[FIX] NUT-15 mpp amount in millisats (#703)

* fix lndrest

* fix clnrest

* fix clnrest and lndrest

* lnd grpc fix

* wallet

* convert amount to millisats in CLI pay invoice

* fix tests

* format

* fix kw arg in regtest test

* fix payment quote validation check

* clean comment

* avoid overwriting variable

* deprecated response with amount

---------

Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>

cashu/lightning/clnrest.py

@@ -332,13 +332,9 @@ class CLNRestWallet(LightningBackend):
         invoice_obj = decode(melt_quote.request)
         assert invoice_obj.amount_msat, "invoice has no amount."
         assert invoice_obj.amount_msat > 0, "invoice has 0 amount."
-        amount_msat = invoice_obj.amount_msat
-        if melt_quote.is_mpp:
-            amount_msat = (
-                Amount(Unit[melt_quote.unit], melt_quote.mpp_amount)
-                .to(Unit.msat)
-                .amount
-            )
+        amount_msat =  melt_quote.mpp_amount if melt_quote.is_mpp else (
+            invoice_obj.amount_msat
+        )
         fees_msat = fee_reserve(amount_msat)
         fees = Amount(unit=Unit.msat, amount=fees_msat)
         amount = Amount(unit=Unit.msat, amount=amount_msat)

cashu/lightning/lnd_grpc/lnd_grpc.py

@@ -371,8 +371,8 @@ class LndRPCWallet(LightningBackend):
         self, melt_quote: PostMeltQuoteRequest
     ) -> PaymentQuoteResponse:
         # get amount from melt_quote or from bolt11
-        amount = (
-            Amount(Unit[melt_quote.unit], melt_quote.mpp_amount)
+        amount_msat = (
+            melt_quote.mpp_amount
             if melt_quote.is_mpp
             else None
         )
@@ -380,9 +380,7 @@ class LndRPCWallet(LightningBackend):
         invoice_obj = bolt11.decode(melt_quote.request)
         assert invoice_obj.amount_msat, "invoice has no amount."
 
-        if amount:
-            amount_msat = amount.to(Unit.msat).amount
-        else:
+        if amount_msat is None:
             amount_msat = int(invoice_obj.amount_msat)
 
         fees_msat = fee_reserve(amount_msat)

cashu/lightning/lndrest.py

@@ -394,19 +394,12 @@ class LndRestWallet(LightningBackend):
     async def get_payment_quote(
         self, melt_quote: PostMeltQuoteRequest
     ) -> PaymentQuoteResponse:
-        # get amount from melt_quote or from bolt11
-        amount = (
-            Amount(Unit[melt_quote.unit], melt_quote.mpp_amount)
-            if melt_quote.is_mpp
-            else None
-        )
+        amount_msat = melt_quote.mpp_amount if melt_quote.is_mpp else None
 
         invoice_obj = decode(melt_quote.request)
         assert invoice_obj.amount_msat, "invoice has no amount."
 
-        if amount:
-            amount_msat = amount.to(Unit.msat).amount
-        else:
+        if amount_msat is None:
             amount_msat = int(invoice_obj.amount_msat)
 
         fees_msat = fee_reserve(amount_msat)

cashu/mint/ledger.py

@@ -666,7 +666,7 @@ class Ledger(LedgerVerification, LedgerSpendingConditions, LedgerTasks, LedgerFe
         if not payment_quote.checking_id:
             raise Exception("quote has no checking id")
         # verify that payment quote amount is as expected
-        if melt_quote.is_mpp and melt_quote.mpp_amount != payment_quote.amount.amount:
+        if melt_quote.is_mpp and melt_quote.mpp_amount != payment_quote.amount.to(Unit.msat).amount:
             raise TransactionError("quote amount not as requested")
         # make sure the backend returned the amount with a correct unit
         if not payment_quote.amount.unit == unit:

