/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde
 * Software engineering by Intevation GmbH
 *
 * This file is Free Software under the GNU AGPL (>=v3)
 * and comes with ABSOLUTELY NO WARRANTY! Check out the
 * documentation coming with Dive4Elements River for details.
 */

package org.dive4elements.river.client.client.ui;

import org.dive4elements.river.client.client.FLYSConstants;
import org.dive4elements.river.client.shared.model.ToLoad;

import com.google.gwt.core.client.GWT;
import com.smartgwt.client.util.SC;
import com.smartgwt.client.widgets.Button;
import com.smartgwt.client.widgets.events.ClickEvent;
import com.smartgwt.client.widgets.events.ClickHandler;
import com.smartgwt.client.widgets.grid.ListGrid;
import com.smartgwt.client.widgets.layout.HLayout;
import com.smartgwt.client.widgets.layout.VLayout;

/**
 * Widget showing two Datacages and a add-this-button.
 * Insert a record into a listgrid when add-this-button clicked.
 */
public class DatacagePairWidget extends VLayout {

    /**
     * Allows for advanced controlling of the behavior of this pair widget.
     */
    public static interface IDatacagePairControler {
        void setup(DatacageWidget leftWidget, DatacageWidget rightWidget, HLayout toolbarLayout);
    }

    /**
     * {@link IDatacagePairControler} implementation that does nothing.
     */
    public static final IDatacagePairControler NIL_CONTROLER = new IDatacagePairControler() {
        @Override
        public void setup(final DatacageWidget leftWidget, final DatacageWidget rightWidget, final HLayout toolbarLayout) {
            // does nothing
        }
    };

    /** i18n resource. */
    private static final FLYSConstants MSG = GWT.create(FLYSConstants.class);

    /** The "remote" ListGrid to insert data to when add-button is clicked. */
    private final ListGrid grid;

    /** First (upper) DataCage Grid. */
    private final DatacageWidget firstDatacageWidget;

    /** Second (lower) DataCage Grid. */
    private final DatacageWidget secondDatacageWidget;

    /** Max number of recommendation pairs to be added */
    private final int maxCount;

    /** errorMsg maxCount */
    private final String msgMaxCount;

    public DatacagePairWidget(final IDatacagePairControler controler, final DatacageWidgetData leftData, final DatacageWidgetData rightData,
            final ListGrid grid, final int maxCount, final String msgMaxCount) {

        this.msgMaxCount = msgMaxCount;
        this.maxCount = maxCount;
        this.grid = grid;

        final HLayout hLayout = new HLayout();

        this.firstDatacageWidget = new DatacageWidget(leftData);
        this.secondDatacageWidget = new DatacageWidget(rightData);

        this.firstDatacageWidget.setIsMutliSelectable(false);
        this.secondDatacageWidget.setIsMutliSelectable(false);

        hLayout.addMember(this.firstDatacageWidget);
        hLayout.addMember(this.secondDatacageWidget);

        final HLayout toolbarLayout = new HLayout();
        toolbarLayout.setAutoHeight();

        final Button plusBtn = new Button(MSG.datacage_add_pair());
        plusBtn.setAutoFit(true);
        plusBtn.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(final ClickEvent event) {
                plusClicked();
            }
        });
        toolbarLayout.addMember(plusBtn);

        addMember(hLayout);
        addMember(toolbarLayout);

        controler.setup(this.firstDatacageWidget, this.secondDatacageWidget, toolbarLayout);
    }

    /**
     * Callback for add-button.
     * Fires to load for every selected element and handler.
     */
    protected final void plusClicked() {
        final ToLoad toLoad1 = this.firstDatacageWidget.getSelection();
        final ToLoad toLoad2 = this.secondDatacageWidget.getSelection();

        // FIXME: allows to select folders... but it should not

        if (toLoad1 == null || toLoad2 == null || toLoad1.toRecommendations().isEmpty() || toLoad2.toRecommendations().isEmpty()) {
            SC.say(MSG.warning_select_two_values());
            return;
        }

        if (this.grid.getTotalRows() >= this.maxCount) {
            SC.say(this.msgMaxCount);
            return;
        }

        this.grid.addData(new RecommendationPairRecord(toLoad1.toRecommendations().get(0), toLoad2.toRecommendations().get(0)));
    }
}