woocommerce-pos / includes / API / V2 / Variations_Controller.php

Variations_Controller.php in WCPOS – Point of Sale (POS) plugin for WooCommerce trunk, at includes/API/V2/Variations_Controller.php

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1	<?php
2	/**
3	* WCPOS sync read surface.
4	*
5	* @package WCPOS\WooCommercePOS\API\V2
6	*/
7
8	namespace WCPOS\WooCommercePOS\API\V2;
9
10	use WC_Product_Variation;
11	use WC_REST_Product_Variations_Controller;
12	use WCPOS\WooCommercePOS\Services\Barcode_Field;
13	use WCPOS\WooCommercePOS\Sync\Api;
14	use WCPOS\WooCommercePOS\Sync\Collection_Rules;
15	use WCPOS\WooCommercePOS\Sync\Collection_Rules_Plan;
16	use WCPOS\WooCommercePOS\Sync\Digest_Index;
17	use WCPOS\WooCommercePOS\Sync\Endpoint_Permissions;
18	use WCPOS\WooCommercePOS\Sync\Pos_Visibility;
19	use WCPOS\WooCommercePOS\Sync\Product_Serializer;
20	use WP_Error;
21	use WP_Query;
22	use WP_REST_Request;
23	use WP_REST_Response;
24	use WP_REST_Server;
25
26	// phpcs:disable Squiz.Commenting, Generic.Commenting -- Ported lab documentation is preserved verbatim.
27
28	/**
29	* Variations document endpoint — the collection's hydration AND list/seed lane (ADR 0034).
30	*
31	* Why a flat route: the change-signal yields BARE variation ids (no parent), and WooCommerce's
32	* only variation routes are parent-mediated (`products/<parent>/variations`). One flat route
33	* IS the cross-parent collection: bare pages seed the complete replica (the idle trickle),
34	* `include=` is one filter on it (targeted hydration, no parent->child dance), and the
35	* SKU/barcode discovery search is another.
36	*
37	* Why it EXTENDS WooCommerce's variations controller: because that is all the route ever needed.
38	* WooCommerce's `get_objects()` already answers a cross-parent query — with no `product_id` in
39	* the route there is no parent constraint, and `include`/`search`/`orderby`/pagination are its
40	* own collection params. 1.9.x did exactly this: `parent::get_items( $request )`, one line
41	* (`API\V1\Product_Variations_Controller::wcpos_get_all_items`).
42	*
43	* The previous version of this class extended a bare `WP_REST_Controller` and rebuilt the query
44	* by hand — ~90 lines of raw postmeta SQL, five hand-declared args, no item schema — on the
45	* stated grounds that "wc/v3 has no cross-parent variations?include=". That claim was false, and
46	* the cost of acting on it was the payload: a variation hydrated through the PRODUCTS controller
47	* carries `images[]` instead of `image`, which blanked every variation thumbnail in the POS on
48	* 1.10.0 and wrote the parent's image onto every order line (#1710).
49	*
50	* What stays ours, and only this: the sync document envelope the engine reads
51	* (`documents[].{id,parent_id,payload,_rxdb_digest}`), POS visibility, the barcode carrier
52	* search, and the request bounds. Everything else is WooCommerce's.
53	*/
54	class Variations_Controller extends WC_REST_Product_Variations_Controller {
55	/**
56	* Request keys the variation Collection Rules plan reads on this lane.
57	*
58	* @var array
59	*/
60	private const WCPOS_SORT_PARAM_MAP = array(
61	'orderby' => 'orderby',
62	'order' => 'order',
63	);
64
65	/**
66	* The request whose declared sort `wcpos_posts_clauses()` applies.
67	*
68	* @var null\|WP_REST_Request
69	*/
70	private $wcpos_sort_request = null;
71
72	use Endpoint_Permissions;
73
74	private const MAX_SKU_LENGTH = 4096;
75	private const MAX_SKU_TERMS = 100;
76	private const MAX_SEARCH_LENGTH = 256;
77	private const MAX_PAGE = 1000;
78
79
80	public function register_routes(): void {
81	/*
82	* ONLY the flat sync route. `parent::register_routes()` is deliberately not called: the
83	* v2 namespace is a read/sync surface, and writes ride Write_Controller, which already
84	* pushes through WooCommerce's nested routes. Registering WC's CRUD routes here would
85	* widen the POS-marker-gated surface for no consumer.
