Add network/fees stub api to rest-java (#12576)

Add a stub REST API endpoint for fee estimation to enable early SDK integration.

* Remove gRPC stub implementation and protobuf definitions
* Add POST /api/v1/network/fees endpoint to OpenAPI specification
* Implement stub endpoint returning test data in NetworkController
* Add test for fee estimation endpoint

---------

Signed-off-by: martingeorgiev1 <[email protected]>
Signed-off-by: Steven Sheehy <[email protected]>
Co-authored-by: Steven Sheehy <[email protected]>

Author: martingeorgiev1

grpc/src/main/java/org/hiero/mirror/grpc/controller/NetworkController.java

@@ -3,19 +3,10 @@
 package org.hiero.mirror.grpc.controller;
 
 import com.google.protobuf.ByteString;
-import com.google.protobuf.InvalidProtocolBufferException;
 import com.hedera.mirror.api.proto.AddressBookQuery;
-import com.hedera.mirror.api.proto.Fee.EstimateMode;
-import com.hedera.mirror.api.proto.Fee.FeeEstimate;
-import com.hedera.mirror.api.proto.Fee.FeeEstimateQuery;
-import com.hedera.mirror.api.proto.Fee.FeeEstimateResponse;
-import com.hedera.mirror.api.proto.Fee.FeeExtra;
-import com.hedera.mirror.api.proto.Fee.NetworkFee;
 import com.hedera.mirror.api.proto.ReactorNetworkServiceGrpc;
 import com.hederahashgraph.api.proto.java.NodeAddress;
 import com.hederahashgraph.api.proto.java.ServiceEndpoint;
-import com.hederahashgraph.api.proto.java.SignedTransaction;
-import io.grpc.Status;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import lombok.CustomLog;
@@ -35,45 +26,8 @@
 @RequiredArgsConstructor
 public class NetworkController extends ReactorNetworkServiceGrpc.NetworkServiceImplBase {
 
-    static final String INVALID_TRANSACTION = "Invalid Transaction.signedTransactionBytes";
-    static final FeeEstimateResponse STUB_RESPONSE = stubResponse();
-
     private final NetworkService networkService;
 
-    private static FeeEstimateResponse stubResponse() {
-        final var feeExtra = FeeExtra.newBuilder()
-                .setCharged(1)
-                .setCount(2)
-                .setFeePerUnit(10_000L)
-                .setIncluded(1)
-                .setName("Test data")
-                .setSubtotal(10_000L);
-        final var feeEstimate = FeeEstimate.newBuilder().setBase(100_000L).addExtras(feeExtra);
-        return FeeEstimateResponse.newBuilder()
-                .addNotes("This API is not yet implemented and only returns stubbed test data")
-                .setMode(EstimateMode.STATE)
-                .setNetwork(NetworkFee.newBuilder().setMultiplier(2).setSubtotal(220_000L))
-                .setNode(feeEstimate)
-                .setService(feeEstimate)
-                .setTotal(440_000L)
-                .build();
-    }
-
-    @Override
-    public Mono<FeeEstimateResponse> getFeeEstimate(FeeEstimateQuery request) {
-        try {
-            var bytes = request.getTransaction().getSignedTransactionBytes();
-            SignedTransaction.parseFrom(bytes);
-        } catch (InvalidProtocolBufferException e) {
-            final var error = Status.INVALID_ARGUMENT
-                    .augmentDescription(INVALID_TRANSACTION)
-                    .asRuntimeException();
-            return Mono.error(error);
-        }
-
-        return Mono.just(STUB_RESPONSE);
-    }
-
     @Override
     public Flux<NodeAddress> getNodes(Mono<AddressBookQuery> request) {
         return request.map(this::toFilter)

grpc/src/test/java/org/hiero/mirror/grpc/controller/NetworkControllerTest.java

@@ -6,12 +6,10 @@
 
 import com.google.protobuf.ByteString;
 import com.hedera.mirror.api.proto.AddressBookQuery;
-import com.hedera.mirror.api.proto.Fee.FeeEstimateQuery;
 import com.hedera.mirror.api.proto.ReactorNetworkServiceGrpc;
 import com.hederahashgraph.api.proto.java.FileID;
 import com.hederahashgraph.api.proto.java.NodeAddress;
 import com.hederahashgraph.api.proto.java.ServiceEndpoint;
-import com.hederahashgraph.api.proto.java.Transaction;
 import io.grpc.Status;
 import io.grpc.StatusRuntimeException;
 import java.net.InetAddress;
@@ -26,7 +24,6 @@
 import org.hiero.mirror.common.domain.addressbook.AddressBookEntry;
 import org.hiero.mirror.common.domain.addressbook.AddressBookServiceEndpoint;
 import org.hiero.mirror.common.domain.entity.EntityId;
-import org.hiero.mirror.common.util.DomainUtils;
 import org.hiero.mirror.grpc.GrpcIntegrationTest;
 import org.hiero.mirror.grpc.util.ProtoUtil;
 import org.junit.jupiter.api.Test;
@@ -45,29 +42,6 @@ final class NetworkControllerTest extends GrpcIntegrationTest {
     @GrpcClient("local")
     private ReactorNetworkServiceGrpc.ReactorNetworkServiceStub reactiveService;
 
