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

from bson import ObjectId
from discord import (
    ApplicationContext,
)

from modules.database import col_events


async def validate_event_validity(
    ctx: ApplicationContext,
    name: str,
    start_date: datetime,
    end_date: datetime,
    event_id: Optional[ObjectId] = None,
    to_utc: bool = False,
) -> bool:
    start_date_internal: datetime = start_date.astimezone(ZoneInfo("UTC")) if to_utc else start_date
    end_date_internal: datetime = end_date.astimezone(ZoneInfo("UTC")) if to_utc else end_date

    if start_date_internal < datetime.now(tz=ZoneInfo("UTC")):
        # TODO Make a nice message
        await ctx.respond("Start date must not be in the past")
        return False

    if end_date_internal < datetime.now(tz=ZoneInfo("UTC")):
        # TODO Make a nice message
        await ctx.respond("End date must not be in the past")
        return False

    if start_date_internal >= end_date_internal:
        # TODO Make a nice message
        await ctx.respond("Start date must be before end date")
        return False

    # TODO Add validation for concurrent events.
    #  Only one event can take place at the same time.
    query: Dict[str, Any] = {
        "name": name,
        "ended": None,
        "ends": {"$gt": datetime.now(tz=ZoneInfo("UTC"))},
        "is_cancelled": {"$ne": True},
    }

    if event_id is not None:
        query["_id"] = {"$ne": event_id}

    if (await col_events.find_one(query)) is not None:
        # TODO Make a nice message
        await ctx.respond("There can only be one active event with the same name")
        return False

    return True