(call, response):
    @as_plugin(call)
    def response_func(db, msg):
        return RollbotResponse(msg, txt=response)
    return response_func


class Rollbot:
    def __init__(self, logger=logging.getLogger(__name__), plugin_classes={}, aliases={}, responses={}, sleep_time=0.0, session_factory=None, callback=None):
        self.logger = logger
        self.session_factory = session_factory or (lambda: None)
        self.post_callback = callback or (lambda txt, gid: self.logger.info(f"Responding to {gid} with {txt}"))
        self.commands = {}
        self.to_start = set()
        self.to_stop = set()

        self.logger.info("Loading command plugins")
        for plugin_class in plugin_classes:
            plugin_instance = plugin_class(self, logger=logger)
            if plugin_instance.command in self.commands:
                self.logger.error(f"Duplicate command word '{plugin_instance.command}'")
                raise ValueError(f"Duplicate command word '{plugin_instance.command}'")
            self.commands[plugin_instance.command] = plugin_instance
            if "on_start" in plugin_class.__dict__:
                self.to_start.add(plugin_instance)
            if "on_shutdown" in plugin_class.__dict__:
                self.to_stop.add(plugin_instance)
        self.logger.info(f"Finished loading plugins, {len(self.commands)} commands found")

        self.logger.info("Loading simple responses")
        for cmd, response in responses.items():
            if cmd in self.commands:
                self.logger.error(f"Duplicate command word '{cmd}'")
                raise ValueError(f"Duplicate command word '{cmd}'")
            self.commands[cmd] = lift_response(cmd, response)(self, logger=logger)
        self.logger.info(f"Finished loading simple responses, {len(self.commands)} total commands available")

        self.logger.info("Loading aliases")
        for alias, cmd in aliases.items():
            if cmd not in self.commands:
                self.logger.error(f"Missing aliased command word '{cmd}'")
                raise ValueError(f"Missing aliased command word '{cmd}'")
            if alias in self.commands:
                self.logger.error(f"Duplicate command word '{alias}'")
                raise ValueError(f"Duplicate command word '{alias}'")
            self.commands[alias] = self.commands[cmd]
        self.logger.info(f"Finished loading aliases, {len(self.commands)} total commands + aliases available")

        self.sleep_time = sleep_time

    def start_plugins(self):
        self.logger.info("Starting plugins")
        with self.session_factory() as session:
            for cmd in self.to_start:
                cmd.on_start(session)
        self.logger.info("Finished starting plugins")

    def shutdown_plugins(self):
        self.logger.info("Shutting down plugins")
        with self.session_factory() as session:
            for cmd in self.to_stop:
                cmd.on_shutdown(session)
        self.logger.info("Finished shutting down plugins")

    def run_command(self, message):
        if not message.is_command:
            self.logger.warn(f"Tried to run non-command message {message.message_id}")
            return RollbotResponse(message, failure=RollbotFailure.INTERNAL_ERROR)

        plugin = self.commands.get(message.command, None)

        if plugin is None:
            self.logger.warn(f"Message {message.message_id} had a command {message.command} that could not be run.")
            return RollbotResponse(message, failure=RollbotFailure.INVALID_COMMAND)

        with self.session_factory() as session:
            response = plugin.on_command(session, message)

        if not response.is_success:
            self.logger.warn(f"Message {message.message_id} caused failure")
            self.logger.warn(response.info)

        return response

    def handle_command(self, message):
        if not message.is_command:
            self.logger.debug("Ignoring non-command message")
            return

        self.logger.info(f"Handling message {message.message_id}")
        t = time.time()
        try:
            response = self.run_command(message)
        except Exception as e:
            self.logger.exception(f"Exception during command execution for message {message.message_id}")
            response = RollbotResponse(message, failure=RollbotFailure.INTERNAL_ERROR)

        if not response.respond:
            self.logger.info(f"Skipping response to message {message.message_id}")
            return

        self.logger.info(f"Responding to message {message.message_id}")

        sleep = self.sleep_time - time.time() + t
        if sleep > 0:
            self.logger.info(f"Sleeping for {sleep:.3f}s before responding")
            time.sleep(sleep)

        if response.is_success:
            if response.txt is not None:
                self.post_callback(response.txt, message.group_id)
            if response.img is not None:
                self.post_callback(response.img, message.group_id)
        else:
            self.post_callback(response.failure_msg, message.group_id)
            self.logger.warning(f"Failed command response: {response}")

        t = time.time() - t
        self.logger.info(f"Exiting command thread for {message.message_id} after {t:.3f}s")

    def manually_post_message(self, message_text, group_id):
        self.post_callback(message_text, group_id)