From 9e7fe794d4de7eee20895b0744510d95687f5817 Mon Sep 17 00:00:00 2001
From: Jan Litzenburger <Jan.Litzenburger@de.ibm.com>
Date: Sun, 24 Jan 2021 18:57:34 +0100
Subject: [PATCH] auto calculation

---
 MMM-Jast.js    |  2 +-
 README.md      |  2 +-
 node_helper.js | 38 +++++++++++++++++++++++++++++++++++---
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/MMM-Jast.js b/MMM-Jast.js
index 5426270..c4db841 100644
--- a/MMM-Jast.js
+++ b/MMM-Jast.js
@@ -6,7 +6,7 @@ Module.register("MMM-Jast", {
   defaults: {
     debug: false,
     header: null,
-    updateIntervalInSeconds: 1800,
+    updateIntervalInSeconds: 0,
     requestIntervalInSeconds: 62,
     fadeSpeedInSeconds: 3.5, // Higher value: vertical -> faster // horizontal -> slower
     stocks: [
diff --git a/README.md b/README.md
index ce9214b..bd2cd79 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ To use this module, add it to the modules array in the `config/config.js` file:
 	position: "top_left",
 	config: {
     maxWidth: "100%",
-		updateIntervalInSeconds: 1800,
+		updateIntervalInSeconds: 0, // 0 = Auto calculation to get a maximum number of 500 requests per day.
 		fadeSpeedInSeconds: 3.5, // Higher value: vertical -> faster // horizontal -> slower
     scroll: "<none, vertical, horizontal>",
     defaultCurrency: "EUR",
diff --git a/node_helper.js b/node_helper.js
index d427696..c1b8c73 100644
--- a/node_helper.js
+++ b/node_helper.js
@@ -1,7 +1,39 @@
+const e = require("express");
 const NodeHelper = require("node_helper");
 const request = require("request");
 
 module.exports = NodeHelper.create({
+  updateInterval: null,
+  getUpdateInterval(config) {
+    if (!this.updateInterval) {
+      if (config.updateIntervalInSeconds === 0) {
+        const exchangeRates = [];
+        config.stocks.forEach((stock) => {
+          if (
+            stock.tradeCurrency &&
+            stock.displayCurrency &&
+            stock.tradeCurrency !== stock.displayCurrency
+          ) {
+            const currentChange = exchangeRates.find(
+              (rate) =>
+                rate.from === stock.tradeCurrency &&
+                rate.to === stock.displayCurrency
+            );
+            if (!currentChange) {
+              exchangeRates.push(currentChange);
+            }
+          }
+        });
+        const numEntities =
+          config.stocks.length + config.crypto.length + exchangeRates.length;
+        const delayPerEntity = 86400 / 500;
+        this.updateInterval = delayPerEntity * numEntities * 1000;
+      } else {
+        this.updateInterval = config.updateIntervalInSeconds * 1000;
+      }
+    }
+    return this.updateInterval;
+  },
   start() {
     console.log(`${this.name} helper method started...`);
   },
@@ -35,7 +67,7 @@ module.exports = NodeHelper.create({
     config.stocks.forEach((stock) => {
       if (
         !stock.lastUpdate ||
-        Date.now() - stock.lastUpdate >= config.updateIntervalInSeconds * 1000
+        Date.now() - stock.lastUpdate >= this.getUpdateInterval(config)
       ) {
         const url = `${config.baseURL}query?function=TIME_SERIES_DAILY&outputsize=compact&apikey=${config.apiKey}&symbol=${stock.symbol}`;
         request(url, { json: true }, (err, _res, body) => {
@@ -76,7 +108,7 @@ module.exports = NodeHelper.create({
     config.crypto.forEach((crypto) => {
       if (
         !crypto.lastUpdate ||
-        Date.now() - crypto.lastUpdate >= config.updateIntervalInSeconds * 1000
+        Date.now() - crypto.lastUpdate >= this.getUpdateInterval(config)
       ) {
         const url = `${config.baseURL}query?function=DIGITAL_CURRENCY_DAILY&symbol=${crypto.symbol}&market=USD&apikey=${config.apiKey}`;
         request(url, { json: true }, (err, _res, body) => {
@@ -132,7 +164,7 @@ module.exports = NodeHelper.create({
           !currentChange ||
           !currentChange.lastUpdate ||
           Date.now() - currentChange.lastUpdate >=
-            config.updateIntervalInSeconds * 1000
+            this.getUpdateInterval(config)
         ) {
           const url = `${config.baseURL}query?function=CURRENCY_EXCHANGE_RATE&from_currency=${stock.tradeCurrency}&to_currency=${stock.displayCurrency}&apikey=${config.apiKey}`;
           request(url, { json: true }, (err, res, body) => {