from datetime import datetime
from typing import Any, Dict, List
from zoneinfo import ZoneInfo

from bson.errors import InvalidId
from discord import (
    ApplicationContext,
    Attachment,
    SlashCommandGroup,
    option,
)
from discord.ext.commands import Cog
from discord.utils import basic_autocomplete

from classes import PycordEvent, PycordEventStage, PycordGuild
from classes.pycord_bot import PycordBot
from modules.utils import (
    autocomplete_active_events,
    get_unix_timestamp,
    is_operation_confirmed,
    validate_event_validity,
)


class CogEvent(Cog):
    """Cog with event management commands."""

    def __init__(self, bot: PycordBot):
        self.bot: PycordBot = bot

    # TODO Introduce i18n
    command_group: SlashCommandGroup = SlashCommandGroup("event", "Event management")

    # TODO Introduce i18n
    @command_group.command(
        name="create",
        description="Create new event",
    )
    @option("name", description="Name of the event", required=True)
    @option("start", description="Date when the event starts (DD.MM.YYYY HH:MM)", required=True)
    @option("end", description="Date when the event ends (DD.MM.YYYY HH:MM)", required=True)
    @option("thumbnail", description="Thumbnail of the event", required=False)
    async def command_event_create(
        self,
        ctx: ApplicationContext,
        name: str,
        start: str,
        end: str,
        thumbnail: Attachment = None,
    ) -> None:
        guild: PycordGuild = await self.bot.find_guild(ctx.guild.id)

        if not guild.is_configured():
            await ctx.respond(self.bot._("guild_unconfigured_admin", "messages", locale=ctx.locale))
            return

        guild_timezone: ZoneInfo = ZoneInfo(guild.timezone)

        try:
            start_date: datetime = datetime.strptime(start, "%d.%m.%Y %H:%M")
            end_date: datetime = datetime.strptime(end, "%d.%m.%Y %H:%M")

            start_date = start_date.replace(tzinfo=guild_timezone)
            end_date = end_date.replace(tzinfo=guild_timezone)
        except ValueError:
            # TODO Introduce i18n
            await ctx.respond(
                "Could not parse start and end dates. Please, make sure these are provided in `DD.MM.YYYY HH:MM` format."
            )
            return

        await validate_event_validity(ctx, name, start_date, end_date, guild_timezone)

        processed_media: List[Dict[str, Any]] = (
            [] if thumbnail is None else await self.bot.process_attachments([thumbnail])
        )

        event: PycordEvent = await self.bot.create_event(
            name=name,
            guild_id=guild.id,
            creator_id=ctx.author.id,
            starts=start_date.astimezone(ZoneInfo("UTC")),
            ends=end_date.astimezone(ZoneInfo("UTC")),
            thumbnail=processed_media[0] if thumbnail else None,
        )

        # TODO Introduce i18n
        await ctx.respond(
            f"Event **{event.name}** has been created and will take place <t:{get_unix_timestamp(event.starts)}:R>."
        )

    # TODO Introduce i18n
    @command_group.command(
        name="edit",
        description="Edit event",
    )
    @option(
        "event",
        description="Name of the event",
        autocomplete=basic_autocomplete(autocomplete_active_events),
        required=True,
    )
    @option("name", description="New name of the event", required=False)
    @option("start", description="Date when the event starts (DD.MM.YYYY HH:MM)", required=False)
    @option("end", description="Date when the event ends (DD.MM.YYYY HH:MM)", required=False)
    @option("thumbnail", description="Thumbnail of the event", required=False)
    async def command_event_edit(
        self,
        ctx: ApplicationContext,
        event: str,
        name: str = None,
        start: str = None,
        end: str = None,
        thumbnail: Attachment = None,
    ) -> None:
        guild: PycordGuild = await self.bot.find_guild(ctx.guild.id)

        try:
            pycord_event: PycordEvent = await self.bot.find_event(event_id=event)
        except (InvalidId, RuntimeError):
            # TODO Make a nice message
            await ctx.respond("Event was not found.")
            return

        if not guild.is_configured():
            await ctx.respond(self.bot._("guild_unconfigured_admin", "messages", locale=ctx.locale))
            return

        guild_timezone: ZoneInfo = ZoneInfo(guild.timezone)

        try:
            start_date: datetime = (
                pycord_event.starts if start is None else datetime.strptime(start, "%d.%m.%Y %H:%M")
            )
            start_date = start_date.replace(tzinfo=guild_timezone)
        except ValueError:
            # TODO Make a nice message
            await ctx.respond("Could not parse the start date.")
            return