86	*
87	* The args and the schema are WooCommerce's own, so `include`, `search`, `orderby`,
88	* `order`, `offset`, `page`, `per_page`, `status` … all behave exactly as they do on
89	* wc/v3, and the route documents itself in the REST index.
90	*/
91	register_rest_route(
92	Api::ROUTE_NAMESPACE,
93	'/variations',
94	array(
95	array(
96	'methods' => WP_REST_Server::READABLE,
97	'callback' => array( $this, 'get_variations' ),
98	'permission_callback' => array( $this, 'permissions_check' ),
99	'args' => $this->get_collection_params(),
100	),
101	'schema' => array( $this, 'get_public_item_schema' ),
102	)
103	);
104	}
105
106	/**
107	* Narrow WooCommerce's variation query to what the POS may serve.
108	*
109	* Everything WooCommerce already understands — `include`, `offset`, `order`, pagination,
110	* status — comes from `parent::prepare_objects_query()`, which also applies
111	* `woocommerce_rest_product_variation_object_query` internally (wc/v3's CRUD controller fires
112	* it there, not in `get_items()`), so third-party query scoping reaches every lane built
113	* through this method. Layered on top — deliberately AFTER that filter, so a third party
114	* cannot widen what the POS may serve: POS visibility, the
115	* barcode-carrier search, and the sort keys the POS grids offer. This is the seam 1.9.x used
116	* for the same job (`API\V1\Product_Variations_Controller::prepare_objects_query`).
117	*
118	* @param WP_REST_Request $request Full details about the request.
119	*
120	* @return array
121	*/
122	protected function prepare_objects_query( $request ) {
123	/*
124	* WooCommerce splits `sku` on commas without trimming, so `sku=A, B` looks for " B".
125	* Normalize before it sees the param rather than reimplementing its matching.
126	*/
127	$sku = (string) ( $request->get_param( 'sku' ) ?? '' );
128	if ( '' !== $sku ) {
129	$terms = array_values(
130	array_filter(
131	array_map( 'trim', explode( ',', $sku ) ),
132	static function ( string $term ): bool {
133	return '' !== $term;
134	}
135	)
136	);
137	$sku = implode( ',', $terms );
138	$request->set_param( 'sku', $sku );
139	}
140
141	$args = parent::prepare_objects_query( $request );
142
143	/*
144	* A product is not a variation document.
145	*
146	* WooCommerce widens `post_type` to `array( 'product', 'product_variation' )` whenever
147	* `sku` is set, because the two share one SKU space. On THIS route that would serve a
148	* simple product as a variation — and the client would file it into its variations
149	* collection, the mirror image of the misfiled-variation pollution it already carries a
150	* one-shot repair for. Type purity on a variations route is ours to enforce.
151	*/
152	$args['post_type'] = $this->post_type;
153
154	/*
155	* `search` means the barcode CARRIERS here, not the post title.
156	*
157	* WooCommerce maps `search` onto `s`, which searches post_title/content — useless for a
158	* variation, whose title is a generated attribute string. The POS searches what a cashier
159	* actually types or scans: the SKU and whichever meta key the store configured as its
160	* barcode field (`Barcode_Field::search_keys()`). The complete phrase must match one carrier.
161	*
162	* `sku` is left to WooCommerce: its own exact/comma-list handling is what the
163	* sku-beats-search precedence rule relies on.
164	*/
165	$search = (string) ( $request->get_param( 'search' ) ?? '' );
166	if ( '' !== $sku ) {
167	// SKU is an exact lookup and outranks a fuzzy one; leaving WooCommerce's post-title
168	// `s` in place would AND the two and return nothing.
