package no.uio.ifi.refaktor.views;


import no.uio.ifi.refaktor.analyze.analyzers.PrefixViewAnalyzer;
import no.uio.ifi.refaktor.analyze.collectors.SelectionValidator;
import no.uio.ifi.refaktor.change.exceptions.RefaktorChangerException;
import no.uio.ifi.refaktor.utils.CompilationUnitTextSelection;
import no.uio.ifi.refaktor.utils.DocumentUtils;
import no.uio.ifi.refaktor.utils.ParseUtils;
import no.uio.ifi.refaktor.utils.RefaktorHandleUtils;

import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.TextSelection;
import org.eclipse.jface.text.TextViewer;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.IPartListener;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.part.ViewPart;
import org.eclipse.ui.texteditor.ITextEditor;


/**
 * This sample class demonstrates how to plug-in a new
 * workbench view. The view shows data obtained from the
 * model. The sample creates a dummy model on the fly,
 * but a real implementation would connect to the model
 * available either in this or another plug-in (e.g. the workspace).
 * The view is connected to the model using a content provider.
 * <p>
 * The view uses a label provider to define how model
 * objects should be presented in the view. Each
 * view can present the same model objects using
 * different labels and icons, if needed. Alternatively,
 * a single label provider can be shared between views
 * in order to ensure that objects of the same type are
 * presented in the same way everywhere.
 * <p>
 * TODO: Open automatically instead of having to go to Show->View->...
 */

public class PrefixView extends ViewPart implements ISelectionChangedListener, IPartListener {

	/**
	 * The ID of the view as specified by the extension.
	 */
	public static final String ID = "no.uio.ifi.refaktor.views.PrefixView";

	private TextViewer viewer;

	private ITextEditor editor;
	private Document doc;

	/**
	 * The constructor.
	 */
	public PrefixView() {
	}

	/**
	 * This is a callback that will allow us
	 * to create the viewer and initialize it.
	 */
	public void createPartControl(Composite parent) {
		viewer = new TextViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
		doc = new Document();
		viewer.setDocument(doc);
		viewer.setInput(getViewSite());
		getSite().getPage().addPartListener(this);
	}

	/**
	 * Passing the focus request to the viewer's control.
	 */
	public void setFocus() {
		viewer.getControl().setFocus();
	}

	@Override
	public void partActivated(IWorkbenchPart part) {
		if (!(part instanceof ITextEditor))
			return;
		editor = (ITextEditor) part;
		editor.getEditorSite().getSelectionProvider().addSelectionChangedListener(this);
	}

	@Override
	public void partBroughtToTop(IWorkbenchPart part) {	}

	@Override
	public void partClosed(IWorkbenchPart part) {	}

	@Override
	public void partDeactivated(IWorkbenchPart part) {	}

	@Override
	public void partOpened(IWorkbenchPart part) {	}

	@Override
	public void selectionChanged(SelectionChangedEvent event) {
		if (!(event.getSelection() instanceof TextSelection))
			return;
		if (editor == null)
			return;
		final TextSelection sel = (TextSelection) event.getSelection();
		final IDocument document = DocumentUtils.getDocumentFrom(editor);
		final ITextSelection strippedTextSelection;
		try {
			strippedTextSelection = ParseUtils.stripTextSelection(document, sel);
			if (strippedTextSelection == null)
				return;
		} catch (RuntimeException r) {
			r.printStackTrace();
			doc.set(r.getMessage());
			return;
		}
		ICompilationUnit compilationUnit = RefaktorHandleUtils.getCompilationUnitFromEditor(editor);
		CompilationUnitTextSelection compilationUnitTextSelection = new CompilationUnitTextSelection(compilationUnit, strippedTextSelection);
		final PrefixViewAnalyzer analyzer = new PrefixViewAnalyzer(compilationUnitTextSelection);
		try {
			SelectionValidator.checkIfSelectionIsValid(compilationUnitTextSelection);
			analyzer.analyze();
			String dialogText = analyzer.toString();
			doc.set(dialogText);
		} catch (RefaktorChangerException e) {
			doc.set(e.getMessage());
		}
	}

}