package org.argeo.eclipse.ui.fs;
   
   import java.io.IOException;
   import java.nio.file.DirectoryIteratorException;
   import java.nio.file.DirectoryStream;
   import java.nio.file.Files;
   import java.nio.file.Path;
   import java.util.ArrayList;
   import java.util.List;
  
  import org.argeo.eclipse.ui.ColumnDefinition;
  import org.eclipse.jface.viewers.ITreeContentProvider;
  import org.eclipse.jface.viewers.TreeViewer;
  import org.eclipse.jface.viewers.TreeViewerColumn;
  import org.eclipse.jface.viewers.Viewer;
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.layout.GridData;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Tree;
  import org.eclipse.swt.widgets.TreeColumn;
  
  /**
   * Canonical implementation of a JFace TreeViewer to display the content of a
   * repository
   */
  public class FsTreeViewer extends TreeViewer {
  	private static final long serialVersionUID = -5632407542678477234L;
  
  	private boolean showHiddenItems = false;
  	private boolean showDirectoryFirst = true;
  	private String orderingProperty = FsUiConstants.PROPERTY_NAME;
  
  	public FsTreeViewer(Composite parent, int style) {
  		super(parent, style | SWT.VIRTUAL);
  	}
  
  	public Tree configureDefaultSingleColumnTable(int tableWidthHint) {
  		Tree tree = this.getTree();
  		tree.setLayoutData(new GridData(SWT.FILL, SWT.FILL, false, false));
  		tree.setLinesVisible(true);
  		tree.setHeaderVisible(false);
  //		CmsUtils.markup(tree);
  
  		TreeViewerColumn column = new TreeViewerColumn(this, SWT.NONE);
  		TreeColumn tcol = column.getColumn();
  		tcol.setWidth(tableWidthHint);
  		column.setLabelProvider(new FileIconNameLabelProvider());
  
  		this.setContentProvider(new MyCP());
  		return tree;
  	}
  
  	public Tree configureDefaultTable(List<ColumnDefinition> columns) {
  		this.setContentProvider(new MyCP());
  		Tree tree = this.getTree();
  		tree.setLinesVisible(true);
  		tree.setHeaderVisible(true);
  //		CmsUtils.markup(tree);
  //		CmsUtils.style(tree, MaintenanceStyles.BROWSER_COLUMN);
  		for (ColumnDefinition colDef : columns) {
  			TreeViewerColumn column = new TreeViewerColumn(this, SWT.NONE);
  			column.setLabelProvider(colDef.getLabelProvider());
  			TreeColumn tcol = column.getColumn();
  			tcol.setResizable(true);
  			tcol.setText(colDef.getLabel());
  			tcol.setWidth(colDef.getMinWidth());
  		}
  		return tree;
  	}
  
  	public void setInput(Path dir, String filter) {
  		try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir, filter)) {
  			// TODO make this lazy
  			List<Path> paths = new ArrayList<>();
  			for (Path entry : stream) {
  				paths.add(entry);
  			}
  			Object[] rows = paths.toArray(new Object[0]);
  			this.setInput(rows);
  			// this.setItemCount(rows.length);
  			this.refresh();
  		} catch (IOException | DirectoryIteratorException e) {
  			throw new FsUiException("Unable to filter " + dir + " children with filter " + filter, e);
  		}
  	}
  
  	/** Directly displays bookmarks **/
  	public void setPathsInput(Path... paths) {
  		this.setInput((Object[]) paths);
  		// this.setItemCount(paths.length);
  		this.refresh();
  	}
  
  	private class MyCP implements ITreeContentProvider {
  		private static final long serialVersionUID = 9096550041395433128L;
  		private Object[] elements;
  
  		public void dispose() {
  		}
 
 		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 			// IMPORTANT: don't forget this: an exception will be thrown if
 			// a selected object is not part of the results anymore.
 			viewer.setSelection(null);
 			this.elements = (Object[]) newInput;
 		}
 
 		@Override
 		public Object[] getElements(Object inputElement) {
 			return elements;
 		}
 
 		@Override
 		public Object[] getChildren(Object parentElement) {
 			Path path = (Path) parentElement;
 			if (!Files.isDirectory(path))
 				return null;
 			else
 				return FsUiUtils.getChildren(path, "*", showHiddenItems, showDirectoryFirst, orderingProperty, false);
 		}
 
 		@Override
 		public Object getParent(Object element) {
 			Path path = (Path) element;
 			return path.getParent();
 		}
 
 		@Override
 		public boolean hasChildren(Object element) {
 			Path path = (Path) element;
 			try {
 				if (!Files.isDirectory(path))
 					return false;
 				else
 					try (DirectoryStream<Path> children = Files.newDirectoryStream(path, "*")) {
 						return children.iterator().hasNext();
 					}
 			} catch (IOException e) {
 				throw new FsUiException("Unable to check child existence on " + path, e);
 			}
 		}
 
 	}
 }