from datetime import datetime, timedelta
import logging
import json
from typing import Dict, List, Tuple
from naff import (
    Client,
    Extension,
    slash_command,
    slash_option,
    InteractionContext,
    OptionTypes,
    Permissions,
    Modal,
    ShortText,
    ParagraphText,
    ModalContext,
    Button,
    ButtonStyles,
    Embed,
    spread_to_rows,
    Message,
    listen,
    Task,
    IntervalTrigger,
    GuildText,
    PartialEmoji,
)
from naff.api import events
from naff.client.errors import HTTPException

from database import Polls as PollsModel, PollVotes as PollVotesModel
from peewee import fn

PollOptions = List[Tuple[str | None, str]]


def datetime_to_discord_time(dt: datetime) -> str:
    t = dt.strftime("%s")
    return f"<t:{int(t)}:R>"


def generate_bar(num: int, total: int, length: int = 10) -> str:
    full_char = "\u2593"
    empty_char = "\u2591"

    if total <= 0:
        return length * empty_char

    result = round(num / total * length)
    percent = num / total * 100
    return (
        result * full_char
        + (length - result) * empty_char
        + f" ({percent: 3.1f}%)".replace(".0", "")
    )


def generate_poll_embed(
    title: str,
    options: PollOptions,
    votes: List[int],
    *,
    multiple_choice: bool = False,
    expires: datetime = None,
) -> Embed:
    data = []
    if multiple_choice:
        data.append("\u2022 Multiple choice")
    if expires:
        data.append(f"\u2022 Expiry: {datetime_to_discord_time(expires)}")

    embed = Embed(
        title=title,
        description=("\n".join(data) if data else None),
    )
    sum_votes = sum(votes)

    for i, (emoji, option) in enumerate(options):
        embed.add_field(
            name=f"**{emoji if emoji else num_to_emoji(i+1)} {option}**",
            value=generate_bar(votes[i], sum_votes) + "\n" + f"{votes[i]} votes",
            inline=False,
        )
    return embed


def num_to_emoji(num: int) -> str:
    match num:
        case 0:
            return "0️⃣"
        case 1:
            return "1️⃣"
        case 2:
            return "2️⃣"
        case 3:
            return "3️⃣"
        case 4:
            return "4️⃣"
        case 5:
            return "5️⃣"
        case 6:
            return "6️⃣"
        case 7:
            return "7️⃣"
        case 8:
            return "8️⃣"
        case 9:
            return "9️⃣"
        case 10:
            return "🔟"

        case _:
            raise ValueError(f"Invalid number: `num` must be 0 <= num <= 10.")


class Polls(Extension):
    def __init__(self, client: Client):
        self.client = client

    @listen(events.Ready)
    async def on_ready(self):
        await self.poll_expiry_check()
        self.poll_expiry_check.start()

    @slash_command(
        name="polls",
        description="Polls",
        sub_cmd_name="create",
        sub_cmd_description="Create a poll",
        dm_permission=False,
        default_member_permissions=Permissions.SEND_MESSAGES,
    )
    @slash_option(
        name="title",
        description="Title of the poll",
        required=True,
        opt_type=OptionTypes.STRING,
    )
    @slash_option(
        name="duration",
        description="Duration of the poll in minutes",
        required=False,
        opt_type=OptionTypes.INTEGER,
    )
    @slash_option(
        name="multiple-choice",
        description="If users can vote for multiple options",
        required=False,
        opt_type=OptionTypes.BOOLEAN,
    )
    async def create_poll(
        self,
        ctx: InteractionContext,
        *,
        title: str,
        duration: int | None = None,
        multiple_choice: bool = False,
    ):
        modal = Modal(
            title="Creating poll",
            components=[
                ShortText(
                    custom_id="title",
                    label="Title",
                    value=title,
                    required=True,
                    max_length=120,
                ),
                ParagraphText(
                    custom_id="options",
                    label="Poll options",
                    placeholder=(
                        "Add poll options here.\n\n" "- ✅: Yes\n" "- ❌: No\n" "- Unsure"
                    ),
                    required=True,
                    max_length=1200,
                ),
            ],
        )

        await ctx.send_modal(modal)
        modal_ctx: ModalContext = await self.client.wait_for_modal(
            modal=modal, author=ctx.author
        )

        duration: datetime | None = (
            (datetime.now() + timedelta(minutes=duration)) if duration else None
        )

        title = modal_ctx.responses["title"]
        options: PollOptions = []
        for i, option in enumerate(
            modal_ctx.responses["options"].replace("-", "", 1).split("\n-")
        ):
            if option == "":
                continue
            parts = option.split(":", 1)
            if len(parts) == 1:
                options.append((None, parts[0].strip()))
            else:
                options.append((parts[0].strip(), parts[1].strip()))

        if len(options) > 10:
            await modal_ctx.send("You can only have up to 10 options.", ephemeral=True)
            return
        if len(options) < 2:
            await modal_ctx.send("You must have at least 2 options.", ephemeral=True)
            return

        poll_entry: PollsModel = PollsModel.create(
            guild_id=ctx.guild.id,
            author_id=ctx.author.id,
            title=title,
            options=json.dumps(options),
            no_options=len(options),
            multiple_choice=multiple_choice,
            expires=duration,
        )

        buttons: List[Button] = []
        for i, option in enumerate(options):
            try:
                emoji = PartialEmoji.from_str((option[0] or num_to_emoji(i + 1)))
            except ValueError:
                emoji = num_to_emoji(i + 1)
            buttons.append(
                Button(
                    emoji=emoji,
                    style=ButtonStyles.PRIMARY,
                    custom_id=f"poll-vote:{poll_entry.id}:{i}",
                )
            )

