package com.mictale.example.client;

import java.util.ArrayList;
import java.util.List;

import com.google.gwt.cell.client.CheckboxCell;
import com.google.gwt.cell.client.FieldUpdater;
import com.google.gwt.cell.client.TextInputCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.editor.client.Editor;
import com.google.gwt.editor.client.LeafValueEditor;
import com.google.gwt.editor.client.SimpleBeanEditorDriver;
import com.google.gwt.editor.client.adapters.HasDataEditor;
import com.google.gwt.editor.client.adapters.ListEditor;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.cellview.client.CellList;
import com.google.gwt.user.cellview.client.CellTable;
import com.google.gwt.user.cellview.client.Column;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.view.client.DefaultSelectionEventManager;
import com.google.gwt.view.client.HasData;
import com.google.gwt.view.client.MultiSelectionModel;


/**
 * Shows how to use {@link HasDataEditor}.
 * 
 * 
{@link HasDataEditor} wraps an implementation of {@link HasData} 
 * so that you can use it with the editor framework. This example wraps 
 * a {@link CellTable} but you can also use it with {@link CellList} and others.
 * 
In this example, the {@link Driver} only implements the workflow 
 * for the {@link List} of persons. Usually, you will have a hierarchy 
 * of {@link Editor}s and one of your model classes would return the list.
 * 
To improve reusability, consider wrapping {@link #persons} 
 * and {@link #editor} into a {@link Widget} that creates
 * the {@link CellTable} and implements 
 * {@code IsEditor>>}.
 * 
 * @author michael@mictale.com
 */
public class HasDataEditorExample implements EntryPoint {
	public interface Driver extends SimpleBeanEditorDriver, ListEditor>> {		
	}

	private final MultiSelectionModel selectionModel = new MultiSelectionModel();
	
	private CellTable persons;

	private ListEditor> editor;
	
	private Driver driver;
	
	public void onModuleLoad() {
		final FlowPanel panel = new FlowPanel();
		panel.add(persons = createList());		
		panel.add(new Button("Delete Selected", new ClickHandler() {
			@Override
			public void onClick(ClickEvent event) {
				editor.getList().removeAll(selectionModel.getSelectedSet());
			}
		}));
		panel.add(new Button("Add New Entry", new ClickHandler() {
			@Override
			public void onClick(ClickEvent event) {
				editor.getList().add(new Person());
			}
		}));
		panel.add(new Button("Save", new ClickHandler() {			
			@Override
			public void onClick(ClickEvent event) {
				doSave();				
			}
		}));

		editor = HasDataEditor.of(persons);
				
		RootPanel.get().add(panel);
	
		driver = GWT.create(Driver.class);
		driver.initialize(editor);
		
		final List persons = loadPersons();
		driver.edit(persons);
	}

	private void doSave() {
		List persons = driver.flush();
		StringBuilder sb = new StringBuilder();
		for (Person p : persons) {
			sb.append(p.toString());
			sb.append("\n");
		}
		
		Window.alert(sb.toString());
	}
	
	/**
	 * Creates and initializes a fake model.
	 * @return the fake model.
	 */
	private List loadPersons() {
		List persons = new ArrayList();
		persons.add(new Person("Michael", "Schollmeyer", "michael@mictale.com"));
		persons.add(new Person("Liv", "Schollmeyer", "liv@mictale.com"));		
		return persons;
	}
	
	/**
	 * Create and initialize a {@link CellList}
	 * @return the new list.
	 */
	private CellTable createList() {
		CellTable list = new CellTable();
		final TextInputCell cell = new TextInputCell();
		
		list.setSelectionModel(selectionModel, DefaultSelectionEventManager. createCheckboxManager());

		Column checkColumn = new Column(new CheckboxCell(true, false)) {
			@Override
			public Boolean getValue(Person object) {
				return selectionModel.isSelected(object);
			}
		};
		list.addColumn(checkColumn, SafeHtmlUtils.fromSafeConstant("
"));
		list.setColumnWidth(checkColumn, 40, Unit.PX);
		
		Column firstNameColumn = new Column(cell) {
			@Override
			public String getValue(Person item) {
				return item.getFirstName();
			}
		};
		firstNameColumn.setFieldUpdater(new FieldUpdater() {
			@Override
			public void update(int index, Person object, String value) {
				object.setFirstName(value);
			}
		});
		list.addColumn(firstNameColumn, "First Name");

		Column lastNameColumn = new Column(cell) {
			@Override
			public String getValue(Person item) {
				return item.getLastName();
			}
		};
		lastNameColumn.setFieldUpdater(new FieldUpdater() {
			@Override
			public void update(int index, Person object, String value) {
				object.setLastName(value);
			}
		});
		list.addColumn(lastNameColumn, "Last Name");

		Column emailColumn = new Column(cell) {
			@Override
			public String getValue(Person item) {
				return item.getEmail();
			}
		};
		emailColumn.setFieldUpdater(new FieldUpdater() {
			@Override
			public void update(int index, Person object, String value) {
				object.setEmail(value);
			}
		});
		list.addColumn(emailColumn, "Email");

		return list;
	}
	
	/**
	 * The elements in the list that we use here.
	 */
	public static class Person {

		private String firstName;
		
		private String lastName;
		
		private String email;

		public Person() {
		}

		public Person(String firstName, String lastName, String email) {
			this.firstName = firstName;
			this.lastName = lastName;
			this.email = email;
		}
		
		public String getFirstName() {
			return firstName;
		}

		public void setFirstName(String firstName) {
			this.firstName = firstName;
		}

		public String getLastName() {
			return lastName;
		}

		public void setLastName(String lastName) {
			this.lastName = lastName;
		}

		public String getEmail() {
			return email;
		}

		public void setEmail(String email) {
			this.email = email;
		}
		
		@Override
		public String toString() {
			return firstName + ", " + lastName + ", " + email;
		}
	}	
}