Merge branch 'pr-990' (iOS Web Share for completed downloads)

ui/src/app/app.html

@@ -854,6 +854,9 @@
                 @if (entry[1].filename) {
                   <a href="{{buildDownloadLink(entry[1])}}" download class="btn btn-link" [attr.aria-label]="'Download result file for ' + entry[1].title"><fa-icon [icon]="faDownload" /></a>
                 }
+                @if (entry[1].filename && canShareDownloads()) {
+                  <button type="button" class="btn btn-link" [attr.aria-label]="'Share result file for ' + entry[1].title" (click)="shareDownload(entry[1])"><fa-icon [icon]="faShareNodes" /></button>
+                }
                 <a href="{{entry[1].url}}" target="_blank" class="btn btn-link" [attr.aria-label]="'Open source URL for ' + entry[1].title"><fa-icon [icon]="faExternalLinkAlt" /></a>
                 <button type="button" class="btn btn-link" [attr.aria-label]="'Delete completed item ' + entry[1].title" (click)="delDownload('done', entry[0])"><fa-icon [icon]="faTrashAlt" /></button>
               </div>

ui/src/app/app.ts

@@ -7,7 +7,7 @@ import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { FontAwesomeModule } from '@fortawesome/angular-fontawesome';
 import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
 import { NgSelectModule } from '@ng-select/ng-select';  
-import { faTrashAlt, faCheckCircle, faTimesCircle, faRedoAlt, faSun, faMoon, faCheck, faCircleHalfStroke, faDownload, faExternalLinkAlt, faFileImport, faFileExport, faCopy, faClock, faTachometerAlt, faSortAmountDown, faSortAmountUp, faChevronRight, faChevronDown, faUpload, faPause, faPlay } from '@fortawesome/free-solid-svg-icons';
+import { faTrashAlt, faCheckCircle, faTimesCircle, faRedoAlt, faSun, faMoon, faCheck, faCircleHalfStroke, faDownload, faExternalLinkAlt, faFileImport, faFileExport, faCopy, faClock, faTachometerAlt, faSortAmountDown, faSortAmountUp, faChevronRight, faChevronDown, faUpload, faPause, faPlay, faShareNodes } from '@fortawesome/free-solid-svg-icons';
 import { faGithub } from '@fortawesome/free-brands-svg-icons';
 import { CookieService } from 'ngx-cookie-service';
 import { AddDownloadPayload, DownloadsService } from './services/downloads.service';
@@ -185,6 +185,7 @@ export class App implements AfterViewInit, OnInit, OnDestroy {
   faUpload = faUpload;
   faPause = faPause;
   faPlay = faPlay;
+  faShareNodes = faShareNodes;
   subtitleLanguages = [
     { id: 'en', text: 'English' },
     { id: 'ar', text: 'Arabic' },
@@ -1189,6 +1190,78 @@ export class App implements AfterViewInit, OnInit, OnDestroy {
     return baseDir + encodeURIComponent(download.filename);
   }
 
+  // Web Share API support — primarily for iOS Safari / Chrome, lets the user
+  // hand the downloaded file off to the platform share sheet (Photos.app,
+  // Files, third-party apps, AirDrop). Falls back silently to the standard
+  // download flow on platforms without navigator.share / canShare.
+  canShareDownloads(): boolean {
+    // navigator.share alone is not enough — Desktop Safari implements
+    // navigator.share but not canShare with files. We explicitly require
+    // both, since we always intend to share a file (not a URL).
+    return typeof navigator !== 'undefined'
+      && typeof navigator.share === 'function'
+      && typeof navigator.canShare === 'function';
+  }
+
+  // Conservative warning threshold for the share sheet — iOS' actual
+  // refusal limit varies between ~50 MB (older versions) and ~150 MB
+  // (recent ones). 80 MB warns the user before the time-wasting fetch+
+  // copy of a too-large file that the platform will then reject.
+  private static readonly SHARE_SIZE_WARN_BYTES = 80 * 1024 * 1024;
+
+  async shareDownload(download: Download): Promise<void> {
+    if (!this.canShareDownloads()) {
+      return;
+    }
+    // Pre-flight size check: warn the user about the iOS share-sheet
+    // soft-fail on large files, before we spend time fetching the whole
+    // file into memory only to have navigator.canShare reject it.
+    if (download.size && download.size > App.SHARE_SIZE_WARN_BYTES) {
+      const sizeMb = Math.round(download.size / 1024 / 1024);
+      const proceed = window.confirm(
+        `This file is ${sizeMb} MB. iOS' share sheet often refuses files ` +
+        `larger than ~100 MB and the share will silently fail. ` +
+        `Try anyway? (Use the download button instead if it fails.)`
+      );
+      if (!proceed) return;
+    }
+    try {
+      const response = await fetch(this.buildDownloadLink(download));
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status} fetching file for share`);
+      }
+      const blob = await response.blob();
+      const file = new File([blob], download.filename, {
+        type: blob.type || 'application/octet-stream',
+      });
+      const payload: ShareData = { files: [file], title: download.title };
+      if (!navigator.canShare(payload)) {
+        // The platform refused the payload — most commonly because the
+        // file is too large for the iOS share sheet, or the MIME type
+        // isn't accepted. Tell the user so they can fall back to the
+        // download button right next to this one instead of staring at
+        // a button that quietly did nothing.
+        console.warn('navigator.canShare rejected payload for', download.filename);
+        window.alert(
+          `Your device's share sheet doesn't accept this file ` +
+          `(most likely because it's too large). ` +
+          `Please use the download button instead.`
+        );
+        return;
+      }
+      await navigator.share(payload);
+    } catch (err) {
+      const e = err as { name?: string; message?: string };
+      // AbortError = user dismissed the share sheet → silent no-op.
+      if (e.name === 'AbortError') return;
+      console.error('Share failed:', err);
+      window.alert(
+        `Share failed: ${e.message || 'unknown error'}. ` +
+        `Please use the download button instead.`
+      );
+    }
+  }
+
   buildResultItemTooltip(download: Download) {
     const parts = [];
     if (download.msg) {