//
   //  ========================================================================
   //  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.start;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.FileVisitOption;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.PathMatcher;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.Objects;
  
  import org.eclipse.jetty.start.config.CommandLineConfigSource;
  import org.eclipse.jetty.start.config.ConfigSource;
  import org.eclipse.jetty.start.config.ConfigSources;
  import org.eclipse.jetty.start.config.DirConfigSource;
  import org.eclipse.jetty.start.config.JettyBaseConfigSource;
  import org.eclipse.jetty.start.config.JettyHomeConfigSource;
  
  /**
   * File access for <code>${jetty.home}</code>, <code>${jetty.base}</code>, directories.
   * <p>
   * By default, both <code>${jetty.home}</code> and <code>${jetty.base}</code> are the same directory, but they can point at different directories.
   * <p>
   * The <code>${jetty.home}</code> directory is where the main Jetty binaries and default configuration is housed.
   * <p>
   * The <code>${jetty.base}</code> directory is where the execution specific configuration and webapps are obtained from.
   */
  public class BaseHome
  {
      public static class SearchDir
      {
          private Path dir;
          private String name;
  
          public SearchDir(String name)
          {
              this.name = name;
          }
  
          public Path getDir()
          {
              return dir;
          }
  
          public Path resolve(Path subpath)
          {
              return dir.resolve(subpath);
          }
  
          public Path resolve(String subpath)
          {
              return dir.resolve(FS.separators(subpath));
          }
  
          public SearchDir setDir(File path)
          {
              if (path != null)
              {
                  return setDir(path.toPath());
              }
              return this;
          }
  
          public SearchDir setDir(Path path)
          {
              if (path != null)
              {
                  this.dir = path.toAbsolutePath();
              }
              return this;
          }
  
          public SearchDir setDir(String path)
          {
              if (path != null)
              {
                  return setDir(FS.toPath(path));
             }
             return this;
         }
 
         public String toShortForm(Path path)
         {
             Path relative = dir.relativize(path);
             return String.format("${%s}%c%s",name,File.separatorChar,relative.toString());
         }
     }
 
     public static final String JETTY_BASE = "jetty.base";
     public static final String JETTY_HOME = "jetty.home";
     private final static EnumSet<FileVisitOption> SEARCH_VISIT_OPTIONS = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
 
     private final static int MAX_SEARCH_DEPTH = Integer.getInteger("org.eclipse.jetty.start.searchDepth",10);
 
     private final ConfigSources sources;
     private final Path homeDir;
     private final Path baseDir;
 
     public BaseHome() throws IOException
     {
         this(new String[0]);
     }
 
     public BaseHome(String cmdLine[]) throws IOException
     {
         this(new CommandLineConfigSource(cmdLine));
     }
 
     public BaseHome(CommandLineConfigSource cmdLineSource) throws IOException
     {
 
         sources = new ConfigSources();
         sources.add(cmdLineSource);
         this.homeDir = cmdLineSource.getHomePath();
         this.baseDir = cmdLineSource.getBasePath();
 
         // TODO this is cyclic construction as start log uses BaseHome, but BaseHome constructor
         // calls other constructors that log.   This appears to be a workable sequence.
         StartLog.getInstance().initialize(this,cmdLineSource);
         
         sources.add(new JettyBaseConfigSource(cmdLineSource.getBasePath()));
         sources.add(new JettyHomeConfigSource(cmdLineSource.getHomePath()));
 
         System.setProperty(JETTY_HOME,homeDir.toAbsolutePath().toString());
         System.setProperty(JETTY_BASE,baseDir.toAbsolutePath().toString());
     }
 
     public BaseHome(ConfigSources sources)
     {
         this.sources = sources;
         Path home = null;
         Path base = null;
         for (ConfigSource source : sources)
         {
             if (source instanceof CommandLineConfigSource)
             {
                 CommandLineConfigSource cmdline = (CommandLineConfigSource)source;
                 home = cmdline.getHomePath();
                 base = cmdline.getBasePath();
             }
             else if (source instanceof JettyBaseConfigSource)
             {
                 base = ((JettyBaseConfigSource)source).getDir();
             }
             else if (source instanceof JettyHomeConfigSource)
             {
                 home = ((JettyHomeConfigSource)source).getDir();
             }
         }
 
         Objects.requireNonNull(home,"jetty.home cannot be null");
         this.homeDir = home;
         this.baseDir = (base != null)?base:home;
 
