retrieve preimage from wallet backends, save it and show on UI dialog.

closes https://github.com/lnbits/lnbits/issues/77

lnbits/core/services.py

@@ -11,7 +11,7 @@ except ImportError:  # pragma: nocover
 from lnbits import bolt11
 from lnbits.helpers import urlsafe_short_hash
 from lnbits.settings import WALLET
-from lnbits.wallets.base import PaymentStatus
+from lnbits.wallets.base import PaymentStatus, PaymentResponse
 
 from .crud import get_wallet, create_payment, delete_payment, check_internal, update_payment_status, get_wallet_payment
 
@@ -110,12 +110,17 @@ def pay_invoice(
         update_payment_status(checking_id=internal, pending=False)
     else:
         # actually pay the external invoice
-        ok, checking_id, fee_msat, error_message = WALLET.pay_invoice(payment_request)
-        if ok:
-            create_payment(checking_id=checking_id, fee=fee_msat, **payment_kwargs)
+        payment: PaymentResponse = WALLET.pay_invoice(payment_request)
+        if payment.ok:
+            create_payment(
+                checking_id=payment.checking_id,
+                fee=payment.fee_msat,
+                preimage=payment.preimage,
+                **payment_kwargs,
+            )
             delete_payment(temp_id)
         else:
-            raise Exception(error_message or "Failed to pay_invoice on backend.")
+            raise Exception(payment.error_message or "Failed to pay_invoice on backend.")
 
     g.db.commit()
     return invoice.payment_hash

lnbits/static/js/components.js

@@ -199,6 +199,10 @@ Vue.component('lnbits-payment-details', {
         <div class="col-3"><b>Payment hash</b>:</div>
         <div class="col-9 text-wrap mono">{{ payment.payment_hash }}</div>
       </div>
+      <div class="row" v-if="payment.preimage">
+        <div class="col-3"><b>Payment proof</b>:</div>
+        <div class="col-9 text-wrap mono">{{ payment.preimage }}</div>
+      </div>
     </div>
   `
 })

lnbits/wallets/base.py

@@ -18,6 +18,7 @@ class PaymentResponse(NamedTuple):
     ok: bool
     checking_id: Optional[str] = None  # payment_hash, rcp_id
     fee_msat: int = 0
+    preimage: Optional[str] = None
     error_message: Optional[str] = None
 
 

lnbits/wallets/clightning.py

@@ -73,8 +73,14 @@ class CLightningWallet(Wallet):
             return InvoiceResponse(False, label, None, error_message)
 
     def pay_invoice(self, bolt11: str) -> PaymentResponse:
-        r = self.ln.pay(bolt11)
-        return PaymentResponse(True, r["payment_hash"], r["msatoshi_sent"] - r["msatoshi"], None)
+        try:
+            r = self.ln.pay(bolt11)
+        except RpcError as exc:
+            return PaymentResponse(False, None, 0, None, str(exc))
+
+        fee_msat = r["msatoshi_sent"] - r["msatoshi"]
+        preimage = r["payment_preimage"]
+        return PaymentResponse(True, r["payment_hash"], fee_msat, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         r = self.ln.listinvoices(checking_id)

lnbits/wallets/lndgrpc.py

@@ -135,11 +135,13 @@ class LndWallet(Wallet):
         resp = self.rpc.send_payment(payment_request=bolt11)
 
         if resp.payment_error:
-            return PaymentResponse(False, "", 0, resp.payment_error)
+            return PaymentResponse(False, "", 0, None, resp.payment_error)
 
         r_hash = hashlib.sha256(resp.payment_preimage).digest()
         checking_id = stringify_checking_id(r_hash)
-        return PaymentResponse(True, checking_id, 0, None)
+        fee_msat = resp.payment_route.total_fees_msat
+        preimage = resp.payment_preimage.hex()
+        return PaymentResponse(True, checking_id, fee_msat, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         try:

lnbits/wallets/lndrest.py

@@ -94,12 +94,13 @@ class LndRestWallet(Wallet):
                 error_message = r.json()["error"]
             except:
                 pass
-            return PaymentResponse(False, None, 0, error_message)
+            return PaymentResponse(False, None, 0, None, error_message)
 
