/*
 * Copyright (c) 2010 Lockheed Martin Corporation
 *
 * 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.eurekastreams.web.client.ui.common.stream.renderers;

import org.eurekastreams.server.action.request.stream.SetActivityLikeRequest;
import org.eurekastreams.server.action.request.stream.SetActivityLikeRequest.LikeActionType;
import org.eurekastreams.web.client.events.ActivityLikedChangeEvent;
import org.eurekastreams.web.client.events.EventBus;
import org.eurekastreams.web.client.events.Observer;
import org.eurekastreams.web.client.model.ActivityLikeModel;
import org.eurekastreams.web.client.ui.pages.master.StaticResourceBundle;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;

/**
 * Widget for liking activity.
 */
public class LikeWidget extends Composite
{
    /** Current state of activity. */
    private Boolean liked;

    /**
     * The widget.
     */
    private FlowPanel widget = new FlowPanel();

    /**
     * The like link.
     */
    private Anchor likeLink = new Anchor();

    /**
     * Default constructor.
     * 
     * @param isLiked
     *            whether its liked by the current user.
     * @param activityId
     *            the activity ID.
     */
    public LikeWidget(final Boolean isLiked, final Long activityId)
    {
        widget.addStyleName(StaticResourceBundle.INSTANCE.coreCss().likeWrapper());
        liked = isLiked;

        likeLink.addStyleName(StaticResourceBundle.INSTANCE.coreCss().linkedLabel());

        likeLink.setText(isLiked ? "Unlike" : "Like");

        widget.add(likeLink);

        likeLink.addClickHandler(new ClickHandler()
        {
            public void onClick(final ClickEvent event)
            {
                final LikeActionType actionType = liked ? LikeActionType.REMOVE_LIKE : LikeActionType.ADD_LIKE;
                liked = !liked;
                likeLink.setText(liked ? "Unlike" : "Like");
                ActivityLikeModel.getInstance().update(new SetActivityLikeRequest(activityId, actionType));
            }
        });

        // keep above likeLink setting on click as it reduces ui bugs due to event lag, this will respond to like
        // count widget liking the action and change appropriately.
        EventBus.getInstance().addObserver(ActivityLikedChangeEvent.class, new Observer<ActivityLikedChangeEvent>()
        {
            public void update(final ActivityLikedChangeEvent event)
            {
                if (event.getActivityId().equals(activityId) && event.getActionType() == LikeActionType.ADD_LIKE)
                {
                    liked = true;
                    likeLink.setText("Unlike");
                }
            }
        });

        initWidget(widget);
    }
}