cleanup coinselect function, estimate fees

cashu/wallet/cli/cli.py

@@ -203,10 +203,8 @@ async def pay(
     quote = await wallet.melt_quote(invoice, amount)
     logger.debug(f"Quote: {quote}")
     total_amount = quote.amount + quote.fee_reserve
-    # we need to include fees so we can use the proofs for melting the `total_amount`
-    send_proofs, ecash_fees = await wallet.select_to_send(
-        wallet.proofs, total_amount, include_fees=True, set_reserved=True
-    )
+    # estimate ecash fee for the coinselected proofs
+    ecash_fees = wallet.coinselect_fee(wallet.proofs, total_amount)
     if not yes:
         potential = (
             f" ({wallet.unit.str(total_amount + ecash_fees)} with potential fees)"
@@ -219,7 +217,10 @@ async def pay(
             abort=True,
             default=True,
         )
-
+    # we need to include fees so we can use the proofs for melting the `total_amount`
+    send_proofs, _ = await wallet.select_to_send(
+        wallet.proofs, total_amount, include_fees=True, set_reserved=True
+    )
     print("Paying Lightning invoice ...", end="", flush=True)
     assert total_amount > 0, "amount is not positive"
     if wallet.available_balance < total_amount:

cashu/wallet/transactions.py

@@ -36,7 +36,7 @@ def get_fees_for_proofs(self, proofs: List[Proof]) -> int:
     def get_fees_for_proofs_ppk(self, proofs: List[Proof]) -> int:
         return sum([self.keysets[p.id].input_fee_ppk for p in proofs])
 
-    async def coinselect(
+    def coinselect(
         self,
         proofs: List[Proof],
         amount_to_send: Union[int, float],
@@ -91,7 +91,7 @@ async def coinselect(
             logger.trace(
                 f"> selecting more proofs from {amount_summary(smaller_proofs[1:], self.unit)} sum: {sum_proofs(smaller_proofs[1:])} to reach {remainder}"
             )
-            selected_proofs += await self.coinselect(
+            selected_proofs += self.coinselect(
                 smaller_proofs[1:], remainder, include_fees=include_fees
             )
         sum_selected_proofs = sum_proofs(selected_proofs)
@@ -105,6 +105,10 @@ async def coinselect(
         )
         return selected_proofs
 
+    def coinselect_fee(self, proofs: List[Proof], amount: int) -> int:
+        proofs_send = self.coinselect(proofs, amount, include_fees=True)
+        return self.get_fees_for_proofs(proofs_send)
+
     async def set_reserved(self, proofs: List[Proof], reserved: bool) -> None:
         """Mark a proof as reserved or reset it in the wallet db to avoid reuse when it is sent.
 

cashu/wallet/wallet.py

@@ -1078,7 +1078,7 @@ async def select_to_send(
             raise Exception("balance too low.")
 
         # coin selection for potentially offline sending
-        send_proofs = await self.coinselect(proofs, amount, include_fees=include_fees)
+        send_proofs = self.coinselect(proofs, amount, include_fees=include_fees)
         fees = self.get_fees_for_proofs(send_proofs)
         logger.trace(
             f"select_to_send: selected: {self.unit.str(sum_proofs(send_proofs))} (+ {self.unit.str(fees)} fees) – wanted: {self.unit.str(amount)}"
@@ -1136,7 +1136,7 @@ async def swap_to_send(
             raise Exception("balance too low.")
 
         # coin selection for swapping, needs to include fees
-        swap_proofs = await self.coinselect(proofs, amount, include_fees=True)
+        swap_proofs = self.coinselect(proofs, amount, include_fees=True)
 
         # Extra rule: add proofs from inactive keysets to swap_proofs to get rid of them
         swap_proofs += [