-        payment_hash = r.json()["payment_hash"]
+        data = r.json()
+        payment_hash = data["payment_hash"]
         checking_id = payment_hash
-
-        return PaymentResponse(True, checking_id, 0, None)
+        preimage = base64.b64decode(data["payment_preimage"]).hex()
+        return PaymentResponse(True, checking_id, 0, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         checking_id = checking_id.replace("_", "/")

lnbits/wallets/lnpay.py

@@ -72,12 +72,19 @@ class LNPayWallet(Wallet):
             headers=self.auth,
             json={"payment_request": bolt11},
         )
-        ok, checking_id, fee_msat, error_message = r.status_code == 201, None, 0, None
 
-        if ok:
-            checking_id = r.json()["lnTx"]["id"]
+        try:
+            data = r.json()
+        except:
+            return PaymentResponse(False, None, 0, None, f"Got invalid JSON: {r.text[:200]}")
+
+        if r.is_error:
+            return PaymentResponse(False, None, 0, None, data["message"])
 
-        return PaymentResponse(ok, checking_id, fee_msat, error_message)
+        checking_id = data["lnTx"]["id"]
+        fee_msat = 0
+        preimage = data["lnTx"]["payment_preimage"]
+        return PaymentResponse(True, checking_id, fee_msat, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         return self.get_payment_status(checking_id)

lnbits/wallets/lntxbot.py

@@ -67,10 +67,13 @@ class LntxbotWallet(Wallet):
                 error_message = r.text
                 pass
 
-            return PaymentResponse(False, None, 0, error_message)
+            return PaymentResponse(False, None, 0, None, error_message)
 
         data = r.json()
-        return PaymentResponse(True, data["decoded"]["payment_hash"], data["fee_msat"], None)
+        checking_id = data["payment_hash"]
+        fee_msat = data["fee_msat"]
+        preimage = data["payment_preimage"]
+        return PaymentResponse(True, checking_id, fee_msat, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         r = httpx.post(url=f"{self.endpoint}/invoicestatus/{checking_id}?wait=false", headers=self.auth)

lnbits/wallets/opennode.py

@@ -62,12 +62,12 @@ class OpenNodeWallet(Wallet):
 
         if r.is_error:
             error_message = r.json()["message"]
-            return PaymentResponse(False, None, 0, error_message)
+            return PaymentResponse(False, None, 0, None, error_message)
 
         data = r.json()["data"]
         checking_id = data["id"]
         fee_msat = data["fee"] * 1000
-        return PaymentResponse(True, checking_id, fee_msat, None)
+        return PaymentResponse(True, checking_id, fee_msat, None, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         r = httpx.get(f"{self.endpoint}/v1/charge/{checking_id}", headers=self.auth)

lnbits/wallets/spark.py

@@ -85,11 +85,12 @@ class SparkWallet(Wallet):
     def pay_invoice(self, bolt11: str) -> PaymentResponse:
         try:
             r = self.pay(bolt11)
-            ok, checking_id, fee_msat, error_message = True, r["payment_hash"], r["msatoshi_sent"] - r["msatoshi"], None
-        except (SparkError, UnknownError) as e:
-            ok, checking_id, fee_msat, error_message = False, None, None, str(e)
+        except (SparkError, UnknownError) as exc:
+            return PaymentResponse(False, None, 0, None, str(exc))
 
-        return PaymentResponse(ok, checking_id, fee_msat, error_message)
+        fee_msat = r["msatoshi_sent"] - r["msatoshi"]
+        preimage = r["payment_preimage"]
+        return PaymentResponse(True, r["payment_hash"], fee_msat, preimage, None)
 
     def get_invoice_status(self, checking_id: str) -> PaymentStatus:
         r = self.listinvoices(label=checking_id)