/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  package org.waarp.common.file;
  
  import org.waarp.common.command.exception.CommandAbstractException;
  import org.waarp.common.command.exception.Reply501Exception;
  import org.waarp.common.command.exception.Reply530Exception;
  import org.waarp.common.command.exception.Reply550Exception;
  import org.waarp.common.command.exception.Reply553Exception;
  import org.waarp.common.logging.WaarpLogger;
  import org.waarp.common.logging.WaarpLoggerFactory;
  import org.waarp.common.utility.DetectionUtils;
  import org.waarp.common.utility.ParametersChecker;
  import org.waarp.common.utility.WaarpStringUtils;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.net.URLDecoder;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Abstract Main Implementation of Directory
   */
  public abstract class AbstractDir implements DirInterface {
    /**
     * Internal Logger
     */
    private static final WaarpLogger logger =
        WaarpLoggerFactory.getLogger(AbstractDir.class);
    /**
     * Current Directory
     */
    protected String currentDir;
    /**
     * SessionInterface
     */
    protected SessionInterface session;
  
    /**
     * Opts command for MLSx. (-1) means not supported, 0 supported but not
     * active, 1 supported and active
     */
    protected OptsMLSxInterface optsMLSx;
    /**
     * Hack to say Windows or Unix (root like X:\ or /)
     */
    protected static final boolean ISUNIX;
    /**
     * Roots for Windows system
     */
    protected static final File[] roots;
  
    /*
     * Init Windows Support
     */
    static {
      ISUNIX = !DetectionUtils.isWindows();
      if (!ISUNIX) {
        roots = File.listRoots();
      } else {
        roots = new File[] { new File("/") };
      }
    }
  
    /**
     * @param file
     *
     * @return The corresponding Root file
     */
    protected final File getCorrespondingRoot(final File file) {
      if (ISUNIX) {
        return new File("/");
      }
      final String path = file.getAbsolutePath();
      for (final File root : roots) {
        if (path.startsWith(root.getAbsolutePath())) {
          return root;
        }
      }
      // hack !
     logger.warn("No root found for " + file.getAbsolutePath());
     return roots[0];
   }
 
   /**
    * Normalize Path to Internal unique representation
    *
    * @param path
    *
    * @return the normalized path
    */
   public static String normalizePath(final String path) {
     return path.replace('\\', SEPARATORCHAR);
   }
 
   /**
    * Convert the URI representation of a file path to a simple path.
    * <p>
    * If the path is not an URI, this method does nothing.
    *
    * @param path
    *
    * @return the normalized path
    */
   public static String pathFromURI(String path) {
 
     if (path.startsWith("file://")) {
       int charToRemove = 7;
 
       if (path.charAt(7) == '/' && path.charAt(9) == ':') {
         charToRemove++;
       }
 
       path = path.substring(charToRemove);
       if (path.contains("%")) {
         try {
           path = URLDecoder.decode(path, WaarpStringUtils.UTF8.name());
         } catch (final UnsupportedEncodingException e) {
           logger.warn("Cannot convert filename to UTF-8: " + path);
         } catch (final IllegalArgumentException e) {
           // ignore: it was propably not url-encoded!
         }
       }
     }
     return path;
   }
 
   /**
    * @return the SessionInterface
    */
   @Override
   public final SessionInterface getSession() {
     return session;
   }
 
   @Override
   public final String validatePath(final String path)
       throws CommandAbstractException {
     String extDir;
     if (isAbsolute(path)) {
       extDir = path;
       final File newDir = new File(extDir);
       try {
         return validatePath(newDir);
       } catch (final Reply553Exception e) {
         // ignore and continue as it could be not absolute
       }
     }
     if (path.charAt(0) == SEPARATORCHAR) {
       extDir = path;
     } else {
       extDir = currentDir + SEPARATOR + path;
     }
     // Get the baseDir (mount point)
     final String baseDir = getSession().getAuth().getBaseDirectory();
     // Get the translated real file path (removing '..')
     final File newDir = new File(baseDir, extDir);
     return validatePath(newDir);
   }
 
   /**
    * @param path
    *
    * @return True if the given Path is an absolute one under Windows System or
    *     should be an absolute one on Unix
    */
   public final boolean isAbsolute(final String path) {
     File file = new File(path);
     if (!ISUNIX) {
       return file.isAbsolute();
     } else {
       file = file.getParentFile();
       return file != null && file.isAbsolute() && file.isDirectory() &&
              !file.getAbsolutePath().equals(File.separator);
     }
   }
 
   /**
    * Consolidate Path as relative or absolute path to an absolute path
    *
    * @param path
    *
    * @return the consolidated path
    *
    * @throws CommandAbstractException
    */
   protected final String consolidatePath(final String path)
       throws CommandAbstractException {
     if (ParametersChecker.isEmpty(path)) {
       throw new Reply501Exception("Path must not be empty");
     }
     // First check if the path is relative or absolute
     if (isAbsolute(path)) {
       return normalizePath(path);
     }
     String extDir = normalizePath(path);
     if (extDir.charAt(0) != SEPARATORCHAR) {
       extDir = currentDir + SEPARATOR + extDir;
     }
     return extDir;
   }
 
