RZL: Add 3D printer time remaining (#78)

* RZL: Add 3D printer time remaining

This pull request closes #20.

config/rzl/index.js

@@ -186,6 +186,21 @@ const config: Config = {
         },
         defaultValue: "0"
       },
+      printer3Dremaining: {
+        state: {
+          name: "/service/ultimaker/job",
+          type: (msg) => {
+            const json = JSON.parse(msg.toString());
+            if(!json || !json["time_elapsed"] || !json["time_total"]) {
+              return "unavailable";
+            } else {
+              const secondsLeft = json["time_total"] - json["time_elapsed"];
+              return new Date(secondsLeft * 1000).toISOString().substr(11, 8);
+            }
+          }
+        },
+        defaultValue: "unavailable"
+      },
       nebenraumPowerStatus: {
         state: {
           name: "/service/nebenraum-power",
@@ -472,6 +487,12 @@ const config: Config = {
           max: 1,
           text: "Printing Progress",
           topic: "printer_3d_progress"
+        },
+        {
+          type: "text",
+          text: "Time Left",
+          icon: mdi("clock"),
+          topic: "printer3Dremaining"
         }
       ]
     },