helpers.py

from fastapi import Request
from lnbits.utils.exchange_rates import get_fiat_rate_satoshis
from lnurl import Lnurl
from lnurl import encode as lnurl_encode
from shortuuid import uuid

from .models import WithdrawLink


def create_lnurl(link: WithdrawLink, req: Request) -> Lnurl:
    if link.is_unique:
        usescssv = link.usescsv.split(",")
        tohash = link.id + link.unique_hash + usescssv[link.number]
        multihash = uuid(name=tohash)
        url = req.url_for(
            "withdraw.api_lnurl_multi_response",
            unique_hash=link.unique_hash,
            id_unique_hash=multihash,
        )
    else:
        url = req.url_for("withdraw.api_lnurl_response", unique_hash=link.unique_hash)

    try:
        return lnurl_encode(str(url))
    except Exception as e:
        raise ValueError(
            f"Error creating LNURL with url: `{url!s}`, "
            "check your webserver proxy configuration."
        ) from e


async def min_max_withdrawable(link: WithdrawLink) -> tuple[int, int]:
    min_withdrawable = link.min_withdrawable
    max_withdrawable = link.max_withdrawable

    if link.currency:
        rate = await get_fiat_rate_satoshis(link.currency)
        min_withdrawable = round(min_withdrawable / 100 * rate)
        max_withdrawable = round(max_withdrawable / 100 * rate)

    return min_withdrawable, max_withdrawable