/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.internal.ui.text;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.dialogs.PopupDialog;
import org.eclipse.jface.text.IInformationControl;
import org.eclipse.jface.text.IInformationControlExtension;
import org.eclipse.jface.text.IInformationControlExtension2;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.ui.IEditorPart;

import org.eclipse.cdt.core.model.ICElement;
import org.eclipse.cdt.core.model.IParent;
import org.eclipse.cdt.ui.CUIPlugin;
import org.eclipse.cdt.ui.actions.CustomFiltersActionGroup;

import org.eclipse.cdt.internal.ui.util.EditorUtility;
import org.eclipse.cdt.internal.ui.util.StringMatcher;

/**
 * Abstract class for "quick" views in light-weight controls.
 *
 * @since 4.0
 */
public abstract class AbstractInformationControl extends PopupDialog implements IInformationControl, IInformationControlExtension, IInformationControlExtension2, DisposeListener {

	/**
	 * The NamePatternFilter selects the elements which
	 * match the given string patterns.
	 */
	protected class NamePatternFilter extends ViewerFilter {

		public NamePatternFilter() {
		}

		/*
		 * Method declared on ViewerFilter.
		 */
		@Override
		public boolean select(Viewer viewer, Object parentElement, Object element) {
			StringMatcher matcher= getMatcher();
			if (matcher == null || !(viewer instanceof TreeViewer))
				return true;
			TreeViewer treeViewer= (TreeViewer) viewer;

			String matchName= ((ILabelProvider) treeViewer.getLabelProvider()).getText(element);
			if (matchName != null && matcher.match(matchName))
				return true;

			return hasUnfilteredChild(treeViewer, element);
		}

		private boolean hasUnfilteredChild(TreeViewer viewer, Object element) {
			if (element instanceof IParent) {
				Object[] children=  ((ITreeContentProvider) viewer.getContentProvider()).getChildren(element);
				for (Object element2 : children)
					if (select(viewer, element, element2))
						return true;
			}
			return false;
		}
	}

	/** The control's text widget */
	private Text fFilterText;
	/** The control's tree widget */
	private TreeViewer fTreeViewer;
	/** The current string matcher */
	protected StringMatcher fStringMatcher;

	/**
	 * Fields that support the dialog menu
	 *  - now appended to framework menu
	 */
	private Composite fViewMenuButtonComposite;

	private CustomFiltersActionGroup fCustomFiltersActionGroup;

	/**
	 * Field for tree style since it must be remembered by the instance.
	 */
	private int fTreeStyle;

	/**
	 * Creates a tree information control with the given shell as parent. The given
	 * styles are applied to the shell and the tree widget.
	 *
	 * @param parent the parent shell
	 * @param shellStyle the additional styles for the shell
	 * @param treeStyle the additional styles for the tree widget
	 * @param invokingCommandId the id of the command that invoked this control or <code>null</code>
	 * @param showStatusField <code>true</code> iff the control has a status field at the bottom
	 */
	public AbstractInformationControl(Shell parent, int shellStyle, int treeStyle, String invokingCommandId, boolean showStatusField) {
		super(parent, shellStyle, true, true, true, true, true, null, null);
		fTreeStyle= treeStyle;
		// Title and status text must be set to get the title label created, so force empty values here. 
		if (hasHeader())
			setTitleText(""); //$NON-NLS-1$
		setInfoText(""); //  //$NON-NLS-1$

		// Create all controls early to preserve the life cycle of the original implementation.
		create();

		// Status field text can only be computed after widgets are created.
		setInfoText(getStatusFieldText());
	}

	/**
	 * Create the main content for this information control.
	 * 
	 * @param parent The parent composite
	 * @return The control representing the main content.
	 * 
	 */
	@Override
	protected Control createDialogArea(Composite parent) {
		fTreeViewer= createTreeViewer(parent, fTreeStyle);

		fCustomFiltersActionGroup= new CustomFiltersActionGroup(getId(), fTreeViewer);

		final Tree tree= fTreeViewer.getTree();
		tree.addKeyListener(new KeyListener() {
			public void keyPressed(KeyEvent e)  {
				if (e.character == 0x1B) // ESC
					dispose();
			}
			public void keyReleased(KeyEvent e) {
				// do nothing
			}
		});

		tree.addSelectionListener(new SelectionListener() {
			public void widgetSelected(SelectionEvent e) {
				// do nothing
			}
			public void widgetDefaultSelected(SelectionEvent e) {
				gotoSelectedElement();
			}
		});

