/*******************************************************************************
 * Copyright (c) 2005 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.sse.ui.internal.search;

import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.widgets.Event;
import org.eclipse.ui.IActionDelegate2;
import org.eclipse.ui.IEditorActionDelegate;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IFileEditorInput;
import org.eclipse.ui.IViewActionDelegate;
import org.eclipse.ui.IViewPart;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.wst.sse.ui.internal.ExtendedConfigurationBuilder;
import org.eclipse.wst.sse.ui.internal.SSEUIMessages;
import org.eclipse.wst.sse.ui.internal.util.PlatformStatusLineUtil;

/**
 * Performs the appropriate FindOccurrencesProcessor action call based on
 * selection. Clients can add processors for different partitions via
 * <code>getProcessors</code>
 * 
 */
abstract public class FindOccurrencesActionDelegate implements IEditorActionDelegate, IActionDelegate2, IViewActionDelegate {
	private IEditorPart fEditor;

	public void setActiveEditor(IAction action, IEditorPart targetEditor) {
		fEditor = targetEditor;
	}

	public void dispose() {
		// nulling out just in case
		fEditor = null;
	}

	public void init(IAction action) {
		if (action != null) {
			action.setText(SSEUIMessages.FindOccurrences_label);
		}
	}

	public void runWithEvent(IAction action, Event event) {
		run(action);
	}

	public void run(IAction action) {
		boolean okay = false;
		if (fEditor instanceof ITextEditor) {
			ITextEditor textEditor = (ITextEditor) fEditor;
			IDocument document = textEditor.getDocumentProvider().getDocument(textEditor.getEditorInput());
			if (document != null) {
				ITextSelection textSelection = getTextSelection(textEditor);
				FindOccurrencesProcessor findOccurrenceProcessor = getProcessorForCurrentSelection(document, textSelection);
				if (findOccurrenceProcessor != null) {
					if (textEditor.getEditorInput() instanceof IFileEditorInput) {
						IFile file = ((IFileEditorInput) textEditor.getEditorInput()).getFile();
						okay = findOccurrenceProcessor.findOccurrences(document, textSelection, file);
					}
				}
			}
		}
		if (okay) {
			// clear status message
			PlatformStatusLineUtil.clearStatusLine();
		}
		else {
			String errorMessage = SSEUIMessages.FindOccurrencesActionProvider_0; //$NON-NLS-1$
			PlatformStatusLineUtil.displayErrorMessage(errorMessage);
			PlatformStatusLineUtil.addOneTimeClearListener();
		}
	}

	public void init(IViewPart view) {
		// do nothing
	}

	public void selectionChanged(IAction action, ISelection selection) {
		// clear status message
		PlatformStatusLineUtil.clearStatusLine();
	}

	/**
	 * Get the appropriate find occurrences processor
	 * 
	 * @param document -
	 *            assumes not null
	 * @param textSelection
	 * @return
	 */
	private FindOccurrencesProcessor getProcessorForCurrentSelection(IDocument document, ITextSelection textSelection) {
		// check if we have an action that's enabled on the current partition
		ITypedRegion tr = getPartition(document, textSelection);
		String partition = tr != null ? tr.getType() : ""; //$NON-NLS-1$

		Iterator it = getProcessors().iterator();
		FindOccurrencesProcessor processor = null;
		while (it.hasNext()) {
			processor = (FindOccurrencesProcessor) it.next();
			// we just choose the first action that can handle the partition
			if (processor.enabledForParitition(partition))
				return processor;
		}
		List extendedFindOccurrencesProcessors = ExtendedConfigurationBuilder.getInstance().getConfigurations(FindOccurrencesProcessor.class.getName(), partition);
		for (int i = 0; i < extendedFindOccurrencesProcessors.size(); i++) {
			Object o = extendedFindOccurrencesProcessors.get(i);
			if (o instanceof FindOccurrencesProcessor) {
				/*
				 * We just choose the first registered processor that
				 * explicitly says it can handle the partition
				 */
				processor = (FindOccurrencesProcessor) it.next();
				if (processor.enabledForParitition(partition))
					return processor;
			}
		}
		return null;
	}

	private ITypedRegion getPartition(IDocument document, ITextSelection textSelection) {
		ITypedRegion region = null;
		if (textSelection != null) {
			try {
				region = document.getPartition(textSelection.getOffset());
			}
			catch (BadLocationException e) {
				region = null;
			}
		}
		return region;
	}

	private ITextSelection getTextSelection(ITextEditor textEditor) {
		ITextSelection textSelection = null;
		ISelection selection = textEditor.getSelectionProvider().getSelection();
		if (selection instanceof ITextSelection && !selection.isEmpty()) {
			textSelection = (ITextSelection) selection;
		}
		return textSelection;
	}

	abstract protected List getProcessors();
}