Create boost create endpoint

service/src/main/java/org/whispersystems/textsecuregcm/controllers/SubscriptionController.java

@@ -35,6 +35,7 @@ import javax.annotation.Nonnull;
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 import javax.validation.Valid;
+import javax.validation.constraints.Min;
 import javax.validation.constraints.NotEmpty;
 import javax.ws.rs.BadRequestException;
 import javax.ws.rs.Consumes;
@@ -409,6 +410,56 @@ public class SubscriptionController {
             Collectors.toMap(entry -> entry.getKey().toUpperCase(Locale.ROOT), Function.identity()))).build());
   }
 
+  public static class CreateBoostRequest {
+
+    private final String currency;
+    private final long amount;
+
+    @JsonCreator
+    public CreateBoostRequest(
+        @JsonProperty("currency") String currency,
+        @JsonProperty("amount") long amount) {
+      this.currency = currency;
+      this.amount = amount;
+    }
+
+    @NotEmpty
+    @ExactlySize(3)
+    public String getCurrency() {
+      return currency;
+    }
+
+    @Min(1)
+    public long getAmount() {
+      return amount;
+    }
+  }
+
+  public static class CreateBoostResponse {
+
+    private final String clientSecret;
+
+    @JsonCreator
+    public CreateBoostResponse(
+        @JsonProperty("clientSecret") String clientSecret) {
+      this.clientSecret = clientSecret;
+    }
+
+    public String getClientSecret() {
+      return clientSecret;
+    }
+  }
+
+  @Timed
+  @POST
+  @Path("/boost/create")
+  @Consumes(MediaType.APPLICATION_JSON)
+  @Produces(MediaType.APPLICATION_JSON)
+  public CompletableFuture<Response> createBoostPaymentIntent(CreateBoostRequest request) {
+    return stripeManager.createPaymentIntent(request.getCurrency(), request.getAmount())
+        .thenApply(paymentIntent -> Response.ok(new CreateBoostResponse(paymentIntent.getClientSecret())).build());
+  }
+
   public static class GetSubscriptionInformationResponse {
 
     public static class Subscription {

service/src/main/java/org/whispersystems/textsecuregcm/stripe/StripeManager.java

@@ -11,6 +11,7 @@ import com.stripe.exception.StripeException;
 import com.stripe.model.Customer;
 import com.stripe.model.Invoice;
 import com.stripe.model.InvoiceLineItem;
+import com.stripe.model.PaymentIntent;
 import com.stripe.model.Price;
 import com.stripe.model.Product;
 import com.stripe.model.SetupIntent;
@@ -22,6 +23,7 @@ import com.stripe.param.CustomerRetrieveParams;
 import com.stripe.param.CustomerUpdateParams;
 import com.stripe.param.CustomerUpdateParams.InvoiceSettings;
 import com.stripe.param.InvoiceListParams;
+import com.stripe.param.PaymentIntentCreateParams;
 import com.stripe.param.PriceRetrieveParams;
 import com.stripe.param.SetupIntentCreateParams;
 import com.stripe.param.SubscriptionCancelParams;
@@ -40,6 +42,7 @@ import java.util.Base64;
 import java.util.Collection;
 import java.util.Comparator;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
@@ -140,6 +143,20 @@ public class StripeManager {
     }, executor);
   }
 
+  public CompletableFuture<PaymentIntent> createPaymentIntent(String currency, long amount) {
+    return CompletableFuture.supplyAsync(() -> {
+      PaymentIntentCreateParams params = PaymentIntentCreateParams.builder()
+          .setAmount(amount)
+          .setCurrency(currency.toLowerCase(Locale.ROOT))
+          .build();
+      try {
+        return PaymentIntent.create(params, commonOptions());
+      } catch (StripeException e) {
+        throw new CompletionException(e);
+      }
+    }, executor);
+  }
+
   public CompletableFuture<Subscription> createSubscription(String customerId, String priceId, long level, long lastSubscriptionCreatedAt) {
     return CompletableFuture.supplyAsync(() -> {
       SubscriptionCreateParams params = SubscriptionCreateParams.builder()