/*
    * 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.maven.scm.provider.git.repository;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.maven.scm.ScmException;
  import org.apache.maven.scm.provider.ScmProviderRepository;
  import org.apache.maven.scm.provider.ScmProviderRepositoryWithHost;
  
  /**
   * @author <a href="mailto:evenisse@apache.org">Emmanuel Venisse</a>
   * @author <a href="mailto:struberg@apache.org">Mark Struberg</a>
   *
   */
  public class GitScmProviderRepository extends ScmProviderRepositoryWithHost {
  
      /**
       * sequence used to delimit the fetch URL
       */
      public static final String URL_DELIMITER_FETCH = "[fetch=]";
  
      /**
       * sequence used to delimit the push URL
       */
      public static final String URL_DELIMITER_PUSH = "[push=]";
  
      /**
       * this trails every protocol
       */
      public static final String PROTOCOL_SEPARATOR = "://";
  
      /**
       * use local file as transport
       */
      public static final String PROTOCOL_FILE = "file";
  
      /**
       * use gits internal protocol
       */
      public static final String PROTOCOL_GIT = "git";
  
      /**
       * use secure shell protocol
       */
      public static final String PROTOCOL_SSH = "ssh";
  
      /**
       * use the standard port 80 http protocol
       */
      public static final String PROTOCOL_HTTP = "http";
  
      /**
       * use the standard port 443 https protocol
       */
      public static final String PROTOCOL_HTTPS = "https";
  
      /**
       * use rsync for retrieving the data
       * TODO implement!
       */
      public static final String PROTOCOL_RSYNC = "rsync";
  
      private static final Pattern HOST_AND_PORT_EXTRACTOR =
              Pattern.compile("([^:/\\\\~]*)(?::(\\d*))?(?:([:/\\\\~])(.*))?");
  
      /**
       * No special protocol specified. Git will either use git://
       * or ssh:// depending on whether we work locally or over the network
       */
      public static final String PROTOCOL_NONE = "";
  
      /**
       * this may either 'git' or 'jgit' depending on the underlying implementation being used
       */
      private String provider;
  
      /**
       * the URL used to fetch from the upstream repository
       */
     private RepositoryUrl fetchInfo;
 
     /**
      * the URL used to push to the upstream repository
      */
     private RepositoryUrl pushInfo;
 
     public GitScmProviderRepository(String url) throws ScmException {
         if (url == null) {
             throw new ScmException("url must not be null");
         }
 
         if (url.startsWith(URL_DELIMITER_FETCH)) {
             String fetch = url.substring(URL_DELIMITER_FETCH.length());
 
             int indexPushDelimiter = fetch.indexOf(URL_DELIMITER_PUSH);
             if (indexPushDelimiter >= 0) {
                 String push = fetch.substring(indexPushDelimiter + URL_DELIMITER_PUSH.length());
                 pushInfo = parseUrl(push);
 
                 fetch = fetch.substring(0, indexPushDelimiter);
             }
 
             fetchInfo = parseUrl(fetch);
 
             if (pushInfo == null) {
                 pushInfo = fetchInfo;
             }
         } else if (url.startsWith(URL_DELIMITER_PUSH)) {
             String push = url.substring(URL_DELIMITER_PUSH.length());
 
             int indexFetchDelimiter = push.indexOf(URL_DELIMITER_FETCH);
             if (indexFetchDelimiter >= 0) {
                 String fetch = push.substring(indexFetchDelimiter + URL_DELIMITER_FETCH.length());
                 fetchInfo = parseUrl(fetch);
 
                 push = push.substring(0, indexFetchDelimiter);
             }
 
             pushInfo = parseUrl(push);
 
             if (fetchInfo == null) {
                 fetchInfo = pushInfo;
             }
         } else {
             fetchInfo = pushInfo = parseUrl(url);
         }
 
