fix(qr): improve QR scanner implementation and error handling

- Implement robust QR scanner factory with platform detection
- Add proper camera permissions to Android manifest
- Improve error handling and logging across scanner implementations
- Add continuous scanning mode for Capacitor/MLKit scanner
- Enhance UI feedback during scanning process
- Fix build configuration for proper platform detection
- Clean up resources properly in scanner components
- Add TypeScript improvements and error wrapping

The changes include:
- Adding CAMERA permission to AndroidManifest.xml
- Setting proper build flags (__IS_MOBILE__, __USE_QR_READER__)
- Implementing continuous scanning mode for better UX
- Adding proper cleanup of scanner resources
- Improving error handling and type safety
- Enhancing UI with loading states and error messages

src/services/QRScanner/CapacitorQRScanner.ts

@@ -10,13 +10,16 @@ import { logger } from "@/utils/logger";
 export class CapacitorQRScanner implements QRScannerService {
   private scanListener: ScanListener | null = null;
   private isScanning = false;
+  private listenerHandles: Array<() => Promise<void>> = [];
 
   async checkPermissions(): Promise<boolean> {
     try {
       const { camera } = await BarcodeScanner.checkPermissions();
       return camera === "granted";
     } catch (error) {
-      logger.error("Error checking camera permissions:", error);
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error checking camera permissions:", wrappedError);
       return false;
     }
   }
@@ -32,7 +35,9 @@ export class CapacitorQRScanner implements QRScannerService {
       const { camera } = await BarcodeScanner.requestPermissions();
       return camera === "granted";
     } catch (error) {
-      logger.error("Error requesting camera permissions:", error);
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error requesting camera permissions:", wrappedError);
       return false;
     }
   }
@@ -42,7 +47,9 @@ export class CapacitorQRScanner implements QRScannerService {
       const { supported } = await BarcodeScanner.isSupported();
       return supported;
     } catch (error) {
-      logger.error("Error checking scanner support:", error);
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error checking scanner support:", wrappedError);
       return false;
     }
   }
@@ -79,17 +86,23 @@ export class CapacitorQRScanner implements QRScannerService {
       };
 
       logger.log("Scanner options:", scanOptions);
-      const result = await BarcodeScanner.scan(scanOptions);
-      logger.log("Scan result:", result);
-
-      if (result.barcodes.length > 0) {
-        this.scanListener?.onScan(result.barcodes[0].rawValue);
-      }
+      
+      // Add listener for barcode scans
+      const handle = await BarcodeScanner.addListener('barcodeScanned', (result) => {
+        if (this.scanListener) {
+          this.scanListener.onScan(result.barcode.rawValue);
+        }
+      });
+      this.listenerHandles.push(handle.remove);
+      
+      // Start continuous scanning
+      await BarcodeScanner.startScan(scanOptions);
     } catch (error) {
-      logger.error("Error during QR scan:", error);
-      this.scanListener?.onError?.(error as Error);
-    } finally {
-      this.isScanning = false;
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error during QR scan:", wrappedError);
+      this.scanListener?.onError?.(wrappedError);
+      throw wrappedError;
     }
   }
 
@@ -100,10 +113,14 @@ export class CapacitorQRScanner implements QRScannerService {
 
     try {
       await BarcodeScanner.stopScan();
-      this.isScanning = false;
     } catch (error) {
-      logger.error("Error stopping QR scan:", error);
-      this.scanListener?.onError?.(error as Error);
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error stopping QR scan:", wrappedError);
+      this.scanListener?.onError?.(wrappedError);
+      throw wrappedError;
+    } finally {
+      this.isScanning = false;
     }
   }
 
@@ -112,7 +129,19 @@ export class CapacitorQRScanner implements QRScannerService {
   }
 
   async cleanup(): Promise<void> {
-    await this.stopScan();
-    this.scanListener = null;
+    try {
+      await this.stopScan();
+      for (const handle of this.listenerHandles) {
+        await handle();
+      }
+    } catch (error) {
+      const wrappedError =
+        error instanceof Error ? error : new Error(String(error));
+      logger.error("Error during cleanup:", wrappedError);
+      throw wrappedError;
+    } finally {
+      this.listenerHandles = [];
+      this.scanListener = null;
+    }
   }
 }