package ie.dcu.apps.ist.actions;


import ie.dcu.apps.ist.views.SegmentationView;
import ie.dcu.segment.SegmentationContext;
import ie.dcu.segment.painters.SegmentationPainter;
import ie.dcu.swt.*;
import ie.dcu.util.FileUtils;

import java.io.*;
import java.util.logging.Level;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.*;


/**
 * Export current view as image.
 * 
 * @author Kevin McGuinness
 */
public class ExportViewAction extends AppAction {
	
	private static final String DEFAULT_SUFFIX = ".png";
	
	private FileDialog dialog;
	private String directory;
	
	public ExportViewAction(ActionManager m) {
		super(m);
	}

	@Override 
	public void run() { 
		if (window.hasContext()) {
			File file = getFile();
			if (file != null) {
				directory = file.getParent();
				export(file);
			}
		}		
	}


	private void export(File file) {
		Image im = paintContext();
		
		try {
			SwtUtils.saveImage(im, file);
			status("View successfully exported as %s", file.getName());
			
		} catch (IOException e) {
		
			handleError(file, e);
			
		} finally {
			
			im.dispose();
		}
	}

	
	private void handleError(File file, IOException e) {
		// Log
		log(Level.WARNING, "Error exporting view as image", e);
		
		// Show error dialog
		error("Error exporting view as image %s: %s", 
				file.getName(), e.getLocalizedMessage()
		);
		
		// Set status message
		status(Error, "Error exporting view as image %s", file.getName());
	}

	
	private File getFile() {
		createExportDialog();
		
		String path = dialog.open();
		if (path != null) {
			return checkFile(path);
		}
		
		return null;
	}
	
	
	private File checkFile(String path) {
		File file = new File(path);

		if (SwtUtils.getImageFormat(file) != -1) {
			return file;
		} 
		
		// Unknown file extension, so assume jpg
		return new File(FileUtils.replaceExtension(path, DEFAULT_SUFFIX));
	}

	
	private void createExportDialog() {
		if (dialog == null) {
			dialog = new FileDialog(window.getShell(), SWT.SAVE | SWT.SHEET);
			dialog.setText(property("ExportViewAction.dialog.text"));
			dialog.setFilterExtensions(getFilters());
			dialog.setFilterNames(getFilterNames());
		}
		
		dialog.setFileName(getFileName());
		
		String dir = getDirectory();
		if (dir != null) {
			// Unfortunately this is buggy on SWT/GTK and
			// the filter path isin't always set :'-(
			dialog.setFilterPath(dir);
		}
	}
	
	private String getFileName() {
		File file = window.getContext().getFile();
		return FileUtils.replaceExtension(file.getName(), DEFAULT_SUFFIX);
	}
	
	
	private String getDirectory() {
		if (directory == null) {
			File folder = window.getContext().getFolder();
			directory = (folder != null) ? 
					directory = folder.getAbsolutePath() : null;
		}
		
		return directory;
	}
	
	
	
	private String[] getFilters() {
		return new String[] { property("ExportViewAction.dialog.filter.exts") };
	}
	
	
	private String[] getFilterNames() {
		return new String[] { property("ExportViewAction.dialog.filter.text") };
	}
	
	
	private Image paintContext() {
		SegmentationView view = window.getView();
		SegmentationContext ctx = window.getContext();
		SegmentationPainter painter = view.getPainter();
		ObservableImage im = createCompatibleImage(ctx);
		painter.paint(ctx, im);
		return im.getImage();
	}
	
	
	private ObservableImage createCompatibleImage(SegmentationContext ctx) {
		Image im = new Image(Display.getCurrent(), ctx.getBounds());
		return new ObservableImage(im);
	}
}