169	unset( $args['s'] );
170	}
171	if ( '' !== $search && '' === $sku ) {
172	unset( $args['s'] );
173	$args['wcpos_variation_search'] = true;
174	$carriers = array( 'relation' => 'OR' );
175	foreach ( Barcode_Field::search_keys() as $key ) {
176	$carriers[] = array(
177	'key' => $key,
178	'value' => trim( $search ),
179	'compare' => 'LIKE',
180	);
181	}
182	$args['meta_query'] = $this->add_meta_query( $args, $carriers ); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
183	}
184
185	/*
186	* This route only ever offers what the store owner has for sale — on EVERY lane, including
187	* `include`.
188	*
189	* WooCommerce's Enabled checkbox on the variation metabox writes `post_status = private`
190	* when unchecked ({@see \WC_Meta_Box_Product_Data::save_variations()}), and WooCommerce
191	* honours that everywhere a customer can reach: `get_visible_children()` and
192	* `get_available_variations()` both drop it. A cashier must not be able to sell a variation
193	* the owner switched off, so the POS behaves the same way.
194	*
195	* The `include` lane is NOT exempt. Being asked for an id by name is not evidence the owner
196	* wants it sold: the client learns those ids from the parent's `variations[]`, which
197	* WooCommerce fills from `get_children()` — publish AND private — and from the change
198	* signal, which journals a disabled variation like any other post. A disabled id simply is
199	* not hydrated, the client's targeted-pull shortfall prunes it, and it leaves every till.
200	* Re-enabling saves the variation, which journals it, and it comes back.
201	*
202	* Set after `parent::prepare_objects_query()` so an explicit `status` param cannot widen it.
203	*/
204	$args['post_status'] = 'publish';
205
206	/*
207	* Leg-3 (ADR 0014 WP-M5): POS-hidden (`online_only`) variations are never served. As a
208	* query exclusion rather than a post-hoc filter of the result, so paging and totals count
209	* the same set the client is allowed to see.
210	*
211	* Through the helper, NOT a raw `post__not_in` merge: `parent::prepare_objects_query()`
212	* maps `include` to `post__in`, and WP_Query IGNORES `post__not_in` when `post__in` is
213	* present — so `?search=X&include=<hidden id>` would have served a hidden variation.
214	* `apply_to_wp_query_args()` already owns that trap: it intersects `post__in` with the
215	* hidden set and pins an empty intersection to `array( 0 )`.
216	*/
217	$args = ( new Pos_Visibility() )->apply_to_wp_query_args( $args, Pos_Visibility::VARIATIONS );
218
219	/*
220	* The POS sorts on fields WooCommerce does not offer as orderby values. They are
221	* declared in Sync\Collection_Rules and projected into get_collection_params()
222	* below — without that, `orderby=sku` is rejected by REST argument validation
223	* before anything here runs.
224	*
225	* They are applied as SQL clauses, NOT as `meta_key` + `orderby => meta_value`:
226	* that pair INNER JOINs postmeta and drops every variation with no value for the
227	* key, so the sort silently filtered. `wcpos_posts_clauses()` LEFT JOINs instead
228	* and orders the meta-less rows last.
229	*/
230	$this->wcpos_sort_request = $request;
231	add_filter( 'posts_clauses', array( $this, 'wcpos_posts_clauses' ), 10, 2 );
232
233	return $args;
234	}
235
236	/**
237	* GET /variations — the flat collection's three lanes, one response shape.
238	*
239	* `?sku=`/`?search=` discovers by barcode carrier; a bare request serves one
240	* collection page (the trickle's seed lane); `?include=12,34` hydrates the
241	* named ids. All three resolve ids through WooCommerce's collection query,
242	* then hydrate through the shared assembly line below. Mirrors the wc/v3
243	* `products?include=` shape; the parent is resolved server-side off the
244	* loaded variation object (get_parent_id), so the client never needs to know
245	* parents. Unknown / non-variation ids are skipped (deletes are handled by
246	* the change-signal tombstone path, not here).
247	*/
248	public function get_variations( WP_REST_Request $request ) {
249	$started = microtime( true );
250	$search_meta = null;
251	if ( $request->has_param( 'sku' ) \|\| $request->has_param( 'search' ) ) {
252	$validation = $this->validate_search_request( $request );
253	if ( is_wp_error( $validation ) ) {
254	return $validation;
255	}
256	list( $ids, $search_meta ) = $this->search_variation_ids( $request );
257	} elseif ( array() === array_filter( (array) $request->get_param( 'include' ) ) ) {
258	/*
259	* A bare collection request — no `include`, no discovery term — answers page one of the
260	* POS-servable set with WooCommerce's own pagination, exactly as its `get_items()` would.
