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

from fastapi import APIRouter, Depends, Request, Response, status
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.errors import from_api_error, http_error
from app.auth.dependencies import get_current_user
from app.db.models import User
from app.db.session import get_session
from app.withdrawals.service import WithdrawalError, request_withdrawal

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


class WithdrawalRequest(BaseModel):
    external_address: str
    amount_sats: int


class WithdrawalResponse(BaseModel):
    txid: str
    amount_requested_sats: int
    amount_sent_sats: int
    status: str


@router.post("", response_model=WithdrawalResponse, status_code=status.HTTP_201_CREATED)
async def create_withdrawal(
    body: WithdrawalRequest,
    request: Request,
    response: Response,
    user: User = Depends(get_current_user),
    session: AsyncSession = Depends(get_session),
) -> WithdrawalResponse:
    listener = request.app.state.electrum_listener
    if listener.client is None:
        raise http_error(
            status.HTTP_503_SERVICE_UNAVAILABLE,
            "network_unavailable",
            "not connected to the network, try again shortly",
        )

    async with request.app.state.user_locks.acquire(user.id):
        try:
            withdrawal = await request_withdrawal(
                session, listener.client, user, body.external_address, body.amount_sats, network=listener
            )
        except WithdrawalError as exc:
            code = (
                status.HTTP_502_BAD_GATEWAY  # the network refused it, not the caller (B-07)
                if exc.code == "broadcast_failed"
                else status.HTTP_503_SERVICE_UNAVAILABLE  # B-88: write lock not granted, nothing sent
                if exc.code == "service_busy"
                else status.HTTP_400_BAD_REQUEST
            )
            raise from_api_error(code, exc) from exc

    if withdrawal.status == "building":
        # B-76 (TX-20, WDR-16): uncertain broadcast — accepted for processing, the
        # reconciler decides whether the transaction left.
        response.status_code = status.HTTP_202_ACCEPTED
    return WithdrawalResponse(
        txid=withdrawal.txid,
        amount_requested_sats=withdrawal.amount_requested_sats,
        amount_sent_sats=withdrawal.amount_sent_sats,
        status=withdrawal.status,
    )