/**
 *
 *   Copyright 2015 sourceforge.
 *
 *   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.gwtopenmaps.openlayers.client;

import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.user.client.ui.RequiresResize;

/**
 * See {@link Map}.
 *
 * @author Erdem Gunay
 * @author Edwin Commandeur
 *
 */
public class MapWidget extends Widget implements RequiresResize {

    private Map map;
    private MapOptions options;

    /**
     * Programmatically creates the element that will contain the map, with the
     * given width and height.
     *
     * The map itself is instantiated upon calling {@link #getMap()}.
     *
     * @param width - a String with the width of the element that will contain
     * the map in CSS units.
     * @param height - a String with the height of the element that will contain
     * the map in CSS units.
     *
     * @since GWT-OL 0.2
     */
    public MapWidget(String width, String height) {
        this(width, height, null);
    }

    /**
     * Programmatically creates the element that will contain the map, with the
     * given width and height.
     *
     * The map itself is instantiated upon calling {@link #getMap()}.
     *
     * @param width - a String with the width of the element that will contain
     * the map in CSS units.
     * @param height - a String with the height of the element that will contain
     * the map in CSS units.
     * @param options - null if no options should be set upon map instantiation
     * or a MapOptions object that is passed to the map upon instantiation.
     *
     * @since GWT-OL 0.2
     */
    public MapWidget(String width, String height, MapOptions options) {
        Element e = DOM.createDiv();
        this.options = options;
        setElement(e);
        setWidth(width);
        setHeight(height);
    }

    /*
     * Uses the elementId to obtain the element that will contain the map from
     * the application html.
     *
     * For example, if the application html contains a div with the id "map":
     * <pre>
     *     MapWidget mapWidget = new MapWidget("map", null);
     * </pre>
     *
     * The map itself is instantiated upon calling {@link #getMap()}.
     *
     * @param element - the element that should contain the map.
     * @param options - null if no options should be set upon map instantiation
     *  	or a MapOptions object that is passed to the map upon instantiation.
     *
     * @since GWT-OL 0.4
     */
    //TODO: this needs more thought - when the map is destroyed a MapWidget
    // created this way can give problems.
	/*
     public MapWidget(String elementId, MapOptions options) {
     Element element = DOM.getElementById(elementId);
     if(element != null){
     this.options = options;
     setElement(element);
     } else {
     throw new RuntimeException("Mapwidget could not be instantiated. " +
     "Failed to get element by id " +  elementId + ".");
     }
     }
     */
    /**
     * Gets the map associated with a MapWidget instance.
     *
     * The map is instantiated when this method is called for the first time.
     *
     * @return Map - see {@link Map}.
     */
    public Map getMap() {
        //The preference here is lazy initalization
        if (map == null) {
            if (options == null) {
                map = new Map(getElement());
            } else {
                map = new Map(getElement(), options);
            }
        }
        return map;
    }

    //TODO do more sophisticated check if height is in CSS units
    public void setHeight(String height) {
        if (height.matches("^\\d+$")) {
            super.setHeight(height + "px");
        } else {
            super.setHeight(height);
        }
    }

    //TODO do more sophisticated check if width is in CSS units
    public void setWidth(String width) {
        if (width.matches("^\\d+$")) {
            super.setWidth(width + "px");
        } else {
            super.setWidth(width);
        }
    }

    /*
     * Overrides onAttach method of Widget, which is called when the widget
     * is attached to the browser's document.
     */
    @Override
    protected void onAttach() {
        super.onAttach();
    }

    /*
     * Overrides onLoad method of Widget, which is called immediately after a widget becomes attached to the
     * browser's document.
     */
    @Override
    protected void onLoad() {
        // We update the size of the map to try to display the map correctly when the MapWidget's size is set with percentage
        Scheduler.get().scheduleDeferred(new ScheduledCommand() {

            public void execute() {
                getMap().updateSize();
            }
        });
    }

    public void onResize() {
        getMap().updateSize();
    }
}