from __future__ import annotations
import asyncio
import datetime
import logging
import time
import traceback
from collections import OrderedDict
from typing import TYPE_CHECKING, Optional
from functools import cache
import sys

import aiohttp

from src.misc import LimitedList
from src.discord.message import DiscordMessage
from src.config import settings
from src.argparser import command_line_args
# from src.discussions import Discussions
from src.statistics import Log, LogType

logger = logging.getLogger("rcgcdb.domain")

if TYPE_CHECKING:
    import src.wiki
    import src.irc_feed


class Domain:
    def __init__(self, name: str):
        self.name = name  # This should be always in format of topname.extension for example fandom.com
        self.task: Optional[asyncio.Task] = None
        self.wikis: OrderedDict[str, src.wiki.Wiki] = OrderedDict()
        self.irc: Optional[src.irc_feed.AioIRCCat] = None
        self.last_failure_report = 0
        self.message_timings: LimitedList = LimitedList(limit=100)
        self.total_discord_messages_sent: int = 0
        # self.discussions_handler: Optional[Discussions] = Discussions(self.wikis) if name == "fandom.com" else None

    def __iter__(self):
        return iter(self.wikis)

    def __str__(self) -> str:
        if len(self.message_timings) > 0:  # min throws exception when used on empty iterable
            tmin, avg, tmax = (self.convert_seconds_to_readable(min(self.message_timings)),
                             self.convert_seconds_to_readable(int(sum(self.message_timings)/len(self.message_timings))),
                             self.convert_seconds_to_readable(max(self.message_timings)))
        else:
            tmin, avg, tmax = 0, 0, 0
        return (f"<Domain name='{self.name}' task='{self.task}' wikis='{self.wikis}' "
                f"irc='{self.irc.connection.connected if self.irc else False}' "
                f"calculated_delay={self.calculate_sleep_time(len(self)) if not self.irc else 'handled by IRC scheduler'} "
                f"msgdelays=(min={tmin}, avg={avg}, max={tmax})>")

    def json(self) -> dict:
        dict_obj = {
            "wikis": [x for x in self.wikis.keys()],
            "irc": self.irc.connection.connected if self.irc else False,
            "delay": self.calculate_sleep_time(len(self)) if not self.irc else 'handled by IRC scheduler',
            "msgdelay": {"min": min(self.message_timings or [0]), "avg": int(sum(self.message_timings)/(len(self.message_timings) or 1)),
                         "max": max(self.message_timings or [0])},
            "discord_messages": self.total_discord_messages_sent,
            "last_failure_report": self.last_failure_report
        }
        return dict_obj
    def __repr__(self):
        return self.__str__()

    def __getitem__(self, item):
        return

    def __len__(self):
        return len(self.wikis)

    @staticmethod
    def convert_seconds_to_readable(seconds: int) -> str:
        """Helper function to prepare human readable times for domain report"""
        return f"{int(seconds/60)}m{seconds % 60}s"

    def destroy(self):
        """Destroy the domain – do all of the tasks that should make sure there is no leftovers before being collected by GC"""
        if self.irc:
            logger.debug("Leaving IRC due to destroy() for domain {}".format(self.name))
            self.irc.connection.die("Leaving")
        # if self.discussions_handler:
        #     self.discussions_handler.close()
        if self.task:
            self.task.cancel()

    def get_wiki(self, item: str, default=None) -> Optional[src.wiki.Wiki]:
        """Return a wiki with given domain name"""
        return self.wikis.get(item, default)

    def set_irc(self, irc_client: src.irc_feed.AioIRCCat):
        """Sets IRC"""
        self.irc = irc_client

    def stop_task(self):
        """Cancells the task"""
        self.task.cancel()  # Be aware that cancelling the task may take time

    def run_domain(self):
        """Starts asyncio task for domain"""
        if not self.task or self.task.cancelled():
            self.task = asyncio.create_task(self.run_wiki_check(), name=self.name)
        else:
            logger.error(f"Tried to start a task for domain {self.name} however the task already exists!")

    def remove_wiki(self, script_url: str):
        self.wikis.pop(script_url)

    async def add_wiki(self, wiki: src.wiki.Wiki, first=False):
        """Adds a wiki to domain list.

        :parameter wiki - Wiki object
        :parameter first (optional) - bool indicating if wikis should be added as first or last in the ordered dict"""
        wiki.set_domain(self)
        if wiki.script_url in self.wikis:
            await self.wikis[wiki.script_url].update_targets()
        else:
            self.wikis[wiki.script_url] = wiki
            await wiki.update_targets()
        if first:
            self.wikis.move_to_end(wiki.script_url, last=False)
        logger.debug(f"Added new wiki {wiki.script_url} to domain {self.name}")

    async def run_wiki_scan(self, wiki: src.wiki.Wiki, reason: Optional[str] = None):
        await wiki.scan()
        wiki.statistics.update(Log(type=LogType.SCAN_REASON, title=str(reason)))
        self.wikis.move_to_end(wiki.script_url)

    def failure_rate_investigation(self) -> Optional[set]:
        """Function is supposed to determine if a notification should be sent regarding a wiki/domain not working properly