         System.setProperty(JETTY_HOME,homeDir.toAbsolutePath().toString());
         System.setProperty(JETTY_BASE,baseDir.toAbsolutePath().toString());
     }
 
     public String getBase()
     {
         if (baseDir == null)
         {
             return null;
         }
         return baseDir.toString();
     }
 
     public Path getBasePath()
     {
         return baseDir;
     }
 
     /**
      * Create a {@link Path} reference to some content in <code>"${jetty.base}"</code>
      * 
      * @param path
      *            the path to reference
      * @return the file reference
      */
     public Path getBasePath(String path)
     {
         return baseDir.resolve(path);
     }
 
     public ConfigSources getConfigSources()
     {
         return this.sources;
     }
 
     public String getHome()
     {
         return homeDir.toString();
     }
 
     public Path getHomePath()
     {
         return homeDir;
     }
 
     /**
      * Get a specific path reference.
      * <p>
      * Path references are searched based on the config source search order.
      * <ol>
      * <li>If provided path is an absolute reference., and exists, return that reference</li>
      * <li>If exists relative to <code>${jetty.base}</code>, return that reference</li>
      * <li>If exists relative to and <code>include-jetty-dir</code> locations, return that reference</li>
      * <li>If exists relative to <code>${jetty.home}</code>, return that reference</li>
      * <li>Return standard {@link Path} reference obtained from {@link java.nio.file.FileSystem#getPath(String, String...)} (no exists check performed)</li>
      * </ol>
      * 
      * @param path
      *            the path to get.
      * @return the path reference.
      */
     public Path getPath(final String path)
     {
         Path apath = FS.toPath(path);
 
         if (apath.isAbsolute())
         {
             if (FS.exists(apath))
             {
                 return apath;
             }
         }
 
         for (ConfigSource source : sources)
         {
             if (source instanceof DirConfigSource)
             {
                 DirConfigSource dirsource = (DirConfigSource)source;
                 Path file = dirsource.getDir().resolve(apath);
                 if (FS.exists(file))
                 {
                     return file;
                 }
             }
         }
 
         // Finally, as an anonymous path
         return FS.toPath(path);
     }
 
     /**
      * Search specified Path with pattern and return hits
      * 
      * @param dir
      *            the path to a directory to start search from
      * @param searchDepth
      *            the number of directories deep to perform the search
      * @param pattern
      *            the raw pattern to use for the search (must be relative)
      * @return the list of Paths found
      * @throws IOException
      *             if unable to search the path
      */
     public List<Path> getPaths(Path dir, int searchDepth, String pattern) throws IOException
     {
         if (PathMatchers.isAbsolute(pattern))
         {
             throw new RuntimeException("Pattern cannot be absolute: " + pattern);
         }
 
         List<Path> hits = new ArrayList<>();
         if (FS.isValidDirectory(dir))
         {
             PathMatcher matcher = PathMatchers.getMatcher(pattern);
             PathFinder finder = new PathFinder();
             finder.setFileMatcher(matcher);
             finder.setBase(dir);
             finder.setIncludeDirsInResults(true);
             Files.walkFileTree(dir,SEARCH_VISIT_OPTIONS,searchDepth,finder);
             hits.addAll(finder.getHits());
             Collections.sort(hits,new NaturalSort.Paths());
         }
         return hits;
     }
 
     /**
      * Get a List of {@link Path}s from a provided pattern.
      * <p>
      * Resolution Steps:
      * <ol>
      * <li>If the pattern starts with "regex:" or "glob:" then a standard {@link PathMatcher} is built using
      * {@link java.nio.file.FileSystem#getPathMatcher(String)} as a file search.</li>
      * <li>If pattern starts with a known filesystem root (using information from {@link java.nio.file.FileSystem#getRootDirectories()}) then this is assumed to
      * be a absolute file system pattern.</li>
      * <li>All other patterns are treated as relative to BaseHome information:
      * <ol>
      * <li>Search ${jetty.home} first</li>
      * <li>Search ${jetty.base} for overrides</li>
      * </ol>
      * </li>
      * </ol>
      * <p>
      * Pattern examples:
      * <dl>
      * <dt><code>lib/logging/*.jar</code></dt>
      * <dd>Relative pattern, not recursive, search <code>${jetty.home}</code> then <code>${jetty.base}</code> for lib/logging/*.jar content</dd>
      * 
      * <dt><code>lib/**&#47;*-dev.jar</code></dt>
      * <dd>Relative pattern, recursive search <code>${jetty.home}</code> then <code>${jetty.base}</code> for files under <code>lib</code> ending in
      * <code>-dev.jar</code></dd>
      * </dl>
      * 
      * <dt><code>etc/jetty.xml</code></dt>
      * <dd>Relative pattern, no glob, search for <code>${jetty.home}/etc/jetty.xml</code> then <code>${jetty.base}/etc/jetty.xml</code></dd>
      * 
      * <dt><code>glob:/opt/app/common/*-corp.jar</code></dt>
      * <dd>PathMapper pattern, glob, search <code>/opt/app/common/</code> for <code>*-corp.jar</code></code></dd>
      * 
      * </dl>
      * 
      * <p>
      * Notes:
      * <ul>
      * <li>FileSystem case sensitivity is implementation specific (eg: linux is case-sensitive, windows is case-insensitive).<br/>
      * See {@link java.nio.file.FileSystem#getPathMatcher(String)} for more details</li>
      * <li>Pattern slashes are implementation neutral (use '/' always and you'll be fine)</li>
      * <li>Recursive searching is limited to 30 levels deep (not configurable)</li>
      * <li>File System loops are detected and skipped</li>
      * </ul>
      * 
      * @param pattern
      *            the pattern to search.
      * @return the collection of paths found
      * @throws IOException
      *             if error during search operation
      */
     public List<Path> getPaths(String pattern) throws IOException
     {
         StartLog.debug("getPaths('%s')",pattern);
         List<Path> hits = new ArrayList<>();
 
