nutshell/cashu/wallet/v1_api.py

import json
import uuid
from posixpath import join
from typing import List, Optional, Tuple, Union

import bolt11
import httpx
from httpx import Response
from loguru import logger

from ..core.base import (
    BlindedMessage,
    BlindedSignature,
    MeltQuoteState,
    Proof,
    ProofSpentState,
    ProofState,
    Unit,
    WalletKeyset,
)
from ..core.crypto.secp import PublicKey
from ..core.db import Database
from ..core.models import (
    CheckFeesResponse_deprecated,
    GetInfoResponse,
    KeysetsResponse,
    KeysetsResponseKeyset,
    KeysResponse,
    PostCheckStateRequest,
    PostCheckStateResponse,
    PostMeltQuoteRequest,
    PostMeltQuoteResponse,
    PostMeltRequest,
    PostMeltRequestOptionMpp,
    PostMeltRequestOptions,
    PostMeltResponse_deprecated,
    PostMintQuoteRequest,
    PostMintQuoteResponse,
    PostMintRequest,
    PostMintResponse,
    PostRestoreResponse,
    PostSplitRequest,
    PostSplitResponse,
)
from ..core.settings import settings
from ..tor.tor import TorProxy
from .crud import (
    get_lightning_invoice,
)
from .wallet_deprecated import LedgerAPIDeprecated


def async_set_httpx_client(func):
    """
    Decorator that wraps around any async class method of LedgerAPI that makes
    API calls. Sets some HTTP headers and starts a Tor instance if none is
    already running and and sets local proxy to use it.
    """

    async def wrapper(self, *args, **kwargs):
        # set proxy
        proxies_dict = {}
        proxy_url: Union[str, None] = None
        if settings.tor and TorProxy().check_platform():
            self.tor = TorProxy(timeout=True)
            self.tor.run_daemon(verbose=True)
            proxy_url = "socks5://localhost:9050"
        elif settings.socks_proxy:
            proxy_url = f"socks5://{settings.socks_proxy}"
        elif settings.http_proxy:
            proxy_url = settings.http_proxy
        if proxy_url:
            proxies_dict.update({"all://": proxy_url})

        headers_dict = {"Client-version": settings.version}

        self.httpx = httpx.AsyncClient(
            verify=not settings.debug,
            proxies=proxies_dict,  # type: ignore
            headers=headers_dict,
            base_url=self.url,
            timeout=None if settings.debug else 60,
        )
        return await func(self, *args, **kwargs)

    return wrapper


def async_ensure_mint_loaded(func):
    """Decorator that ensures that the mint is loaded before calling the wrapped
    function. If the mint is not loaded, it will be loaded first.
    """

    async def wrapper(self, *args, **kwargs):
        if not self.keysets:
            await self.load_mint()
        return await func(self, *args, **kwargs)

    return wrapper


class LedgerAPI(LedgerAPIDeprecated, object):
    tor: TorProxy
    db: Database  # we need the db for melt_deprecated
    httpx: httpx.AsyncClient

    def __init__(self, url: str, db: Database):
        self.url = url
        self.db = db

    @async_set_httpx_client
    async def _init_s(self):
        """Dummy function that can be called from outside to use LedgerAPI.s"""
        return

    @staticmethod
    def raise_on_error_request(
        resp: Response,
    ) -> None:
        """Raises an exception if the response from the mint contains an error.

        Args:
            resp_dict (Response): Response dict (previously JSON) from mint

        Raises:
            Exception: if the response contains an error
        """
        try:
            resp_dict = resp.json()
        except json.JSONDecodeError:
            # if we can't decode the response, raise for status
            resp.raise_for_status()
            return
        if "detail" in resp_dict:
            logger.trace(f"Error from mint: {resp_dict}")
            error_message = f"Mint Error: {resp_dict['detail']}"
            if "code" in resp_dict:
                error_message += f" (Code: {resp_dict['code']})"
            raise Exception(error_message)
        # raise for status if no error
        resp.raise_for_status()

