/*
    * 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.commons.vfs2.provider;
  
  import org.apache.commons.vfs2.FileName;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileSystemManager;
  import org.apache.commons.vfs2.FileType;
  import org.apache.commons.vfs2.VFS;
  import org.apache.commons.vfs2.util.Cryptor;
  import org.apache.commons.vfs2.util.CryptorFactory;
  
  /**
   * Implementation for any URL based file system.
   * <p>
   * Parses the URL into user/password/host/port/path. Does not handle a query string (after ?).
   * </p>
   *
   * @see URLFileNameParser URLFileNameParser for the implementation which also handles the query string too.
   */
  public class HostFileNameParser extends AbstractFileNameParser {
  
      /**
       * Parsed authority info (scheme, hostname, username/password, port).
       */
      protected static class Authority {
  
          private String hostName;
          private String password;
          private int port;
          private String scheme;
          private String userName;
  
          /**
           * Constructs a new instance.
           */
          public Authority() {
              // empty
          }
  
          /**
           * Gets the host name.
           *
           * @return the host name.
           * @since 2.0
           */
          public String getHostName() {
              return hostName;
          }
  
          /**
           * Gets the user password.
           *
           * @return the password or null.
           * @since 2.0
           */
          public String getPassword() {
              return password;
          }
  
          /**
           * Gets the port.
           *
           * @return the port or -1.
           * @since 2.0
           */
          public int getPort() {
              return port;
          }
  
          /**
           * Gets the connection schema.
           *
           * @return the connection scheme.
           * @since 2.0
           */
          public String getScheme() {
              return scheme;
          }
  
          /**
           * Gets the user name.
           *
           * @return the user name or null.
           * @since 2.0
          */
         public String getUserName() {
             return userName;
         }
 
         /**
          * Sets the host name.
          *
          * @param hostName the host name.
          * @since 2.0
          */
         public void setHostName(final String hostName) {
             this.hostName = hostName;
         }
 
         /**
          * Sets the user password.
          *
          * @param password the user password.
          * @since 2.0
          */
         public void setPassword(final String password) {
             this.password = password;
         }
 
         /**
          * Sets the connection port.
          *
          * @param port the port number or -1.
          * @since 2.0
          */
         public void setPort(final int port) {
             this.port = port;
         }
 
         /**
          * Sets the connection schema.
          *
          * @param scheme the connection scheme.
          * @since 2.0
          */
         public void setScheme(final String scheme) {
             this.scheme = scheme;
         }
 
         /**
          * Sets the user name.
          *
          * @param userName the user name.
          * @since 2.0
          */
         public void setUserName(final String userName) {
             this.userName = userName;
         }
     }
 
     private static boolean isHostNameTerminatingChar(final char ch, final boolean isIPv6Host) {
         if (isIPv6Host) {
             return ch == ']';
         }
 
         return ch == '/' || ch == ';' || ch == '?' || ch == ':' || ch == '@' || ch == '&' || ch == '=' || ch == '+'
                 || ch == '$' || ch == ',';
     }
 
     private static boolean isIPv6Host(final String name) {
         return name.length() > 0 && isIPv6HostHeadingChar(name.charAt(0));
     }
 
     private static boolean isIPv6HostHeadingChar(final char ch) {
         return ch == '[';
     }
 
     private final int defaultPort;
 
     /**
      * Constructs a new instance.
      *
      * @param defaultPort The default port.
      */
      public HostFileNameParser(final int defaultPort) {
         this.defaultPort = defaultPort;
     }
 
     /**
      * Extracts the hostname from a URI.
      *
      * @param name string buffer with the "scheme://[userinfo@]" part has been removed already. Will be modified.
      * @return the host name or null.
      */
     protected String extractHostName(final StringBuilder name) {
         final int maxlen = name.length();
         final boolean isIPv6Host = isIPv6Host(name.toString());
         int pos = 0;
         for (; pos < maxlen; pos++) {
             final char ch = name.charAt(pos);
             if (isHostNameTerminatingChar(ch, isIPv6Host)) {
                 break;
             }
         }
         if (pos == 0) {
             return null;
         }
 
         if (isIPv6Host && pos < maxlen) {
             if (pos == 1) {
                 return null; // Returning empty host
             }
 
             pos++; // Including terminating ']' into the extracted host string for IPv6 hosts
         }
 
         final String hostname = name.substring(0, pos);
         name.delete(0, pos);
         return hostname;
     }
 
