import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.bson.Document;

import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class MongoDAO {
	
	private static final String SERVER_URL = "";
	private static final String USER = "";
	private static final String PASSWORD = "";
	private static final String DATABASE = "";
	private static final String COLLECTION = "";
	private static final String FSCOLLECTION = "";
	
	private MongoCredential credential = MongoCredential.createCredential(USER, database, PASSWORD.toCharArray());
	private MongoClient client;
	
	public void create(Document document) throws Exception {
		getCollection().insertOne(document);
	}
	
	public List<Document> read(Document filter) throws Exception {
		final List<Document> result = new ArrayList<Document>();
		FindIterable<Document> iterable = getCollection().find(filter);
		iterable.forEach(new Block<Document>() {
		    @Override
		    public void apply(final Document document) {
		    	result.add(document);
		    }
		});
		return result;
	}
	
	public void update(Document filter, Document update) throws Exception {
		getCollection().updateMany(filter, update);
	}
	
	public void updateOne(Document filter, Document update) throws Exception {
		getCollection().updateOne(filter, update);
	}
	
	public void delete(Document filter) throws Exception {
		getCollection().deleteMany(filter);
	}
	
	public void deleteOne(Document filter) throws Exception {
		getCollection().deleteOne(filter);
	}
	
	public InputStream getStream(String id) throws Exception {
		@SuppressWarnings("deprecation")
		GridFS gfsPhoto = new GridFS(getClient().getDB(FSCOLLECTION));
		GridFSDBFile file = gfsPhoto.findOne(new ObjectId(id));
		if (file == null) {
			return null;
		} else {
			return file.getInputStream();
		}
	}
	
	private MongoCollection<Document> getCollection() throws Exception {
		MongoDatabase database = getDatabase();
		MongoCollection<Document> collection = database.getCollection(MongoDAO.COLLECTION);
		return collection;
	}
	
	private MongoDatabase getDatabase() throws Exception {
		MongoDatabase database = getClient().getDatabase(MongoDAO.DATABASE);
		return database;
	}
	
	private MongoClient getClient() throws Exception {
		if (client == null) {
			client = new MongoClient(new ServerAddress(SERVER_URL), Arrays.asList(credential));
		}
		return client;
	}
}