fix: preview video on new tab (#933)

src/components/code-editor/view/subcomponents/CodeEditorMediaPreview.tsx

@@ -0,0 +1,289 @@
+import { useEffect, useState } from 'react';
+
+import { authenticatedFetch } from '../../../../utils/api';
+import type { CodeEditorFile } from '../../types/types';
+import { getPreviewMimeType, type PreviewKind } from '../../utils/previewableFile';
+
+type CodeEditorMediaPreviewProps = {
+  file: CodeEditorFile;
+  kind: PreviewKind;
+  // DB projectId used to build the raw-content URL; falls back to projectPath
+  // for older callers, mirroring useCodeEditorDocument.
+  projectId?: string;
+  isSidebar: boolean;
+  isFullscreen: boolean;
+  onClose: () => void;
+  onToggleFullscreen: () => void;
+  labels: {
+    loading: string;
+    error: string;
+    openInNewTab: string;
+    fullscreen: string;
+    exitFullscreen: string;
+    close: string;
+  };
+};
+
+// Reject a "PDF" whose bytes aren't actually a PDF before handing it to the
+// same-origin iframe, so a mislabeled HTML/SVG file can't run in the app origin.
+const PDF_HEADER_SCAN_BYTES = 1024;
+
+const looksLikePdf = async (blob: Blob): Promise<boolean> => {
+  const header = await blob.slice(0, PDF_HEADER_SCAN_BYTES).arrayBuffer();
+  // PDFs must contain the "%PDF-" marker at the very start of the file.
+  return new TextDecoder('latin1').decode(header).includes('%PDF-');
+};
+
+export default function CodeEditorMediaPreview({
+  file,
+  kind,
+  projectId,
+  isSidebar,
+  isFullscreen,
+  onClose,
+  onToggleFullscreen,
+  labels,
+}: CodeEditorMediaPreviewProps) {
+  const [url, setUrl] = useState<string | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [loading, setLoading] = useState(true);
+  // Identifies which file the current `url` was loaded for. Rendering is gated on
+  // this so a blob from a previously-opened file can never show under the new
+  // file (the editor reuses this component instance across files).
+  const [loadedKey, setLoadedKey] = useState<string | null>(null);
+  const sourceKey = `${projectId ?? ''}:${file.path}:${kind}`;
+
+  useEffect(() => {
+    if (!projectId) {
+      setUrl(null);
+      setLoadedKey(null);
+      setError(labels.error);
+      setLoading(false);
+      return;
+    }
+
+    let objectUrl: string | null = null;
+    const controller = new AbortController();
+
+    const loadMedia = async () => {
+      try {
+        setLoading(true);
+        setError(null);
+        setUrl(null);
+
+        // The content endpoint requires the auth header, so we fetch the bytes
+        // ourselves and hand the media element a blob URL instead of a bare src.
+        // Fetching a blob (rather than streaming) also lets <video>/<audio> seek.
+        const contentUrl = `/api/projects/${projectId}/files/content?path=${encodeURIComponent(file.path)}`;
+        const response = await authenticatedFetch(contentUrl, { signal: controller.signal });
+
+        if (!response.ok) {
+          throw new Error(`Request failed with status ${response.status}`);
+        }
+
+        const blob = await response.blob();
+
+        // Pick the MIME type to expose to the browser. Preserve a valid
+        // Content-Type from the server, but supply an extension-specific
+        // default when it is missing or generic (application/octet-stream),
+        // otherwise formats like webm/ogg/flac/svg won't render.
+        const fallbackMime = getPreviewMimeType(file.name);
+        const isGenericType = !blob.type || blob.type === 'application/octet-stream';
+        const isMislabeledVideo = kind === 'video' && Boolean(fallbackMime) && !blob.type.startsWith('video/');
+        let outType = isGenericType || isMislabeledVideo ? (fallbackMime ?? blob.type) : blob.type;
+
+        if (kind === 'pdf') {
+          // The PDF renders in a same-origin <iframe>, so verify the bytes are
+          // really a PDF and pin the type to application/pdf. That forces the
+          // browser's PDF handler and prevents a mislabeled HTML/SVG file from
+          // executing scripts in the app's origin.