                Cases considered worthy of notification:
                An entire farm (20% of wikis when 15+ wikis from domain) is responding with errors for the past 10 minutes
                A single wiki returning connection errors either for full queue_length or for an hour
                """
        if len(self) > 15:
            affected = set()
            for wiki_url, wiki_obj in self.wikis.items():
                failures = 0
                logs_last_10 = wiki_obj.statistics.filter_by_time(10 * 60)
                for log in logs_last_10:
                    if log.type == LogType.CONNECTION_ERROR:
                        failures += 1
                if max(len(logs_last_10)/2, 1) <= failures:
                    affected.add(wiki_url)
            if len(affected) > len(self)/5:
                return affected
        else:
            affected = set()
            for wiki_url, wiki_obj in self.wikis.items():
                if all([x.type in (LogType.CONNECTION_ERROR, LogType.MEDIAWIKI_ERROR, LogType.HTTP_ERROR) for x in wiki_obj.statistics.filter_by_time(60*60)]):
                    affected.add(wiki_url)
            if affected:
                return affected

    def register_message_timing_report(self, initial_time: datetime.datetime, send_time: Optional[datetime.datetime] = None) -> None:
        """This function registers time between edit being made and message with given edit being sent on Discord
        For metrics and debugging"""
        if send_time is None:
            send_time = datetime.datetime.now(tz=datetime.timezone.utc)
        self.message_timings.append((send_time - initial_time).seconds)

    def discord_message_registration(self):
        self.total_discord_messages_sent += 1

    async def irc_scheduler(self):
        try:
            while True:
                try:
                    wiki_url = self.irc.updated_wikis.pop()
                except KeyError:
                    break
                try:
                    wiki = self.wikis[wiki_url]
                except KeyError:
                    logger.error(f"Could not find a wiki with URL {wiki_url} in the domain group!")
                    continue
                await self.run_wiki_scan(wiki, "IRC feed event")
            while True:  # Iterate until hitting return, we don't have to iterate using for since we are sending wiki to the end anyways
                wiki: src.wiki.Wiki = next(iter(self.wikis.values()))
                if (int(time.time()) - (wiki.statistics.last_checked_rc or 0)) > settings.get("irc_overtime", 3600):
                    await self.run_wiki_scan(wiki, "IRC backup check")
                else:
                    return  # Recently scanned wikis will get at the end of the self.wikis, so we assume what is first hasn't been checked for a while
        except Exception as e:
            if command_line_args.debug:
                logger.exception("IRC scheduler task for domain {} failed!".format(self.name))
            else:  # production
                if not (time.time()-172800 > self.last_failure_report):  # If we haven't reported for more than 2 days or at all
                    return
                traceback.print_exc()
                wikis = self.failure_rate_investigation()
                if wikis:
                    await self.send_exception_to_monitoring(e, wikis)
                    self.last_failure_report = time.time()

    async def regular_scheduler(self):
        try:
            while True:
                await asyncio.sleep(self.calculate_sleep_time(len(self)))  # To make sure that we don't spam domains with one wiki every second we calculate a sane timeout for domains with few wikis
                await self.run_wiki_scan(next(iter(self.wikis.values())), "regular check")
        except Exception as e:
            if command_line_args.debug:
                logger.exception("Regular scheduler task for domain {} failed!".format(self.name))
            else:
                if not (time.time()-172800 > self.last_failure_report):  # If we haven't reported for more than 2 days or at all
                    return
                traceback.print_exc()
                wikis = self.failure_rate_investigation()
                if wikis:
                    await self.send_exception_to_monitoring(e, wikis)
                    self.last_failure_report = time.time()

    @cache
    def calculate_sleep_time(self, queue_length: int):
        return max(int(125/queue_length), 1)

    async def run_wiki_check(self):
        """Runs appropriate scheduler depending on existence of IRC"""
        if self.irc:
            try:
                while True:
                    await self.irc_scheduler()
                    await asyncio.sleep(10.0)
            except asyncio.exceptions.CancelledError:
                for wiki in self.wikis.values():
                    await wiki.session.close()
                    self.irc.connection.disconnect()
                raise
        else:
            try:
                while True:
                    await self.regular_scheduler()
            except asyncio.exceptions.CancelledError:
                for wiki in self.wikis.values():
                    await wiki.session.close()
                raise

    async def send_exception_to_monitoring(self, ex: Exception, wikis: set):
        discord_message = DiscordMessage("embed", "generic", [""])
        discord_message["title"] = "Domain scheduler exception for {} (recovered)".format(self.name)
        discord_message["description"] = "Affected wikis: {}".format(", ".join(wikis)) + "\n" + str(ex)
        discord_message["description"] = discord_message["description"][0:2000]
        # discord_message.add_field("Failure count", str(self.failures))
        header = settings["header"]
        header['Content-Type'] = 'application/json'
        header['X-RateLimit-Precision'] = "millisecond"
        try:
            async with aiohttp.ClientSession(headers=header, timeout=aiohttp.ClientTimeout(total=6)) as session:
                async with session.post("https://discord.com/api/webhooks/{}".format(settings["monitoring_webhook"]),
                                        data=repr(discord_message)) as resp:
                    pass
        except (aiohttp.ServerConnectionError, aiohttp.ServerTimeoutError):
            logger.exception("Couldn't communicate with Discord as a result of Server Error when trying to signal domain task issue!")