package org.apache.directmemory.server.commons;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonToken;

import java.io.IOException;
import java.io.InputStream;

/**
 * @author Olivier Lamy
 */
public class DirectMemoryParser
{

    private JsonFactory jsonFactory;

    private static DirectMemoryParser INSTANCE = new DirectMemoryParser();


    private DirectMemoryParser()
    {
        this.jsonFactory = new JsonFactory();
    }

    public static DirectMemoryParser instance()
    {
        return INSTANCE;
    }

    public DirectMemoryRequest buildRequest( InputStream inputStream )
        throws DirectMemoryException
    {
        try
        {
            JsonParser jp = this.jsonFactory.createJsonParser( inputStream );
            DirectMemoryRequest rq = new DirectMemoryRequest();
            JsonToken jsonToken = jp.nextToken();
            while ( jsonToken != JsonToken.END_OBJECT && jsonToken != null )
            {
                String fieldName = jp.getCurrentName();
                if ( DirectMemoryConstants.KEY_FIELD_NAME.equals( fieldName ) )
                {
                    rq.setKey( jp.getText() );
                }
                if ( DirectMemoryConstants.PUT_FIELD_NAME.equals( fieldName ) )
                {
                    rq.setUpdate( jp.getValueAsBoolean() );
                }
                if ( DirectMemoryConstants.EXPIRES_IN_FIELD_NAME.equals( fieldName ) )
                {
                    rq.setExpiresIn( jp.getValueAsInt() );
                }
                if ( DirectMemoryConstants.CACHE_CONTENT_FIELD_NAME.equals( fieldName ) )
                {
                    // binaryValue need to go to nextToken
                    jp.nextToken();
                    rq.setCacheContent( jp.getBinaryValue() );
                }
                jsonToken = jp.nextToken();
            }

            jp.close();

            return rq;
        }
        catch ( JsonParseException e )
        {
            throw new DirectMemoryException( e.getMessage(), e );

        }
        catch ( IOException e )
        {
            throw new DirectMemoryException( e.getMessage(), e );
        }
    }

    public DirectMemoryResponse buildResponse( InputStream inputStream )
        throws DirectMemoryException
    {
        try
        {
            JsonParser jp = this.jsonFactory.createJsonParser( inputStream );
            DirectMemoryResponse rs = new DirectMemoryResponse();

            JsonToken jsonToken = jp.nextToken();

            while ( jsonToken != JsonToken.END_OBJECT && jsonToken != null)
            {
                String fieldName = jp.getCurrentName();
                if ( DirectMemoryConstants.FOUND_FIELD_NAME.equals( fieldName ) )
                {
                    rs.setFound( jp.getValueAsBoolean() );
                }
                if ( DirectMemoryConstants.KEY_FIELD_NAME.equals( fieldName ) )
                {
                    rs.setKey( jp.getText() );
                }
                if ( DirectMemoryConstants.CACHE_CONTENT_FIELD_NAME.equals( fieldName ) )
                {
                    // binaryValue need to go to nextToken
                    jp.nextToken();
                    rs.setCacheContent( jp.getBinaryValue() );
                }
                jsonToken = jp.nextToken();
            }


            return rs;
        }
        catch ( JsonParseException e )
        {
            throw new DirectMemoryException( e.getMessage(), e );

        }
        catch ( IOException e )
        {
            throw new DirectMemoryException( e.getMessage(), e );
        }
    }

}