/*
 * Copyright 2015 Open Networking Laboratory
 *
 * 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.onosproject.ui.impl;

import com.fasterxml.jackson.databind.JsonNode;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Service;
import org.onosproject.ui.UiExtension;
import org.onosproject.ui.UiExtensionService;
import org.onosproject.ui.UiMessageHandlerFactory;
import org.onosproject.ui.UiView;
import org.onosproject.ui.UiViewHidden;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.Map;
import java.util.Set;

import static com.google.common.collect.ImmutableList.of;
import static java.util.stream.Collectors.toSet;
import static org.onosproject.ui.UiView.Category.NETWORK;
import static org.onosproject.ui.UiView.Category.PLATFORM;

/**
 * Manages the user interface extensions.
 */
@Component(immediate = true)
@Service
public class UiExtensionManager implements UiExtensionService, SpriteService {

    private final Logger log = LoggerFactory.getLogger(getClass());

    // List of all extensions
    private final List<UiExtension> extensions = Lists.newArrayList();

    // Map of views to extensions
    private final Map<String, UiExtension> views = Maps.newHashMap();

    // Core views & core extension
    private final UiExtension core = createCoreExtension();


    // Creates core UI extension
    private static UiExtension createCoreExtension() {
        List<UiView> coreViews = of(new UiView(PLATFORM, "app", "Applications"),
                                    new UiView(PLATFORM, "cluster", "Cluster Nodes"),
                                    new UiView(NETWORK, "topo", "Topology"),
                                    new UiView(NETWORK, "device", "Devices"),
                                    new UiViewHidden("flow"),
                                    new UiView(NETWORK, "link", "Links"),
                                    new UiView(NETWORK, "host", "Hosts"),
                                    new UiView(NETWORK, "intent", "Intents"));

        UiMessageHandlerFactory messageHandlerFactory =
                () -> ImmutableList.of(
                        new TopologyViewMessageHandler(),
                        new DeviceViewMessageHandler(),
                        new LinkViewMessageHandler(),
                        new HostViewMessageHandler(),
                        new IntentViewMessageHandler(),
                        new ApplicationViewMessageHandler(),
                        new ClusterViewMessageHandler()
                );

        return new UiExtension(coreViews, messageHandlerFactory, "core",
                               UiExtensionManager.class.getClassLoader());
    }

    @Activate
    public void activate() {
        register(core);
        log.info("Started");
    }

    @Deactivate
    public void deactivate() {
        unregister(core);
        log.info("Stopped");
    }

    @Override
    public synchronized void register(UiExtension extension) {
        if (!extensions.contains(extension)) {
            extensions.add(extension);
            for (UiView view : extension.views()) {
                views.put(view.id(), extension);
            }
        }
    }

    @Override
    public synchronized void unregister(UiExtension extension) {
        extensions.remove(extension);
        extension.views().stream().map(UiView::id).collect(toSet()).forEach(views::remove);
    }

    @Override
    public synchronized List<UiExtension> getExtensions() {
        return ImmutableList.copyOf(extensions);
    }

    @Override
    public synchronized UiExtension getViewExtension(String viewId) {
        return views.get(viewId);
    }


    // Provisional tracking of sprite definitions
    private Map<String, JsonNode> sprites = Maps.newHashMap();

    @Override
    public Set<String> getNames() {
        return ImmutableSet.copyOf(sprites.keySet());
    }

    @Override
    public void put(String name, JsonNode spriteData) {
        log.info("Registered sprite definition [{}]", name);
        sprites.put(name, spriteData);
    }

    @Override
    public JsonNode get(String name) {
        return sprites.get(name);
    }

}