         // set the default values for backward compatibility from the push url
         // because it's more likely that the push URL contains 'better' credentials
         setUser(pushInfo.getUserName());
         setPassword(pushInfo.getPassword());
         setHost(pushInfo.getHost());
         if (pushInfo.getPort() != null && pushInfo.getPort().length() > 0) {
             setPort(Integer.parseInt(pushInfo.getPort()));
         }
     }
 
     public GitScmProviderRepository(String url, String user, String password) throws ScmException {
         this(url);
 
         setUser(user);
 
         setPassword(password);
     }
 
     /**
      * @return either 'git' or 'jgit' depending on the underlying implementation being used
      */
     public String getProvider() {
         return provider;
     }
 
     public RepositoryUrl getFetchInfo() {
         return fetchInfo;
     }
 
     public RepositoryUrl getPushInfo() {
         return pushInfo;
     }
 
     /**
      * @return the URL used to fetch from the upstream repository
      */
     public String getFetchUrl() {
         return getUrl(fetchInfo);
     }
 
     /**
      * @return the URL used to push to the upstream repository
      */
     public String getPushUrl() {
         return getUrl(pushInfo);
     }
 
     /**
      * Parse the given url string and store all the extracted
      * information in a {@code RepositoryUrl}
      *
      * @param url to parse
      * @return filled with the information from the given URL
      * @throws ScmException
      */
     private RepositoryUrl parseUrl(String url) throws ScmException {
         RepositoryUrl repoUrl = new RepositoryUrl();
 
         url = parseProtocol(repoUrl, url);
         url = parseUserInfo(repoUrl, url);
         url = parseHostAndPort(repoUrl, url);
         // the rest of the url must be the path to the repository on the server
         repoUrl.setPath(url);
         return repoUrl;
     }
 
     /**
      * @param repoUrl
      * @return TODO
      */
     private String getUrl(RepositoryUrl repoUrl) {
         StringBuilder urlSb = new StringBuilder(repoUrl.getProtocol());
         boolean urlSupportsUserInformation = false;
 
         if (PROTOCOL_SSH.equals(repoUrl.getProtocol())
                 || PROTOCOL_RSYNC.equals(repoUrl.getProtocol())
                 || PROTOCOL_GIT.equals(repoUrl.getProtocol())
                 || PROTOCOL_HTTP.equals(repoUrl.getProtocol())
                 || PROTOCOL_HTTPS.equals(repoUrl.getProtocol())
                 || PROTOCOL_NONE.equals(repoUrl.getProtocol())) {
             urlSupportsUserInformation = true;
         }
 
         if (repoUrl.getProtocol() != null && repoUrl.getProtocol().length() > 0) {
             urlSb.append("://");
         }
 
         // add user information if given and allowed for the protocol
         if (urlSupportsUserInformation) {
             String userName = repoUrl.getUserName();
             // if specified on the commandline or other configuration, we take this.
             if (getUser() != null && getUser().length() > 0) {
                 userName = getUser();
             }
 
             String password = repoUrl.getPassword();
             if (getPassword() != null && getPassword().length() > 0) {
                 password = getPassword();
             }
 
             if (userName != null && userName.length() > 0) {
                 String userInfo = userName;
                 if (password != null && password.length() > 0) {
                     userInfo += ":" + password;
                 }
 
                 try {
                     URI uri = new URI(null, userInfo, "localhost", -1, null, null, null);
                     urlSb.append(uri.getRawUserInfo());
                 } catch (URISyntaxException e) {
                     // Quite impossible...
                     // Otherwise throw a RTE since this method is also used by toString()
                     e.printStackTrace();
                 }
 
                 urlSb.append('@');
             }
         }
 
         // add host and port information
         urlSb.append(repoUrl.getHost());
         if (repoUrl.getPort() != null && repoUrl.getPort().length() > 0) {
             urlSb.append(':').append(repoUrl.getPort());
         }
 
         // finaly we add the path to the repo on the host
         urlSb.append(repoUrl.getPath());
 
         return urlSb.toString();
     }
 
     /**
      * Parse the protocol from the given url and fill it into the given RepositoryUrl.
      *
      * @param repoUrl
      * @param url
      * @return the given url with the protocol parts removed
      */
     private String parseProtocol(RepositoryUrl repoUrl, String url) throws ScmException {
         // extract the protocol
         if (url.startsWith(PROTOCOL_FILE + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_FILE);
         } else if (url.startsWith(PROTOCOL_HTTPS + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_HTTPS);
         } else if (url.startsWith(PROTOCOL_HTTP + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_HTTP);
         } else if (url.startsWith(PROTOCOL_SSH + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_SSH);
         } else if (url.startsWith(PROTOCOL_GIT + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_GIT);
         } else if (url.startsWith(PROTOCOL_RSYNC + PROTOCOL_SEPARATOR)) {
             repoUrl.setProtocol(PROTOCOL_RSYNC);
         } else {
             // when no protocol is specified git will pick either ssh:// or git://
             // depending on whether we work locally or over the network
             repoUrl.setProtocol(PROTOCOL_NONE);
             return url;
         }
 
