/*******************************************************************************
 * Copyright (c) 2014, 2015 IBM Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *******************************************************************************/
package hulo.localization.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.wink.json4j.JSON;
import org.apache.wink.json4j.JSONException;

public abstract class JSONBodyHandler {

	public abstract Object getResult(Object source) throws JSONException;

	public void exec(HttpServletRequest request, HttpServletResponse response) throws IOException {
		InputStream is = null;
		OutputStream os = null;
		try {
			BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream(), "utf-8"));
			StringBuffer sb = new StringBuffer();
			String line;
			while((line = br.readLine()) != null) {
				sb.append(line);
			}

			Object result = getResult(JSON.parse(sb.toString()));
			if (result == null) {
				response.sendError(HttpServletResponse.SC_BAD_REQUEST);
			} else {
				response.setCharacterEncoding("UTF-8");
				response.setContentType("application/json");
				(os = response.getOutputStream()).write(result.toString().getBytes("UTF-8"));
				os.flush();
			}
		} catch (Exception e) {
			e.printStackTrace();
			response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		} finally {
			if (is != null) {
				is.close();
			}
			if (os != null) {
				os.close();
			}
		}
	}
}
