package ie.dcu.apps.ist.dialogs;

import java.util.Properties;

import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Dialog;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.*;
import org.eclipse.jface.resource.JFaceResources;
import ie.dcu.apps.ist.AppWindow;
import ie.dcu.swt.SwtUtils;
import ie.dcu.swt.layout.LayoutFactory;

public class SaveReminderDialog extends Dialog {

	// Result
	private ResultChoice result;
	
	// Top level components
	private AppWindow window;
	private Shell shell;
	private Composite content;
	private Composite upper;
	private Composite lower;
	
	// Text
	private static final String TITLE = "Save Reminder";
	private static final String QUESTION = "Do you wish to save your work before closing this file?";
	private static final String SAVE_TEXT = "Save now and then close this file:";
	private static final String NOSAVE_TEXT = "Just close it (CAUTION: unsaved changes will be lost):";
	private static final String CANCEL_TEXT = "Do NOT close this file:";
	
	// Dialog buttons
	private Button saveButton;
	private Button noSaveButton;
	private Button cancelButton;
	
	public enum ResultChoice {
		SAVE, NOSAVE, CANCEL
	}

	public SaveReminderDialog(Shell shell, AppWindow window) {
		super(shell);
		setText(TITLE);
		this.window = window;
	}
	
	public ResultChoice open() {
		Shell parent = getParent();
		shell = new Shell(parent, SWT.DIALOG_TRIM | 
			SWT.APPLICATION_MODAL | SWT.SHEET);
		shell.setText(getText());
		shell.setLayout(new FillLayout());
		
		createUI();
		
		shell.pack();
		SwtUtils.center(parent, shell);
		shell.open();
		Display display = parent.getDisplay();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) display.sleep();
		}
		return result;
	}

	/*
	 * overall layout
	 */
	private void createUI() {
		// outer composite
		content = new Composite(shell, 0);
		content.setLayout(LayoutFactory.createGridLayout(0, 0, 1, false));

		// upper composite
		upper = new Composite(content, 0);
		upper.setLayout(LayoutFactory.createGridLayout(10, 5, 1, false));
		upper.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

		hline(content);

		// lower composite
		lower = new Composite(content, 0);
		lower.setLayout(LayoutFactory.createGridLayout(10, 5, 2, false));
		lower.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false));
		
		// add inner content
		banner(upper, QUESTION);

		label(lower, SAVE_TEXT);
		saveButton = button(lower,"save");

		label(lower, NOSAVE_TEXT);
		noSaveButton = button(lower,"no-save");

		label(lower, CANCEL_TEXT);
		cancelButton = button(lower,"cancel");

		// Set the default button
		shell.setDefaultButton(saveButton);
		
		// Add listeners
		addListeners();
	}

	private void addListeners() {
		saveButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				result = ResultChoice.SAVE;
				shell.dispose();
			}
		});

		noSaveButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				result = ResultChoice.NOSAVE;
				shell.dispose();
			}
		});

		cancelButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				result = ResultChoice.CANCEL;
				shell.dispose();
			}
		});
	}

	private Label hline(Composite parent) {
		Label label = new Label(parent, SWT.SEPARATOR | SWT.HORIZONTAL);
		GridData data = new GridData(SWT.FILL, SWT.CENTER, false, false);
		data.horizontalSpan = 2;
		data.heightHint = 10;
		label.setLayoutData(data);
		return label;
	}

	private Label banner(Composite parent, String text) {
		// Create label
		Label lb = new Label(parent, SWT.NONE);
		lb.setText(text);
		lb.setFont(JFaceResources.getBannerFont());
		return lb;
	}

	private Label label(Composite parent, String text) {
		Label label = new Label(parent, SWT.NONE);
		label.setText(text);
		label.setLayoutData(layoutUpper());
		return label;
	}
	
	private Button button(Composite parent, String key) {
		Button bt = new Button(parent, SWT.PUSH);
		bt.setLayoutData(layoutLower());
		configure(bt, key);
		return bt;
	}
	
	private void configure(Button bt, String key) {
		// Read properties
		String text = property(key, "text", "");
		String icon = property(key, "icon", null);
		String ttip = property(key, "ttip", null);
		
		// Set values
		bt.setText(text);
		bt.setImage(image(icon));
		bt.setToolTipText(ttip);
		bt.setData(key);
	}

	private String property(String key, String type, String def) {
		Properties p = window.getProperties();
		String prop = String.format("SaveReminderDialog.%s.%s", key, type);
		return p.getProperty(prop, def);
	}

	private Image image(String url) {
		return (url != null) ? window.getIcon(url) :  null;
	}

	private GridData layoutUpper() {
		return new GridData(SWT.LEFT, SWT.CENTER, false, false);
	}
	
	private GridData layoutLower() {
		return new GridData(SWT.FILL, SWT.CENTER, true, false);
	}
	
}