/* 
 * Copyright (c) 2008 Stiftung Deutsches Elektronen-Synchrotron, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
 package org.csstudio.sds.ui.logic;

import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;

import org.eclipse.core.filesystem.URIUtil;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jface.operation.IRunnableContext;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.ide.FileStoreEditorInput;
import org.eclipse.ui.part.FileEditorInput;
import org.eclipse.ui.texteditor.AbstractDocumentProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Document provider for SDS script rules.
 * 
 * @author Alexander Will
 * @version $Revision: 1.3 $
 * 
 */
public class ScriptDocumentProvider extends AbstractDocumentProvider {
	
    private static final Logger LOG = LoggerFactory.getLogger(ScriptDocumentProvider.class);

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected IAnnotationModel createAnnotationModel(Object element)
			throws CoreException {
		return null;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected IRunnableContext getOperationRunner(IProgressMonitor monitor) {
		return null;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean isModifiable(Object element) {
		return true;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean isReadOnly(Object element) {
		return false;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected IDocument createDocument(Object element) throws CoreException {
		if (element instanceof IEditorInput) {
			IDocument document = new Document();
			if (setDocumentContent(document, (IEditorInput) element)) {
				return document;
			}
		}

		return null;
	}

	/**
	 * Set the document content.
	 * 
	 * @param document
	 *            target document.
	 * @param editorInput
	 *            the editor input to fetch the content from.
	 * @return true, if the content could be set.
	 * @throws CoreException
	 *             if an error occurred.
	 */
	protected boolean setDocumentContent(IDocument document,
			IEditorInput editorInput) throws CoreException {

		boolean result = false;

		if (editorInput instanceof FileEditorInput) {
			IFile file = ((FileEditorInput) editorInput).getFile();

			InputStreamReader inReader = new InputStreamReader(file
					.getContents());
			StringBuffer buffer = new StringBuffer();

			try {
				char[] readBuffer = new char[2048];
				int n = inReader.read(readBuffer);
				while (n > 0) {
					buffer.append(readBuffer, 0, n);
					n = inReader.read(readBuffer);
				}

				document.set(buffer.toString());
				result = true;
			} catch (IOException e) {
				LOG.error(e.toString());
			} finally {
				try {
					inReader.close();
				} catch (IOException e) {
					LOG.error(e.toString());
				}
			}
		}

		return result;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected void doSaveDocument(IProgressMonitor monitor, Object element,
			IDocument document, boolean overwrite) throws CoreException {
		try {
			if (element instanceof FileEditorInput) {
				ByteArrayInputStream bais = new ByteArrayInputStream(document
						.get().getBytes());
				((FileEditorInput) element).getFile().setContents(bais, false,
						false, null);
				monitor.done();
			} else if (element instanceof FileStoreEditorInput) {
				File file = URIUtil.toPath(
						((FileStoreEditorInput) element).getURI()).toFile();
				String content = document.get();
				try {
					FileWriter fileWriter = new FileWriter(file, false);
					BufferedWriter writer = new BufferedWriter(fileWriter);
					writer.write(content);
					writer.flush();
					writer.close();
					monitor.done();
				} catch (IOException e) {
					LOG.error(e.toString());
					monitor.setCanceled(true);
				}
			}
		} catch (CoreException e) {
			LOG.error(e.toString());
			monitor.setCanceled(true);
		}
	}
}