001/*
002 * SPDX-License-Identifier: Apache-2.0
003 *
004 * Copyright 2024-2026 The Enola <https://enola.dev> Authors
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *     https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package dev.enola.common.protobuf;
019
020import com.google.protobuf.Descriptors;
021import com.google.protobuf.Descriptors.Descriptor;
022import com.google.protobuf.DynamicMessage;
023
024import dev.enola.common.io.resource.ReadableResource;
025import dev.enola.common.io.resource.WritableResource;
026import dev.enola.common.io.resource.convert.CatchingResourceConverter;
027
028import java.io.IOException;
029
030/** Converts Resources containing Protocol Buffer messages using the {@link ProtoIO} utility. */
031public class MessageResourceConverter implements CatchingResourceConverter {
032
033    private final DescriptorProvider descriptorProvider;
034    private final ProtoIO protoIO;
035
036    public MessageResourceConverter(ProtoIO protoIO, DescriptorProvider descriptorProvider) {
037        this.descriptorProvider = descriptorProvider;
038        this.protoIO = protoIO;
039    }
040
041    @Override
042    public boolean convertIntoThrows(ReadableResource from, WritableResource into)
043            throws IOException {
044        var fromProtoFQN = ProtobufMediaTypes.getProtoMessageFQN(from.mediaType());
045        if (fromProtoFQN.isPresent()) {
046            Descriptors.Descriptor descriptor =
047                    (Descriptor) descriptorProvider.findByName(fromProtoFQN.get());
048            // TODO Use new Messages (EnolaMessages) utility here #performance
049            var builder = DynamicMessage.newBuilder(descriptor);
050            protoIO.convert(from, builder, into);
051            return true;
052        } else {
053            return false;
054        }
055    }
056}