package com.jbw.jsonProvider;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

@Provider
@Produces("application/json")
@Consumes("application/json")
public class GsonProvider implements MessageBodyWriter<Object>, MessageBodyReader<Object> {

	private final Gson gson;

	public GsonProvider() {
		gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().setDateFormat("yyyy-MM-dd").create();
	}

	public long getSize(Object arg0, Class<?> arg1, Type arg2, Annotation[] arg3, MediaType arg4) {
		return -1;
	}

	public boolean isWriteable(Class<?> arg0, Type arg1, Annotation[] arg2, MediaType arg3) {
		return true;
	}

	public void writeTo(Object obj, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
			MultivaluedMap<String, Object> multivaluedMap, OutputStream entityStream)
			throws IOException, WebApplicationException {
		Type jsonType;
		if (type.equals(genericType)) {
			jsonType = type;
		} else {
			jsonType = genericType;
		}
		entityStream.write(gson.toJson(obj, jsonType).getBytes("UTF-8"));
	}

	public boolean isReadable(Class<?> arg0, Type arg1, Annotation[] arg2, MediaType arg3) {
		return true;
	}

	public Object readFrom(Class<Object> type, Type genericType, Annotation[] annotations, MediaType mediaType,
			MultivaluedMap<String, String> multivaluedMap, InputStream entityStream)
			throws IOException, WebApplicationException {
		Type jsonType;
		if (type.equals(genericType)) {
			jsonType = type;
		} else {
			jsonType = genericType;
		}
		return gson.fromJson(new InputStreamReader(entityStream, "UTF-8"), jsonType);
	}

}