/*
 * Copyright 2017-present 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.yang;

import com.google.common.annotations.Beta;
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.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.Service;
import org.onosproject.core.CoreService;
import org.onosproject.yang.model.ModelConverter;
import org.onosproject.yang.model.ModelObjectData;
import org.onosproject.yang.model.NodeKey;
import org.onosproject.yang.model.ResourceData;
import org.onosproject.yang.model.ResourceId;
import org.onosproject.yang.model.SchemaContext;
import org.onosproject.yang.model.SchemaContextProvider;
import org.onosproject.yang.model.YangModel;
import org.onosproject.yang.runtime.CompositeData;
import org.onosproject.yang.runtime.CompositeStream;
import org.onosproject.yang.runtime.ModelRegistrationParam;
import org.onosproject.yang.runtime.RuntimeContext;
import org.onosproject.yang.runtime.YangModelRegistry;
import org.onosproject.yang.runtime.YangRuntimeService;
import org.onosproject.yang.runtime.YangSerializer;
import org.onosproject.yang.runtime.YangSerializerRegistry;
import org.onosproject.yang.runtime.impl.DefaultModelConverter;
import org.onosproject.yang.runtime.impl.DefaultYangModelRegistry;
import org.onosproject.yang.runtime.impl.DefaultYangRuntimeHandler;
import org.onosproject.yang.runtime.impl.DefaultYangSerializerRegistry;
import org.onosproject.yang.serializers.json.JsonSerializer;
import org.onosproject.yang.serializers.xml.XmlSerializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Set;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Represents implementation of YANG runtime manager.
 */
@Beta
@Service
@Component(immediate = true)
public class YangRuntimeManager implements YangModelRegistry,
        YangSerializerRegistry, YangRuntimeService, ModelConverter,
        SchemaContextProvider {

    private static final String APP_ID = "org.onosproject.yang";
    private final Logger log = LoggerFactory.getLogger(getClass());

    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
    protected CoreService coreService;

    private DefaultYangModelRegistry modelRegistry;
    private DefaultYangSerializerRegistry serializerRegistry;
    private DefaultYangRuntimeHandler runtimeService;
    private DefaultModelConverter modelConverter;

    @Activate
    public void activate() {
        coreService.registerApplication(APP_ID);
        serializerRegistry = new DefaultYangSerializerRegistry();
        modelRegistry = new DefaultYangModelRegistry();
        runtimeService =
                new DefaultYangRuntimeHandler(serializerRegistry, modelRegistry);
        serializerRegistry.registerSerializer(new JsonSerializer());
        serializerRegistry.registerSerializer(new XmlSerializer());
        modelConverter = new DefaultModelConverter(modelRegistry);
        log.info("Started");
    }

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


    @Override
    public void registerModel(ModelRegistrationParam p) {
        modelRegistry.registerModel(p);
    }

    @Override
    public void unregisterModel(ModelRegistrationParam p) {
        modelRegistry.unregisterModel(p);
    }

    @Override
    public Set<YangModel> getModels() {
        return modelRegistry.getModels();
    }

    @Override
    public void registerSerializer(YangSerializer ys) {
        serializerRegistry.registerSerializer(ys);
    }

    @Override
    public void unregisterSerializer(YangSerializer ys) {
        serializerRegistry.unregisterSerializer(ys);
    }

    @Override
    public Set<YangSerializer> getSerializers() {
        return serializerRegistry.getSerializers();
    }

    @Override
    public CompositeData decode(CompositeStream cs, RuntimeContext rc) {
        return runtimeService.decode(cs, rc);
    }

    @Override
    public CompositeStream encode(CompositeData cd, RuntimeContext rc) {
        return runtimeService.encode(cd, rc);
    }

    @Override
    public ModelObjectData createModel(ResourceData resourceData) {
        return modelConverter.createModel(resourceData);
    }

    @Override
    public ResourceData createDataNode(ModelObjectData modelObjectData) {
        return modelConverter.createDataNode(modelObjectData);
    }

    @Override
    public SchemaContext getSchemaContext(ResourceId resourceId) {
        checkNotNull(resourceId, " resource id can't be null.");
        NodeKey key = resourceId.nodeKeys().get(0);
        if (resourceId.nodeKeys().size() == 1 &&
                "/".equals(key.schemaId().name())) {
            return modelRegistry;
        }
        log.info("To be implemented.");
        return null;
    }
}