plm-lottery/app/api/routes/rounds.py

from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, Depends, Request
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):
    server_time: str
    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
    draw_animation_seconds: int
    winner_user_id: int | None = None
    winner_amount_sats: int | None = None
    chain_tip_height: int | None = None
    lottery_paused: bool = False


@router.get("/current", response_model=CurrentRoundResponse)
async def current_round(request: Request, session: AsyncSession = Depends(get_session)) -> CurrentRoundResponse:
    config = await get_round_config(session)
    round_ = await get_active_round(session)
    listener = request.app.state.electrum_listener
    chain_tip_height = listener.tip_height or None
    if round_ is None:
        await session.commit()
        return CurrentRoundResponse(
            server_time=datetime.now(timezone.utc).isoformat(),
            bet_amount_sats=config.bet_amount_sats,
            draw_animation_seconds=config.draw_animation_seconds,
            chain_tip_height=chain_tip_height,
            lottery_paused=config.paused,
        )

    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()

    # Shown to players as "jackpot": the winner's 70% share of the pool (same
    # split rounds/scheduler.py applies at payout time), not the full pool —
    # what's displayed should match what the winner actually receives.
    pool_amount_sats = participant_count * config.bet_amount_sats
    jackpot_sats = pool_amount_sats * 70 // 100

    return CurrentRoundResponse(
        server_time=datetime.now(timezone.utc).isoformat(),
        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=jackpot_sats,
        draw_animation_seconds=config.draw_animation_seconds,
        winner_user_id=round_.winner_user_id,
        winner_amount_sats=round_.winner_amount_sats,
        chain_tip_height=chain_tip_height,
        lottery_paused=config.paused,
    )