init

2026-05-31 20:25:41 +00:00
commit 0a07ab8593
275 changed files with 52660 additions and 0 deletions
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+import type { CogniteClient, FileInfo } from '@cognite/sdk';
+import {
+  getComputedMimeType,
+  isNativelySupportedMimeType,
+  doesDocumentPreviewApiSupportFile,
+  DocumentMimeType,
+} from './mimeTypes';
+
+// ============================================================================
+// Cache
+// ============================================================================
+
+/** CDF URLs expire after 60 min with extendedExpiration — refresh at 59 min. */
+const URL_CACHE_EXPIRE_MS = 59 * 60 * 1000;
+const MAX_CACHE_SIZE = 200;
+
+interface CacheEntry {
+  url: string;
+  mimeType: string;
+  expiresAt: number;
+}
+
+const urlCache = new Map<string, CacheEntry>();
+
+/** Evict expired entries; if still over limit, drop oldest inserted. */
+function evictStaleEntries(): void {
+  const now = Date.now();
+  for (const [key, entry] of urlCache) {
+    if (entry.expiresAt <= now) urlCache.delete(key);
+  }
+  if (urlCache.size > MAX_CACHE_SIZE) {
+    for (const key of Array.from(urlCache.keys()).slice(0, urlCache.size - MAX_CACHE_SIZE)) {
+      urlCache.delete(key);
+    }
+  }
+}
+
+export function clearFileCache(fileId: number, project?: string): void {
+  const prefix = project ? `${project}:` : '';
+  urlCache.delete(`${prefix}${fileId}`);
+}
+
+export function clearAllFileCache(): void {
+  urlCache.clear();
+}
+
+// ============================================================================
+// Download URL helpers
+// ============================================================================
+
+/**
+ * Get download URL with extended expiration (59 min instead of default ~30 min).
+ * The JS SDK doesn't expose `extendedExpiration`, so we call the API directly.
+ */
+async function getDownloadUrlExtended(
+  client: CogniteClient,
+  fileId: number,
+): Promise<string> {
+  const result = await client.post<{ items: Array<{ downloadUrl: string }> }>(
+    `/api/v1/projects/${client.project}/files/downloadlink`,
+    {
+      data: { items: [{ id: fileId }] },
+      params: { extendedExpiration: true },
+    },
+  );
+  const downloadUrl = result.data.items[0]?.downloadUrl;
+  if (!downloadUrl) throw new Error(`No download URL for file ${fileId}`);
+  return downloadUrl;
+}
+
+/**
+ * Get a temporary PDF link via the Document Preview API.
+ * Converts Office documents to PDF.
+ */
+async function getPdfTemporaryLink(
+  client: CogniteClient,
+  fileId: number,
+): Promise<string> {
+  const response = await client.documents.preview.pdfTemporaryLink(fileId);
+  return response.temporaryLink;
+}
+
+// ============================================================================
+// Main resolution function
+// ============================================================================
+
+export interface ResolvedFileConfig {
+  url: string;
+  mimeType: string;
+}
+
+/**
+ * Resolve a CDF file to a download URL and effective MIME type.
+ *
+ * Strategy:
+ * 1. Natively supported (images, PDF, text) → direct download with extended expiry
+ * 2. Office documents → PDF conversion via Document Preview API
+ * 3. Otherwise → throws
+ *
+ * Results are cached for 59 minutes.
+ */
+export async function resolveFileDownloadConfig(
+  client: CogniteClient,
+  file: FileInfo,
+): Promise<ResolvedFileConfig> {
+  const cacheKey = `${client.project}:${file.id}`;
+  const now = Date.now();
+  const cached = urlCache.get(cacheKey);
+  if (cached && cached.expiresAt > now) {
+    return { url: cached.url, mimeType: cached.mimeType };
+  }
+
+  const computedMimeType = getComputedMimeType(file);
+
+  let resolved: ResolvedFileConfig;
+
+  if (computedMimeType && isNativelySupportedMimeType(computedMimeType)) {
+    const url = await getDownloadUrlExtended(client, file.id);
+    resolved = { url, mimeType: computedMimeType };
+  } else if (doesDocumentPreviewApiSupportFile(file)) {
+    const url = await getPdfTemporaryLink(client, file.id);
+    resolved = { url, mimeType: DocumentMimeType.PDF };
+  } else {
+    throw new Error(
+      `Unsupported file type (id: ${file.id}, name: ${file.name}, mimeType: ${file.mimeType})`,
+    );
+  }
+
+  urlCache.set(cacheKey, { ...resolved, expiresAt: now + URL_CACHE_EXPIRE_MS });
+  evictStaleEntries();
+  return resolved;
+}