+          if (!(await looksLikePdf(blob))) {
+            throw new Error('File is not a valid PDF');
+          }
+          outType = 'application/pdf';
+        }
+
+        const typed = outType && outType !== blob.type ? new Blob([blob], { type: outType }) : blob;
+        objectUrl = URL.createObjectURL(typed);
+
+        // The cleanup may have already run (deps changed during an await), in
+        // which case it revoked nothing because objectUrl was still null. Don't
+        // publish a URL the cleanup will never revoke — drop it ourselves.
+        if (controller.signal.aborted) {
+          URL.revokeObjectURL(objectUrl);
+          objectUrl = null;
+          return;
+        }
+
+        setUrl(objectUrl);
+        setLoadedKey(sourceKey);
+      } catch (loadError: unknown) {
+        if (loadError instanceof Error && loadError.name === 'AbortError') {
+          return;
+        }
+        console.error('Error loading preview:', loadError);
+        setError(labels.error);
+      } finally {
+        setLoading(false);
+      }
+    };
+
+    loadMedia();
+
+    return () => {
+      controller.abort();
+      if (objectUrl) {
+        URL.revokeObjectURL(objectUrl);
+      }
+    };
+  }, [file.path, file.name, projectId, kind, sourceKey, labels.error]);
+
+  // Only expose the blob once it matches the file currently being shown, so a
+  // stale URL from the previous file is never rendered during a switch.
+  const currentUrl = url && loadedKey === sourceKey ? url : null;
+
+  // SVGs render safely inline via <img> (scripts don't execute there), but the
+  // open-in-new-tab link is a top-level navigation. A blob URL inherits the
+  // app's origin, so a user-controlled SVG with an embedded <script> would run
+  // as same-origin script. Withhold the new-tab action for SVGs.
+  const isSvg = getPreviewMimeType(file.name) === 'image/svg+xml';
+  const canOpenInNewTab = Boolean(currentUrl) && !isSvg;
+
+  const renderMedia = () => {
+    if (!currentUrl) return null;
+    switch (kind) {
+      case 'image':
+        return (
+          <img
+            src={currentUrl}
+            alt={file.name}
+            className="max-h-full max-w-full object-contain"
+          />
+        );
+      case 'pdf':
+        // Not sandboxed on purpose: the browser's built-in PDF viewer refuses to
+        // load inside a sandboxed frame (any `sandbox` value yields a broken
+        // viewer). Script execution is instead prevented upstream by validating
+        // the PDF magic bytes and pinning the blob's MIME type to application/pdf.
