package org.webslinger.commons.vfs.cow;

 import java.io.IOException;

 import java.util.Arrays;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.Iterator;

 import java.util.LinkedHashSet;

 import java.util.Set;

 import org.apache.commons.vfs.FileObject;

 import org.apache.commons.vfs.FileSystemException;

 import org.webslinger.commons.vfs.VFSUtil;

 public class COWEntryImpl implements COWEntry {

     private final COWState state;

     private String name;

     private boolean deleted;

     private String symlink;

     private String[] bases;

     private COWFileObject[] baseFiles;

     COWEntryImpl(COWState state, String name) {

         this.state = state;

         this.name = name;

         bases = new String[0];

     }

     synchronized void absorb(boolean deleted, String symlink, Collection<String> bases) {

         this.deleted = deleted;

         this.symlink = symlink;

         LinkedHashSet<String> tmpBases = new LinkedHashSet<String>(bases);

         this.bases = tmpBases.toArray(new String[tmpBases.size()]);

     }

     public String getName() {

         return name;

     }

     public synchronized boolean isDeleted() {

         return deleted;

     }

     public synchronized void clear() throws FileSystemException {

         deleted = false;

         symlink = null;

         bases = new String[0];

         baseFiles = null;

         onChange();

     }

     public synchronized boolean isEmpty() {

         return !deleted && symlink == null && bases.length == 0;

     }

     public synchronized boolean setDeleted(boolean deleted) throws FileSystemException {

         if (deleted) {

             if (this.deleted) return false;

             this.deleted = true;

             symlink = null;

         } else {

             if (!this.deleted) return false;

             this.deleted = false;

         }

         baseFiles = null;

         onChange();

         return true;

     }

     public synchronized String getSymlink() {

         return symlink;

     }

     public synchronized boolean setSymlink(String symlink) throws FileSystemException {

         if (symlink != null && symlink.length() == 0) symlink = null;

         if (symlink == null) {

             if (this.symlink == null) return false;

             this.symlink = null;

         } else {

             if (symlink.equals(this.symlink)) return false;

             this.symlink = symlink;

         }

         baseFiles = null;

         onChange();

         return true;

     }

     public synchronized Collection<String> getBases() {

         return Arrays.asList(bases);

     }

     public synchronized Collection<COWFileObject> getBaseFiles() throws FileSystemException {

         synchronized (this) {

             if (baseFiles != null) return Arrays.asList(baseFiles);

             COWFileObject dir = state.getDir();

             COWFileObject[] baseFiles = new COWFileObject[bases.length];

             for (int i = 0; i < bases.length; i++) {

                 baseFiles[i] = dir.resolveFile(bases[i]);

             }

             this.baseFiles = baseFiles;

             return Arrays.asList(baseFiles);

         }

     }

     public synchronized boolean addBase(String base) throws FileSystemException {

         LinkedHashSet<String> tmpBases = new LinkedHashSet<String>(Arrays.asList(bases));

         if (!tmpBases.add(base)) return false;

         this.bases = tmpBases.toArray(new String[tmpBases.size()]);

         baseFiles = null;

         onChange();

         return true;

     }

     public synchronized boolean removeBase(String base) throws FileSystemException {

         LinkedHashSet<String> tmpBases = new LinkedHashSet<String>(Arrays.asList(bases));

         if (!tmpBases.remove(base)) return false;

         this.bases = tmpBases.toArray(new String[tmpBases.size()]);

         baseFiles = null;

         onChange();

         return true;

     }

     protected void onChange() throws FileSystemException {

         state.save();

         if (state.getCOWFileSystem() != null) state.getCOWFileSystem().newGeneration();

         // clear local cache

     }

     public synchronized String toString() {

         StringBuilder sb = new StringBuilder();

         sb.append('(').append(name);

         if (deleted) sb.append(", deleted");

         if (symlink != null) sb.append(", symlink[").append(symlink).append(']');

         sb.append(", bases").append(bases).append(')');

         return sb.toString();

     }

     public int getSerial() {

         return state.getSerial();

     }

     public boolean checkSerial(int serial) throws FileSystemException {

         try {

             return state.checkSerial(serial);

         } catch (IOException e) {

             throw VFSUtil.makeFileSystemException(e);

         }

     }

 }