blink.py

import asyncio
import hashlib
import json
from collections.abc import AsyncGenerator

import httpx
from loguru import logger
from pydantic import BaseModel
from websockets import Subprotocol, connect

from lnbits import bolt11 as bolt11_lib
from lnbits.helpers import normalize_endpoint
from lnbits.settings import settings

from .base import (
    InvoiceResponse,
    PaymentResponse,
    PaymentStatus,
    StatusResponse,
    Wallet,
)


class BlinkWallet(Wallet):
    """https://dev.blink.sv/"""

    def __init__(self):
        if not settings.blink_api_endpoint:
            raise ValueError(
                "cannot initialize BlinkWallet: missing blink_api_endpoint"
            )
        if not settings.blink_ws_endpoint:
            raise ValueError("cannot initialize BlinkWallet: missing blink_ws_endpoint")
        if not settings.blink_token:
            raise ValueError("cannot initialize BlinkWallet: missing blink_token")

        self.endpoint = normalize_endpoint(settings.blink_api_endpoint)

        self.auth = {
            "X-API-KEY": settings.blink_token,
            "User-Agent": settings.user_agent,
        }
        self.ws_endpoint = normalize_endpoint(settings.blink_ws_endpoint)
        self.ws_auth = {
            "type": "connection_init",
            "payload": {"X-API-KEY": settings.blink_token},
        }
        self.client = httpx.AsyncClient(base_url=self.endpoint, headers=self.auth)
        self.ws = None
        self._wallet_id = None

    @property
    def wallet_id(self):
        if self._wallet_id:
            return self._wallet_id
        raise ValueError("Wallet id not initialized.")

    async def cleanup(self):
        try:
            await self.client.aclose()
        except RuntimeError as e:
            logger.warning(f"Error closing wallet connection: {e}")

        try:
            if self.ws:
                await self.ws.close(reason="Shutting down.")
        except RuntimeError as e:
            logger.warning(f"Error closing websocket connection: {e}")

    async def status(self) -> StatusResponse:
        try:
            await self._init_wallet_id()

            payload = {"query": q.balance_query, "variables": {}}
            response = await self._graphql_query(payload)
            wallets = (
                response.get("data", {})
                .get("me", {})
                .get("defaultAccount", {})
                .get("wallets", [])
            )
            btc_balance = next(
                (
                    wallet["balance"]
                    for wallet in wallets
                    if wallet["walletCurrency"] == "BTC"
                ),
                None,
            )
            if btc_balance is None:
                return StatusResponse("No BTC balance", 0)

            # multiply balance by 1000 to get msats balance
            return StatusResponse(None, btc_balance * 1000)
        except ValueError as exc:
            return StatusResponse(str(exc), 0)
        except Exception as exc:
            logger.warning(exc)
            return StatusResponse(f"Unable to connect, got: '{exc}'", 0)

    async def create_invoice(
        self,
        amount: int,
        memo: str | None = None,
        description_hash: bytes | None = None,
        unhashed_description: bytes | None = None,
        **kwargs,
    ) -> InvoiceResponse:
        # https://dev.blink.sv/api/btc-ln-receive

        invoice_variables = {
            "input": {
                "amount": amount,
                "recipientWalletId": self.wallet_id,
            }
        }
        if description_hash:
            invoice_variables["input"]["descriptionHash"] = description_hash.hex()
        elif unhashed_description:
            invoice_variables["input"]["descriptionHash"] = hashlib.sha256(
                unhashed_description
            ).hexdigest()
        else:
            invoice_variables["input"]["memo"] = memo or ""

        data = {"query": q.invoice_query, "variables": invoice_variables}

        try:
            response = await self._graphql_query(data)

            errors = (
                response.get("data", {})
                .get("lnInvoiceCreateOnBehalfOfRecipient", {})
                .get("errors", {})
            )
            if len(errors) > 0:
                error_message = errors[0].get("message")
                return InvoiceResponse(ok=False, error_message=error_message)

            payment_request = (
                response.get("data", {})
                .get("lnInvoiceCreateOnBehalfOfRecipient", {})
                .get("invoice", {})
                .get("paymentRequest", None)
            )
            checking_id = (
                response.get("data", {})
                .get("lnInvoiceCreateOnBehalfOfRecipient", {})
                .get("invoice", {})
                .get("paymentHash", None)
            )