261	*
262	* This used to be a 400. That refusal is why the client still counts variations on the
263	* FROZEN `wcpos/v1` lane — the single remaining v1 call in the app — because the census
264	* probes a collection route and reads `X-WP-Total`, and no v2 variations route could
265	* answer "how many". Refusing the question was never a safety property: `include` is a
266	* filter, and a collection route with no filter is a collection.
267	*/
268	list( $ids, $search_meta ) = $this->collection_page( $request );
269	} else {
270	/*
271	* The ask runs through the SAME query WooCommerce's own collection read builds
272	* (#1751): `parent::prepare_objects_query()` maps `include` to `post__in` and — in
273	* wc/v3's CRUD controller — applies `woocommerce_rest_product_variation_object_query`
274	* internally, so third-party query scoping reaches this lane like every other
275	* (hook-parity contract #1738). The collection and discovery lanes always had that
276	* property; this lane loaded ids directly and bypassed it. POS visibility and the
277	* publish gate ride the same args (layered in our override).
278	*
279	* The paging/ordering params are PINNED, not honoured: this lane answers a named
280	* ask, so `per_page` covers the whole ask, `offset`/`page` cannot skip any of it
281	* (a skipped id is absent from documents, which the client reads as "prune this
282	* id"), and `orderby=include` keeps WooCommerce from ordering by a meta key whose
283	* EXISTS join would silently drop every variation lacking that meta row. Pinning
284	* `orderby` also keeps the args complete for direct (non-dispatched) invocations,
285	* which carry no route defaults. Served order is the include order either way —
286	* the intersect below is the final authority.
287	*/
288	$include_ids = array_values( array_unique( array_map( 'intval', (array) $request->get_param( 'include' ) ) ) );
289	// Pins live on a QUERY-ONLY clone: the dispatched request stays exactly
290	// as the client sent it, for the serializer's prepare-filters and for
291	// anything downstream reading it after dispatch.
292	$query_request = clone $request;
293	$query_request->set_param( 'per_page', max( 1, count( $include_ids ) ) );
294	$query_request->set_param( 'page', 1 );
295	$query_request->set_param( 'offset', 0 );
296	$query_request->set_param( 'orderby', 'include' );
297	$query_request->set_param( 'order', 'asc' );
298	$args = $this->prepare_objects_query( $query_request );
299
300	/*
301	* The ask is a CEILING. WooCommerce's variations controller UNIONS some
302	* collection params into `post__in` (`on_sale=true` array-unions every on-sale
303	* id on top of the ask), so without this intersection a stray param would
304	* hydrate the whole store into the till. No request param or filter may widen
305	* the served set beyond the named ids — narrowing is fine, that is what the
306	* object_query filter and the visibility exclusion are for. An emptied ask pins
307	* to `array( 0 )`, the same never-matches sentinel Pos_Visibility uses.
308	*/
309	$post_in = array_values( array_intersect( array_map( 'intval', (array) ( $args['post__in'] ?? array() ) ), $include_ids ) );
310	$args['post__in'] = array() === $post_in ? array( 0 ) : $post_in;
311	$results = $this->get_objects( $args );
312
313	$allowed_ids = array();
314	foreach ( $results['objects'] as $object ) {
315	if ( $object instanceof WC_Product_Variation ) {
316	$allowed_ids[] = $object->get_id();
317	}
318	}
319	$ids = array_values( array_intersect( $include_ids, $allowed_ids ) );
320	}
321	_prime_post_caches( $ids, true, true );
322
323	// Hydrate through THE product assembly line (Product_Serializer), the same
324	// seam resolve/changes use (ADR 0003 — values come from the REST
325	// representation, never raw SQL). wc_get_product() returns a
326	// WC_Product_Variation for a variation id; the instanceof guard keeps a
327	// product id from being hydrated through this lane.
