"""
.. module:: PyIRCBot
   :synopsis: Main IRC bot class

.. moduleauthor:: Dave Pedu <dave@davepedu.com>

"""

import logging
import sys
from pyircbot.rpc import BotRPC
from pyircbot.irccore import IRCCore
from collections import namedtuple
from socket import AF_INET, AF_INET6
from json import load
import os.path
import asyncio
import traceback


ParsedCommand = namedtuple("ParsedCommand", "command args args_str message")


class PyIRCBot(object):
    """:param botconfig: The configuration of this instance of the bot. Passed by main.py.
    :type botconfig: dict
    """
    version = "4.1.0"

    def __init__(self, botconfig):
        self.log = logging.getLogger('PyIRCBot')
        """Reference to logger object"""

        """saved copy of the instance config"""
        self.botconfig = botconfig

        """storage of imported modules"""
        self.modules = {}

        """instances of modules"""
        self.moduleInstances = {}

        """Reference to BotRPC thread"""
        self.rpc = BotRPC(self)

        """IRC protocol handler"""
        self.irc = IRCCore(servers=self.botconfig["connection"]["servers"])
        if self.botconfig.get("connection").get("force_ipv6", False):
            self.irc.connection_family = AF_INET6
        elif self.botconfig.get("connection").get("force_ipv4", False):
            self.irc.connection_family = AF_INET
        self.irc.bind_addr = self.botconfig.get("connection").get("bind", None)

        # legacy support
        self.act_PONG = self.irc.act_PONG
        self.act_USER = self.irc.act_USER
        self.act_NICK = self.irc.act_NICK
        self.act_JOIN = self.irc.act_JOIN
        self.act_PRIVMSG = self.irc.act_PRIVMSG
        self.act_MODE = self.irc.act_MODE
        self.act_ACTION = self.irc.act_ACTION
        self.act_KICK = self.irc.act_KICK
        self.act_QUIT = self.irc.act_QUIT
        self.act_PASS = self.irc.act_PASS
        self.get_nick = self.irc.get_nick
        self.decodePrefix = IRCCore.decodePrefix

        # Load modules
        self.initModules()

        # Internal usage hook
        self.irc.addHook("PRIVMSG", self._hook_privmsg_internal)

    def run(self):
        self.loop = asyncio.get_event_loop()

        self.client = asyncio.ensure_future(self.irc.loop(self.loop), loop=self.loop)
        try:
            self.loop.set_debug(True)
            self.loop.run_until_complete(self.client)
        finally:
            logging.debug("Escaped main loop")

    def disconnect(self, message):
        """Send quit message and disconnect from IRC.

        :param message: Quit message
        :type message: str
        :param reconnect: True causes a reconnection attempt to be made after the disconnect
        :type reconnect: bool
        """
        self.log.info("disconnect")
        self.kill(message=message)

    def kill(self, message="Help! Another thread is killing me :("):
        """Shut down the bot violently

        :param sys_exit: True causes sys.exit(0) to be called
        :type sys_exit: bool
        :param message: Quit message
        :type message: str
        """
        self.closeAllModules()
        asyncio.run_coroutine_threadsafe(self.irc.kill(message=message), self.loop)

    def initModules(self):
        """load modules specified in instance config"""
        " append module location to path "
        sys.path.append(os.path.dirname(__file__) + "/modules/")

        " append usermodule dir to beginning of path"
        for path in self.botconfig["bot"]["usermodules"]:
            sys.path.insert(0, path + "/")

        for modulename in self.botconfig["modules"]:
            self.loadmodule(modulename)

    def _hook_privmsg_internal(self, msg):
        """
        IRC hook handler. Calling point for IRCHook based module hooks. This method is called when a PRIVMSG is
        received. It tests all hooks in all modules against the message can calls the hooked function on hits.
        """
        for module_name, module in self.moduleInstances.items():
            for hook in module.irchooks:
                if hook.hook.validate(msg, self):
                    hook.call(msg)

