from datetime import timedelta, timezone

from fastapi import APIRouter, Depends
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.db.models import RoundParticipant
from app.db.session import get_session
from app.rounds.config import get_round_config
from app.rounds.service import get_active_round

router = APIRouter(prefix="/rounds", tags=["rounds"])


class CurrentRoundResponse(BaseModel):
    round_id: int | None = None
    status: str | None = None
    opened_at: str | None = None
    closes_at: str | None = None
    participant_count: int = 0
    bet_amount_sats: int
    jackpot_sats: int = 0


@router.get("/current", response_model=CurrentRoundResponse)
async def current_round(session: AsyncSession = Depends(get_session)) -> CurrentRoundResponse:
    config = await get_round_config(session)
    round_ = await get_active_round(session)
    if round_ is None:
        await session.commit()
        return CurrentRoundResponse(bet_amount_sats=config.bet_amount_sats)

    participant_count = await session.scalar(
        select(func.count()).select_from(RoundParticipant).where(RoundParticipant.round_id == round_.id)
    ) or 0
    opened_at = round_.opened_at.replace(tzinfo=timezone.utc)
    closes_at = opened_at + timedelta(seconds=config.round_duration_seconds)
    await session.commit()

    return CurrentRoundResponse(
        round_id=round_.id,
        status=round_.status,
        opened_at=opened_at.isoformat(),
        closes_at=closes_at.isoformat(),
        participant_count=participant_count,
        bet_amount_sats=config.bet_amount_sats,
        jackpot_sats=participant_count * config.bet_amount_sats,
    )