        buttons.append(
            Button(
                emoji="🔒",
                label="Lock",
                style=ButtonStyles.DANGER,
                custom_id=f"poll-lock:{poll_entry.id}",
            )
        )
        embed = generate_poll_embed(
            title,
            options,
            len(options) * [0],
            multiple_choice=multiple_choice,
            expires=duration,
        )
        try:
            poll_message: Message = await modal_ctx.send(
                embed=embed,
                components=spread_to_rows(*buttons),
            )
        except HTTPException as e:
            logging.error(f"Error sending poll: {e}")
            await modal_ctx.send(
                "Error during poll creation. NB: You can not use server-specific emojis",
                ephemeral=True,
            )
            return

        poll_entry.message_id = poll_message.id
        poll_entry.channel_id = poll_message.channel.id
        poll_entry.save()

    @listen(events.Button)
    async def on_button(self, button: events.Button):
        ctx = button.context
        await ctx.defer(ephemeral=True)

        if ctx.custom_id.startswith("poll-vote:"):
            poll_id, option_num = ctx.custom_id.split(":", 1)[1].split(":", 1)

            poll_entry: PollsModel | None = PollsModel.get_or_none(
                guild_id=ctx.guild.id, id=poll_id
            )
            if not poll_entry:
                return

            if poll_entry.expires and datetime.now() > poll_entry.expires:
                return

            if not poll_entry.multiple_choice:
                votes_q: List[PollVotesModel] = PollVotesModel.select().where(
                    PollVotesModel.poll_id == poll_id,
                    PollVotesModel.user_id == ctx.author.id,
                )
                if votes_q.count() > 1:
                    for vote in votes_q:
                        vote.delete().execute()

                    PollVotesModel.create(
                        poll_id=poll_id,
                        user_id=ctx.author.id,
                        option=option_num,
                    )
                elif votes_q.count() == 1:
                    if int(votes_q[0].option) == int(option_num):
                        votes_q[0].delete_instance()
                        await ctx.send("You have removed your vote.")
                    else:
                        votes_q[0].option = option_num
                        votes_q[0].save()
                        await ctx.send("You have changed your vote.")
                else:
                    PollVotesModel.create(
                        poll_id=poll_id,
                        user_id=ctx.author.id,
                        option=option_num,
                    )
                    await ctx.send("You have voted.")
            else:
                votes_q: List[PollVotesModel] = PollVotesModel.select().where(
                    PollVotesModel.poll_id == poll_id,
                    PollVotesModel.user_id == ctx.author.id,
                )

                exists = False
                for vote in votes_q:
                    if int(vote.option) == (option_num):
                        exists = True
                        vote.delete_instance()
                        await ctx.send("You have removed your vote.")
                        break

                if not exists:
                    PollVotesModel.create(
                        poll_id=poll_id,
                        user_id=ctx.author.id,
                        option=option_num,
                    )
                    await ctx.send("You have voted.")

            votes_q: List[PollVotesModel] = (
                PollVotesModel.select(
                    PollVotesModel.poll_id,
                    PollVotesModel.option,
                    fn.COUNT(PollVotesModel.option).alias("count"),
                )
                .where(PollVotesModel.poll_id == poll_id)
                .group_by(PollVotesModel.option)
                .order_by(PollVotesModel.option)
            )

            # This is such absolutely an awful way to do this. I'm sorry.
            # It's the cost of not adding the options in a separate table, I guess.
            # Anyway this just gets the votes for each option, and adds them to
            # the list `votes`. They're in the same order as the options.
            options: PollOptions = json.loads(poll_entry.options)
            votes = len(options) * [0]

            for i, vote in enumerate(votes_q):
                votes[int(vote.option)] = vote.count

            embed = generate_poll_embed(
                poll_entry.title,
                options,
                votes,
                multiple_choice=poll_entry.multiple_choice,
                expires=poll_entry.expires,
            )

            await ctx.message.edit(embed=embed)

        elif ctx.custom_id.startswith("poll-lock:"):
            poll_id = ctx.custom_id.split(":", 1)[1]

            poll_entry: PollsModel | None = PollsModel.get_or_none(
                guild_id=ctx.guild.id, id=poll_id
            )
            if not poll_entry:
                await ctx.send("That poll doesn't exist.")
                return

            if not ctx.author.id == int(
                poll_entry.author_id
            ) or not ctx.author.has_permission(Permissions.MANAGE_MESSAGES):
                await ctx.send("You don't have permission to lock that poll.")
                return

            poll_entry.expires = datetime.now() - timedelta(minutes=1)
            poll_entry.save()

            await self.poll_expiry_check()
            await ctx.send("Poll locked.")

    @Task.create(IntervalTrigger(minutes=1))
    async def poll_expiry_check(self):
        logging.info("Checking for expired polls.")
        now = datetime.now()

        polls_q: List[PollsModel] = PollsModel.select().where(PollsModel.expires < now)
        for poll_entry in polls_q:
            channel: GuildText = await self.client.fetch_channel(
                int(poll_entry.channel_id)
            )
            if not channel:
                continue

            message: Message = await channel.fetch_message(int(poll_entry.message_id))
            if not message:
                continue

            await message.edit(components=[])


def setup(client: Client):
    PollsModel.create_table()
    PollVotesModel.create_table()
    Polls(client)
    logging.info("Polls extension loaded")