		tree.addMouseMoveListener(new MouseMoveListener()	 {
			TreeItem fLastItem= null;
			public void mouseMove(MouseEvent e) {
				if (tree.equals(e.getSource())) {
					Object o= tree.getItem(new Point(e.x, e.y));
					if (o instanceof TreeItem) {
						if (!o.equals(fLastItem)) {
							fLastItem= (TreeItem)o;
							tree.setSelection(new TreeItem[] { fLastItem });
						} else if (e.y < tree.getItemHeight() / 4) {
							// Scroll up
							Point p= tree.toDisplay(e.x, e.y);
							Item item= fTreeViewer.scrollUp(p.x, p.y);
							if (item instanceof TreeItem) {
								fLastItem= (TreeItem)item;
								tree.setSelection(new TreeItem[] { fLastItem });
							}
						} else if (e.y > tree.getBounds().height - tree.getItemHeight() / 4) {
							// Scroll down
							Point p= tree.toDisplay(e.x, e.y);
							Item item= fTreeViewer.scrollDown(p.x, p.y);
							if (item instanceof TreeItem) {
								fLastItem= (TreeItem)item;
								tree.setSelection(new TreeItem[] { fLastItem });
							}
						}
					}
				}
			}
		});

		tree.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseUp(MouseEvent e) {

				if (tree.getSelectionCount() < 1)
					return;

				if (e.button != 1)
					return;

				if (tree.equals(e.getSource())) {
					Object o= tree.getItem(new Point(e.x, e.y));
					TreeItem selection= tree.getSelection()[0];
					if (selection.equals(o))
						gotoSelectedElement();
				}
			}
		});

		installFilter();

		addDisposeListener(this);
		return fTreeViewer.getControl();
	}
	
	/**
	 * Creates a tree information control with the given shell as parent. The given
	 * styles are applied to the shell and the tree widget.
	 *
	 * @param parent the parent shell
	 * @param shellStyle the additional styles for the shell
	 * @param treeStyle the additional styles for the tree widget
	 */
	public AbstractInformationControl(Shell parent, int shellStyle, int treeStyle) {
		this(parent, shellStyle, treeStyle, null, false);
	}

	protected abstract TreeViewer createTreeViewer(Composite parent, int style);

	/**
	 * Returns the name of the dialog settings section.
	 *
	 * @return the name of the dialog settings section
	 */
	protected abstract String getId();

	protected TreeViewer getTreeViewer() {
		return fTreeViewer;
	}

	/**
	 * Returns <code>true</code> if the control has a header, <code>false</code> otherwise.
	 * <p>
	 * The default is to return <code>false</code>.
	 * </p>
	 * 
	 * @return <code>true</code> if the control has a header
	 */
	protected boolean hasHeader() {
		// default is to have no header
		return false;
	}

	protected Text getFilterText() {
		return fFilterText;
	}

	protected Text createFilterText(Composite parent) {
		fFilterText= new Text(parent, SWT.NONE);

		GridData data= new GridData(GridData.FILL_HORIZONTAL);
		GC gc= new GC(parent);
		gc.setFont(parent.getFont());
		FontMetrics fontMetrics= gc.getFontMetrics();
		gc.dispose();

		data.heightHint= Dialog.convertHeightInCharsToPixels(fontMetrics, 1);
		data.horizontalAlignment= GridData.FILL;
		data.verticalAlignment= GridData.CENTER;
		fFilterText.setLayoutData(data);

		fFilterText.addKeyListener(new KeyListener() {
			public void keyPressed(KeyEvent e) {
				if (e.keyCode == 0x0D) // return
					gotoSelectedElement();
				if (e.keyCode == SWT.ARROW_DOWN)
					fTreeViewer.getTree().setFocus();
				if (e.keyCode == SWT.ARROW_UP)
					fTreeViewer.getTree().setFocus();
				if (e.character == 0x1B) // ESC
					dispose();
			}
			public void keyReleased(KeyEvent e) {
				// do nothing
			}
		});

		return fFilterText;
	}

	protected String getStatusFieldText() {
		return ""; //$NON-NLS-1$
	}

	private void installFilter() {
		fFilterText.setText(""); //$NON-NLS-1$

		fFilterText.addModifyListener(new ModifyListener() {
			public void modifyText(ModifyEvent e) {
				String text= ((Text) e.widget).getText();
				int length= text.length();
				if (length > 0 && text.charAt(length -1 ) != '*') {
					text= text + '*';
				}
				setMatcherString(text, true);
			}
		});
	}