     /**
      * Extracts the port from a URI.
      *
      * @param name string buffer with the "scheme://[userinfo@]hostname" part has been removed already. Will be
      *            modified.
      * @param uri full URI for error reporting.
      * @return The port, or -1 if the URI does not contain a port.
      * @throws FileSystemException if URI is malformed.
      * @throws NumberFormatException if port number cannot be parsed.
      */
     protected int extractPort(final StringBuilder name, final String uri) throws FileSystemException {
         if (name.length() < 1 || name.charAt(0) != ':') {
             return -1;
         }
 
         final int maxlen = name.length();
         int pos = 1;
         for (; pos < maxlen; pos++) {
             final char ch = name.charAt(pos);
             if (ch < '0' || ch > '9') {
                 break;
             }
         }
 
         final String port = name.substring(1, pos);
         name.delete(0, pos);
         if (port.isEmpty()) {
             throw new FileSystemException("vfs.provider/missing-port.error", uri);
         }
 
         return Integer.parseInt(port);
     }
 
     /**
      * Extracts the scheme, userinfo, hostname and port components of a generic URI.
      *
      * @param uri The absolute URI to parse.
      * @param name Used to return the remainder of the URI.
      * @return Authority extracted host authority, never null.
      * @throws FileSystemException if authority cannot be extracted.
      * @deprecated Use {@link #extractToPath(VfsComponentContext, String, StringBuilder)}.
      */
     @Deprecated
     protected Authority extractToPath(final String uri, final StringBuilder name) throws FileSystemException {
         return extractToPath(null, uri, name);
     }
 
     /**
      * Extracts the scheme, userinfo, hostname and port components of a generic URI.
      *
      * @param context component context.
      * @param uri The absolute URI to parse.
      * @param name Used to return the remainder of the URI.
      * @return Authority extracted host authority, never null.
      * @throws FileSystemException if authority cannot be extracted.
      */
     protected Authority extractToPath(final VfsComponentContext context, final String uri, final StringBuilder name) throws FileSystemException {
         final Authority auth = new Authority();
 
         final FileSystemManager fsm;
         if (context != null) {
             fsm = context.getFileSystemManager();
         } else {
             fsm = VFS.getManager();
         }
 
         // Extract the scheme
         auth.scheme = UriParser.extractScheme(fsm.getSchemes(), uri, name);
 
         // Expecting "//"
         if (name.length() < 2 || name.charAt(0) != '/' || name.charAt(1) != '/') {
             throw new FileSystemException("vfs.provider/missing-double-slashes.error", uri);
         }
         name.delete(0, 2);
 
         // Extract userinfo, and split into username and password
         final String userInfo = extractUserInfo(name);
         final String userName;
         final String password;
         if (userInfo != null) {
             final int idx = userInfo.indexOf(':');
             if (idx == -1) {
                 userName = userInfo;
                 password = null;
             } else {
                 userName = userInfo.substring(0, idx);
                 password = userInfo.substring(idx + 1);
             }
         } else {
             userName = null;
             password = null;
         }
         auth.userName = UriParser.decode(userName);
         auth.password = UriParser.decode(password);
 
         if (auth.password != null && auth.password.startsWith("{") && auth.password.endsWith("}")) {
             try {
                 final Cryptor cryptor = CryptorFactory.getCryptor();
                 auth.password = cryptor.decrypt(auth.password.substring(1, auth.password.length() - 1));
             } catch (final Exception ex) {
                 throw new FileSystemException("Unable to decrypt password", ex);
             }
         }
 
         // Extract hostname, and normalize (lowercase)
         final String hostName = extractHostName(name);
         if (hostName == null) {
             throw new FileSystemException("vfs.provider/missing-hostname.error", uri);
         }
         if (isIPv6Host(hostName) && !isHostNameTerminatingChar(hostName.charAt(hostName.length() - 1), true)) {
             throw new FileSystemException("vfs.provider/unterminated-ipv6-hostname.error", uri);
         }
 
         auth.hostName = hostName.toLowerCase();
 
         // Extract port
         auth.port = extractPort(name, uri);
 
         // Expecting '/' or empty name
         if (name.length() > 0 && name.charAt(0) != '/') {
             throw new FileSystemException("vfs.provider/missing-hostname-path-sep.error", uri);
         }
 
         return auth;
     }
 
     /**
      * Extracts the user info from a URI.
      *
      * @param name string buffer with the "scheme://" part has been removed already. Will be modified.
      * @return the user information up to the '@' or null.
      */
     protected String extractUserInfo(final StringBuilder name) {
         final int maxlen = name.length();
         for (int pos = 0; pos < maxlen; pos++) {
             final char ch = name.charAt(pos);
             if (ch == '@') {
                 // Found the end of the user info
                 final String userInfo = name.substring(0, pos);
                 name.delete(0, pos + 1);
                 return userInfo;
             }
             if (ch == '/' || ch == '?') {
                 // Not allowed in user info
                 break;
             }
         }
 
         // Not found
         return null;
     }
 
     /**
      * Gets the default port.
      *
      * @return the default port.
      */
     public int getDefaultPort() {
         return defaultPort;
     }
 
     @Override
     public FileName parseUri(final VfsComponentContext context, final FileName base, final String fileName)
             throws FileSystemException {
         // FTP URI are generic URI (as per RFC 2396)
         final StringBuilder name = new StringBuilder();
 
         // Extract the scheme and authority parts
         final Authority auth = extractToPath(context, fileName, name);
 
         // Decode and normalize the file name
         UriParser.canonicalizePath(name, 0, name.length(), this);
         UriParser.fixSeparators(name);
         final FileType fileType = UriParser.normalisePath(name);
         final String path = name.toString();
 
         return new GenericFileName(auth.scheme, auth.hostName, auth.port, defaultPort, auth.userName, auth.password,
                 path, fileType);
     }
 }