lnrpc: report invoice state

Expose the new invoice state field over rpc.

lnrpc/rpc.proto

@@ -1699,7 +1699,7 @@ message Invoice {
     int64 value = 5 [json_name = "value"];
 
     /// Whether this invoice has been fulfilled
-    bool settled = 6 [json_name = "settled"];
+    bool settled = 6 [json_name = "settled", deprecated = true];
 
     /// When this invoice was created
     int64 creation_date = 7 [json_name = "creation_date"];
@@ -1777,7 +1777,18 @@ message Invoice {
     here as well.
     */
     int64 amt_paid_msat = 20 [json_name = "amt_paid_msat"];
+
+    enum InvoiceState {
+        OPEN = 0;
+        SETTLED = 1;
+    }
+
+    /**
+    The state the invoice is in.
+    */
+    InvoiceState state = 21 [json_name = "state"];
 }
+
 message AddInvoiceResponse {
     bytes r_hash = 1 [json_name = "r_hash"];
 

lnrpc/rpc.swagger.json

@@ -1127,6 +1127,14 @@
       ],
       "default": "COOPERATIVE_CLOSE"
     },
+    "InvoiceInvoiceState": {
+      "type": "string",
+      "enum": [
+        "OPEN",
+        "SETTLED"
+      ],
+      "default": "OPEN"
+    },
     "PendingChannelsResponseClosedChannel": {
       "type": "object",
       "properties": {
@@ -2125,6 +2133,10 @@
           "type": "string",
           "format": "int64",
           "description": "*\nThe amount that was accepted for this invoice, in millisatoshis. This will\nONLY be set if this invoice has been settled. We provide this field as if\nthe invoice was created with a zero value, then we need to record what\namount was ultimately accepted. Additionally, it's possible that the sender\npaid MORE that was specified in the original invoice. So we'll record that\nhere as well."
+        },
+        "state": {
+          "$ref": "#/definitions/InvoiceInvoiceState",
+          "description": "*\nThe state the invoice is in."
         }
       }
     },

rpcserver.go

@@ -3305,6 +3305,16 @@ func createRPCInvoice(invoice *channeldb.Invoice) (*lnrpc.Invoice, error) {
 
 	isSettled := invoice.Terms.State == channeldb.ContractSettled
 
+	var state lnrpc.Invoice_InvoiceState
+	switch invoice.Terms.State {
+	case channeldb.ContractOpen:
+		state = lnrpc.Invoice_OPEN
+	case channeldb.ContractSettled:
+		state = lnrpc.Invoice_SETTLED
+	default:
+		return nil, fmt.Errorf("unknown invoice state")
+	}
+
 	return &lnrpc.Invoice{
 		Memo:            string(invoice.Memo[:]),
 		Receipt:         invoice.Receipt[:],
@@ -3326,6 +3336,7 @@ func createRPCInvoice(invoice *channeldb.Invoice) (*lnrpc.Invoice, error) {
 		AmtPaidSat:      int64(satAmtPaid),
 		AmtPaidMsat:     int64(invoice.AmtPaid),
 		AmtPaid:         int64(invoice.AmtPaid),
+		State:           state,
 	}, nil
 }