feat: add support for lud-14 (#54)

Author: dni

README.md

@@ -30,7 +30,7 @@ Check out the LUDS repository: [luds](https://github.com/lnurl/luds/)
 - [x] LUD-11
 - [x] LUD-12
 - [ ] LUD-13
-- [ ] LUD-14
+- [x] LUD-14
 - [ ] LUD-15
 - [x] LUD-16
 - [ ] LUD-17

lnurl/models.py

@@ -14,6 +14,8 @@
     InitializationVectorBase64,
     LightningInvoice,
     LightningNodeUri,
+    LnAddress,
+    Lnurl,
     LnurlPayMetadata,
     Max144Str,
     OnionUrl,
@@ -159,8 +161,11 @@ class LnurlWithdrawResponse(LnurlResponseModel):
     min_withdrawable: MilliSatoshi = Field(..., alias="minWithdrawable", gt=0)
     max_withdrawable: MilliSatoshi = Field(..., alias="maxWithdrawable", gt=0)
     default_description: str = Field("", alias="defaultDescription")
+    # LUD-14: balanceCheck: reusable withdrawRequests
+    balance_check: Optional[Union[ClearnetUrl, OnionUrl, DebugUrl]] = Field(None, alias="balanceCheck")
+    current_balance: Optional[MilliSatoshi] = Field(None, alias="currentBalance")
     # LUD-19: Pay link discoverable from withdraw link.
-    pay_link: Optional[str] = Field(None, alias="payLink")
+    pay_link: Optional[Union[LnAddress, Lnurl]] = Field(None, alias="payLink")
 
     @validator("max_withdrawable")
     def max_less_than_min(cls, value, values):