/**
 * Adapter that shapes PhotoPrism's `q=stack:true` photo list into a
 * `DuplicateGroup[]` the UI consumes. Mirrors mule-image's
 * `DuplicateGroup` interface so the view code stays declarative.
 *
 * PhotoPrism's `/photos?merged=true` inlines `Files[]` on each row
 * already — no follow-up GET per group needed (confirmed against
 * photoprism/photoprism:latest, May 2026).
 */

import { listPhotos } from '$lib/services/photoprism';
import type { PpFile, PpPhoto } from '$lib/types/photoprism';

export interface DuplicateGroup {
	/** The Photo record that owns this stack. Carries marks, keywords,
	 *  taken_at — everything the metadata sidebar reads off of. */
	photo: PpPhoto;
	/** The variants the user picks among. Always 2+ entries; groups with
	 *  a single file are filtered out (PhotoPrism shouldn't return them
	 *  for `stack:true` anyway, but the guard is cheap). */
	files: PpFile[];
	/** Pre-selected "keep this" file = the one PhotoPrism marks Primary.
	 *  The view starts with this highlighted and updates it on click. */
	bestFileUid: string;
}

export async function listDuplicateGroups(): Promise<DuplicateGroup[]> {
	const photos = await listPhotos({
		q: 'stack:true',
		count: 200,
		merged: true,
		order: 'newest'
	});
	return photos
		.filter((p) => (p.Files?.length ?? 0) > 1)
		.map((p) => {
			const files = p.Files ?? [];
			const primary = files.find((f) => f.Primary) ?? files[0];
			return { photo: p, files, bestFileUid: primary.UID };
		});
}