package com.smartgwt.sample.client;

import com.smartgwt.client.data.Record;
import com.smartgwt.client.widgets.Canvas;
import com.smartgwt.client.widgets.IButton;
import com.smartgwt.client.widgets.Label;
import com.smartgwt.client.widgets.Window;
import com.smartgwt.client.widgets.events.ClickEvent;
import com.smartgwt.client.widgets.events.ClickHandler;
import com.smartgwt.client.widgets.layout.HLayout;
import com.smartgwt.client.widgets.layout.VLayout;
import com.smartgwt.client.widgets.viewer.DetailViewer;
import com.smartgwt.client.widgets.viewer.DetailViewerField;

/**
 * A window to be displayed when concurrency save occurs. Will display both the
 * database record and the currently edited record, and allow user to opt to 
 * continue editing, to cancel his changes or to overwrite the database values. 
 */
public class ConcurrentConflictDialog extends Window 
{
	/**
	 * Possible user actions
	 */
	public enum UserAction
	{
		UNKNOWN,
		KEEP_EDITING,
		SAVE_ANYWAY,
		DISCARD_CHANGES
	}
	
	public UserAction userAction;
	ConcurrentConflictDialogCallback callback;
	
	/**
	 * Constructs this conflict dialog with user supplied data to be displayed to user and a callback
	 * through which to act upon a choice made by the user.
	 *  
	 * @param serverValues the current row values as they are in the database. these values 
	 * are server sent back by the server
	 * 
	 * @param editedValues the edited row values. This should include the changes the user made
	 * 
	 * @param fields the list of fields each record has.
	 * 
	 * @param cb the callback to be called on action performed.
	 */
	public ConcurrentConflictDialog(Record serverValues, Record editedValues, String[] fields, 
			final ConcurrentConflictDialogCallback cb)
	{
		super();
		
		this.callback = cb;
		userAction = UserAction.UNKNOWN;
		
		// set some general attributes
		setWidth(500);
		setHeight(350);
		setTitle("Concurrent change detected!");
		setShowMinimizeButton(false);
		setShowCloseButton(false);
		setIsModal(true);
		setShowModalMask(true);
		centerInPage();
		
		//create a horizontal layout for the labels on top of detail viewer
		// and place inside the detail labels.
		HLayout labels = new HLayout(5);
		labels.setWidth100();
		labels.setHeight(30);
		labels.setMargin(10);
		Label l1= new Label("Current database record");
		l1.setWidth("50%");
		Label l2 = new Label("Your record");
		l2.setWidth("50%");
		labels.addMember(l1);
		labels.addMember(l2);
		
		// create a horizontal layout for the detail viewers
		HLayout details = new HLayout();
		details.setWidth100();
		details.setHeight("*");
		details.setPadding(5);
		details.setMembersMargin(5);
		
		// create a detail viewer to display the values we got from the server
		final DetailViewer old = new DetailViewer();
		old.setData(new Record[]{serverValues});
		old.setTitle("Concurent changes");
		
		// create a detail viewer to display values we changed
		DetailViewer nw = new DetailViewer();
		nw.setData(new Record[]{editedValues});
		nw.setTitle("New changes");

		// set the fields to be displayed in both detail viewers
		DetailViewerField[] f = new DetailViewerField[fields.length];		
		for(int i=0;i<fields.length;i++)
		{
			f[i] = new DetailViewerField(fields[i]);
		}
		old.setFields(f);
		nw.setFields(f);

		// set both of them as tall ass possible, and 50% wide so they'll fill up space evenly
		old.setHeight("*");
		nw.setHeight("*");
		old.setWidth("50%");
		nw.setWidth("50%");
		
		// add them to the layout
		details.addMember(old);
		details.addMember(nw);
		
		// create a horizontal layout for the row of buttons on bottom, 
		HLayout buttons = new HLayout(10);
		buttons.setWidth100();
		buttons.setHeight(30);
		buttons.setMargin(10);
		
		IButton keepEditing = new IButton("Keep Editing");
		keepEditing.addClickHandler(new ClickHandler() {
			
			@Override
			public void onClick(ClickEvent event) {
				if (callback != null)
				{
					// call the user supplied callback notifying the caller about
					// user continuing the edit
					callback.dialogClosed(UserAction.KEEP_EDITING);
				}
				destroy();
			}
		});
		
		buttons.addMember(keepEditing);
						
		IButton saveAnyway = new IButton("Save Anyway");
		saveAnyway.addClickHandler(new ClickHandler() {
			
			@Override
			public void onClick(ClickEvent e) {
										
				if (callback != null)
				{
					// call the user supplied callback notifying the caller about
					// user opting to overwrite database record with his changes
					callback.dialogClosed(UserAction.SAVE_ANYWAY);
				}
				destroy();
			}
		});
		buttons.addMember(saveAnyway);
		
		// spacing, as the discard button will be a bit more to the right
		Canvas c = new Canvas();
		c.setWidth("*");
		buttons.addMember(c);
		
		IButton discardChanges = new IButton("Discard Changes");
		discardChanges.addClickHandler(new ClickHandler() {
			
			@Override
			public void onClick(ClickEvent e) {
			
				if (callback != null)
				{
					// call the user supplied callback notifying the caller about
					// user discarding the changes
					cb.dialogClosed(UserAction.DISCARD_CHANGES);
				}
				destroy();
			}
		});
		buttons.addMember(discardChanges);
		
		// place all 3 horizontal layouts in a vertical layout
		VLayout vl = new VLayout();
		vl.setHeight100();
		vl.setWidth100();
		
		vl.addMember(labels);
		vl.addMember(details);
		vl.addMember(buttons);
		
		// add vertical layout to the window
		addItem(vl);
	}
}