Treat additional Pinterest redeem error codes as terminal

src/AdCredits.php

@@ -91,13 +91,9 @@ public static function check_if_coupon_was_redeemed() {
 		$redeem_status = $account_data['coupon_redeem_info']['redeem_status'] ?? false;
 		$error_id      = $account_data['coupon_redeem_info']['error_id'] ?? false;
 
-		if ( PinterestApiException::OFFER_ALREADY_REDEEMED === $error_id ) {
-			// Advertiser has already redeemed the coupon.
-			return true;
-		}
-
-		if ( PinterestApiException::OFFER_ALREADY_REDEEMED_BY_ANOTHER_ADVERTISER === $error_id ) {
-			// Different advertiser id has already redeemed the coupon.
+		if ( in_array( $error_id, PinterestApiException::TERMINAL_REDEEM_ERRORS, true ) ) {
+			// A prior attempt hit a terminal error from Pinterest (e.g., the
+			// offer has already been redeemed). Do not retry.
 			return true;
 		}
 

src/PinterestApiException.php

@@ -58,6 +58,28 @@ class PinterestApiException extends \Exception {
 	 */
 	public const OFFER_ALREADY_REDEEMED_BY_ANOTHER_ADVERTISER = 2318;
 
+	/**
+	 * Offer already redeemed — additional Pinterest error code observed for
+	 * the same condition.
+	 *
+	 * Observed during investigation for PIN4WOO-74. Pinterest returns this
+	 * code alongside 2324 / 2318 for offer-redemption conflicts; the exact
+	 * distinction is not documented in the public API, but it has the same
+	 * terminal semantics as the other already-redeemed codes.
+	 */
+	public const OFFER_ALREADY_REDEEMED_VARIANT = 2322;
+
+	/**
+	 * Pinterest error codes that indicate a terminal, non-retryable failure of
+	 * the `ads_credit/redeem` endpoint. All of these mean the offer cannot be
+	 * redeemed again from this plugin's perspective.
+	 */
+	public const TERMINAL_REDEEM_ERRORS = array(
+		self::OFFER_ALREADY_REDEEMED,
+		self::OFFER_ALREADY_REDEEMED_BY_ANOTHER_ADVERTISER,
+		self::OFFER_ALREADY_REDEEMED_VARIANT,
+	);
+
 	/**
 	 * Merchant has been disapproved.
 	 * Some feeds, when deleting, may fail to delete due to the merchant has been disapproved.