	/**
	 * The string matcher has been modified. The default implementation
	 * refreshes the view and selects the first matched element
	 */
	protected void stringMatcherUpdated() {
		// refresh viewer to re-filter
		fTreeViewer.getControl().setRedraw(false);
		fTreeViewer.refresh();
		fTreeViewer.expandAll();
		selectFirstMatch();
		fTreeViewer.getControl().setRedraw(true);
	}

	/**
	 * Sets the patterns to filter out for the receiver.
	 * <p>
	 * The following characters have special meaning:
	 *   ? => any character
	 *   * => any string
	 * </p>
	 *
	 * @param pattern the pattern
	 * @param update <code>true</code> if the viewer should be updated
	 */
	protected void setMatcherString(String pattern, boolean update) {
		if (pattern.length() == 0) {
			fStringMatcher= null;
		} else {
			boolean ignoreCase= pattern.toLowerCase().equals(pattern);
			fStringMatcher= new StringMatcher(pattern, ignoreCase, false);
		}
		
		if (update)
			stringMatcherUpdated();
	}

	protected StringMatcher getMatcher() {
		return fStringMatcher;
	}

	/**
	 * Implementers can modify
	 *
	 * @return the selected element
	 */
	protected Object getSelectedElement() {
		if (fTreeViewer == null)
			return null;

		return ((IStructuredSelection) fTreeViewer.getSelection()).getFirstElement();
	}

	private void gotoSelectedElement() {
		Object selectedElement= getSelectedElement();
		if (selectedElement != null) {
			try {
				dispose();
				IEditorPart part= EditorUtility.openInEditor(selectedElement, true);
				if (part != null && selectedElement instanceof ICElement)
					EditorUtility.revealInEditor(part, (ICElement) selectedElement);
			} catch (CoreException ex) {
				CUIPlugin.log(ex);
			}
		}
	}

	/**
	 * Selects the first element in the tree which
	 * matches the current filter pattern.
	 */
	protected void selectFirstMatch() {
		Tree tree= fTreeViewer.getTree();
		Object element= findElement(tree.getItems());
		if (element != null)
			fTreeViewer.setSelection(new StructuredSelection(element), true);
		else
			fTreeViewer.setSelection(StructuredSelection.EMPTY);
	}

	private ICElement findElement(TreeItem[] items) {
		ILabelProvider labelProvider= (ILabelProvider)fTreeViewer.getLabelProvider();
		for (TreeItem item2 : items) {
			Object item= item2.getData();
			ICElement element= null;
			if (item instanceof ICElement) {
				element= (ICElement)item;
				if (fStringMatcher == null)
					return element;
	
				String label= labelProvider.getText(element);
				if (fStringMatcher.match(label))
					return element;
			}
			element= findElement(item2.getItems());
			if (element != null)
				return element;
		}
		return null;
	}

	/**
	 * {@inheritDoc}
	 */
	public void setInformation(String information) {
		// this method is ignored, see IInformationControlExtension2
	}

	/**
	 * {@inheritDoc}
	 */
	public abstract void setInput(Object information);

	/**
	 * Fills the view menu.
	 * Clients can extend or override.
	 *
	 * @param viewMenu the menu manager that manages the menu
	 */
	protected void fillViewMenu(IMenuManager viewMenu) {
		fCustomFiltersActionGroup.fillViewMenu(viewMenu);
	}

	/*
	 * Overridden to call the old framework method.
	 * 
	 * @see org.eclipse.jface.dialogs.PopupDialog#fillDialogMenu(IMenuManager)
	 * 
	 */
	@Override
	protected void fillDialogMenu(IMenuManager dialogMenu) {
		super.fillDialogMenu(dialogMenu);
		fillViewMenu(dialogMenu);
	}

	protected void inputChanged(Object newInput, Object newSelection) {
		fFilterText.setText(""); //$NON-NLS-1$
		fTreeViewer.setInput(newInput);
		if (newSelection != null) {
			fTreeViewer.setSelection(new StructuredSelection(newSelection));
		}
	}

	/**
	 * {@inheritDoc}
	 */
	public void setVisible(boolean visible) {
		if (visible) {
			open();
		} else {
			saveDialogBounds(getShell());
			getShell().setVisible(false);
		}
	}

	/**
	 * {@inheritDoc}
	 */
	public final void dispose() {
		close();
	}

	/**
	 * {@inheritDoc}
	 * @param event can be null
	 * <p>
	 * Subclasses may extend.
	 * </p>
	 */
	public void widgetDisposed(DisposeEvent event) {
		fTreeViewer= null;
		fFilterText= null;
	}

