/*=============================================================================#
 # Copyright (c) 2000, 2020 IBM Corporation and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0
 # 
 # Contributors:
 #     IBM Corporation - org.eclipse.jdt: initial API and implementation
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ltk.ui.sourceediting;

import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.AbstractInformationControl;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.editors.text.EditorsUI;

import org.eclipse.statet.ecommons.ui.util.LayoutUtils;


/**
 * Information control to show sources or other text in a source viewer.
 */
public class SourceViewerInformationControl extends AbstractInformationControl {
	
	
	private static final int MODE_SIMPLE= 1;
	private static final int MODE_FOCUS= 2;
	
	
	private final int mode;
	
	private Composite contentComposite;
	
	/** The control's text widget */
	private StyledText text;
	/** The control's source viewer */
	private SourceViewer viewer;
	
	private final SourceEditorViewerConfigurator configurator;
	
	private IInformationControlCreator informationCreator;
	
	/**
	 * The orientation of the shell
	 */
	private final int orientation;
	
	
	/**
	 * Creates a source viewer information control with the given shell as parent. The given
	 * styles are applied to the created styled text widget. The status field will
	 * contain the given text or be hidden.
	 * 
	 * @param parent the parent shell
	 * @param configurator used to configure the source viewer of the hover
	 * @param informationConfigurator used to configure the source viewer of the information presenter
	 * @param orientation the orientation
	 */
	public SourceViewerInformationControl(final Shell parent, final SourceEditorViewerConfigurator configurator, final int orientation, final IInformationControlCreator informationCreator) {
		super(parent, EditorsUI.getTooltipAffordanceString());
		
		assert (orientation == SWT.RIGHT_TO_LEFT || orientation == SWT.LEFT_TO_RIGHT || orientation == SWT.NONE);
		
		this.mode= MODE_SIMPLE;
		this.configurator= configurator;
		this.orientation= orientation;
		this.informationCreator= informationCreator;
		create();
	}
	
	public SourceViewerInformationControl(final Shell parent, final SourceEditorViewerConfigurator configurator, final int orientation) {
		super(parent, true);
		
		assert (orientation == SWT.RIGHT_TO_LEFT || orientation == SWT.LEFT_TO_RIGHT || orientation == SWT.NONE);
		
		this.mode= MODE_FOCUS;
		this.configurator= configurator;
		this.orientation= orientation;
		create();
	}
		
	@Override
	protected void createContent(final Composite parent) {
		this.contentComposite= new Composite(parent, SWT.NONE) {
			@Override
			public Point computeSize(final int width, final int height, final boolean changed) {
				return super.computeSize(width, height, changed || width != getSize().x);
			}
		};
		this.contentComposite.setBackground(parent.getBackground());
		
		final GridLayout gridLayout= LayoutUtils.newCompositeGrid(1);
		this.contentComposite.setLayout(gridLayout);
		
		final int vIndent= Math.max(1, LayoutUtils.defaultVSpacing() / 4);
		final int hIndent= Math.max(2, LayoutUtils.defaultHSpacing() / 3);
		
		// Source viewer
		this.viewer= new SourceViewer(this.contentComposite, null, null, false, (this.mode == MODE_FOCUS ?
				(SWT.V_SCROLL | SWT.H_SCROLL) : SWT.NONE) | SWT.MULTI | SWT.READ_ONLY | this.orientation);
		this.viewer.setEditable(false);
		final ViewerSourceEditorAdapter editor= new ViewerSourceEditorAdapter(this.viewer, this.configurator);
		this.configurator.setTarget(editor);
		
		this.text= this.viewer.getTextWidget();
		final GridData gd= new GridData(SWT.FILL, SWT.FILL, true, true);
		this.text.setLayoutData(gd);
		this.text.setFont(JFaceResources.getTextFont());
		this.text.setIndent(hIndent);
		
//		this.text.addKeyListener(new KeyListener() {
//			public void keyPressed(final KeyEvent e)  {
//				if (e.character == 0x1B) // ESC
//					this.shell.dispose();
//			}
//			public void keyReleased(final KeyEvent e) {}
//		});
		setBackgroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
		setForegroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
	}
	
	@Override
	public void setBackgroundColor(final Color background) {
		super.setBackgroundColor(background);
		this.text.setBackground(background);
	}
	
	@Override
	public void setForegroundColor(final Color foreground) {
		super.setForegroundColor(foreground);
		this.text.setForeground(foreground);
	}
	
	@Override
	public void setInformation(String content) {
		if (content == null) {
			this.viewer.setInput(null);
			return;
		}
		
		if (content.length() > 2 
				&& content.charAt(content.length()-1) == '\n') {
			if (content.charAt(content.length()-2) == '\r') {
				content= content.substring(0, content.length()-2);
			}
			else {
				content= content.substring(0, content.length()-1);
			}
		}
		
		final IDocument document= new Document(content);
		this.configurator.getDocumentSetupParticipant().setup(document);
		this.viewer.setInput(document);
	}
	
	@Override
	public final void dispose() {
		if (this.configurator != null) {
			this.configurator.unconfigureTarget();
		}
		super.dispose();
		this.text= null;
	}
	
	@Override
	public void setFocus() {
		this.text.setFocus();
		super.setFocus();
	}
	
	@Override
	public boolean hasContents() {
		return this.text.getCharCount() > 0;
	}
	
	protected ISourceViewer getViewer()  {
		return this.viewer;
	}
	
	@Override
	public Point computeSizeHint() {
		final Point sizeConstraints= getSizeConstraints();
		final Rectangle trim= computeTrim();
		
		int widthHint= this.text.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x + LayoutUtils.defaultHSpacing();
		final int widthMax= ((sizeConstraints != null && sizeConstraints.x != SWT.DEFAULT) ?
				sizeConstraints.x : LayoutUtils.hintWidth(this.text, null, 80)) - trim.width;
		if (widthHint > widthMax) {
			widthHint= widthMax;
		}
		
		final int heightMax= ((sizeConstraints != null && sizeConstraints.y != SWT.DEFAULT) ?
				sizeConstraints.y :
				this.text.getLineHeight()*12) - trim.height;
		
		final Point size= this.contentComposite.computeSize(widthHint, SWT.DEFAULT, false);
		size.x= Math.max(Math.min(size.x, widthMax), 200) + trim.width;
		size.y= Math.max(Math.min(size.y, heightMax), 80) + trim.height;
		return size;
	}
	
	@Override
	public Rectangle computeTrim() {
		final Rectangle trim= super.computeTrim();
		
		final Rectangle textTrim= this.text.computeTrim(0, 0, 0, 0);
		trim.x+= textTrim.x;
		trim.y+= textTrim.y;
		trim.width+= textTrim.width;
		trim.height+= textTrim.height;
		
		return trim;
	}
	
	@Override
	public Point computeSizeConstraints(final int widthInChars, final int heightInChars) {
		final GC gc= new GC(this.text);
		gc.setFont(JFaceResources.getDialogFont());
		final double width= gc.getFontMetrics().getAverageCharacterWidth() * widthInChars;
		final int height= gc.getFontMetrics().getHeight() * heightInChars;
		gc.dispose();
		
		return new Point((int)Math.round(width + 0x1.FFFFFp-2), height);
	}
	
	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
		return this.informationCreator;
	}
	
}