import asyncio
import logging
import sqlite3
from datetime import datetime, timedelta
from pathlib import Path

import discord
import pandas as pd

from msg import message_df, full_reaction_df, message_dict, LOGGER, reaction_df

LOGGER = logging.getLogger(__name__)


class MsgData:
    msgs: pd.DataFrame
    reactions: pd.DataFrame
    lock: asyncio.Lock

    @classmethod
    async def create(cls, client: discord.Client, **kwargs):
        self = MsgData()
        self.lock = asyncio.Lock()
        self.msgs: pd.DataFrame = await message_df(client, **kwargs)
        self.msgs = self.msgs.sort_values('created')
        self.reactions: pd.DataFrame = full_reaction_df(self.msgs['object'].tolist())
        return self

    @classmethod
    def from_sql(cls, db, local_tz='US/Central'):
        if isinstance(db, (str, Path)):
            con = sqlite3.connect(db)
        elif isinstance(db, sqlite3.Connection):
            con = db

        self = MsgData()
        self.msgs: pd.DataFrame = pd.read_sql('select * from msgs', con=con, index_col='id')
        self.msgs['created'] = pd.to_datetime(self.msgs['created']).dt.tz_convert(local_tz)
        self.reactions: pd.DataFrame = pd.read_sql('select * from reactions', con).set_index(['msg id', 'emoji'])
        return self

    def to_sql(self, db):
        if isinstance(db, (str, Path)):
            con = sqlite3.connect(db)
        elif isinstance(db, sqlite3.Connection):
            con = db
        else:
            raise TypeError(f'db argument is not a valid type: {type(db)}')

        self.msgs.drop('object', axis=1).to_sql(
            name='msgs',
            con=con,
            if_exists='replace',
            index=True,
            index_label=self.msgs.index.name
        )
        self.reactions.drop('object', axis=1).to_sql(
            name='reactions',
            con=con,
            if_exists='replace',
            index=True,
            index_label=self.reactions.index.name
        )

    def __str__(self):
        return str(self.msgs) + '\n\n' + str(self.reactions)

    def __repr__(self):
        return f'<{__name__}.{self.__class__.__name__} with {self.msgs.shape[0]} messages and {self.reactions.shape[0]} reactions>'

    def __getitem__(self, item):
        if isinstance(item, str):
            return self.emoji_messages(emoji_name=item).sort_values('count', ascending=False)
        elif isinstance(item, int):
            return self.reactions.loc[pd.IndexSlice[item, :],].fillna(0).applymap(int)

    async def add_msg(self, message: discord.Message):
        async with self.lock:
            mdict = message_dict(message)
            mdict.pop('id')
            self.msgs.loc[message.id] = pd.Series(mdict)
            LOGGER.info(f'Added message id {message.id} from {message.author}: {message.content}')

    async def update_reaction(self, msg: discord.Message):
        # Drop all the reactions for this message id, if there are any
        try:
            async with self.lock:
                self.reactions.drop(msg.id, level=0, axis=0, inplace=True)
        except KeyError as e:
            pass

        # If there are reactions on the message after the change
        if len(msg.reactions) > 0:
            new = reaction_df(msg)
            async with self.lock:
                self.reactions = pd.concat([self.reactions, new])
            LOGGER.info(str(new.droplevel(level=0, axis=0).loc[:, 'count']))

            if msg.id not in self.msgs.index:
                await self.add_msg(msg)

            return new

    def emoji_messages(self, emoji_name: str, days: int = None) -> pd.DataFrame:
        """Creates a DataFrame of the messages that have reactions with a certain emoji. Includes a 'count' column"""
        counts: pd.Series = self.emoji_counts(emoji_name)

        # Get the ids of messages that that have the targeted emoji
        message_id_counts: pd.Index = counts.index.drop_duplicates()

        # There could be a situation where a message id in message_id_counts isn't actually in the self.msgs DataFrame
        # Filter to keep only the messages that have actually been captured in the self.msgs DataFrame
        message_id_counts: pd.Index = message_id_counts[message_id_counts.isin(self.msgs.index.get_level_values(0))]

        # If there were actually some message ids found
        if message_id_counts.shape[0] > 0:
            res: pd.DataFrame = self.msgs.loc[message_id_counts]

            res['count'] = counts

            if days is not None and days > 0:
                res = res[res['created'] >= (datetime.today() - timedelta(days=days)).astimezone()]

            return res.sort_values('created', ascending=False)

        else:
            raise KeyError(f'No messages found with {emoji_name} reactions')

    def emoji_counts(self, emoji_name: str) -> pd.Series:
        """Creates a Series indexed by message id and with the number of reactions with emoji_name as values"""
        assert isinstance(emoji_name, str), f'emoji_name must be a string'
        try:
            return self.reactions.loc[pd.IndexSlice[:, emoji_name], 'count'].droplevel(1).sort_values(ascending=False)
        except KeyError as e:
            LOGGER.error(f' {emoji_name} not found out of {self.unique_emojis.shape[0]} unique emojis')
            LOGGER.error(f'{self.reactions.index.get_level_values(1)}')
            raise

    @property
    def unique_emojis(self) -> pd.Index:
        return self.reactions.index.get_level_values(1).drop_duplicates()

    def emoji_totals(self, emoji_name: str, days: int = None) -> pd.Series:
        """Creates a Series indexed by user id and with the number of reactions with emoji_name as values"""
        return (self
                .emoji_messages(emoji_name, days)
                .groupby('user id')
                .apply(lambda gdf: gdf['count'].sum())
                .sort_values(ascending=False))

    async def emoji_user_counts(self, client: discord.Client, emoji_name: str, days: int):
        counts: pd.Series = self.emoji_totals(emoji_name, days)
        counts.index = pd.Index([(await client.fetch_user(user_id=uid)).display_name for uid in counts.index])
        return counts

    def worst_offsenses(self, user: str, days: int):
        cdf = self.emoji_messages('cancelled', days=days)
        cdf = cdf[cdf['display_name'].str.contains(user, case=False)]

        if cdf.shape[0] > 0:
            res = f'{user}\'s top 5 cancellations in the last {days} days:\n'
            res += f'\n'.join(
                f'`{row["count"]:<2.0f}cancellations`\n{row["link"]}' for idx, row in cdf.iloc[:5].iterrows())
        else:
            res = f'No cancellations for {user} in the past {days} days'

        return res

    async def biggest_single(self, client: discord.Client, emoji: str, days: int) -> str:
        data: pd.Series = self.emoji_totals(emoji_name=emoji, days=days)
        user: discord.User = await client.fetch_user(user_id=data.index[0])
        LOGGER.info(f'User: {user.mention}')
        return f'{user.mention} with {data.iloc[0]:.0f} over the past {int(days)} days'