integrations/rest-management/rest-management/src/main/java/org/apache/aries/jax/rs/rest/management/internal/RestManagementActivator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.aries.jax.rs.rest.management.internal;

import static org.apache.aries.component.dsl.OSGi.all;
import static org.apache.aries.component.dsl.OSGi.ignore;
import static org.apache.aries.component.dsl.OSGi.register;
import static org.apache.aries.component.dsl.OSGi.service;
import static org.apache.aries.component.dsl.OSGi.serviceReferences;
import static org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants.JAX_RS_APPLICATION_SELECT;
import static org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants.JAX_RS_EXTENSION;
import static org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants.JAX_RS_EXTENSION_SELECT;
import static org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants.JAX_RS_NAME;
import static org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants.JAX_RS_RESOURCE;

import java.util.HashMap;
import java.util.function.BiFunction;

import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.core.Application;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;

import org.apache.aries.component.dsl.OSGiResult;
import org.apache.aries.jax.rs.rest.management.handler.RestManagementMessageBodyHandler;
import org.osgi.annotation.bundle.Header;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.PrototypeServiceFactory;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.jaxrs.whiteboard.JaxrsWhiteboardConstants;
import org.osgi.service.rest.client.RestClientFactory;

import io.swagger.v3.oas.models.OpenAPI;
import io.swagger.v3.oas.models.info.Contact;
import io.swagger.v3.oas.models.info.Info;

@Header(name = Constants.BUNDLE_ACTIVATOR, value = "${@class}")
public class RestManagementActivator implements BundleActivator {

    public static final String RMS_BASE = "/rms";

    private OSGiResult result;

    @Override
    public void start(BundleContext bundleContext) throws Exception {
        result = all(
            ignore(
                register(
                    Application.class,
                    () -> new RestManagementApplication(),
                    () -> {
                        HashMap<String, Object> map = new HashMap<>();

                        map.put(JAX_RS_NAME, RestManagementApplication.class.getSimpleName());
                        map.put(
                            JaxrsWhiteboardConstants.JAX_RS_APPLICATION_BASE, RMS_BASE);

                        return map;
                    }
                )
            ),
            ignore(
                service(
                    serviceReferences(ClientBuilder.class)
                ).flatMap(
                    clientBuilder -> register(
                        RestClientFactory.class,
                        new RestClientFactoryImpl(clientBuilder),
                        null
                    )
                )
            ),
            ignore(
                register(
                    new String[] {
                        MessageBodyReader.class.getName(),
                        MessageBodyWriter.class.getName()
                    },
                    () -> new PrototypeWrapper<>(
                        (b, r) -> new RestManagementMessageBodyHandler()
                    ),
                    () -> {
                        HashMap<String, Object> map = new HashMap<>();

                        map.put(JAX_RS_NAME, RestManagementMessageBodyHandler.class.getSimpleName());
                        map.put(
                            JAX_RS_APPLICATION_SELECT,
                            String.format(
                                "(%s=%s)", JAX_RS_NAME,
                                RestManagementApplication.class.getSimpleName()));
                        map.put(JAX_RS_EXTENSION, true);

                        return map;
                    }
                )
            ),
            ignore(
                register(
                    FrameworkResource.class,
                    () -> new FrameworkResource(bundleContext),
                    () -> {
                        HashMap<String, Object> map = new HashMap<>();

                        map.put(
                            JAX_RS_APPLICATION_SELECT,
                            String.format(
                                "(%s=%s)", JAX_RS_NAME,
                                RestManagementApplication.class.getSimpleName()));
                        map.put(JAX_RS_RESOURCE, true);
                        map.put(JAX_RS_EXTENSION_SELECT, new String[] {
                            String.format(
                                "(%s=%s)", JAX_RS_NAME,
                                RestManagementMessageBodyHandler.class.getSimpleName())
                        });

                        return map;
                    }
                )
            ),
            ignore(
                register(
                    OpenAPI.class,
                    () -> {
                        OpenAPI openAPI = new OpenAPI();

                        openAPI.info(
                            new Info()
                                .title("Apache Aries OSGi Rest Management Service")
                                .description("Apache Aries OSGi Rest Management Service REST API")
                                .contact(
                                    new Contact()
                                        .email("dev@aries.apache.org"))
                        );

                        return openAPI;
                    },
                    () -> {
                        HashMap<String, Object> map = new HashMap<>();

                        map.put(
                            JAX_RS_APPLICATION_SELECT,
                            String.format(
                                "(%s=%s)", JAX_RS_NAME,
                                RestManagementApplication.class.getSimpleName()));

                        return map;
                    }
                )
            )
        ).run(bundleContext);
    }

    @Override
    public void stop(BundleContext context) throws Exception {
        result.close();
    }

    class PrototypeWrapper<S> implements PrototypeServiceFactory<S> {

        private final BiFunction<Bundle, ServiceRegistration<S>, S> function;

        public PrototypeWrapper(BiFunction<Bundle, ServiceRegistration<S>, S> function) {
            this.function = function;
        }

        @Override
        public S getService(Bundle bundle, ServiceRegistration<S> registration) {
            return function.apply(bundle, registration);
        }

        @Override
        public void ungetService(Bundle bundle, ServiceRegistration<S> registration, S service) {
        }

    }

}