+        return <iframe src={currentUrl} title={file.name} className="h-full w-full border-0 bg-white" />;
+      case 'video':
+        return (
+          <video src={currentUrl} controls className="max-h-full max-w-full" autoPlay={false}>
+            {labels.error}
+          </video>
+        );
+      case 'audio':
+        return (
+          <div className="flex w-full max-w-xl flex-col items-center gap-4 px-6">
+            <p className="max-w-full truncate text-sm text-muted-foreground">{file.name}</p>
+            <audio src={currentUrl} controls className="w-full">
+              {labels.error}
+            </audio>
+          </div>
+        );
+      default:
+        return null;
+    }
+  };
+
+  const previewBody = (
+    <div className="relative flex h-full w-full flex-col items-center justify-center bg-muted/30 p-2">
+      {loading && (
+        <div className="text-sm text-muted-foreground">{labels.loading}</div>
+      )}
+
+      {!loading && currentUrl && renderMedia()}
+
+      {!loading && !currentUrl && (
+        <div className="flex flex-col items-center gap-3 p-8 text-center text-muted-foreground">
+          <p className="text-sm">{error || labels.error}</p>
+          <p className="break-all text-xs">{file.path}</p>
+        </div>
+      )}
+    </div>
+  );
+
+  const headerActions = (
+    <div className="flex shrink-0 items-center gap-0.5">
+      {canOpenInNewTab && currentUrl && (
+        <a
+          href={currentUrl}
+          target="_blank"
+          rel="noopener noreferrer"
+          className="flex items-center justify-center rounded-md p-1.5 text-gray-600 hover:bg-gray-100 hover:text-gray-900 dark:text-gray-400 dark:hover:bg-gray-800 dark:hover:text-white"
+          aria-label={labels.openInNewTab}
+          title={labels.openInNewTab}
+        >
+          <svg aria-hidden="true" className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10 6H6a2 2 0 00-2 2v10a2 2 0 002 2h10a2 2 0 002-2v-4M14 4h6m0 0v6m0-6L10 14" />
+          </svg>
+        </a>
+      )}
+      {!isSidebar && (
+        <button
+          type="button"
+          onClick={onToggleFullscreen}
+          className="flex items-center justify-center rounded-md p-1.5 text-gray-600 hover:bg-gray-100 hover:text-gray-900 dark:text-gray-400 dark:hover:bg-gray-800 dark:hover:text-white"
+          aria-label={isFullscreen ? labels.exitFullscreen : labels.fullscreen}
+          title={isFullscreen ? labels.exitFullscreen : labels.fullscreen}
+        >
+          {isFullscreen ? (
+            <svg aria-hidden="true" className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 9V4.5M9 9H4.5M9 9L3.5 3.5M9 15v4.5M9 15H4.5M9 15l-5.5 5.5M15 9h4.5M15 9V4.5M15 9l5.5-5.5M15 15h4.5M15 15v4.5m0-4.5l5.5 5.5" />
+            </svg>
+          ) : (
+            <svg aria-hidden="true" className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 8V4m0 0h4M4 4l5 5m11-1V4m0 0h-4m4 0l-5 5M4 16v4m0 0h4m-4 0l5-5m11 5l-5-5m5 5v-4m0 4h-4" />
+            </svg>
+          )}
+        </button>
+      )}
+      <button
+        type="button"
+        onClick={onClose}
+        className="flex items-center justify-center rounded-md p-1.5 text-gray-600 hover:bg-gray-100 hover:text-gray-900 dark:text-gray-400 dark:hover:bg-gray-800 dark:hover:text-white"
+        aria-label={labels.close}
+        title={labels.close}
+      >
+        <svg aria-hidden="true" className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+        </svg>
+      </button>
+    </div>
+  );
+
+  const header = (
+    <div className="flex flex-shrink-0 items-center justify-between border-b border-border px-3 py-1.5">
+      <div className="flex min-w-0 flex-1 items-center gap-2">
+        <h3 className="truncate text-sm font-medium text-gray-900 dark:text-white">{file.name}</h3>
+      </div>
+      {headerActions}
+    </div>
+  );
+
+  if (isSidebar) {
+    return (
+      <div className="flex h-full w-full flex-col bg-background">
+        {header}
+        {previewBody}
+      </div>
+    );
+  }
+
+  const containerClassName = isFullscreen
+    ? 'fixed inset-0 z-[9999] bg-background flex flex-col'
+    : 'fixed inset-0 z-[9999] md:bg-black/50 md:flex md:items-center md:justify-center md:p-4';
+
+  const innerClassName = isFullscreen
+    ? 'bg-background flex flex-col w-full h-full'
+    : 'bg-background shadow-2xl flex flex-col w-full h-full md:rounded-lg md:shadow-2xl md:w-full md:max-w-6xl md:h-[80vh] md:max-h-[80vh]';
+
+  return (
+    <div className={containerClassName}>
+      <div className={innerClassName}>
+        {header}
+        {previewBody}
+      </div>
+    </div>
+  );
+}