    """
    ENDPOINTS
    """

    @async_set_httpx_client
    async def _get_keys(self) -> List[WalletKeyset]:
        """API that gets the current keys of the mint

        Args:
            url (str): Mint URL

        Returns:
            WalletKeyset: Current mint keyset

        Raises:
            Exception: If no keys are received from the mint
        """
        resp = await self.httpx.get(
            join(self.url, "/v1/keys"),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self._get_keys_deprecated(self.url)
            return [ret]
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        keys_dict: dict = resp.json()
        assert len(keys_dict), Exception("did not receive any keys")
        keys = KeysResponse.parse_obj(keys_dict)
        logger.debug(
            f"Received {len(keys.keysets)} keysets from mint:"
            f" {' '.join([k.id + f' ({k.unit})' for k in keys.keysets])}."
        )
        ret = [
            WalletKeyset(
                id=keyset.id,
                unit=keyset.unit,
                public_keys={
                    int(amt): PublicKey(bytes.fromhex(val), raw=True)
                    for amt, val in keyset.keys.items()
                },
                mint_url=self.url,
            )
            for keyset in keys.keysets
        ]
        return ret

    @async_set_httpx_client
    async def _get_keyset(self, keyset_id: str) -> WalletKeyset:
        """API that gets the keys of a specific keyset from the mint.


        Args:
            keyset_id (str): base64 keyset ID, needs to be urlsafe-encoded before sending to mint (done in this method)

        Returns:
            WalletKeyset: Keyset with ID keyset_id

        Raises:
            Exception: If no keys are received from the mint
        """
        keyset_id_urlsafe = keyset_id.replace("+", "-").replace("/", "_")
        resp = await self.httpx.get(
            join(self.url, f"/v1/keys/{keyset_id_urlsafe}"),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self._get_keyset_deprecated(self.url, keyset_id)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)

        keys_dict = resp.json()
        assert len(keys_dict), Exception("did not receive any keys")
        keys = KeysResponse.parse_obj(keys_dict)
        this_keyset = keys.keysets[0]
        keyset_keys = {
            int(amt): PublicKey(bytes.fromhex(val), raw=True)
            for amt, val in this_keyset.keys.items()
        }
        keyset = WalletKeyset(
            id=keyset_id,
            unit=this_keyset.unit,
            public_keys=keyset_keys,
            mint_url=self.url,
        )
        return keyset

    @async_set_httpx_client
    async def _get_keysets(self) -> List[KeysetsResponseKeyset]:
        """API that gets a list of all active keysets of the mint.

        Returns:
            KeysetsResponse (List[str]): List of all active keyset IDs of the mint

        Raises:
            Exception: If no keysets are received from the mint
        """
        resp = await self.httpx.get(
            join(self.url, "/v1/keysets"),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self._get_keysets_deprecated(self.url)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)

        keysets_dict = resp.json()
        keysets = KeysetsResponse.parse_obj(keysets_dict).keysets
        if not keysets:
            raise Exception("did not receive any keysets")
        return keysets

    @async_set_httpx_client
    async def _get_info(self) -> GetInfoResponse:
        """API that gets the mint info.

        Returns:
            GetInfoResponse: Current mint info

        Raises:
            Exception: If the mint info request fails
        """
        resp = await self.httpx.get(
            join(self.url, "/v1/info"),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self._get_info_deprecated()
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        data: dict = resp.json()
        mint_info: GetInfoResponse = GetInfoResponse.parse_obj(data)
        return mint_info

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def mint_quote(self, amount: int, unit: Unit) -> PostMintQuoteResponse:
        """Requests a mint quote from the server and returns a payment request.