328	// Leg-3 (ADR 0014): attach each variation's stored 64-bit digest as `_rxdb_digest` so the client
329	// seeds its existence-reconcile manifest from this pull too (products get theirs via the proxy
330	// filter). Bulk-read once for the whole include set. A string — the digest exceeds int range.
331	// ::class, never the bare string: from inside this namespace
332	// class_exists( 'Digest_Index' ) probes the GLOBAL namespace and is
333	// forever false, so variation digests would never emit (review finding 3).
334	// Variations read the PRODUCTS id-space — one registry row owns both
335	// object types, so this lane cannot drift from the proxy lane's answer.
336	$digests = class_exists( Digest_Index::class )
337	? ( new Digest_Index() )->read_digests( 'products', $ids )
338	: array();
339
340	$serializer = new Product_Serializer();
341	// A CLONE of the live request, not a synthetic bare one (so prepare-filters
342	// see the real request context), and not the live request itself (the
343	// serializer stamps store scope and a per-variation `product_id` onto
344	// whatever it is handed; the dispatched request must leave this method as
345	// the client sent it).
346	$serialization_request = clone $request;
347	$documents = array();
348	foreach ( $ids as $id ) {
349	$variation = wc_get_product( $id );
350	if ( ! $variation instanceof WC_Product_Variation ) {
351	continue;
352	}
353	/*
354	* DISABLED variations are never hydrated — see the `post_status` note in
355	* prepare_objects_query(). The query-level publish gate covers ALL lanes, including
356	* `include`; this check only guards a status change between the id query and object load.
357	*
358	* `meta.requested` now counts the query-eligible ask: a disabled or query-filtered id is
359	* absent from $ids. The client's targeted-pull shortfall — absence from documents — is
360	* unchanged.
361	*/
362	if ( 'publish' !== $variation->get_status() ) {
363	continue;
364	}
365	$payload = $serializer->serialize( $variation, $serialization_request );
366	$document = array(
367	'id' => $id,
368	'parent_id' => (int) $variation->get_parent_id(),
369	'payload' => $payload,
370	);
371	if ( isset( $digests[ $id ] ) ) {
372	$document['_rxdb_digest'] = $digests[ $id ];
373	}
374	$documents[] = $document;
375	}
376
377	$meta = array(
378	'duration_ms' => round( ( microtime( true ) - $started ) * 1000, 3 ),
379	'requested' => \count( $ids ),
380	'returned' => \count( $documents ),
381	);
382	if ( null !== $search_meta ) {
383	$meta = array_merge( $meta, $search_meta );
384	}
385
386	$response = rest_ensure_response(
387	array(
388	'documents' => $documents,
389	'meta' => $meta,
390	)
391	);
392
393	/*
394	* The pagination WooCommerce would have sent.
395	*
396	* No v2 route emitted `X-WP-Total`/`X-WP-TotalPages` — including this one, the only one
397	* that paginates. The client asks for them on every v2 GET (the response envelope mirrors
398	* them into the body), so it has been receiving an empty mirror and falling back to
399	* short-page detection, which cannot tell "last page" from "the server truncated".
400	*/
401	if ( null !== $search_meta && $response instanceof WP_REST_Response ) {
402	$response->header( 'X-WP-Total', (string) $search_meta['total'] );
403	$response->header(
404	'X-WP-TotalPages',
405	(string) ( $search_meta['per_page'] > 0 ? (int) ceil( $search_meta['total'] / $search_meta['per_page'] ) : 0 )
406	);
407	}
408
409	return $response;
410	}
411
412	/**
413	* Reject search requests that could build excessively large SQL queries or offsets.