         if (PathMatchers.isAbsolute(pattern))
         {
             // Perform absolute path pattern search
 
             // The root to start search from
             Path root = PathMatchers.getSearchRoot(pattern);
             // The matcher for file hits
             PathMatcher matcher = PathMatchers.getMatcher(pattern);
 
             if (FS.isValidDirectory(root))
             {
                 PathFinder finder = new PathFinder();
                 finder.setIncludeDirsInResults(true);
                 finder.setFileMatcher(matcher);
                 finder.setBase(root);
                 Files.walkFileTree(root,SEARCH_VISIT_OPTIONS,MAX_SEARCH_DEPTH,finder);
                 hits.addAll(finder.getHits());
             }
         }
         else
         {
             // Perform relative path pattern search
             Path relativePath = PathMatchers.getSearchRoot(pattern);
             PathMatcher matcher = PathMatchers.getMatcher(pattern);
             PathFinder finder = new PathFinder();
             finder.setIncludeDirsInResults(true);
             finder.setFileMatcher(matcher);
 
             // walk config sources backwards ...
             ListIterator<ConfigSource> iter = sources.reverseListIterator();
             while (iter.hasPrevious())
             {
                 ConfigSource source = iter.previous();
                 if (source instanceof DirConfigSource)
                 {
                     DirConfigSource dirsource = (DirConfigSource)source;
                     Path dir = dirsource.getDir();
                     Path deepDir = dir.resolve(relativePath);
                     if (FS.isValidDirectory(deepDir))
                     {
                         finder.setBase(dir);
                         Files.walkFileTree(deepDir,SEARCH_VISIT_OPTIONS,MAX_SEARCH_DEPTH,finder);
                     }
                 }
             }
 
             hits.addAll(finder.getHits());
         }
 
         Collections.sort(hits,new NaturalSort.Paths());
         return hits;
     }
 
     public boolean isBaseDifferent()
     {
         return homeDir.compareTo(baseDir) != 0;
     }
 
     /**
      * Convenience method for <code>toShortForm(file.toPath())</code>
      */
     public String toShortForm(final File path)
     {
         return toShortForm(path.toPath());
     }
 
     /**
      * Replace/Shorten arbitrary path with property strings <code>"${jetty.home}"</code> or <code>"${jetty.base}"</code> where appropriate.
      * 
      * @param path
      *            the path to shorten
      * @return the potentially shortened path
      */
     public String toShortForm(final Path path)
     {
         Path apath = path.toAbsolutePath();
 
         for (ConfigSource source : sources)
         {
             if (source instanceof DirConfigSource)
             {
                 DirConfigSource dirsource = (DirConfigSource)source;
                 Path dir = dirsource.getDir();
                 if (apath.startsWith(dir))
                 {
                     if (dirsource.isPropertyBased())
                     {
                         Path relative = dir.relativize(apath);
                         return String.format("%s%c%s",dirsource.getId(),File.separatorChar,relative.toString());
                     }
                     else
                     {
                         return apath.toString();
                     }
                 }
             }
         }
 
         return apath.toString();
     }
 
     /**
      * Replace/Shorten arbitrary path with property strings <code>"${jetty.home}"</code> or <code>"${jetty.base}"</code> where appropriate.
      * 
      * @param path
      *            the path to shorten
      * @return the potentially shortened path
      */
     public String toShortForm(final String path)
     {
         if ((path == null) || (path.charAt(0) == '<'))
         {
             return path;
         }
 
         return toShortForm(FS.toPath(path));
     }
 }