/*
 * Copyright (C) 2013 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jboss.errai.demo.jpa.client.local;

import javax.persistence.EntityManager;

import org.jboss.errai.demo.jpa.client.shared.Album;
import org.jboss.errai.demo.jpa.client.shared.Artist;
import org.jboss.errai.demo.jpa.client.shared.Format;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.ListBox;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.datepicker.client.DatePicker;

/**
 * A form for editing an instance of Album.
 *
 * @author Jonathan Fuerth <jfuerth@gmail.com>
 */
public class AlbumForm extends Composite {

    // Note: for simplicity, and to keep this JPA demo on-topic, we are using
    // plain GWT programmatic layout rather than ErraiUI, UIBinder, or Errai Data
    // Binding. See the grocery list demo for the full-on Errai development experience.

    private final EntityManager em;

    private final Album album;

    private final TextBox name = new TextBox();
    private final ListBox artist = new ListBox();
    private final ListBox format = new ListBox();
    private final DatePicker releaseDate = new DatePickerWithYearSelector();

    private final Button saveButton = new Button("Save");

    private RowOperationHandler<Album> saveHandler;

    public AlbumForm(final Album album, EntityManager em) {
        this.album = album;
        this.em = em;

        for (Artist a : em.createNamedQuery("allArtistsByName", Artist.class).getResultList()) {
            artist.addItem(a.getName(), String.valueOf(a.getId()));
        }

        for (Format f : Format.values()) {
            format.addItem(f.name());
        }

        saveButton.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                updateAlbumFromUI();
                if (saveHandler != null) {
                    saveHandler.handle(album);
                }
            }
        });

        updateUIFromAlbum();

        final Grid g = new Grid(5, 2);

        int row = 0;
        g.setText(row, 0, "Name:");
        g.setWidget(row, 1, name);

        row++;
        g.setText(row, 0, "Artist:");
        g.setWidget(row, 1, artist);

        row++;
        g.setText(row, 0, "Format:");
        g.setWidget(row, 1, format);

        row++;
        g.setText(row, 0, "Release Date:");
        g.setWidget(row, 1, releaseDate);

        row++;
        g.setWidget(row, 1, saveButton);

        initWidget(g);
    }

    protected void updateAlbumFromUI() {
        album.setName(name.getText());
        long artistId = Long.parseLong(artist.getValue(artist.getSelectedIndex()));
        album.setArtist(em.find(Artist.class, artistId));
        album.setFormat(Format.valueOf(format.getValue(format.getSelectedIndex())));
        album.setReleaseDate(releaseDate.getValue());
    }

    private void updateUIFromAlbum() {

        // Note: with Errai Data Sync, the code in this method would be unnecessary. See the Grocery List demo for an example.

        name.setText(album.getName());

        if (album.getArtist() != null) {
            for (int i = 0; i < artist.getItemCount(); i++) {
                if (Long.parseLong(artist.getValue(i)) == album.getArtist().getId()) {
                    artist.setSelectedIndex(i);
                }
            }
        }

        if (album.getFormat() != null) {
            format.setSelectedIndex(album.getFormat().ordinal());
        }
        else {
            format.setSelectedIndex(Format.LP.ordinal());
        }

        if (album.getReleaseDate() != null) {
            releaseDate.setValue(album.getReleaseDate());
            releaseDate.setCurrentMonth(album.getReleaseDate());
        }
    }

    public void setSaveHandler(RowOperationHandler<Album> handler) {
        this.saveHandler = handler;
    }

    public void grabFocus() {
        name.setFocus(true);
    }
}