            # TODO: add preimage to response
            return InvoiceResponse(
                ok=True, checking_id=checking_id, payment_request=payment_request
            )
        except json.JSONDecodeError:
            return InvoiceResponse(
                ok=False, error_message="Server error: 'invalid json response'"
            )
        except Exception as exc:
            logger.warning(exc)
            return InvoiceResponse(
                ok=False, error_message=f"Unable to connect to {self.endpoint}."
            )

    async def pay_invoice(self, bolt11: str, fee_limit_msat: int) -> PaymentResponse:
        # https://dev.blink.sv/api/btc-ln-send
        # Future: add check fee estimate is < fee_limit_msat before paying invoice

        payment_variables = {
            "input": {
                "paymentRequest": bolt11,
                "walletId": self.wallet_id,
                "memo": "Payment memo",
            }
        }
        data = {"query": q.payment_query, "variables": payment_variables}
        try:
            response = await self._graphql_query(data)

            errors = (
                response.get("data", {})
                .get("lnInvoicePaymentSend", {})
                .get("errors", {})
            )
            if len(errors) > 0:
                error_message = errors[0].get("message")
                return PaymentResponse(ok=False, error_message=error_message)

            checking_id = bolt11_lib.decode(bolt11).payment_hash

            payment_status = await self.get_payment_status(checking_id)
            fee_msat = payment_status.fee_msat
            preimage = payment_status.preimage
            return PaymentResponse(
                ok=True, checking_id=checking_id, fee_msat=fee_msat, preimage=preimage
            )
        except Exception as exc:
            logger.info(f"Failed to pay invoice {bolt11}")
            logger.warning(exc)
            return PaymentResponse(
                error_message=f"Unable to connect to {self.endpoint}."
            )

    async def get_invoice_status(self, checking_id: str) -> PaymentStatus:

        statuses = {
            "EXPIRED": False,
            "PENDING": None,
            "PAID": True,
        }

        variables = {"paymentHash": checking_id, "walletId": self.wallet_id}
        data = {"query": q.status_query, "variables": variables}

        try:
            response = await self._graphql_query(data)
            if response.get("errors") is not None:
                logger.trace(response.get("errors"))
                return PaymentStatus(None)

            status = response["data"]["me"]["defaultAccount"]["walletById"][
                "invoiceByPaymentHash"
            ]["paymentStatus"]
            return PaymentStatus(statuses[status])
        except Exception as e:
            logger.warning(f"Error getting invoice status: {e}")
            return PaymentStatus(None)

    async def get_payment_status(self, checking_id: str) -> PaymentStatus:

        variables = {
            "walletId": self.wallet_id,
            "transactionsByPaymentHash": checking_id,
        }
        data = {"query": q.tx_query, "variables": variables}

        statuses = {
            "FAILURE": False,
            "EXPIRED": False,
            "PENDING": None,
            "PAID": True,
            "SUCCESS": True,
        }

        try:
            response = await self._graphql_query(data)

            response_data = response.get("data")
            if response_data is None:
                raise ValueError("No data found in response.")
            txs_data = (
                response_data.get("me", {})
                .get("defaultAccount", {})
                .get("walletById", {})
                .get("transactionsByPaymentHash", [])
            )
            tx_data = next((t for t in txs_data if t.get("direction") == "SEND"), None)
            if not tx_data:
                raise ValueError("No SEND data found.")
            fee = tx_data.get("settlementFee")
            preimage = tx_data.get("settlementVia", {}).get("preImage")
            status = tx_data.get("status")

            return PaymentStatus(
                paid=statuses[status], fee_msat=fee * 1000, preimage=preimage
            )
        except Exception as e:
            logger.error(f"Error getting payment status: {e}")
            return PaymentStatus(None)

    async def paid_invoices_stream(self) -> AsyncGenerator[str, None]:
        subscription_id = "blink_payment_stream"
        while settings.lnbits_running:
            try:
                async with connect(
                    self.ws_endpoint, subprotocols=[Subprotocol("graphql-transport-ws")]
                ) as ws:
                    logger.info("Connected to blink invoices stream.")
                    self.ws = ws
                    await ws.send(json.dumps(self.ws_auth))
                    confirmation = await ws.recv()
                    ack = json.loads(confirmation)
                    if ack.get("type") != "connection_ack":
                        raise ValueError("Websocket connection not acknowledged.")

