import math
from redbot.core import commands
from redbot.core import Config, checks
import discord
import re


class SacrificeCog(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
        self.config = Config.get_conf(self, identifier=154776548)
        default_global = {
            "elo": {},
            "tracked_msgs": {}
        }
        self.config.register_global(**default_global)

    @staticmethod
    def is_valid_winloss(s):
        r = r"[wWlL]+"
        regx = re.compile(r)
        fm = regx.fullmatch(s)
        return fm

    async def get_rank(self, discord_id: str):
        elos = await self.config.elo()
        if discord_id not in elos:
            return None, None
        sorted_players = sorted(elos, key=elos.get, reverse=True)
        return sorted_players.index(discord_id) + 1, len(sorted_players)

    @commands.Cog.listener()
    async def on_raw_reaction_add(self, payload):
        tracked = await self.config.tracked_msgs()
        await self.log(str(payload.message_id))
        await self.log(tracked.keys())
        if str(payload.message_id) in tracked.keys():
            # fetch channel
            channel = await self.bot.fetch_channel(620879085739966464)  # channel
            if not channel:
                tracked.remove(payload.message_id)
                await self.config.tracked_msgs.set(tracked)
                return
            # fetch msg
            orig_msg = await channel.fetch_message(payload.message_id)
            if not orig_msg:
                tracked.remove(payload.message_id)
                await self.config.tracked_msgs.set(tracked)
                return
            opponents = orig_msg.mentions
            if not opponents:
                tracked.remove(payload.message_id)
                await self.config.tracked_msgs.set(tracked)
                return

            opponent = opponents[0]

            if str(payload.user_id) == str(opponent.id) and payload.emoji.name == "👍":
                await self.log("true")
                outcome = orig_msg.content.split(" ")[2]
                if SacrificeCog.is_valid_winloss(outcome):
                    for c in outcome:
                        if c.lower() == "w":
                            await self.win(str(orig_msg.author.id), str(opponent.id))
                        elif c.lower() == "l":
                            await self.win(str(opponent.id), str(orig_msg.author.id))

                    new_elo = await self.get_elo(str(orig_msg.author.id))
                    new_elo_2 = await self.get_elo(str(opponent.id))

                    bot_msg = await channel.fetch_message(tracked[str(payload.message_id)])

                    await bot_msg.edit(content="**%s**, your new ELO is: **%s**\n**%s**, your new ELO is: **%s**" % (
                        orig_msg.author.mention, round(new_elo), opponent.mention, round(new_elo_2))
                    )

                    del tracked[str(payload.message_id)]
                    await self.config.tracked_msgs.set(tracked)
                    return

    async def track_msg(self, orig_message_id: str, bot_msg_id: str):
        tracked = await self.config.tracked_msgs()
        tracked[orig_message_id] = bot_msg_id
        await self.config.tracked_msgs.set(tracked)

    @commands.command()
    async def rank(self, ctx, opponent: discord.Member = None, winloss: str = None):
        author_id = str(ctx.author.id)
        if not opponent and not winloss:
            # send elo to player
            rank, count = await self.get_rank(author_id)
            if rank:
                elo = await self.get_elo(author_id)
                await ctx.send("**%s**, your ELO is: **%s** (ranked #%s/%s)" % (ctx.author.mention, round(elo), rank, count))
            else:
                await ctx.send("**%s**, you are not ranked yet" % ctx.author.mention)
            return
        elif opponent and not winloss:
            # show opponent rank
            opponent_id = str(opponent.id)
            rank, count = await self.get_rank(opponent_id)
            if rank:
                elo = await self.get_elo(opponent_id)
                await ctx.send("**%s**' ELO is: **%s** (ranked #%s/%s)" % (opponent.display_name, round(elo), rank, count))
            else:
                await ctx.send("**%s** is not ranked yet" % opponent.display_name)
            return
        elif opponent and winloss:
            if not SacrificeCog.is_valid_winloss(winloss):
                await ctx.send("Invalid win/losses")
                return

            bot_msg = await ctx.send("Waiting for %s' :thumbsup: reaction to previous message..." % opponent.display_name)
            await self.track_msg(str(ctx.message.id), str(bot_msg.id))
            return

    @staticmethod
    def expection(d):
        # https://fr.wikipedia.org/wiki/Classement_Elo#Relation_entre_diff%C3%A9rence_de_points_Elo_et_probabilit%C3%A9_de_gain
        return 1/(1+math.pow(10, -d/400))

    async def win(self, winner_id: str, looser_id: str) -> None:
        elo_winner = await self.get_elo(winner_id)
        elo_looser = await self.get_elo(looser_id)
        diff = elo_winner - elo_looser
        expection_winner = SacrificeCog.expection(diff)
        expection_looser = SacrificeCog.expection(-diff)
        k_winner = 40  # TODO: should be lowered after many games
        k_looser = 40  # TODO: should be lowered after many games
        new_elo_winner = elo_winner + k_winner * (1 - expection_winner)
        new_elo_looser = elo_looser + k_looser * (0 - expection_looser)
        await self.save_elo({winner_id: new_elo_winner, looser_id: new_elo_looser})

    async def save_elo(self, scores: dict) -> None:
        elos = await self.config.elo()
        elos.update(scores)
        await self.config.elo.set(elos)

    async def get_elo(self, discord_id: str) -> int:
        elos = await self.config.elo()
        if discord_id in elos:
            return elos[discord_id]
        else:
            # set new elo = 1500
            return 1500