From 147016278a5b411eea49d4b84461b4c96cefe1d2 Mon Sep 17 00:00:00 2001
From: Alicia Sykes <alicia@omg.lol>
Date: Mon, 4 Mar 2024 21:29:53 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Auto-rebuild=20script=20done,=20wit?=
 =?UTF-8?q?h=20debounce=20and=20term=20logging?=
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---
 services/watch-for-changes.js | 90 +++++++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 20 deletions(-)

diff --git a/services/watch-for-changes.js b/services/watch-for-changes.js
index 51b2c8f9..a66000b2 100644
--- a/services/watch-for-changes.js
+++ b/services/watch-for-changes.js
@@ -1,28 +1,78 @@
 const fs = require('fs');
 const { exec } = require('child_process');
 const path = require('path');
+const crypto = require('crypto');
 
-const configFile = path.resolve(__dirname, './public/conf.yml');
+// Default location of config file in container
+const configFileName = '../public/conf.yml';
+// Real path of config file in container
+const configFilePath = path.resolve(__dirname, configFileName);
+// Amount of time to ignore file after change detected
+const debounceTimeMs = 2000;
+
+// Store current timeout
 let timeout = null;
+// Store last hash of file
+let lastHash = null;
 
-console.log(`Watching for file changes on ${configFile}`);
+/**
+ * Calculate hash of file, used for de-bounce mechanism to
+ * prevent successive updates if file content not changed
+ */
+const hashFileContent = (filePath) => {
+  const content = fs.readFileSync(filePath, 'utf8');
+  return crypto.createHash('sha256').update(content).digest('hex');
+};
 
-fs.watch(configFile, (eventType, filename) => {
-  if (filename && eventType === 'change') {
-    console.log(`${filename} file Changed, preparing to build...`);
-    // Clear the existing timeout, if there is one
-    if (timeout) clearTimeout(timeout);
-    // Set a new timeout
-    timeout = setTimeout(() => {
-      console.log('Running build...');
-      exec('yarn build', (error, stdout, stderr) => {
-        if (error) {
-          console.error(`exec error: ${error}`);
-          return;
-        }
-        console.log(`stdout: ${stdout}`);
-        console.error(`stderr: ${stderr}`);
-      });
-    }, 1000); // Adjust the debounce time as necessary, here it's 1000 milliseconds (1 second)
+/**
+ * Just logs a given message to terminal so user knows what's happening
+ */
+const logInfo = (message, msgLevel = 'OUTPUT') => {
+  const RESET = '\x1b[0m';
+  let logLevels = {};
+  switch (msgLevel) {
+    case 'ERROR': logLevels = { col: '\x1b[31m', func: console.error }; break;
+    case 'WARNING': logLevels = { col: '\x1b[33m', func: console.warn }; break;
+    case 'INFO': logLevels = { col: '\x1b[36m', func: console.info }; break;
+    case 'SUCCESS': logLevels = { col: '\x1b[32m', func: console.log }; break;
+    default: logLevels = { col: RESET, func: console.log };
   }
-});
+  logLevels.func(`${logLevels.col}\x1b[1m[${msgLevel}]${RESET} ${logLevels.col}${message}${RESET}\n`);
+};
+
+// Log initial message to user
+logInfo(`When '${configFileName}' is updated, a rebuild will be triggered.\n`);
+
+/**
+ * Code to be executed when a watch event is triggered
+ * Will check correctly expected file and time frame,
+ * then ensure the hash is different from last hash,
+ * and then trigger -rebuild of frontend with yarn build
+ * outputting the stdrout and stderr to user's terminal
+ */
+const watchAction = (eventType, filename) => {
+  if (filename && eventType === 'change') {
+    if (timeout) clearTimeout(timeout);
+    timeout = setTimeout(() => {
+      const currentHash = hashFileContent(configFilePath);
+      if (currentHash !== lastHash) {
+        lastHash = currentHash;
+        logInfo(`${filename} file Changed, running build...`);
+        exec('yarn build', (error, stdout, stderr) => {
+          if (error) {
+            logInfo(error, 'ERROR');
+            return;
+          }
+          logInfo(stdout);
+          logInfo(stderr, 'WARNING');
+          logInfo('Build completed successfully.\n', 'SUCCESS');
+        });
+      } else {
+        logInfo(`${filename} file Detected change, but content is the same. Skipping....`, 'WARNING');
+      }
+    }, debounceTimeMs);
+  }
+};
+
+// Watch given config path, with the watch action function
+fs.watch(configFilePath, watchAction);