   /**
    * Construct the CanonicalPath without taking into account symbolic link
    *
    * @param dir
    *
    * @return the canonicalPath
    */
   protected final String getCanonicalPath(final File dir) {
     if (ISUNIX) {
       // resolve it without getting symbolic links
       final StringBuilder builder = new StringBuilder();
       // Get the path in reverse order from end to start
       final List<String> list = new ArrayList<String>();
       File newdir = dir;
       String lastdir = newdir.getName();
       list.add(lastdir);
       File parent = newdir.getParentFile();
       while (parent != null) {
         newdir = parent;
         lastdir = newdir.getName();
         list.add(lastdir);
         parent = newdir.getParentFile();
       }
       // Now filter on '..' or '.'
       for (int i = list.size() - 1; i >= 0; i--) {
         final String curdir = list.get(i);
         if (".".equals(curdir)) {
           list.remove(i);// removes '.'
         } else if ("..".equals(curdir)) {
           list.remove(i);// removes '..'
           final int len = list.size();
           if (len > 0 && i < len) {
             list.remove(i);// and removes parent dir
           }
         }
       }
       if (list.isEmpty()) {
         return "/";
       }
 
       for (int i = list.size() - 1; i >= 0; i--) {
         builder.append('/').append(list.get(i));
       }
       return builder.toString();
     }
     // Windows version
     // no link so just use the default version of canonical Path
     try {
       return dir.getCanonicalPath();
     } catch (final IOException e) {
       return dir.getAbsolutePath();
     }
   }
 
   /**
    * Same as validatePath but from a FileInterface
    *
    * @param dir
    *
    * @return the construct and validated path (could be different than the one
    *     given as argument, example: '..'
    *     are removed)
    *
    * @throws CommandAbstractException
    */
   protected final String validatePath(final File dir)
       throws CommandAbstractException {
     String extDir;
     extDir = normalizePath(getCanonicalPath(dir));
     // Get the relative business path
     extDir = getSession().getAuth().getRelativePath(extDir);
     // Check if this business path is valid
     if (getSession().getAuth().isBusinessPathValid(extDir)) {
       return extDir;
     }
     throw new Reply553Exception("Pathname not allowed");
   }
 
   @Override
   public final boolean isPathInCurrentDir(final String path) {
     final String extDir;
     if (isAbsolute(path)) {
       extDir = path;
       final File newDir = new File(extDir);
       return isPathInCurrentDir(newDir);
     }
     if (path.charAt(0) == SEPARATORCHAR) {
       extDir = path;
     } else {
       extDir = currentDir + SEPARATOR + path;
     }
     // Get the baseDir (mount point)
     final String baseDir = getSession().getAuth().getBaseDirectory();
     // Get the translated real file path (removing '..')
     final File newDir = new File(baseDir, extDir);
     return isPathInCurrentDir(newDir);
   }
 
   /**
    * Validate a file according to the current Directory
    *
    * @param dir
    *
    * @return True if validated
    *
    * @throws CommandAbstractException
    */
   protected final boolean isPathInCurrentDir(final File dir) {
     String extDir;
     extDir = normalizePath(getCanonicalPath(dir));
     // Get the relative business path
     extDir = getSession().getAuth().getRelativePath(extDir);
     // Check if this business path is valid
     if (extDir.startsWith(currentDir)) {
       return true;
     }
     logger.warn("File not OK: {} not in {}", extDir, currentDir);
     return false;
   }
 
   /**
    * Finds all files matching a wildcard expression (based on '?', '~' or
    * '*').
    *
    * @param pathWithWildcard The wildcard expression with a business
    *     path.
    *
    * @return List of String as relative paths matching the wildcard
    *     expression.
    *     Those files are tested as valid
    *     from business point of view. If Wildcard support is not active,
    *     if the
    *     path contains any wildcards,
    *     it will throw an error.
    *
    * @throws CommandAbstractException
    */
   protected abstract List<String> wildcardFiles(String pathWithWildcard)
       throws CommandAbstractException;
 
   @Override
   public final String getPwd() {
     return currentDir;
   }
 
   @Override
   public final boolean changeParentDirectory() throws CommandAbstractException {
     return changeDirectory("..");
   }
 
   @Override
   public FileInterface setFile(final String path, final boolean append)
       throws CommandAbstractException {
     checkIdentify();
     final String newpath = consolidatePath(path);
     final List<String> paths = wildcardFiles(newpath);
     if (paths.size() != 1) {
       throw new Reply550Exception(
           "File not found: " + paths.size() + " founds");
     }
     final String extDir = paths.get(0);
     return newFile(extDir, append);
   }
 
   @Override
   public final void checkIdentify() throws Reply530Exception {
     if (!getSession().getAuth().isIdentified()) {
       throw new Reply530Exception("User not authentified");
     }
   }
 
   @Override
   public final void clear() {
     currentDir = null;
   }
 
   @Override
   public final void initAfterIdentification() {
     currentDir = getSession().getAuth().getBusinessPath();
   }
 
   @Override
   public final OptsMLSxInterface getOptsMLSx() {
     return optsMLSx;
   }
 
 }