Add service fee to specific wallet (#2050)

* add service fee to specific wallet

* add to .env.example

* Added service fee wallet to manage server

* cleaned

* prettier

* Added badge for service fee

* Added tooltip

* Added service fee max

* allow ignoring service fee for internal transactions

* add fee_reserve_total helper funciton that includes service_fee

* html for admin ui

* typo

* Update .env.example

Co-authored-by: Pavol Rusnak <pavol@rusnak.io>

* fix .env.template comment

* bundle

* WIP: expose fee reserve endpoint

---------

Co-authored-by: Arc <ben@arc.wales>
Co-authored-by: dni ⚡ <office@dnilabs.com>
Co-authored-by: Pavol Rusnak <pavol@rusnak.io>

lnbits/core/views/api.py

@@ -104,6 +104,7 @@ from ..services import (
     PaymentFailure,
     check_transaction_status,
     create_invoice,
+    fee_reserve_total,
     pay_invoice,
     perform_lnurlauth,
     websocketManager,
@@ -386,6 +387,21 @@ async def api_payments_create(
         )
 
 
+@api_router.get("/api/v1/payments/fee-reserve")
+async def api_payments_fee_reserve(invoice: str = Query("invoice")) -> JSONResponse:
+    invoice_obj = bolt11.decode(invoice)
+    if invoice_obj.amount_msat:
+        response = {
+            "fee_reserve": fee_reserve_total(invoice_obj.amount_msat),
+        }
+        return JSONResponse(response)
+    else:
+        raise HTTPException(
+            status_code=HTTPStatus.BAD_REQUEST,
+            detail="Invoice has no amount.",
+        )
+
+
 @api_router.post("/api/v1/payments/lnurl")
 async def api_payments_pay_lnurl(
     data: CreateLnurl, wallet: WalletTypeInfo = Depends(require_admin_key)