/******************************************************************************
 * Copyright (c) 2010 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.wst.css.ui.internal.contentassist;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jface.internal.text.html.BrowserInformationControl;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DefaultInformationControl;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IInformationControl;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension3;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension5;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.wst.css.core.internal.metamodel.CSSMMNode;

public class CompletionProposal implements ICompletionProposal, ICompletionProposalExtension3, ICompletionProposalExtension5 {

	/** The string to be displayed in the completion proposal popup. */
	private String fDisplayString;
	/** The replacement string. */
	private String fReplacementString;
	/** The replacement offset. */
	private int fReplacementOffset;
	/** The replacement length. */
	private int fReplacementLength;
	/** The cursor position after this proposal has been applied. */
	private int fCursorPosition;
	/** The image to be displayed in the completion proposal popup. */
	private Image fImage;
	/** The context information of this proposal. */
	private IContextInformation fContextInformation;
	/** The additional info of this proposal. */
	private String fAdditionalProposalInfo;
	private CSSMMNode fNode;
	/** The information control creator */
	private IInformationControlCreator fCreator;

	/**
	 * Creates a new completion proposal based on the provided information. The replacement string is
	 * considered being the display string too. All remaining fields are set to <code>null</code>.
	 *
	 * @param replacementString the actual string to be inserted into the document
	 * @param replacementOffset the offset of the text to be replaced
	 * @param replacementLength the length of the text to be replaced
	 * @param cursorPosition the position of the cursor following the insert relative to replacementOffset
	 */
	public CompletionProposal(String replacementString, int replacementOffset, int replacementLength, int cursorPosition) {
		this(replacementString, replacementOffset, replacementLength, cursorPosition, null, null, null, null);
	}

	/**
	 * Creates a new completion proposal. All fields are initialized based on the provided information.
	 *
	 * @param replacementString the actual string to be inserted into the document
	 * @param replacementOffset the offset of the text to be replaced
	 * @param replacementLength the length of the text to be replaced
	 * @param cursorPosition the position of the cursor following the insert relative to replacementOffset
	 * @param image the image to display for this proposal
	 * @param displayString the string to be displayed for the proposal
	 * @param contextInformation the context information associated with this proposal
	 * @param additionalProposalInfo the additional information associated with this proposal
	 */
	public CompletionProposal(String replacementString, int replacementOffset, int replacementLength, int cursorPosition, Image image, String displayString, IContextInformation contextInformation, String additionalProposalInfo) {
		this(replacementString, replacementOffset, replacementLength, cursorPosition, null, null, null, null, null);
	}

	public CompletionProposal(String replacementString, int replacementOffset, int replacementLength, int cursorPosition, Image image, String displayString, IContextInformation contextInformation, String additionalProposalInfo, CSSMMNode node) {
		Assert.isNotNull(replacementString);
		Assert.isTrue(replacementOffset >= 0);
		Assert.isTrue(replacementLength >= 0);
		Assert.isTrue(cursorPosition >= 0);

		fReplacementString= replacementString;
		fReplacementOffset= replacementOffset;
		fReplacementLength= replacementLength;
		fCursorPosition= cursorPosition;
		fImage= image;
		fDisplayString= displayString;
		fContextInformation= contextInformation;
		fAdditionalProposalInfo= additionalProposalInfo;
		fNode = node;
	}
	/*
	 * @see ICompletionProposal#apply(IDocument)
	 */
	public void apply(IDocument document) {
		try {
			document.replace(fReplacementOffset, fReplacementLength, fReplacementString);
		} catch (BadLocationException x) {
			// ignore
		}
	}

	/*
	 * @see ICompletionProposal#getSelection(IDocument)
	 */
	public Point getSelection(IDocument document) {
		return new Point(fReplacementOffset + fCursorPosition, 0);
	}

	/*
	 * @see ICompletionProposal#getContextInformation()
	 */
	public IContextInformation getContextInformation() {
		return fContextInformation;
	}

	/*
	 * @see ICompletionProposal#getImage()
	 */
	public Image getImage() {
		return fImage;
	}

	/*
	 * @see ICompletionProposal#getDisplayString()
	 */
	public String getDisplayString() {
		if (fDisplayString != null)
			return fDisplayString;
		return fReplacementString;
	}

	/*
	 * @see ICompletionProposal#getAdditionalProposalInfo()
	 */
	public String getAdditionalProposalInfo() {
		return fAdditionalProposalInfo;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension5#getAdditionalProposalInfo(org.eclipse.core.runtime.IProgressMonitor)
	 */
	public Object getAdditionalProposalInfo(IProgressMonitor monitor) {
		return ProposalInfoFactory.getProposalInfo(fNode);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension3#getInformationControlCreator()
	 */
	public IInformationControlCreator getInformationControlCreator() {
		if (fCreator == null) {
			fCreator = new AbstractReusableInformationControlCreator() {

				protected IInformationControl doCreateInformationControl(Shell parent) {
					if (BrowserInformationControl.isAvailable(parent)) {
						BrowserInformationControl control = new BrowserInformationControl(parent, JFaceResources.DIALOG_FONT, false);
						return control;
					} else {
						return new DefaultInformationControl(parent, true);
					}
				}
			};
		}
		return fCreator;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension3#getPrefixCompletionText(org.eclipse.jface.text.IDocument, int)
	 */
	public CharSequence getPrefixCompletionText(IDocument document, int completionOffset) {
		return null;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension3#getPrefixCompletionStart(org.eclipse.jface.text.IDocument, int)
	 */
	public int getPrefixCompletionStart(IDocument document, int completionOffset) {
		return 0;
	}

}