services/self-service/src/main/java/com/epam/dlab/backendapi/service/impl/MavenCentralLibraryService.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 com.epam.dlab.backendapi.service.impl;

import com.epam.dlab.backendapi.domain.MavenSearchArtifactResponse;
import com.epam.dlab.backendapi.resources.dto.LibraryDTO;
import com.epam.dlab.backendapi.service.ExternalLibraryService;
import com.epam.dlab.constants.ServiceConsts;
import com.epam.dlab.exceptions.ResourceNotFoundException;
import com.epam.dlab.rest.client.RESTService;
import com.google.inject.Singleton;
import com.google.inject.name.Named;
import lombok.extern.slf4j.Slf4j;

import javax.inject.Inject;
import java.net.URI;

import static java.lang.String.format;
import static java.lang.String.join;

@Singleton
@Slf4j
public class MavenCentralLibraryService implements ExternalLibraryService {

	private static final String QUOTE_ENCODED = "%22";
	private static final String SEARCH_API_QUERY_FORMAT = "/solrsearch/select?q=%s&rows=20&wt=json&core=gav&p=jar";
	private static final String LIB_NOT_FOUND_MSG = "No matches found";
	private final RESTService restClient;

	@Inject
	public MavenCentralLibraryService(@Named(ServiceConsts.MAVEN_SEARCH_API) RESTService restClient) {
		this.restClient = restClient;
	}

	@Override
	public LibraryDTO getLibrary(String groupId, String artifactId, String version) {
		return getMavenLibrary(groupId, artifactId, version);

	}

	private LibraryDTO getMavenLibrary(String groupId, String artifactId, String version) {
		final String query = and(artifactQuery(artifactId), groupQuery(groupId), versionQuery(version), jarOrBundlePackage());
		return restClient.get(URI.create(String.format(SEARCH_API_QUERY_FORMAT, query)),
				MavenSearchArtifactResponse.class)
				.getArtifacts()
				.stream()
				.findFirst()
				.map(artifact -> new LibraryDTO(join(":", groupId, artifactId), version))
				.orElseThrow(() -> new ResourceNotFoundException(format(LIB_NOT_FOUND_MSG, artifactId, groupId,
						version)));
	}

	private String groupQuery(String groupId) {
		return "g:" + QUOTE_ENCODED + groupId + QUOTE_ENCODED;
	}

	private String artifactQuery(String artifactId) {
		return "a:" + QUOTE_ENCODED + artifactId + QUOTE_ENCODED;
	}

	private String versionQuery(String version) {
		return "v:" + QUOTE_ENCODED + version + QUOTE_ENCODED;
	}

	private String jarOrBundlePackage() {
		return "(p:" + QUOTE_ENCODED + "jar" + QUOTE_ENCODED + "%20OR%20p:" + QUOTE_ENCODED + "bundle" + QUOTE_ENCODED + ")";
	}

	private String and(String... strings) {
		return join("+AND+", strings);
	}

}