/*
 * Copyright (C) 2012 Jan Pokorsky
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package cz.cas.lib.proarc.webapp.client.widget;

import com.smartgwt.client.data.Record;
import com.smartgwt.client.util.BooleanCallback;
import com.smartgwt.client.widgets.Canvas;
import cz.cas.lib.proarc.webapp.client.ClientMessages;
import cz.cas.lib.proarc.webapp.client.action.Action;
import cz.cas.lib.proarc.webapp.client.action.ActionEvent;
import cz.cas.lib.proarc.webapp.client.action.Actions;
import cz.cas.lib.proarc.webapp.client.action.RefreshAction.Refreshable;
import cz.cas.lib.proarc.webapp.client.action.SaveAction;
import cz.cas.lib.proarc.webapp.client.ds.DigitalObjectDataSource.DigitalObject;
import cz.cas.lib.proarc.webapp.client.ds.RelationDataSource;
import cz.cas.lib.proarc.webapp.client.widget.ImportParentChooser.ImportParentHandler;

/**
 * Edits parent object of given digital object.
 *
 * @author Jan Pokorsky
 */
public final class DigitalObjectParentEditor implements BatchDatastreamEditor, Refreshable {

    private final ImportParentChooser chooser;
    private DigitalObject[] digitalObjects;
    private boolean autosave = false;
    private SaveAction saveAction;
    private final ClientMessages i18n;

    public DigitalObjectParentEditor(ClientMessages i18n) {
        this.i18n = i18n;
        chooser = new ImportParentChooser(i18n);
        chooser.setHandler(new ImportParentHandler() {

            @Override
            public void onParentSelectionUpdated() {
                if (autosave) {
//                    save();
                }
            }
        });
        initActions();
    }

    @Override
    public void edit(DigitalObject digitalObject) {
        DigitalObject[] dobjs = digitalObject == null
                ? null : new DigitalObject[] { digitalObject };
        edit(dobjs);
    }

    /**
     * Starts editing of parent object of passed digital objects.
     * For now objects <b>MUST HAVE</b> common parent objects!
     */
    @Override
    public void edit(DigitalObject[] items) {
        this.digitalObjects = items;
        if (items != null && items.length > 0) {
            // pass first object to the chooser to fetch current parent
            String pid = items[0].getPid();
            chooser.setDigitalObject(pid);
        } else {
            throw new IllegalStateException("missing pid and batchId");
        }
    }

    @Override
    public void focus() {
        chooser.focus();
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T getCapability(Class<T> clazz) {
        // refresh
        T c = null;
        if (Refreshable.class.equals(clazz) || BatchDatastreamEditor.class.equals(clazz)) {
            c = (T) this;
        }
        return c;
    }

    @Override
    public Canvas[] getToolbarItems() {
        return new Canvas[] {
            Actions.asIconButton(saveAction, this)
        };
    }

    private Action[] initActions() {
        saveAction = new SaveAction(i18n) {

            @Override
            public void performAction(ActionEvent event) {
                save();
            }
        };
        return new Action[] {saveAction};
    }

    @Override
    public Canvas getUI() {
        return chooser.getUI();
    }

    @Override
    public void refresh() {
        edit(digitalObjects);
    }

    private void save() {
        if (chooser.isChanged()) {
            final Record newParent = chooser.getSelectedParent();
            String parentPid = chooser.getSelectedParentPid();
            String oldParentPid = chooser.getOldParentPid();
            final RelationDataSource ds = RelationDataSource.getInstance();
            String[] pids = DigitalObject.toPidArray(digitalObjects);
            BooleanCallback saveCallback = new BooleanCallback() {

                @Override
                public void execute(Boolean value) {
                    if (value != null && value) {
                        chooser.onSave(newParent);
                        StatusView.getInstance().show(i18n.SaveAction_Done_Msg());
                        ds.fireRelationChange(digitalObjects[0].getPid());
                    }
                    // else refresh?
                }
            };

            if (oldParentPid == null && parentPid != null) {
                ds.addChild(parentPid, pids, saveCallback);
            } else if (oldParentPid != null && parentPid == null) {
                ds.removeChild(oldParentPid, pids, saveCallback);
            } else {
                ds.moveChild(pids, oldParentPid, parentPid, saveCallback);
            }
        }
    }

}