feat(client): implement batchCheck, listRelations, and non-transaction write

src/main/java/dev/openfga/sdk/api/client/OpenFgaClient.java

@@ -18,8 +18,12 @@
 import dev.openfga.sdk.api.configuration.*;
 import dev.openfga.sdk.api.model.*;
 import dev.openfga.sdk.errors.*;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.Executors;
+import java.util.function.Consumer;
 
 public class OpenFgaClient {
     private final ApiClient apiClient;
@@ -383,7 +387,29 @@ public CompletableFuture<ClientCheckResponse> check(ClientCheckRequest request,
      *
      * @throws FgaInvalidParameterException When the Store ID is null, empty, or whitespace
      */
-    // TODO
+    public CompletableFuture<List<ClientCheckResponse>> batchCheck(
+            List<ClientCheckRequest> requests, ClientBatchCheckOptions options) {
+        int maxParallelRequests = options.getMaxParallelRequests() != null
+                ? options.getMaxParallelRequests()
+                : DEFAULT_MAX_METHOD_PARALLEL_REQS;
+        var executor = Executors.newWorkStealingPool(maxParallelRequests);
+
+        var responses = new ConcurrentLinkedQueue<ClientCheckResponse>();
+
+        final var clientCheckOptions = options.asClientCheckOptions();
+
+        Consumer<ClientCheckRequest> singleClientCheckRequest =
+                request -> call(() -> this.check(request, clientCheckOptions)).thenApply(responses::add);
+
+        requests.forEach(request -> executor.execute(() -> singleClientCheckRequest.accept(request)));
+
+        try {
+            executor.wait();
+            return CompletableFuture.completedFuture(new ArrayList<>(responses));
+        } catch (InterruptedException e) {
+            return CompletableFuture.failedFuture(e);
+        }
+    }
 
     /**
      * Expand - Expands the relationships in userset tree format (evaluates)

src/main/java/dev/openfga/sdk/api/configuration/ClientBatchCheckOptions.java

@@ -0,0 +1,40 @@
+/*
+ * OpenFGA
+ * A high performance and flexible authorization/permission engine built for developers and inspired by Google Zanzibar.
+ *
+ * The version of the OpenAPI document: 0.1
+ * Contact: [email protected]
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package dev.openfga.sdk.api.configuration;
+
+public class ClientBatchCheckOptions {
+    private Integer maxParallelRequests;
+    private String authorizationModelId;
+
+    public ClientBatchCheckOptions maxParallelRequests(Integer maxParallelRequests) {
+        this.maxParallelRequests = maxParallelRequests;
+        return this;
+    }
+
+    public Integer getMaxParallelRequests() {
+        return maxParallelRequests;
+    }
+
+    public ClientBatchCheckOptions authorizationModelId(String authorizationModelId) {
+        this.authorizationModelId = authorizationModelId;
+        return this;
+    }
+
+    public String getAuthorizationModelId() {
+        return authorizationModelId;
+    }
+
+    public ClientCheckOptions asClientCheckOptions() {
+        return new ClientCheckOptions().authorizationModelId(authorizationModelId);
+    }
+}