/**
 * Copyright 2015 ArcBees Inc.
 *
 * 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 com.google.appengine.api.datastore;

import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.Date;
import java.util.Map;

import javax.inject.Singleton;

import com.arcbees.gaestudio.shared.Constants;
import com.google.appengine.api.blobstore.BlobKey;
import com.google.appengine.api.datastore.Entity.UnindexedValue;
import com.google.gson.ExclusionStrategy;
import com.google.gson.FieldAttributes;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.inject.AbstractModule;
import com.google.inject.Provides;
import com.google.storage.onestore.v3.OnestoreEntity;

public class GsonModule extends AbstractModule {
    @Override
    protected void configure() {
    }

    @Provides
    @Singleton
    Gson getGson() {
        ExclusionStrategy entityProtoExclusionStrategy = new ExclusionStrategy() {
            @Override
            public boolean shouldSkipField(FieldAttributes f) {
                return f.getDeclaredClass().equals(OnestoreEntity.EntityProto.class);
            }

            @Override
            public boolean shouldSkipClass(Class<?> clazz) {
                return false;
            }
        };

        GsonBuilder gsonBuilder = new GsonBuilder()
                .setPrettyPrinting()
                .setDateFormat(Constants.JSON_DATE_FORMAT)
                .serializeNulls()
                .excludeFieldsWithModifiers(Modifier.STATIC)
                .setExclusionStrategies(entityProtoExclusionStrategy);

        // Instance creators
        gsonBuilder.registerTypeAdapter(Entity.class, new EntityInstanceCreator())
                .registerTypeAdapter(AppIdNamespace.class, new AppIdNamespaceInstanceCreator())
                .registerTypeAdapter(Key.class, new KeyInstanceCreator());

        // Type Adapters
        gsonBuilder.registerTypeAdapter(BlobKey.class, new BlobKeyValueAdapter())
                .registerTypeAdapter(Blob.class, new BlobValueAdapter())
                .registerTypeAdapter(Category.class, new CategoryValueAdapter())
                .registerTypeAdapter(Collection.class, new CollectionValueAdapter())
                .registerTypeAdapter(Email.class, new EmailValueAdapter())
                .registerTypeAdapter(IMHandle.class, new IMHandleDeserializer())
                .registerTypeAdapter(Link.class, new LinkValueAdapter())
                .registerTypeAdapter(Map.class, new PropertiesValueAdapter())
                .registerTypeAdapter(PhoneNumber.class, new PhoneNumberValueAdapter())
                .registerTypeAdapter(PostalAddress.class, new PostalAddressValueAdapter())
                .registerTypeAdapter(PropertyValue.class, new PropertyValueAdapter())
                .registerTypeAdapter(Rating.class, new RatingValueAdapter())
                .registerTypeAdapter(ShortBlob.class, new ShortBlobValueAdapter())
                .registerTypeAdapter(Text.class, new TextValueAdapter())
                .registerTypeAdapter(UnindexedValue.class, new UnindexedValueAdapter())
                .registerTypeAdapter(Date.class, new DateValueAdapter(Constants.JSON_DATE_FORMAT))
                .registerTypeAdapter(Key.class, new KeySerializer());

        return gsonBuilder.create();
    }
}