        Args:
            amount (int): Amount of tokens to mint

        Returns:
            PostMintQuoteResponse: Mint Quote Response

        Raises:
            Exception: If the mint request fails
        """
        logger.trace("Requesting mint: GET /v1/mint/bolt11")
        payload = PostMintQuoteRequest(unit=unit.name, amount=amount)
        resp = await self.httpx.post(
            join(self.url, "/v1/mint/quote/bolt11"), json=payload.dict()
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self.request_mint_deprecated(amount)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        return_dict = resp.json()
        return PostMintQuoteResponse.parse_obj(return_dict)

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def mint(
        self, outputs: List[BlindedMessage], quote: str
    ) -> List[BlindedSignature]:
        """Mints new coins and returns a proof of promise.

        Args:
            outputs (List[BlindedMessage]): Outputs to mint new tokens with
            quote (str): Quote ID.

        Returns:
            list[Proof]: List of proofs.

        Raises:
            Exception: If the minting fails
        """
        outputs_payload = PostMintRequest(outputs=outputs, quote=quote)
        logger.trace("Checking Lightning invoice. POST /v1/mint/bolt11")

        def _mintrequest_include_fields(outputs: List[BlindedMessage]):
            """strips away fields from the model that aren't necessary for the /mint"""
            outputs_include = {"id", "amount", "B_"}
            return {
                "quote": ...,
                "outputs": {i: outputs_include for i in range(len(outputs))},
            }

        payload = outputs_payload.dict(include=_mintrequest_include_fields(outputs))  # type: ignore
        resp = await self.httpx.post(
            join(self.url, "/v1/mint/bolt11"),
            json=payload,  # type: ignore
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self.mint_deprecated(outputs, quote)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        response_dict = resp.json()
        logger.trace("Lightning invoice checked. POST /v1/mint/bolt11")
        promises = PostMintResponse.parse_obj(response_dict).signatures
        return promises

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def melt_quote(
        self, payment_request: str, unit: Unit, amount: Optional[int] = None
    ) -> PostMeltQuoteResponse:
        """Checks whether the Lightning payment is internal."""
        invoice_obj = bolt11.decode(payment_request)
        assert invoice_obj.amount_msat, "invoice must have amount"
        # add mpp amount for partial melts
        melt_options = None
        if amount:
            melt_options = PostMeltRequestOptions(
                mpp=PostMeltRequestOptionMpp(amount=amount)
            )

        payload = PostMeltQuoteRequest(
            unit=unit.name, request=payment_request, options=melt_options
        )

        resp = await self.httpx.post(
            join(self.url, "/v1/melt/quote/bolt11"),
            json=payload.dict(),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret: CheckFeesResponse_deprecated = await self.check_fees_deprecated(
                payment_request
            )
            quote_id = "deprecated_" + str(uuid.uuid4())
            return PostMeltQuoteResponse(
                quote=quote_id,
                amount=amount or invoice_obj.amount_msat // 1000,
                fee_reserve=ret.fee or 0,
                paid=False,
                state=MeltQuoteState.unpaid.value,
                expiry=invoice_obj.expiry,
            )
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        return_dict = resp.json()
        return PostMeltQuoteResponse.parse_obj(return_dict)

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def melt(
        self,
        quote: str,
        proofs: List[Proof],
        outputs: Optional[List[BlindedMessage]],
    ) -> PostMeltQuoteResponse:
        """
        Accepts proofs and a lightning invoice to pay in exchange.
        """

        payload = PostMeltRequest(quote=quote, inputs=proofs, outputs=outputs)

        def _meltrequest_include_fields(
            proofs: List[Proof], outputs: List[BlindedMessage]
        ):
            """strips away fields from the model that aren't necessary for the /melt"""
            proofs_include = {"id", "amount", "secret", "C", "witness"}
            outputs_include = {"id", "amount", "B_"}
            return {
                "quote": ...,
                "inputs": {i: proofs_include for i in range(len(proofs))},
                "outputs": {i: outputs_include for i in range(len(outputs))},
            }