	/**
	 * {@inheritDoc}
	 */
	public boolean hasContents() {
		return fTreeViewer != null && fTreeViewer.getInput() != null;
	}

	/**
	 * {@inheritDoc}
	 */
	public void setSizeConstraints(int maxWidth, int maxHeight) {
		// ignore
	}

	/**
	 * {@inheritDoc}
	 */
	public Point computeSizeHint() {
		// return the shell's size - note that it already has the persisted size if persisting
		// is enabled.
		return getShell().getSize();
	}

	/**
	 * {@inheritDoc}
	 */
	public void setLocation(Point location) {
		/*
		 * If the location is persisted, it gets managed by PopupDialog - fine. Otherwise, the location is
		 * computed in Window#getInitialLocation, which will center it in the parent shell / main
		 * monitor, which is wrong for two reasons:
		 * - we want to center over the editor / subject control, not the parent shell
		 * - the center is computed via the initalSize, which may be also wrong since the size may 
		 *   have been updated since via min/max sizing of AbstractInformationControlManager.
		 * In that case, override the location with the one computed by the manager. Note that
		 * the call to constrainShellSize in PopupDialog.open will still ensure that the shell is
		 * entirely visible.
		 */
		if (!getPersistLocation() || getDialogSettings() == null)
			getShell().setLocation(location);
	}

	/**
	 * {@inheritDoc}
	 */
	public void setSize(int width, int height) {
		getShell().setSize(width, height);
	}

	/**
	 * {@inheritDoc}
	 */
	public void addDisposeListener(DisposeListener listener) {
		getShell().addDisposeListener(listener);
	}

	/**
	 * {@inheritDoc}
	 */
	public void removeDisposeListener(DisposeListener listener) {
		getShell().removeDisposeListener(listener);
	}

	/**
	 * {@inheritDoc}
	 */
	public void setForegroundColor(Color foreground) {
		applyForegroundColor(foreground, getContents());
	}

	/**
	 * {@inheritDoc}
	 */
	public void setBackgroundColor(Color background) {
		applyBackgroundColor(background, getContents());
	}

	/**
	 * {@inheritDoc}
	 */
	public boolean isFocusControl() {
		return fTreeViewer.getControl().isFocusControl() || fFilterText.isFocusControl();
	}

	/**
	 * {@inheritDoc}
	 */
	public void setFocus() {
		getShell().forceFocus();
		fFilterText.setFocus();
	}

	/**
	 * {@inheritDoc}
	 */
	public void addFocusListener(FocusListener listener) {
		getShell().addFocusListener(listener);
	}

	/**
	 * {@inheritDoc}
	 */
	public void removeFocusListener(FocusListener listener) {
		getShell().removeFocusListener(listener);
	}

	/*
	 * @see org.eclipse.jface.dialogs.PopupDialog#getDialogSettings()
	 */
	@Override
	protected IDialogSettings getDialogSettings() {
		String sectionName= getId();

		IDialogSettings settings= CUIPlugin.getDefault().getDialogSettings().getSection(sectionName);
		if (settings == null)
			settings= CUIPlugin.getDefault().getDialogSettings().addNewSection(sectionName);

		return settings;
	}
	
	/*
	 * Overridden to insert the filter text into the title and menu area.
	 */
	@Override
	protected Control createTitleMenuArea(Composite parent) {
		fViewMenuButtonComposite= (Composite) super.createTitleMenuArea(parent);

		// If there is a header, then the filter text must be created
		// underneath the title and menu area.

		if (hasHeader()) {
			fFilterText= createFilterText(parent);
		}

		return fViewMenuButtonComposite;
	}

	/*
	 * Overridden to insert the filter text into the title control
	 * if there is no header specified.
	 * 
	 */
	@Override
	protected Control createTitleControl(Composite parent) {
		if (hasHeader()) {
			return super.createTitleControl(parent);
		}
		fFilterText= createFilterText(parent);
		return fFilterText;
	}
	
	/*
	 * @see org.eclipse.jface.dialogs.PopupDialog#setTabOrder(org.eclipse.swt.widgets.Composite)
	 */
	@Override
	protected void setTabOrder(Composite composite) {
		if (hasHeader()) {
			composite.setTabList(new Control[] { fFilterText, fTreeViewer.getTree() });
		} else {
			fViewMenuButtonComposite.setTabList(new Control[] { fFilterText });
			composite.setTabList(new Control[] { fViewMenuButtonComposite, fTreeViewer.getTree() });
		}
	}
}
