/*

  * This file is part of dependency-check-core.

  *

  * Licensed 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.

  *

  * Copyright (c) 2014 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.data.central;

 import java.io.FileNotFoundException;

 import java.io.IOException;

 import java.net.HttpURLConnection;

 import java.net.URL;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.logging.Logger;

 import javax.xml.parsers.DocumentBuilder;

 import javax.xml.parsers.DocumentBuilderFactory;

 import javax.xml.xpath.XPath;

 import javax.xml.xpath.XPathConstants;

 import javax.xml.xpath.XPathFactory;

 import org.owasp.dependencycheck.data.nexus.MavenArtifact;

 import org.owasp.dependencycheck.utils.Settings;

 import org.owasp.dependencycheck.utils.URLConnectionFactory;

 import org.w3c.dom.Document;

 import org.w3c.dom.NodeList;

 /**

  * Class of methods to search Maven Central via Central.

  *

  * @author colezlaw

  */

 public class CentralSearch {

     /**

      * The URL for the Central service

      */

     private final URL rootURL;

     /**

      * Whether to use the Proxy when making requests

      */

     private boolean useProxy;

     /**

      * Used for logging.

      */

     private static final Logger LOGGER = Logger.getLogger(CentralSearch.class.getName());

     /**

      * Creates a NexusSearch for the given repository URL.

      *

      * @param rootURL the URL of the repository on which searches should execute. Only parameters are added to this (so

      * it should end in /select)

      */

     public CentralSearch(URL rootURL) {

         this.rootURL = rootURL;

         if (null != Settings.getString(Settings.KEYS.PROXY_SERVER)) {

             useProxy = true;

             LOGGER.fine("Using proxy");

         } else {

             useProxy = false;

             LOGGER.fine("Not using proxy");

         }

     }

     /**

      * Searches the configured Central URL for the given sha1 hash. If the artifact is found, a

      * <code>MavenArtifact</code> is populated with the GAV.

      *

      * @param sha1 the SHA-1 hash string for which to search

      * @return the populated Maven GAV.

      * @throws IOException if it's unable to connect to the specified repository or if the specified artifact is not

      * found.

      */

     public List<MavenArtifact> searchSha1(String sha1) throws IOException {

         if (null == sha1 || !sha1.matches("^[0-9A-Fa-f]{40}$")) {

             throw new IllegalArgumentException("Invalid SHA1 format");

         }

         final URL url = new URL(rootURL + String.format("?q=1:\"%s\"&wt=xml", sha1));

         LOGGER.fine(String.format("Searching Central url %s", url.toString()));

         // Determine if we need to use a proxy. The rules:

         // 1) If the proxy is set, AND the setting is set to true, use the proxy

         // 2) Otherwise, don't use the proxy (either the proxy isn't configured,

         // or proxy is specifically set to false)

         final HttpURLConnection conn = URLConnectionFactory.createHttpURLConnection(url, useProxy);

         conn.setDoOutput(true);

         // JSON would be more elegant, but there's not currently a dependency

         // on JSON, so don't want to add one just for this

         conn.addRequestProperty("Accept", "application/xml");

         conn.connect();

         if (conn.getResponseCode() == 200) {

             boolean missing = false;

             try {

                 final DocumentBuilder builder = DocumentBuilderFactory

                         .newInstance().newDocumentBuilder();

                 final Document doc = builder.parse(conn.getInputStream());

                 final XPath xpath = XPathFactory.newInstance().newXPath();

                 final String numFound = xpath.evaluate("/response/result/@numFound", doc);

                 if ("0".equals(numFound)) {

                     missing = true;

                 } else {

                     final ArrayList<MavenArtifact> result = new ArrayList<MavenArtifact>();

                     final NodeList docs = (NodeList) xpath.evaluate("/response/result/doc", doc, XPathConstants.NODESET);

                     for (int i = 0; i < docs.getLength(); i++) {

                         final String g = xpath.evaluate("./str[@name='g']", docs.item(i));

                         LOGGER.finest(String.format("GroupId: %s", g));

                         final String a = xpath.evaluate("./str[@name='a']", docs.item(i));

                         LOGGER.finest(String.format("ArtifactId: %s", a));

                         final String v = xpath.evaluate("./str[@name='v']", docs.item(i));

                         LOGGER.finest(String.format("Version: %s", v));

                         result.add(new MavenArtifact(g, a, v, url.toString()));

                     }

                     return result;

                 }

             } catch (Throwable e) {

                 // Anything else is jacked up XML stuff that we really can't recover

                 // from well

                 throw new IOException(e.getMessage(), e);

             }

             if (missing) {

                 throw new FileNotFoundException("Artifact not found in Central");

             }

         } else {

             final String msg = String.format("Could not connect to Central received response code: %d %s",

                     conn.getResponseCode(), conn.getResponseMessage());

             LOGGER.fine(msg);

             throw new IOException(msg);

         }

         return null;

     }

 }