414	*
415	* @return true\|WP_Error
416	*/
417	private function validate_search_request( WP_REST_Request $request ) {
418	$sku = (string) ( $request->get_param( 'sku' ) ?? '' );
419	$skus = array_filter(
420	array_map( 'trim', explode( ',', $sku ) ),
421	static function ( string $term ): bool {
422	return '' !== $term;
423	}
424	);
425	if ( array() !== $skus ) {
426	$sku = implode( ',', $skus );
427	if ( self::MAX_SKU_LENGTH < \strlen( $sku ) ) {
428	return new WP_Error( 'woocommerce_pos_variations_search_limit_exceeded', 'sku must not exceed 4096 bytes', array( 'status' => 400 ) );
429	}
430	if ( self::MAX_SKU_TERMS < \count( $skus ) ) {
431	return new WP_Error( 'woocommerce_pos_variations_search_limit_exceeded', 'sku must not contain more than 100 comma-separated terms', array( 'status' => 400 ) );
432	}
433	} else {
434	$search = (string) $request->get_param( 'search' );
435	if ( self::MAX_SEARCH_LENGTH < \strlen( $search ) ) {
436	return new WP_Error( 'woocommerce_pos_variations_search_limit_exceeded', 'search must not exceed 256 bytes', array( 'status' => 400 ) );
437	}
438	}
439
440	if ( self::MAX_PAGE < (int) $request->get_param( 'page' ) ) {
441	return new WP_Error( 'woocommerce_pos_variations_search_limit_exceeded', 'page must not exceed 1000', array( 'status' => 400 ) );
442	}
443
444	return true;
445	}
446
447	/**
448	* Apply the declared POS variation sorts to the SQL clauses.
449	*
450	* `posts_clauses` fires for EVERY WP_Query, so the body is guarded by post type and by
451	* the plan itself — it contributes nothing unless this request claimed one of the
452	* declared sorts.
453	*
454	* @param array $clauses Associative array of the clauses for the query.
455	* @param WP_Query $wp_query The WP_Query instance.
456	*
457	* @return array
458	*/
459	public function wcpos_posts_clauses( array $clauses, WP_Query $wp_query ): array {
460	if ( null === $this->wcpos_sort_request ) {
461	return $clauses;
462	}
463
464	$post_type = $wp_query->query_vars['post_type'] ?? null;
465	if ( 'product_variation' !== $post_type && ( ! \is_array( $post_type ) \|\| ! \in_array( 'product_variation', $post_type, true ) ) ) {
466	return $clauses;
467	}
468
469	$plan = Collection_Rules::for_request( 'variations', $this->wcpos_sort_request, self::WCPOS_SORT_PARAM_MAP );
470
471	return $plan->filter( Collection_Rules_Plan::HOOK_POSTS_CLAUSES, $clauses, $wp_query );
472	}
473
474	/**
475	* WooCommerce's collection params, plus the sort keys the POS grids offer.
476	*
477	* `orderby` is a validated enum. Appending here is what lets `prepare_objects_query()` act on
478	* these four — otherwise the request 400s during argument validation and the switch is dead
479	* code. 1.9.x extended the same enum for the same reason.
480	*/
481	public function get_collection_params() {
482	$params = parent::get_collection_params();
483	$params['search']['sanitize_callback'] = 'rest_sanitize_request_arg';
484
485	if ( isset( $params['orderby']['enum'] ) && \is_array( $params['orderby']['enum'] ) ) {
486	$params['orderby']['enum'] = array_values(
487	array_unique(
488	array_merge(
489	$params['orderby']['enum'],
490	Collection_Rules::orderby_enum( 'variations' )
491	)
492	)
493	);
494	}
495
496	return $params;
497	}
498
499	/**
500	* De-duplicate variation searches joined through matching meta rows.
501	*
502	* @param string $groupby Existing GROUP BY clause.
503	* @param WP_Query $query Query being filtered.
504	*/
505	public function group_search_results( string $groupby, WP_Query $query ): string {
506	global $wpdb;
507
508	return ! empty( $query->query_vars['wcpos_variation_search'] ) ? "{$wpdb->posts}.ID" : $groupby;
509	}
510
511	/**
512	* Does this discovery request still carry a term after normalization?
513	*
514	* `has_param()` is what selects discovery mode, and an empty or whitespace-only value passes
515	* it. This is the check that decides whether a query would actually be constrained.
516	*/
517	private function has_discovery_constraint( WP_REST_Request $request ): bool {
518	$sku = (string) ( $request->get_param( 'sku' ) ?? '' );
519	if ( '' !== trim( $sku, " \t\n\r\0\x0B," ) ) {
520	return true;
521	}
522
523	$search = (string) ( $request->get_param( 'search' ) ?? '' );
524
525	return array() !== (array) preg_split( '/\s+/', trim( $search ), -1, PREG_SPLIT_NO_EMPTY );
526	}
527
528	/**
529	* One page of the POS-servable variation collection, with its total.
