/*
 * Copyright 2015 MovingBlocks
 *
 * 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.terasology.rendering.world.viewDistance;

import org.terasology.config.Config;
import org.terasology.config.RenderingConfig;
import org.terasology.entitySystem.entity.EntityRef;
import org.terasology.entitySystem.systems.BaseComponentSystem;
import org.terasology.entitySystem.systems.RegisterMode;
import org.terasology.entitySystem.systems.RegisterSystem;
import org.terasology.logic.players.LocalPlayer;
import org.terasology.registry.In;
import org.terasology.rendering.world.WorldRenderer;

import java.beans.PropertyChangeListener;

/**
 * Handles view distance changes on the client.
 */
@RegisterSystem(RegisterMode.CLIENT)
public class ClientViewDistanceSystem extends BaseComponentSystem {

    @In
    private Config config;

    @In
    private WorldRenderer worldRenderer;

    @In
    private LocalPlayer localPlayer;

    private PropertyChangeListener propertyChangeListener;

    @Override
    public void initialise() {
        propertyChangeListener = evt -> {
            if (evt.getPropertyName().equals(RenderingConfig.VIEW_DISTANCE)) {
                onChangeViewDistanceChange();
            }
        };
        config.getRendering().subscribe(propertyChangeListener);
    }

    public void onChangeViewDistanceChange() {
        ViewDistance viewDistance = config.getRendering().getViewDistance();

        if (worldRenderer != null) {
            worldRenderer.setViewDistance(viewDistance);
        }

        EntityRef clientEntity = localPlayer.getClientEntity();
        clientEntity.send(new ViewDistanceChangedEvent(viewDistance));
    }

    @Override
    public void shutdown() {
        config.getRendering().unsubscribe(propertyChangeListener);
    }
}