    def importmodule(self, name):
        """Import a module

        :param moduleName: Name of the module to import
        :type moduleName: str"""
        " check if already exists "
        if name not in self.modules:
            self.log.info("Importing %s" % name)
            " attempt to load "
            try:
                moduleref = __import__(name)
                self.modules[name] = moduleref
                return (True, None)
            except Exception as e:
                " on failure (usually syntax error in Module code) print an error "
                self.log.error("Module %s failed to load: " % name)
                self.log.error("Module load failure reason: " + str(e))
                traceback.print_exc()
                return (False, str(e))
        else:
            self.log.warning("Module %s already imported" % name)
            return (False, "Module already imported")

    def deportmodule(self, name):
        """Remove a module's code from memory. If the module is loaded it will be unloaded silently.

        :param moduleName: Name of the module to import
        :type moduleName: str"""
        self.log.info("Deporting %s" % name)
        " unload if necessary "
        if name in self.moduleInstances:
            self.unloadmodule(name)
        " delete all references to the module"
        if name in self.modules:
            del self.modules[name]
            " delete copy that python stores in sys.modules "
            if name in sys.modules:
                del sys.modules[name]

    def loadmodule(self, name):
        """Activate a module.

        :param moduleName: Name of the module to activate
        :type moduleName: str"""
        " check if already loaded "
        if name in self.moduleInstances:
            self.log.warning("Module %s already loaded" % name)
            return False
        " check if needs to be imported, and verify it was "
        if name not in self.modules:
            importResult = self.importmodule(name)
            if not importResult[0]:
                return importResult
        " init the module "
        self.moduleInstances[name] = getattr(self.modules[name], name)(self, name)
        " load hooks "
        self.loadModuleHooks(self.moduleInstances[name])
        self.moduleInstances[name].onenable()

    def unloadmodule(self, name):
        """Deactivate a module.

        :param moduleName: Name of the module to deactivate
        :type moduleName: str"""
        if name in self.moduleInstances:
            " notify the module of disabling "
            self.moduleInstances[name].ondisable()
            " unload all hooks "
            self.unloadModuleHooks(self.moduleInstances[name])
            " remove & delete the instance "
            self.moduleInstances.pop(name)
            self.log.info("Module %s unloaded" % name)
            return (True, None)
        else:
            self.log.info("Module %s not loaded" % name)
            return (False, "Module not loaded")

    def reloadmodule(self, name):
        """Deactivate and activate a module.

        :param moduleName: Name of the target module
        :type moduleName: str"""
        " make sure it's imporeted"
        if name in self.modules:
            " remember if it was loaded before"
            loadedbefore = name in self.moduleInstances
            self.log.info("Reloading %s" % self.modules[name])
            " unload "
            self.unloadmodule(name)
            " load "
            if loadedbefore:
                self.loadmodule(name)
            return (True, None)
        return (False, "Module is not loaded")

    def redomodule(self, name):
        """Reload a running module from disk

        :param moduleName: Name of the target module
        :type moduleName: str"""
        " remember if it was loaded before "
        loadedbefore = name in self.moduleInstances
        " unload/deport "
        self.deportmodule(name)
        " import "
        importResult = self.importmodule(name)
        if not importResult[0]:
            return importResult
        " load "
        if loadedbefore:
            self.loadmodule(name)
        return (True, None)

    def loadModuleHooks(self, module):
        """**Internal.** Enable (connect) hooks of a module

        :param module: module object to hook in
        :type module: object"""
        " activate a module's hooks "
        for hook in module.hooks:
            if type(hook.hook) == list:
                for hookcmd in hook.hook:
                    self.irc.addHook(hookcmd, hook.method)
            else:
                self.irc.addHook(hook.hook, hook.method)

    def unloadModuleHooks(self, module):
        """**Internal.** Disable (disconnect) hooks of a module

