Add charges and the billing limit for trusted apps

src/Id/Concerns/ManagesUserBilling.php

@@ -3,8 +3,10 @@
 namespace Anikeen\Id\Concerns;
 
 use Anikeen\Id\Exceptions\ApiException;
+use Anikeen\Id\Resources\AppCharge;
 use Anikeen\Id\Resources\AppCheckoutSessions;
 use Anikeen\Id\Resources\AppOrders;
+use Anikeen\Id\Resources\BillingLimit;
 use Anikeen\Id\Result;
 use Anikeen\Id\Support\AppRequest;
 use Throwable;
@@ -123,4 +125,101 @@ trait ManagesUserBilling
     {
         return $this->asApp()->request('POST', 'v1/admin/transactions', [...$attributes, 'user_id' => $userId]);
     }
+
+    /**
+     * Book a charge onto a user's open monthly bill of the app, e.g. a shipped item: one line,
+     * no subscription, charged with the bill on the 1st. Trusted apps that Anikeen allowed to
+     * charge (with a maximum per charge), for users connected to the app (they authorised it or
+     * the app bills them). The user's billing limit is checked when it is booked.
+     *
+     * Retrying with the same idempotency key and the same fields returns the existing charge
+     * (also after the limit was reached); other fields with that key: 409
+     * "idempotency_key_conflict" (`charge_id` in body()).
+     *
+     * @param string $userId The user's Anikeen ID.
+     * @param array{
+     *     idempotency_key: string,
+     *     name: string,
+     *     description?: null|string,
+     *     type?: string,
+     *     quantity: int,
+     *     unit_price: float|int|string,
+     *     currency_iso?: string,
+     *     group?: null|string,
+     *     occurred_at?: string,
+     *     reference?: null|string,
+     *     metadata?: null|array<string, string>,
+     *     image_url?: null|string
+     * } $attributes idempotency_key: unique per app and user, ≤ 255 (e.g. "shipment-123").
+     *               name: the line on the bill, ≤ 255. description: ≤ 255.
+     *               type: digital (default), physical or physical-reduced (the VAT treatment).
+     *               quantity: 1–10000 pieces. unit_price: net per piece, > 0, ≤ 100000, up to 6
+     *               decimals; quantity × unit_price rounded to cents must be at least 0.01.
+     *               currency_iso: EUR only (default).
+     *               group: null, or a group in which the app already bills the user (a running
+     *               subscription or an open monthly bill of the app).
+     *               occurred_at: the service date, not in the future, at most 31 days ago
+     *               (default now).
+     *               reference: the app's own id (≤ 255). metadata: ≤ 20 keys (≤ 40 characters),
+     *               string values ≤ 500. Both are not on the bill; put nothing sensitive there.
+     *               image_url: http(s) URL of an image for the line.
+     *
+     * @throws ApiException 403 "client_not_allowed" (not a trusted app), "charges_not_enabled";
+     *     404 "user_not_found" (unknown, deleted or not connected); 409 "billing_limit_reached"
+     *     (isBillingLimitReached(); body() has limit, used, remaining, remaining_net, required,
+     *     currency, resets_at), "charge_exceeds_maximum" (+ max_charge_net),
+     *     "group_not_allowed", "idempotency_key_conflict" (+ charge_id),
+     *     "billing_address_missing"; 422 validation; 429 "too_many_requests"
+     */
+    public function createChargeForUser(string $userId, array $attributes): AppCharge
+    {
+        return new AppCharge(AppRequest::send('POST', $this->chargesPath($userId), $attributes)->data);
+    }
+
+    /**
+     * A charge of the app (or of a client delegated to the same app) for a user.
+     *
+     * @throws ApiException 403 "client_not_allowed", "charges_not_enabled"; 404 "user_not_found",
+     *     "charge_not_found"; 429 "too_many_requests"
+     */
+    public function findChargeForUser(string $userId, string $chargeId): AppCharge
+    {
+        return new AppCharge(AppRequest::send('GET', $this->chargesPath($userId, $chargeId))->data);
+    }
+
+    /**
+     * Void a charge while its bill is open: the line is removed and the bill's total drops. An
+     * already voided charge is returned as it is. Once the bill is closed only a refund of the
+     * order by Anikeen credits it.
+     *
+     * @param string|null $reason why (≤ 255), stored with the charge
+     * @throws ApiException 409 "charge_already_billed" (+ charge_id); 404 "charge_not_found",
+     *     "user_not_found"; 403 "client_not_allowed", "charges_not_enabled"; 429 "too_many_requests"
+     */
+    public function voidChargeForUser(string $userId, string $chargeId, ?string $reason = null): AppCharge
+    {
+        $payload = $reason === null ? null : ['reason' => $reason];
+
+        return new AppCharge(AppRequest::send('POST', $this->chargesPath($userId, $chargeId) . '/void', $payload)->data);
+    }
+
+    /**
+     * A user's monthly billing limit as the app sees it, e.g. to pause paid features while it is
+     * reached. Advisory only: it reserves nothing; a charge is checked when it is booked. Trusted
+     * apps that may charge or that Anikeen allowed to read limits, for users connected to the app.
+     *
+     * @throws ApiException 403 "client_not_allowed", "billing_limit_not_enabled"; 404
+     *     "user_not_found"; 429 "too_many_requests"
+     */
+    public function billingLimitForUser(string $userId): BillingLimit
+    {
+        return new BillingLimit(AppRequest::send('GET', sprintf('v1/client/users/%s/billing-limit', rawurlencode($userId)))->data);
+    }
+
+    private function chargesPath(string $userId, ?string $chargeId = null): string
+    {
+        $path = sprintf('v1/client/users/%s/charges', rawurlencode($userId));
+
+        return $chargeId === null ? $path : $path . '/' . rawurlencode($chargeId);
+    }
 }