[mirotalksfu] - add HtmlInjector

app/src/HtmlInjector.js

@@ -0,0 +1,95 @@
+const fs = require('fs');
+
+const Logger = require('./Logger');
+
+const log = new Logger('HtmlInjection');
+
+class HtmlInjector {
+    constructor(filesPath, config) {
+        this.filesPath = filesPath; // Array of file paths to cache
+        this.cache = {}; // Object to store cached files
+        this.config = config; // Configuration containing metadata (OG, title, etc.)
+        this.injectData = this.getInjectData(); // Initialize dynamic injection data
+        this.preloadPages(filesPath); // Preload pages at startup
+        this.watchFiles(filesPath); // Watch files for changes
+        log.info('filesPath cached', this.filesPath);
+    }
+
+    // Function to get dynamic data for injection (e.g., OG data, title, etc.)
+    getInjectData() {
+        return {
+            OG_TYPE: this.config.og?.type || 'app-webrtc',
+            OG_SITE_NAME: this.config.og?.siteName || 'MiroTalk SFU',
+            OG_TITLE: this.config.og?.title || 'Click the link to make a call.',
+            OG_DESCRIPTION:
+                this.config.og?.description ||
+                'MiroTalk SFU calling provides real-time video calls, messaging and screen sharing.',
+            OG_IMAGE: this.config.og?.image || 'https://sfu.mirotalk.com/images/mirotalksfu.png',
+            OG_URL: this.config.og?.url || 'https://sfu.mirotalk.com',
+            // Add more data here as needed with fallbacks
+        };
+    }
+
+    // Function to load a file into the cache
+    loadFileToCache(filePath) {
+        try {
+            const content = fs.readFileSync(filePath, 'utf-8');
+            this.cache[filePath] = content; // Store the content in cache
+        } catch (err) {
+            log.error(`Error reading file: ${filePath}`, err);
+        }
+    }
+
+    // Function to preload pages into the cache
+    preloadPages(filePaths) {
+        filePaths.forEach((filePath) => this.loadFileToCache(filePath));
+    }
+
+    // Function to watch a file for changes and reload the cache
+    watchFileForChanges(filePath) {
+        fs.watch(filePath, (eventType) => {
+            if (eventType === 'change') {
+                log.debug(`File changed: ${filePath}`);
+                this.loadFileToCache(filePath);
+                log.debug(`Reload the file ${filePath} into cache`);
+            }
+        });
+    }
+
+    // Function to watch all files for changes
+    watchFiles(filePaths) {
+        filePaths.forEach((filePath) => this.watchFileForChanges(filePath));
+    }
+
+    // Function to inject dynamic data (e.g., OG, TITLE, etc.) into a given file
+    injectHtml(filePath, res) {
+        // return res.send(this.cache[filePath]);
+
+        if (!this.cache[filePath]) {
+            log.error(`File not cached: ${filePath}`);
+            if (!res.headersSent) {
+                return res.status(500).send('Server Error');
+            }
+            return;
+        }
+
+        try {
+            // Replace placeholders with dynamic data (OG, TITLE, etc.)
+            const modifiedHTML = this.cache[filePath].replace(
+                /{{(OG_[A-Z_]+)}}/g,
+                (_, key) => this.injectData[key] || '',
+            );
+
+            if (!res.headersSent) {
+                res.send(modifiedHTML);
+            }
+        } catch (error) {
+            log.error('Error injecting HTML data:', error);
+            if (!res.headersSent) {
+                res.status(500).send('Server Error');
+            }
+        }
+    }
+}
+
+module.exports = HtmlInjector;