feat: add withdraw execute to core and cli (#31)

also adds bolt11 library for decoding for checking amount the amount of
the invoice

lnurl/core.py

@@ -1,12 +1,14 @@
 from typing import Any, Optional, Union
 
 import requests
+from bolt11 import Bolt11Exception, MilliSatoshi
+from bolt11 import decode as bolt11_decode
 from pydantic import ValidationError
 
 from .exceptions import InvalidLnurl, InvalidUrl, LnurlResponseException
 from .helpers import lnurlauth_signature, url_encode
-from .models import LnurlAuthResponse, LnurlPayResponse, LnurlResponse, LnurlResponseModel
-from .types import ClearnetUrl, DebugUrl, LnAddress, Lnurl, MilliSatoshi, OnionUrl
+from .models import LnurlAuthResponse, LnurlPayResponse, LnurlResponse, LnurlResponseModel, LnurlWithdrawResponse
+from .types import ClearnetUrl, DebugUrl, LnAddress, Lnurl, OnionUrl
 
 
 def decode(bech32_lnurl: str) -> Union[OnionUrl, ClearnetUrl, DebugUrl]:
@@ -66,13 +68,14 @@ def execute(bech32_or_address: str, value: str) -> LnurlResponseModel:
         return execute_pay_request(res, value)
     elif isinstance(res, LnurlAuthResponse) and res.tag == "login":
         return execute_login(res, value)
+    elif isinstance(res, LnurlWithdrawResponse) and res.tag == "withdrawRequest":
+        return execute_withdraw(res, value)
 
     raise LnurlResponseException(f"{res.tag} not implemented")  # type: ignore
 
 
 def execute_pay_request(res: LnurlPayResponse, msat: str) -> LnurlResponseModel:
-    print(res)
-    if res.min_sendable > MilliSatoshi(msat) > res.max_sendable:
+    if not res.min_sendable <= MilliSatoshi(msat) <= res.max_sendable:
         raise LnurlResponseException(f"Amount {msat} not in range {res.min_sendable} - {res.max_sendable}")
     try:
         req = requests.get(
@@ -102,3 +105,26 @@ def execute_login(res: LnurlAuthResponse, secret: str) -> LnurlResponseModel:
         return LnurlResponse.from_dict(req.json())
     except Exception as e:
         raise LnurlResponseException(str(e))
+
+
+def execute_withdraw(res: LnurlWithdrawResponse, pr: str) -> LnurlResponseModel:
+    try:
+        invoice = bolt11_decode(pr)
+    except Bolt11Exception as exc:
+        raise LnurlResponseException(str(exc))
+    # if invoice does not have amount use the min withdrawable amount
+    amount = invoice.amount_msat or res.min_withdrawable
+    if not res.min_withdrawable <= MilliSatoshi(amount) <= res.max_withdrawable:
+        raise LnurlResponseException(f"Amount {amount} not in range {res.min_withdrawable} - {res.max_withdrawable}")
+    try:
+        req = requests.get(
+            res.callback,
+            params={
+                "k1": res.k1,
+                "pr": pr,
+            },
+        )
+        req.raise_for_status()
+        return LnurlResponse.from_dict(req.json())
+    except Exception as exc:
+        raise LnurlResponseException(str(exc))

lnurl/models.py

@@ -1,6 +1,7 @@
 import math
 from typing import List, Literal, Optional, Union
 
+from bolt11 import MilliSatoshi
 from pydantic import BaseModel, Field, validator
 
 from .exceptions import LnurlResponseException
@@ -12,7 +13,6 @@
     LightningNodeUri,
     LnurlPayMetadata,
     Max144Str,
-    MilliSatoshi,
     OnionUrl,
 )
 
@@ -102,8 +102,8 @@ class LnurlHostedChannelResponse(LnurlResponseModel):
 class LnurlPayResponse(LnurlResponseModel):
     tag: Literal["payRequest"] = "payRequest"
     callback: Union[ClearnetUrl, OnionUrl, DebugUrl]
-    min_sendable: MilliSatoshi = Field(..., alias="minSendable")
-    max_sendable: MilliSatoshi = Field(..., alias="maxSendable")
+    min_sendable: MilliSatoshi = Field(..., alias="minSendable", gt=0)
+    max_sendable: MilliSatoshi = Field(..., alias="maxSendable", gt=0)
     metadata: LnurlPayMetadata
 
     @validator("max_sendable")
@@ -144,8 +144,8 @@ class LnurlWithdrawResponse(LnurlResponseModel):
     tag: Literal["withdrawRequest"] = "withdrawRequest"
     callback: Union[ClearnetUrl, OnionUrl, DebugUrl]
     k1: str
-    min_withdrawable: MilliSatoshi = Field(..., alias="minWithdrawable")
-    max_withdrawable: MilliSatoshi = Field(..., alias="maxWithdrawable")
+    min_withdrawable: MilliSatoshi = Field(..., alias="minWithdrawable", gt=0)
+    max_withdrawable: MilliSatoshi = Field(..., alias="maxWithdrawable", gt=0)
     default_description: str = Field("", alias="defaultDescription")
 
     @validator("max_withdrawable")

lnurl/types.py

@@ -9,7 +9,6 @@
     ConstrainedStr,
     HttpUrl,
     Json,
-    PositiveInt,
     ValidationError,
     parse_obj_as,
     validator,
@@ -131,18 +130,6 @@ def validate_host(cls, parts: Parts) -> Tuple[str, Optional[str], str, bool]:
 class LightningInvoice(Bech32):
     """Bech32 Lightning invoice."""
 
-    @property
-    def amount(self) -> int:
-        raise NotImplementedError
-
-    @property
-    def prefix(self) -> str:
-        raise NotImplementedError
-
-    @property
-    def h(self):
-        raise NotImplementedError
-
 
 class LightningNodeUri(ReprMixin, str):
     """Remote node address of form `node_key@ip_address:port_number`."""
@@ -296,7 +283,3 @@ class InitializationVector(ConstrainedStr):
 
 class Max144Str(ConstrainedStr):
     max_length = 144
-
-
-class MilliSatoshi(PositiveInt):
-    """A thousandth of a satoshi."""