From 9e0feffc3c9461f56bb3663a01bf33d342bc6967 Mon Sep 17 00:00:00 2001
From: Evert Prants <evert@lunasqu.ee>
Date: Wed, 18 May 2022 13:52:27 +0300
Subject: [PATCH] hopefully fix currency exchange

---
 squeebot.repo.json  |  2 +-
 utility/plugin.json |  2 +-
 utility/plugin.ts   | 61 +++++++++++++++++++++------------------------
 3 files changed, 31 insertions(+), 34 deletions(-)

diff --git a/squeebot.repo.json b/squeebot.repo.json
index 7305833..4cd01d0 100644
--- a/squeebot.repo.json
+++ b/squeebot.repo.json
@@ -43,7 +43,7 @@
     },
     {
       "name": "utility",
-      "version": "3.2.1"
+      "version": "3.2.2"
     }
   ],
   "typescript": true
diff --git a/utility/plugin.json b/utility/plugin.json
index f574b73..406aaf6 100644
--- a/utility/plugin.json
+++ b/utility/plugin.json
@@ -2,7 +2,7 @@
   "main": "plugin.js",
   "name": "utility",
   "description": "Utility commands and math operations",
-  "version": "3.2.1",
+  "version": "3.2.2",
   "tags": [
     "commands",
     "tools"
diff --git a/utility/plugin.ts b/utility/plugin.ts
index 136de5c..af0b5fd 100644
--- a/utility/plugin.ts
+++ b/utility/plugin.ts
@@ -611,28 +611,32 @@ function addCommands(plugin: UtilityPlugin, commands: any): void {
       prefix: string,
       ...simplified: any[]
     ): Promise<boolean> => {
-      let ctw: CEXResponse | null = plugin.cexCache.cache as CEXResponse;
+      let cexData: CEXResponse | null = plugin.cexCache.cache as CEXResponse;
+      const currentStamp = new Date().toISOString().replace(/T(.*)$/, '');
       if (plugin.cexCache.expiry < Date.now()) {
         let fetched;
         try {
-          const data = await httpGET('https://api.exchangerate.host/latest');
+          const data = await httpGET(`https://api.exchangerate.host/latest?v=${currentStamp}`);
           fetched = JSON.parse(data);
           logger.log('[utility] Fetched currency exchange rates successfully.');
         } catch (e) {
-          ctw = null;
+          fetched = null;
         }
 
-        if (!ctw || !fetched.rates) {
+        if (!fetched?.rates) {
           msg.resolve(
             'Could not fetch currency exchange rates at this time. Please try again later.'
           );
           return true;
         }
 
-        plugin.cexCache.cache = fetched.rates;
-        plugin.cexCache.date = fetched.date;
-        plugin.cexCache.expiry = Date.now() + 86400000; // day
-        ctw = plugin.cexCache.cache as CEXResponse;
+        Object.assign(plugin.cexCache, {
+          cache: fetched.rates,
+          date: fetched.date,
+          expiry: Date.now() + 86400000 / 2 // half-day
+        });
+
+        cexData = fetched.rates as CEXResponse;
       }
 
       if (simplified[0] === 'date') {
@@ -643,50 +647,43 @@ function addCommands(plugin: UtilityPlugin, commands: any): void {
         return true;
       } else if (simplified[0] === 'list') {
         msg.resolve(
-          'Currently supported currencies: EUR, %s',
-          Object.keys(plugin.cexCache.cache).join(', ')
+          'Currently supported currencies: %s',
+          Object.keys(cexData).join(', ')
         );
         return true;
       }
 
-      const n = parseFloat(simplified[0]);
-      let f = simplified[1];
-      let t = simplified[2];
-      if (isNaN(n) || !f || !t) {
+      const inputValue = parseFloat(simplified[0]);
+      let fromCurrency = simplified[1];
+      let toCurrency = simplified[2];
+      if (isNaN(inputValue) || !fromCurrency || !toCurrency) {
         msg.resolve('Invalid parameters.');
         return true;
       }
-      f = f.toUpperCase();
-      t = t.toUpperCase();
 
-      if (f !== 'EUR' && !ctw[f]) {
+      fromCurrency = fromCurrency.toUpperCase();
+      toCurrency = toCurrency.toUpperCase();
+
+      if (fromCurrency !== 'EUR' && !cexData[fromCurrency]) {
         msg.resolve('This currency is currently not supported.');
         return true;
       }
 
-      if (t !== 'EUR' && !ctw[t]) {
+      if (toCurrency !== 'EUR' && !cexData[toCurrency]) {
         msg.resolve('This currency is currently not supported.');
         return true;
       }
 
-      if (f === t) {
-        msg.resolve('%f %s', n, f);
+      if (fromCurrency === toCurrency) {
+        msg.resolve('%f %s', inputValue, fromCurrency);
         return true;
       }
 
-      let ramnt: string;
-      if (f === 'EUR') {
-        ramnt = (n * ctw[t]).toFixed(4);
-        msg.resolve('%f EUR => %f %s', n, ramnt, t);
-        return true;
-      } else if (t === 'EUR') {
-        ramnt = (n / ctw[f]).toFixed(4);
-        msg.resolve('%f %s => %f EUR', n, f, ramnt);
-        return true;
-      }
+      const resultValue = ((cexData[toCurrency] * inputValue) / cexData[fromCurrency]).toFixed(4);
+      const conversionRate = (cexData[toCurrency] / cexData[fromCurrency]).toFixed(4);
+      const conversionRateString = inputValue !== 1 ? `(1 = ${conversionRate})` : '';
 
-      const amnt = ((ctw[t] * n) / ctw[f]).toFixed(4);
-      msg.resolve('%f %s => %f %s', n, f, amnt, t);
+      msg.resolve(`${inputValue} ${fromCurrency} => ${resultValue} ${toCurrency} ${conversionRateString}`);
       return true;
     },
     description: 'Convert between currencies.',