        resp = await self.httpx.post(
            join(self.url, "/v1/melt/bolt11"),
            json=payload.dict(include=_meltrequest_include_fields(proofs, outputs)),  # type: ignore
            timeout=None,
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            invoice = await get_lightning_invoice(id=quote, db=self.db)
            assert invoice, f"no invoice found for id {quote}"
            ret: PostMeltResponse_deprecated = await self.melt_deprecated(
                proofs=proofs, outputs=outputs, invoice=invoice.bolt11
            )
            return PostMeltQuoteResponse(
                quote=quote,
                amount=0,
                fee_reserve=0,
                paid=ret.paid or False,
                state=(
                    MeltQuoteState.paid.value
                    if ret.paid
                    else MeltQuoteState.unpaid.value
                ),
                payment_preimage=ret.preimage,
                change=ret.change,
                expiry=None,
            )
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        return_dict = resp.json()
        return PostMeltQuoteResponse.parse_obj(return_dict)

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def split(
        self,
        proofs: List[Proof],
        outputs: List[BlindedMessage],
    ) -> List[BlindedSignature]:
        """Consume proofs and create new promises based on amount split."""
        logger.debug("Calling split. POST /v1/swap")
        split_payload = PostSplitRequest(inputs=proofs, outputs=outputs)

        # construct payload
        def _splitrequest_include_fields(proofs: List[Proof]):
            """strips away fields from the model that aren't necessary for /v1/swap"""
            proofs_include = {
                "id",
                "amount",
                "secret",
                "C",
                "witness",
            }
            return {
                "outputs": ...,
                "inputs": {i: proofs_include for i in range(len(proofs))},
            }

        resp = await self.httpx.post(
            join(self.url, "/v1/swap"),
            json=split_payload.dict(include=_splitrequest_include_fields(proofs)),  # type: ignore
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self.split_deprecated(proofs, outputs)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        promises_dict = resp.json()
        mint_response = PostSplitResponse.parse_obj(promises_dict)
        promises = [BlindedSignature(**p.dict()) for p in mint_response.signatures]

        if len(promises) == 0:
            raise Exception("received no splits.")

        return promises

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def check_proof_state(self, proofs: List[Proof]) -> PostCheckStateResponse:
        """
        Checks whether the secrets in proofs are already spent or not and returns a list of booleans.
        """
        payload = PostCheckStateRequest(Ys=[p.Y for p in proofs])
        resp = await self.httpx.post(
            join(self.url, "/v1/checkstate"),
            json=payload.dict(),
        )
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self.check_proof_state_deprecated(proofs)
            # convert CheckSpendableResponse_deprecated to CheckSpendableResponse
            states: List[ProofState] = []
            for spendable, pending, p in zip(ret.spendable, ret.pending, proofs):
                if spendable and not pending:
                    states.append(ProofState(Y=p.Y, state=ProofSpentState.unspent))
                elif spendable and pending:
                    states.append(ProofState(Y=p.Y, state=ProofSpentState.pending))
                else:
                    states.append(ProofState(Y=p.Y, state=ProofSpentState.spent))
            ret = PostCheckStateResponse(states=states)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        return PostCheckStateResponse.parse_obj(resp.json())

    @async_set_httpx_client
    @async_ensure_mint_loaded
    async def restore_promises(
        self, outputs: List[BlindedMessage]
    ) -> Tuple[List[BlindedMessage], List[BlindedSignature]]:
        """
        Asks the mint to restore promises corresponding to outputs.
        """
        payload = PostMintRequest(quote="restore", outputs=outputs)
        resp = await self.httpx.post(join(self.url, "/v1/restore"), json=payload.dict())
        # BEGIN backwards compatibility < 0.15.0
        # assume the mint has not upgraded yet if we get a 404
        if resp.status_code == 404:
            ret = await self.restore_promises_deprecated(outputs)
            return ret
        # END backwards compatibility < 0.15.0
        self.raise_on_error_request(resp)
        response_dict = resp.json()
        returnObj = PostRestoreResponse.parse_obj(response_dict)

        # BEGIN backwards compatibility < 0.15.1
        # if the mint returns promises, duplicate into signatures
        if returnObj.promises:
            returnObj.signatures = returnObj.promises
        # END backwards compatibility < 0.15.1

        return returnObj.outputs, returnObj.signatures