        :param module: module object to unhook
        :type module: object"""
        " remove a modules hooks "
        for hook in module.hooks:
            if type(hook.hook) == list:
                for hookcmd in hook.hook:
                    self.irc.removeHook(hookcmd, hook.method)
            else:
                self.irc.removeHook(hook.hook, hook.method)

    def getmodulebyname(self, name):
        """Get a module object by name

        :param name: name of the module to return
        :type name: str
        :returns: object -- the module object"""
        if name not in self.moduleInstances:
            return None
        return self.moduleInstances[name]

    def getmodulesbyservice(self, service):
        """Get a list of modules that provide the specified service

        :param service: name of the service searched for
        :type service: str
        :returns: list -- a list of module objects"""
        validModules = []
        for module in self.moduleInstances:
            if service in self.moduleInstances[module].services:
                validModules.append(self.moduleInstances[module])
        return validModules

    def getBestModuleForService(self, service):
        """Get the first module that provides the specified service

        :param service: name of the service searched for
        :type service: str
        :returns: object -- the module object, if found. None if not found."""
        m = self.getmodulesbyservice(service)
        if len(m) > 0:
            return m[0]
        return None

    def closeAllModules(self):
        """ Deport all modules (for shutdown). Modules are unloaded in the opposite order listed in the config. """
        loaded = list(self.moduleInstances.keys())
        loadOrder = self.botconfig["modules"]
        loadOrder.reverse()
        for key in loadOrder:
            if key in loaded:
                loaded.remove(key)
                self.deportmodule(key)
        for key in loaded:
            self.deportmodule(key)

    " Filesystem Methods "
    def getDataPath(self, moduleName):
        """Return the absolute path for a module's data dir

        :param moduleName: the module who's data dir we want
        :type moduleName: str"""
        module_dir = os.path.join(self.botconfig["bot"]["datadir"], "data", moduleName)
        if not os.path.exists(module_dir):
            os.mkdir(module_dir)
        return module_dir

    def getConfigPath(self, moduleName):
        """Return the absolute path for a module's config file

        :param moduleName: the module who's config file we want
        :type moduleName: str"""

        basepath = "%s/config/%s" % (self.botconfig["bot"]["datadir"], moduleName)

        if os.path.exists("%s.json" % basepath):
            return "%s.json" % basepath
        return None

    " Utility methods "
    @staticmethod
    def messageHasCommand(command, message, requireArgs=False):
        """Check if a message has a command with or without args in it

        :param command: the command string to look for, like !ban. If a list is passed, the first match is returned.
        :type command: str or list
        :param message: the message string to look in, like "!ban Lil_Mac"
        :type message: str
        :param requireArgs: if true, only validate if the command use has any amount of trailing text
        :type requireArgs: bool"""

        if not type(command) == list:
            command = [command]
        for item in command:
            cmd = PyIRCBot.messageHasCommandSingle(item, message, requireArgs)
            if cmd:
                return cmd
        return False

    @staticmethod
    def messageHasCommandSingle(command, message, requireArgs=False):
        # Check if the message at least starts with the command
        messageBeginning = message[0:len(command)]
        if messageBeginning != command:
            return False
        # Make sure it's not a subset of a longer command (ie .meme being set off by .memes)
        subsetCheck = message[len(command):len(command) + 1]
        if subsetCheck != " " and subsetCheck != "":
            return False

        # We've got the command! Do we need args?
        argsStart = len(command)
        args = ""
        if argsStart > 0:
            args = message[argsStart + 1:]

        if requireArgs and args.strip() == '':
            return False

        # Verified! Return the set.
        return ParsedCommand(command,
                             args.split(" "),
                             args,
                             message)

    @staticmethod
    def load(filepath):
        """Return an object from the passed filepath

        :param filepath: path to a json file. filename must end with .json
        :type filepath: str
        :Returns:    | dict
        """

        if filepath.endswith(".json"):
            with open(filepath, 'r') as f:
                return load(f)
        else:
            raise Exception("Unknown config format")