530	*
531	* WooCommerce's query pair, same as {@see search_variation_ids()} — the only difference is that
532	* a bare collection request carries no discovery constraint to normalize away, so the
533	* blank-scan guard that turns `?search=%20` into zero rows must NOT apply here. Visibility and
534	* `post_status` narrowing both ride `prepare_objects_query()`, so this page counts exactly what
535	* the client is allowed to receive.
536	*
537	* @return array{0: array<int, int>, 1: array{total: int, page: int, per_page: int}}
538	*/
539	private function collection_page( WP_REST_Request $request ): array {
540	$per_page = max( 1, min( 100, (int) ( $request->get_param( 'per_page' ) ?? 10 ) ) );
541	$page = max( 1, (int) ( $request->get_param( 'page' ) ?? 1 ) );
542	$request->set_param( 'per_page', $per_page );
543	$request->set_param( 'page', $page );
544
545	$results = $this->get_objects( $this->prepare_objects_query( $request ) );
546
547	$ids = array();
548	foreach ( $results['objects'] as $object ) {
549	if ( $object instanceof WC_Product_Variation ) {
550	$ids[] = $object->get_id();
551	}
552	}
553
554	return array(
555	$ids,
556	array(
557	'total' => (int) ( $results['total'] ?? \count( $ids ) ),
558	'page' => $page,
559	'per_page' => $per_page,
560	),
561	);
562	}
563
564	/**
565	* Discover a page of published, POS-visible variation ids by SKU/barcode.
566	*
567	* The query is WooCommerce's — `prepare_objects_query()` + `get_objects()`, the same pair its
568	* own `get_items()` uses. This method previously hand-built the SQL: a `wp_posts`/`wp_postmeta`
569	* INNER JOIN with `LIKE` predicates assembled per (field, term) pair, a second COUNT(DISTINCT)
570	* query for the total, and the hidden-id exclusion spliced into the same placeholder list. All
571	* of it duplicated `WP_Query` — which is where such copies go wrong, quietly and later.
572	*
573	* @return array{0: array<int, int>, 1: array{total: int, page: int, per_page: int}}
574	*/
575	private function search_variation_ids( WP_REST_Request $request ): array {
576	$per_page = max( 1, min( 100, (int) ( $request->get_param( 'per_page' ) ?? 10 ) ) );
577	$page = max( 1, (int) ( $request->get_param( 'page' ) ?? 1 ) );
578	$request->set_param( 'per_page', $per_page );
579	$request->set_param( 'page', $page );
580
581	$query_args = $this->prepare_objects_query( $request );
582
583	/*
584	* A discovery request whose terms normalize away — `?sku=`, `?sku=,%20`, `?search=%20` —
585	* has no constraint left. Inherited, that query would return the FIRST PAGE OF EVERY
586	* VARIATION and advertise the catalogue-wide total; the replaced SQL deliberately used
587	* `1 = 0`. A blank scan must hydrate nothing, not everything.
588	*/
589	if ( ! $this->has_discovery_constraint( $request ) ) {
590	return array(
591	array(),
592	array(
593	'total' => 0,
594	'page' => $page,
595	'per_page' => $per_page,
596	),
597	);
598	}
599
600	add_filter( 'posts_groupby', array( $this, 'group_search_results' ), 10, 2 );
601	try {
602	$results = $this->get_objects( $query_args );
603	} finally {
604	remove_filter( 'posts_groupby', array( $this, 'group_search_results' ), 10 );
605	}
606
607	$ids = array();
608	foreach ( $results['objects'] as $object ) {
609	if ( $object instanceof WC_Product_Variation ) {
610	$ids[] = $object->get_id();
611	}
612	}
613
614	return array(
615	$ids,
616	array(
617	'total' => (int) ( $results['total'] ?? \count( $ids ) ),
618	'page' => $page,
619	'per_page' => $per_page,
620	),
621	);
622	}
623	}
624