feat(smartpdf): add automatic port allocation and multi-instance support

ts/smartpdf.classes.smartpdf.ts

@@ -7,10 +7,16 @@ import { execFile } from 'child_process';
 
 declare const document: any;
 
+export interface ISmartPdfOptions {
+  port?: number;
+  portRangeStart?: number;
+  portRangeEnd?: number;
+}
+
 export class SmartPdf {
   // STATIC
-  public static async create() {
-    const smartpdfInstance = new SmartPdf();
+  public static async create(optionsArg?: ISmartPdfOptions) {
+    const smartpdfInstance = new SmartPdf(optionsArg);
     return smartpdfInstance;
   }
 
@@ -21,9 +27,15 @@ export class SmartPdf {
   externalBrowserBool: boolean = false;
   private _readyDeferred: plugins.smartpromise.Deferred<void>;
   private _candidates: { [key: string]: PdfCandidate } = {};
+  private _options: ISmartPdfOptions;
 
-  constructor() {
+  constructor(optionsArg?: ISmartPdfOptions) {
     this._readyDeferred = new plugins.smartpromise.Deferred();
+    this._options = {
+      portRangeStart: 20000,
+      portRangeEnd: 30000,
+      ...optionsArg
+    };
   }
 
   async start(headlessBrowserArg?: plugins.smartpuppeteer.puppeteer.Browser) {
@@ -39,7 +51,37 @@ export class SmartPdf {
       });
     }
 
-    // setup server
+    // Find an available port BEFORE creating server
+    const smartnetworkInstance = new plugins.smartnetwork.SmartNetwork();
+    
+    if (this._options.port) {
+      // If a specific port is requested, check if it's available
+      const isPortAvailable = await smartnetworkInstance.isLocalPortUnused(this._options.port);
+      if (isPortAvailable) {
+        this.serverPort = this._options.port;
+      } else {
+        // Clean up browser if we created one
+        if (!this.externalBrowserBool && this.headlessBrowser) {
+          await this.headlessBrowser.close();
+        }
+        throw new Error(`Requested port ${this._options.port} is already in use`);
+      }
+    } else {
+      // Find a free port in the specified range
+      this.serverPort = await smartnetworkInstance.findFreePort(
+        this._options.portRangeStart,
+        this._options.portRangeEnd
+      );
+      if (!this.serverPort) {
+        // Clean up browser if we created one
+        if (!this.externalBrowserBool && this.headlessBrowser) {
+          await this.headlessBrowser.close();
+        }
+        throw new Error(`No free ports available in range ${this._options.portRangeStart}-${this._options.portRangeEnd}`);
+      }
+    }
+    
+    // Now setup server after we know we have a valid port
     const app = plugins.express();
     app.get('/:pdfId', (req, res) => {
       const wantedCandidate = this._candidates[req.params.pdfId];
@@ -51,10 +93,10 @@ export class SmartPdf {
       res.send(wantedCandidate.htmlString);
     });
     this.htmlServerInstance = plugins.http.createServer(app);
-    const smartnetworkInstance = new plugins.smartnetwork.SmartNetwork();
-    const portAvailable = smartnetworkInstance.isLocalPortUnused(3210);
-    this.htmlServerInstance.listen(3210, 'localhost');
+    
+    this.htmlServerInstance.listen(this.serverPort, 'localhost');
     this.htmlServerInstance.on('listening', () => {
+      console.log(`SmartPdf server listening on port ${this.serverPort}`);
       this._readyDeferred.resolve();
       done.resolve();
     });
@@ -87,7 +129,7 @@ export class SmartPdf {
       width: 794,
       height: 1122,
     });
-    const response = await page.goto(`http://localhost:3210/${pdfCandidate.pdfId}`, {
+    const response = await page.goto(`http://localhost:${this.serverPort}/${pdfCandidate.pdfId}`, {
       waitUntil: 'networkidle2',
     });
     const headers = response.headers();