                    logger.info("Websocket connection acknowledged.")
                    subscription_req = {
                        "id": subscription_id,
                        "type": "subscribe",
                        "payload": {"query": q.my_updates_query, "variables": {}},
                    }
                    await ws.send(json.dumps(subscription_req))

                    while settings.lnbits_running:
                        message = await ws.recv()
                        resp = json.loads(message)
                        if resp.get("id") != subscription_id:
                            continue
                        tx = (
                            resp.get("payload", {})
                            .get("data", {})
                            .get("myUpdates", {})
                            .get("update", {})
                            .get("transaction", {})
                        )
                        if tx.get("direction") != "RECEIVE":
                            continue

                        if not tx.get("initiationVia"):
                            continue

                        payment_hash = tx.get("initiationVia").get("paymentHash")
                        if payment_hash:
                            yield payment_hash

            except Exception as exc:
                logger.error(
                    f"lost connection to blink invoices stream: '{exc}'"
                    "retrying in 5 seconds"
                )
                await asyncio.sleep(5)

    async def _graphql_query(self, payload) -> dict:
        response = await self.client.post(self.endpoint, json=payload, timeout=10)
        response.raise_for_status()
        return response.json()

    async def _init_wallet_id(self) -> str:
        """
        Get the defaultAccount wallet id, required for payments.
        """

        if self._wallet_id:
            return self._wallet_id

        try:
            payload = {
                "query": q.wallet_query,
                "variables": {},
            }
            response = await self._graphql_query(payload)
            wallets = (
                response.get("data", {})
                .get("me", {})
                .get("defaultAccount", {})
                .get("wallets", [])
            )
            btc_wallet_ids = [
                wallet["id"] for wallet in wallets if wallet["walletCurrency"] == "BTC"
            ]

            if not btc_wallet_ids:
                raise ValueError("BTC Wallet not found")

            self._wallet_id = btc_wallet_ids[0]
            return self._wallet_id
        except Exception as exc:
            logger.warning(exc)
            raise ValueError(f"Unable to connect to '{self.endpoint}'") from exc


class BlinkGrafqlQueries(BaseModel):
    balance_query: str
    invoice_query: str
    payment_query: str
    status_query: str
    wallet_query: str
    tx_query: str
    my_updates_query: str


q = BlinkGrafqlQueries(
    balance_query="""
        query Me {
          me {
            defaultAccount {
              wallets {
                walletCurrency
                balance
              }
            }
          }
        }
        """,
    invoice_query="""
        mutation LnInvoiceCreateOnBehalfOfRecipient(
          $input: LnInvoiceCreateOnBehalfOfRecipientInput!
        ) {
          lnInvoiceCreateOnBehalfOfRecipient(input: $input) {
            invoice {
              paymentRequest
              paymentHash
              paymentSecret
              satoshis
            }
            errors {
              message
            }
          }
        }
        """,
    payment_query="""
        mutation LnInvoicePaymentSend($input: LnInvoicePaymentInput!) {
          lnInvoicePaymentSend(input: $input) {
            status
            errors {
              message
              path
              code
            }
          }
        }
        """,
    status_query="""
        query InvoiceByPaymentHash($walletId: WalletId!, $paymentHash: PaymentHash!) {
          me {
            defaultAccount {
              walletById(walletId: $walletId) {
                invoiceByPaymentHash(paymentHash: $paymentHash) {
                  ... on LnInvoice {
                    paymentStatus
                  }
                }
              }
            }
          }
        }
        """,
    wallet_query="""
        query me {
          me {
            defaultAccount {
              wallets {
                id
                walletCurrency
              }
            }
          }
        }
        """,
    tx_query="""
        query TransactionsByPaymentHash(
          $walletId: WalletId!
          $transactionsByPaymentHash: PaymentHash!
        ) {
          me {
            defaultAccount {
              walletById(walletId: $walletId) {
                walletCurrency
                ... on BTCWallet {
                  transactionsByPaymentHash(paymentHash: $transactionsByPaymentHash) {
                    settlementFee
                    status
                    direction
                    settlementVia {
                      ... on SettlementViaLn {
                        preImage
                      }
                    }
                  }
                }
              }
            }
          }
        }
        """,
    my_updates_query="""
        subscription {
          myUpdates {
            update {
              ... on LnUpdate {
                transaction {
                  initiationVia {
                    ... on InitiationViaLn {
                      paymentHash
                    }
                  }
                  direction
                }
              }
            }
          }
        }
        """,
)