        try:
            end_date: datetime = pycord_event.ends if end is None else datetime.strptime(end, "%d.%m.%Y %H:%M")
            end_date = end_date.replace(tzinfo=guild_timezone)
        except ValueError:
            # TODO Make a nice message
            await ctx.respond("Could not parse the end date.")
            return

        await validate_event_validity(ctx, name, start_date, end_date, guild_timezone)

        processed_media: List[Dict[str, Any]] = (
            [] if thumbnail is None else await self.bot.process_attachments([thumbnail])
        )

        await pycord_event.update(
            self.bot.cache,
            starts=start_date,
            ends=end_date,
            name=pycord_event.name if name is None else name,
            thumbnail=pycord_event.thumbnail if thumbnail is None else processed_media[0],
        )

        # TODO Notify participants about time changes

        # TODO Make a nice message
        await ctx.respond(
            f"Event **{pycord_event.name}** has been updated and will take place <t:{get_unix_timestamp(pycord_event.starts)}:R>."
        )

    # TODO Introduce i18n
    @command_group.command(
        name="cancel",
        description="Cancel event",
    )
    @option(
        "event",
        description="Name of the event",
        autocomplete=basic_autocomplete(autocomplete_active_events),
        required=True,
    )
    @option("confirm", description="Confirmation of the operation", required=False)
    async def command_event_cancel(
        self,
        ctx: ApplicationContext,
        event: str,
        confirm: bool = False,
    ) -> None:
        if not (await is_operation_confirmed(ctx, confirm)):
            return

        guild: PycordGuild = await self.bot.find_guild(ctx.guild.id)

        try:
            pycord_event: PycordEvent = await self.bot.find_event(event_id=event)
        except (InvalidId, RuntimeError):
            # TODO Make a nice message
            await ctx.respond("Event was not found.")
            return

        if not guild.is_configured():
            await ctx.respond(self.bot._("guild_unconfigured_admin", "messages", locale=ctx.locale))
            return

        start_date: datetime = pycord_event.starts.replace(tzinfo=ZoneInfo("UTC"))
        end_date: datetime = pycord_event.ends.replace(tzinfo=ZoneInfo("UTC"))

        # TODO Make ongoing events cancellable
        if (
            pycord_event.ended is not None
            or end_date <= datetime.now(tz=ZoneInfo("UTC"))
            or start_date <= datetime.now(tz=ZoneInfo("UTC"))
        ):
            # TODO Make a nice message
            await ctx.respond("Finished or ongoing events cannot be cancelled.")
            return

        await pycord_event.cancel()

        # TODO Notify participants about cancellation

        # TODO Make a nice message
        await ctx.respond(f"Event **{pycord_event.name}** was cancelled.")

    # TODO Introduce i18n
    @command_group.command(
        name="show",
        description="Show the details about certain event",
    )
    @option(
        "event",
        description="Name of the event",
        autocomplete=basic_autocomplete(autocomplete_active_events),
        required=True,
    )
    async def command_event_show(self, ctx: ApplicationContext, event: str) -> None:
        guild: PycordGuild = await self.bot.find_guild(ctx.guild.id)

        try:
            pycord_event: PycordEvent = await self.bot.find_event(event_id=event)
        except (InvalidId, RuntimeError):
            # TODO Make a nice message
            await ctx.respond("Event was not found.")
            return

        starts_date: datetime = pycord_event.starts.replace(tzinfo=ZoneInfo("UTC"))
        ends_date: datetime = pycord_event.ends.replace(tzinfo=ZoneInfo("UTC"))

        stages: List[PycordEventStage] = await self.bot.get_event_stages(pycord_event)

        # TODO Make a nice message
        stages_string: str = "\n\n".join(
            f"**Stage {stage.sequence+1}**\nQuestion: {stage.question}\nAnswer: ||{stage.answer}||"
            for stage in stages
        )

        # TODO Show users registered for the event

        # TODO Introduce i18n
        await ctx.respond(
            f"**Event details**\n\nName: {pycord_event.name}\nStarts: <t:{get_unix_timestamp(starts_date)}>\nEnds: <t:{get_unix_timestamp(ends_date)}>\n\nStages:\n{stages_string}"
        )


def setup(bot: PycordBot) -> None:
    bot.add_cog(CogEvent(bot))