cashu/wallet/cli/cli.py

@@ -263,7 +263,10 @@ async def pay(
     await wallet.load_mint()
     await print_balance(ctx)
     payment_hash = bolt11.decode(invoice).payment_hash
-    quote = await wallet.melt_quote(invoice, amount)
+    if amount:
+        # we assume `amount` to be in sats
+        amount_mpp_msat = amount * 1000
+    quote = await wallet.melt_quote(invoice, amount_mpp_msat)
     logger.debug(f"Quote: {quote}")
     total_amount = quote.amount + quote.fee_reserve
     # estimate ecash fee for the coinselected proofs

cashu/wallet/v1_api.py

@@ -434,16 +434,17 @@ class LedgerAPI(LedgerAPIDeprecated, SupportsAuth):
     @async_set_httpx_client
     @async_ensure_mint_loaded
     async def melt_quote(
-        self, payment_request: str, unit: Unit, amount: Optional[int] = None
+        self, payment_request: str, unit: Unit, amount_msat: 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:
+        if amount_msat:
             melt_options = PostMeltRequestOptions(
-                mpp=PostMeltRequestOptionMpp(amount=amount)
+                mpp=PostMeltRequestOptionMpp(amount=amount_msat)
             )
 
         payload = PostMeltQuoteRequest(
@@ -462,9 +463,12 @@ class LedgerAPI(LedgerAPIDeprecated, SupportsAuth):
                 payment_request
             )
             quote_id = f"deprecated_{uuid.uuid4()}"
+            amount_sat = (
+                amount_msat // 1000 if amount_msat else invoice_obj.amount_msat // 1000
+            )
             return PostMeltQuoteResponse(
                 quote=quote_id,
-                amount=amount or invoice_obj.amount_msat // 1000,
+                amount=amount_sat,
                 fee_reserve=ret.fee or 0,
                 paid=False,
                 state=MeltQuoteState.unpaid.value,

cashu/wallet/wallet.py

@@ -701,14 +701,14 @@ class Wallet(
         return keep_proofs, send_proofs
 
     async def melt_quote(
-        self, invoice: str, amount: Optional[int] = None
+        self, invoice: str, amount_msat: Optional[int] = None
     ) -> PostMeltQuoteResponse:
         """
         Fetches a melt quote from the mint and either uses the amount in the invoice or the amount provided.
         """
-        if amount and not self.mint_info.supports_mpp("bolt11", self.unit):
+        if amount_msat and not self.mint_info.supports_mpp("bolt11", self.unit):
             raise Exception("Mint does not support MPP, cannot specify amount.")
-        melt_quote_resp = await super().melt_quote(invoice, self.unit, amount)
+        melt_quote_resp = await super().melt_quote(invoice, self.unit, amount_msat)
         logger.debug(
             f"Mint wants {self.unit.str(melt_quote_resp.fee_reserve)} as fee reserve."
         )

tests/test_wallet_regtest_mpp.py

@@ -52,7 +52,7 @@ async def test_regtest_pay_mpp(wallet: Wallet, ledger: Ledger):
 
     async def _mint_pay_mpp(invoice: str, amount: int, proofs: List[Proof]):
         # wallet pays 32 sat of the invoice
-        quote = await wallet.melt_quote(invoice, amount=amount)
+        quote = await wallet.melt_quote(invoice, amount_msat=amount*1000)
         assert quote.amount == amount
         await wallet.melt(
             proofs,
@@ -118,7 +118,7 @@ async def test_regtest_pay_mpp_incomplete_payment(wallet: Wallet, ledger: Ledger
     async def pay_mpp(amount: int, proofs: List[Proof], delay: float = 0.0):
         await asyncio.sleep(delay)
         # wallet pays 32 sat of the invoice
-        quote = await wallet.melt_quote(invoice_payment_request, amount=amount)
+        quote = await wallet.melt_quote(invoice_payment_request, amount_msat=amount*1000)
         assert quote.amount == amount
         await wallet.melt(
             proofs,
@@ -154,5 +154,5 @@ async def test_regtest_internal_mpp_melt_quotes(wallet: Wallet, ledger: Ledger):
 
     # try and create a multi-part melt quote
     await assert_err(
-        wallet.melt_quote(mint_quote.request, 100), "internal mpp not allowed"
+        wallet.melt_quote(mint_quote.request, 100*1000), "internal mpp not allowed"
     )