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CADAM-master/shared/imageRefs.ts

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+// Helpers for resolving uploaded-image file parts to private-storage objects.
+//
+// Uploaded images live in the (private, RLS-protected) `images` bucket at
+// `${userId}/${conversationId}/${imageId}`. An AI SDK file part carries the
+// image id in its `filename` (`${imageId}.png`); the part's `url` is a stable
+// REFERENCE string, not something to fetch directly. The bytes are resolved
+// from storage by id at the two boundaries that actually need them:
+//   * the chat server downloads them to base64 for the model, and
+//   * the client downloads them via a signed URL for display.
+//
+// Persisting a base64 data URL in the part (as the AI SDK migration
+// accidentally did) duplicates the whole image into `messages.parts`; a raw
+// `/storage/.../public/...` path (as the backfill wrote) never resolves
+// because the bucket is private. Both are avoided by keeping `url` a
+// reference and resolving by id.
+
+export function imageIdFromFilename(
+  filename: string | null | undefined,
+): string | null {
+  if (!filename) return null;
+  return filename.replace(/\.[^.]+$/, '') || null;
+}
+
+export function imageStoragePath(
+  userId: string,
+  conversationId: string,
+  imageId: string,
+): string {
+  return `${userId}/${conversationId}/${imageId}`;
+}
+
+// Canonical reference persisted in a file part's `url`. Kept in the exact
+// shape the 2026-05-18 AI-SDK backfill produced so every row in
+// `messages.parts` carries a single, uniform format. Never fetched directly —
+// see the note above.
+export function imageFilePartUrl(
+  userId: string,
+  conversationId: string,
+  imageId: string,
+): string {
+  return `/storage/v1/object/public/images/${imageStoragePath(
+    userId,
+    conversationId,
+    imageId,
+  )}`;
+}