-    @Test
-    void getFeeEstimate() {
-        final var query = FeeEstimateQuery.newBuilder().build();
-        StepVerifier.withVirtualTime(() -> reactiveService.getFeeEstimate(Mono.just(query)))
-                .thenAwait(WAIT)
-                .consumeNextWith(n -> assertThat(n).isEqualTo(NetworkController.STUB_RESPONSE))
-                .expectComplete()
-                .verify(WAIT);
-    }
-
-    @Test
-    void getFeeEstimateInvalidTransaction() {
-        final var query = FeeEstimateQuery.newBuilder()
-                .setTransaction(Transaction.newBuilder()
-                        .setSignedTransactionBytes(DomainUtils.fromBytes(domainBuilder.bytes(50))))
-                .build();
-        StepVerifier.withVirtualTime(() -> reactiveService.getFeeEstimate(Mono.just(query)))
-                .thenAwait(WAIT)
-                .expectErrorSatisfies(
-                        t -> assertException(t, Status.Code.INVALID_ARGUMENT, NetworkController.INVALID_TRANSACTION))
-                .verify(WAIT);
-    }
-
     @Test
     void getNodesMissingFileId() {
         final var query = AddressBookQuery.newBuilder().build();

protobuf/src/main/proto/com/hedera/mirror/api/proto/fee.proto

@@ -7,7 +7,6 @@ package com.hedera.mirror.api.proto;
 option java_multiple_files = true; // Required for the reactor-grpc generator to work correctly
 option java_package = "com.hedera.mirror.api.proto";
 
-import "com/hedera/mirror/api/proto/fee.proto";
 import "services/basic_types.proto";
 
 /**
@@ -22,11 +21,6 @@ message AddressBookQuery {
  * Provides cross network APIs like address book queries
  */
 service NetworkService {
-  /**
-   * Query to estimate the fees when submitting a transaction to the network.
-   */
-  rpc getFeeEstimate(FeeEstimateQuery) returns (FeeEstimateResponse);
-
   /**
    * Query for an address book and return its nodes. The nodes are returned in ascending order by node ID. The
    * response is not guaranteed to be a byte-for-byte equivalent to the NodeAddress in the Hedera file on

protobuf/src/main/proto/com/hedera/mirror/api/proto/network_service.proto

@@ -2,7 +2,11 @@
 
 package org.hiero.mirror.restjava.config;
 
+import com.google.protobuf.ExtensionRegistry;
+import com.google.protobuf.Message;
 import jakarta.annotation.PostConstruct;
+import java.io.IOException;
+import java.util.ArrayList;
 import lombok.RequiredArgsConstructor;
 import org.hiero.mirror.restjava.jooq.DomainRecordMapperProvider;
 import org.springframework.boot.autoconfigure.jooq.DefaultConfigurationCustomizer;
@@ -11,6 +15,10 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.format.support.FormattingConversionService;
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.http.converter.protobuf.ProtobufHttpMessageConverter;
 import org.springframework.web.filter.ShallowEtagHeaderFilter;
 
 @Configuration
@@ -19,6 +27,12 @@ class RestJavaConfiguration {
 
     private final FormattingConversionService mvcConversionService;
 
+    @PostConstruct
+    void initialize() {
+        // Register application converters to use case-insensitive string to enum converter.
+        ApplicationConversionService.addApplicationConverters(mvcConversionService);
+    }
+
     @Bean
     DefaultConfigurationCustomizer configurationCustomizer(DomainRecordMapperProvider domainRecordMapperProvider) {
         return c -> c.set(domainRecordMapperProvider).settings().withRenderSchema(false);
@@ -31,9 +45,31 @@ FilterRegistrationBean<ShallowEtagHeaderFilter> etagFilter() {
         return filterRegistrationBean;
     }
 
-    @PostConstruct
-    void initialize() {
-        // Register application converters to use case-insensitive string to enum converter.
-        ApplicationConversionService.addApplicationConverters(mvcConversionService);
+    @Bean
+    ProtobufHttpMessageConverter protobufHttpMessageConverter() {
+        final var protobufMediaType = new MediaType("application", "protobuf");
+        final var extensionRegistry = ExtensionRegistry.newInstance();
+
+        final var converter = new ProtobufHttpMessageConverter() {
+            @Override
+            protected Message readInternal(Class<? extends Message> clazz, HttpInputMessage inputMessage)
+                    throws IOException, HttpMessageNotReadableException {
+                final var message = super.readInternal(clazz, inputMessage);
+                final var contentType = inputMessage.getHeaders().getContentType();
+
+                if (protobufMediaType.isCompatibleWith(contentType)) {
+                    return message.toBuilder()
+                            .mergeFrom(inputMessage.getBody(), extensionRegistry)
+                            .build();
+                }
+
+                return message;
+            }
+        };
+
+        final var mediaTypes = new ArrayList<>(converter.getSupportedMediaTypes());
+        mediaTypes.add(protobufMediaType);
+        converter.setSupportedMediaTypes(mediaTypes);
+        return converter;
     }
 }