         url = url.substring(repoUrl.getProtocol().length() + 3);
 
         return url;
     }
 
     /**
      * Parse the user information from the given url and fill
      * user name and password into the given RepositoryUrl.
      *
      * @param repoUrl
      * @param url
      * @return the given url with the user parts removed
      */
     private String parseUserInfo(RepositoryUrl repoUrl, String url) throws ScmException {
         if (PROTOCOL_FILE.equals(repoUrl.getProtocol())) {
             // a file:// URL may contain userinfo according to RFC 8089, but our implementation is broken
             return url;
         }
         // extract user information, broken see SCM-907
         int indexAt = url.lastIndexOf('@');
         if (indexAt >= 0) {
             String userInfo = url.substring(0, indexAt);
             int indexPwdSep = userInfo.indexOf(':');
             if (indexPwdSep < 0) {
                 repoUrl.setUserName(userInfo);
             } else {
                 repoUrl.setUserName(userInfo.substring(0, indexPwdSep));
                 repoUrl.setPassword(userInfo.substring(indexPwdSep + 1));
             }
 
             url = url.substring(indexAt + 1);
         }
         return url;
     }
 
     /**
      * Parse server and port from the given url and fill it into the
      * given RepositoryUrl.
      *
      * @param repoUrl
      * @param url
      * @return the given url with the server parts removed
      * @throws ScmException
      */
     private String parseHostAndPort(RepositoryUrl repoUrl, String url) throws ScmException {
 
         repoUrl.setPort("");
         repoUrl.setHost("");
 
         if (PROTOCOL_FILE.equals(repoUrl.getProtocol())) {
             // a file:// URL doesn't need any further parsing as it cannot contain a port, etc
             return url;
         } else {
 
             Matcher hostAndPortMatcher = HOST_AND_PORT_EXTRACTOR.matcher(url);
             if (hostAndPortMatcher.matches()) {
                 if (hostAndPortMatcher.groupCount() > 1 && hostAndPortMatcher.group(1) != null) {
                     repoUrl.setHost(hostAndPortMatcher.group(1));
                 }
                 if (hostAndPortMatcher.groupCount() > 2 && hostAndPortMatcher.group(2) != null) {
                     repoUrl.setPort(hostAndPortMatcher.group(2));
                 }
 
                 StringBuilder computedUrl = new StringBuilder();
                 if (hostAndPortMatcher.group(hostAndPortMatcher.groupCount() - 1) != null) {
                     computedUrl.append(hostAndPortMatcher.group(hostAndPortMatcher.groupCount() - 1));
                 }
                 if (hostAndPortMatcher.group(hostAndPortMatcher.groupCount()) != null) {
                     computedUrl.append(hostAndPortMatcher.group(hostAndPortMatcher.groupCount()));
                 }
                 return computedUrl.toString();
             } else {
                 // Pattern doesn't match, let's return the original url
                 return url;
             }
         }
     }
 
     /**
      * {@inheritDoc}
      */
     public String getRelativePath(ScmProviderRepository ancestor) {
         if (ancestor instanceof GitScmProviderRepository) {
             GitScmProviderRepository gitAncestor = (GitScmProviderRepository) ancestor;
 
             // X TODO review!
             String url = getFetchUrl();
             String path = url.replaceFirst(gitAncestor.getFetchUrl() + "/", "");
 
             if (!path.equals(url)) {
                 return path;
             }
         }
         return null;
     }
 
     /**
      * {@inheritDoc}
      */
     public String toString() {
         // yes we really like to check if those are the exact same instance!
         if (fetchInfo == pushInfo) {
             return getUrl(fetchInfo);
         }
         return URL_DELIMITER_FETCH + getUrl(fetchInfo) + URL_DELIMITER_PUSH + getUrl(pushInfo);
     }
 }