package com.framsticks.framclipse.editors.hover;

import java.util.List;

import org.eclipse.jface.internal.text.html.BrowserInformationControl;
import org.eclipse.jface.internal.text.html.HTMLTextPresenter;
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.IInformationControlExtension4;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextHover;
import org.eclipse.jface.text.ITextHoverExtension;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.information.IInformationProviderExtension2;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.editors.text.EditorsUI;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.xpath.XPath;

import com.framsticks.framclipse.Framclipse;
import com.framsticks.framclipse.editors.codeCompletion.SyntaxUtils;


public class FramscriptTextHover implements ITextHover, ITextHoverExtension, IInformationProviderExtension2 {
	
	private static final class PresenterControlCreator extends AbstractReusableInformationControlCreator {

		public IInformationControl doCreateInformationControl(Shell parent) {
//			int shellStyle= SWT.RESIZE | SWT.TOOL;
//			int style= SWT.V_SCROLL | SWT.H_SCROLL;
//			if (BrowserInformationControl.isAvailable(parent)) {
//				return new BrowserInformationControl(parent, JFaceResources.DIALOG_FONT, true);
//				return new BrowserInformationControl(parent, shellStyle, style);
//			} else
//				return new DefaultInformationControl(parent, shellStyle, style, new HTMLTextPresenter(false));
				return new DefaultInformationControl(parent, true);
		}
	}

	private static final class HoverControlCreator extends AbstractReusableInformationControlCreator {
		
		public IInformationControl doCreateInformationControl(Shell parent) {
//			if (BrowserInformationControl.isAvailable(parent)) {
//				return new BrowserInformationControl(parent, JFaceResources.DIALOG_FONT, true);
//				return new BrowserInformationControl(parent, SWT.TOOL | SWT.NO_TRIM, SWT.NONE, EditorsUI.getTooltipAffordanceString());
//			} else {
//				return new DefaultInformationControl(parent, SWT.NONE, new HTMLTextPresenter(true), EditorsUI.getTooltipAffordanceString());
				return new DefaultInformationControl(parent, true);
//			}
		}

		/*
		 * @see org.eclipse.jdt.internal.ui.text.java.hover.AbstractReusableInformationControlCreator#canReuse(org.eclipse.jface.text.IInformationControl)
		 */
		public boolean canReuse(IInformationControl control) {
			if (!super.canReuse(control))
				return false;
			
			if (control instanceof IInformationControlExtension4)
				((IInformationControlExtension4)control).setStatusText(EditorsUI.getTooltipAffordanceString());
			
			return true;
		}
	}



	private static final int DESCRIPTION_LENGTH = 60;
	
	private IInformationControlCreator fHoverControlCreator;
	
	private IInformationControlCreator fPresenterControlCreator;
	
	public IInformationControlCreator getInformationPresenterControlCreator() {
		if (fPresenterControlCreator == null)
			fPresenterControlCreator= new PresenterControlCreator();
		return fPresenterControlCreator;
	}

	public IInformationControlCreator getHoverControlCreator() {
		if (fHoverControlCreator == null)
			fHoverControlCreator= new HoverControlCreator();
		return fHoverControlCreator;
	}

	public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
		int offset = hoverRegion.getOffset() + hoverRegion.getLength();
		IDocument document = textViewer.getDocument();

		List<String> elements = SyntaxUtils.getElementsAt(document, offset);

		if (elements.size() == 0) {
			return null;
		}

		String name = elements.remove(elements.size() - 1);
		String elementFormat = "%s[@" + SyntaxUtils.NAME_ATTRIBUTE + "='%s']/";
		String query = SyntaxUtils.ROOT + "/";

		if (elements.size() == 0) {
			query += String.format(elementFormat, SyntaxUtils.TYPE_ELEMENT, name);
		} else { // elements.size() > 1
			String parent;
			try {
				parent = SyntaxUtils.getLastElementType(elements);
			} catch (JDOMException e) {
				e.printStackTrace();
				return null;
			}
			query += String.format(elementFormat, SyntaxUtils.TYPE_ELEMENT, parent)
					+ String.format(elementFormat, SyntaxUtils.ELEMENT_ELEMENT, name);
		}
		query += SyntaxUtils.DESCRIPTION_ELEMENT;

		Document syntax = Framclipse.getDefault().getFramscriptSyntax();
		try {
			XPath xpath = XPath.newInstance(query);
			Element element = (Element) xpath.selectSingleNode(syntax);
			if (element == null) {
				return null;
			}

			return formatDescription(element.getValue());
		} catch (Exception e) {
			e.printStackTrace();
		}

		return null;
	}

	public IRegion getHoverRegion(ITextViewer textViewer, int offset) {
		IDocument document = textViewer.getDocument();
		String after = SyntaxUtils.getElementAfter(document, offset);

		int line = 0;
		try {
			line = document.getLineOfOffset(offset);
		} catch (BadLocationException e) {
			e.printStackTrace();
		}

		int lineStart = offset;
		try {
			lineStart = document.getLineInformation(line).getOffset();
		} catch (BadLocationException e) {
			e.printStackTrace();
		}
		IRegion region = new Region(lineStart, offset + after.length() - lineStart);

		return region;
	}

	private static String formatDescription(String description) {
		String result = "";
		int offset = 0;
		while (offset < description.length()) {
			int length = DESCRIPTION_LENGTH;
			if (offset + length > description.length()) {
				result += description.substring(offset);
				return result;
			}

			for (int i = length; i > 0; i--) {
				if (Character.isWhitespace(description.charAt(offset + i))) {
					length = i;
					i = 0;
				}
			}

			result += description.substring(offset, offset + length) + "\n";
			offset += length + 1;
		}
		return result;
	}
}