EDIT

// $Id$

/**

* Copyright (C) 2007 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.remote.view;

import java.io.PrintWriter;

import java.util.Collection;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSON;

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

import net.sf.json.JsonConfig;

import net.sf.json.xml.XMLSerializer;

import org.apache.log4j.Logger;

import org.springframework.web.servlet.View;

import eu.etaxonomy.cdm.remote.config.DataSourceProperties;

public class JsonView extends BaseView implements View{

    public static final Logger logger = Logger.getLogger(JsonView.class);

    private JsonConfig jsonConfig;

    private DataSourceProperties dataSourceProperties;

    public DataSourceProperties getDataSourceProperties() {

        return dataSourceProperties;

    }

    public void setDataSourceProperties(DataSourceProperties dataSourceProperties) {

        this.dataSourceProperties = dataSourceProperties;

    }

    public enum Type{

        JSON("application/json"),

        XML("application/xml");

        private final String contentType;

        Type(String contentType){

            this.contentType = contentType;

        }

        public String getContentType(){

            return contentType;

        }

    }

    private Type type = Type.JSON;

    private String xsl = null;

    public void setXsl(String xsl) {

        this.xsl = xsl;

    }

    public String getXsl() {

        return xsl;

    }

    public Type getType() {

        return type;

    }

    /**

     * Default is Type.JSON

     * @param type

     */

    public void setType(Type type) {

        this.type = type;

    }

    public void setJsonConfig(JsonConfig jsonConfig) {

        this.jsonConfig = jsonConfig;

    }

    /*

     * (non-Javadoc)

     * @see org.springframework.web.servlet.View#getContentType()

     */

    @Override

    public String getContentType() {

        return type.getContentType();

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.cdm.remote.view.BaseView#render(java.lang.Object, java.io.PrintWriter, java.lang.String, java.lang.String)

     */

    @Override

    public void render(Object entity, PrintWriter writer, String jsonpCallback, HttpServletRequest request, HttpServletResponse response) throws Exception {

        String contextPath = null;

        if (request != null)

        	{

        	contextPath = request.getContextPath();

        	}

        if(jsonConfig == null){

            logger.error("The jsonConfig must not be null. It must be set in the applicationContext.");

        }

        // option to skip json processing for debugging purposes, see #4925

        if(System.getProperty("SkipJSON") == null) {

        // create JSON Object

//        long start = System.currentTimeMillis();

        boolean isCollectionType = false;

        JSON jsonObj;

        if (entity == null){

          jsonObj = JSONObject.fromObject("{}");

        } else if(Collection.class.isAssignableFrom(entity.getClass())){

            isCollectionType = true;

            jsonObj = JSONArray.fromObject(entity, jsonConfig);

        }else if(entity instanceof String){

            jsonObj = JSONObject.fromObject("{\"String\":\""+entity.toString().replace("\"", "\\\"")+"\"}");

        } else if(entity instanceof Integer){

            jsonObj = JSONObject.fromObject("{\"Integer\":"+((Integer)entity).intValue()+"}");

        } else if(entity instanceof Boolean){

            jsonObj = JSONObject.fromObject("{\"Boolean\":"+((Boolean)entity).toString()+"}");

        } else {

            jsonObj = JSONObject.fromObject(entity, jsonConfig);

        }

//        System.err.println("create JSON Object " + (System.currentTimeMillis() - start));

        if(type.equals(Type.XML)){

            XMLSerializer xmlSerializer = new XMLSerializer();

            if(isCollectionType){

                xmlSerializer.setArrayName(entity.getClass().getSimpleName());

                Class elementType = Object.class;

                Collection c = (Collection)entity;

                if(c.size() > 0){

                    elementType = c.iterator().next().getClass();

                }

                xmlSerializer.setObjectName(elementType.getSimpleName());

            } else if(entity != null){

                xmlSerializer.setObjectName(entity.getClass().getSimpleName());

            }

            String xml = xmlSerializer.write( jsonObj );

            if(type.equals(Type.XML) && xsl != null){

                if(contextPath == null){

                    contextPath = "";

                }

                String basepath = dataSourceProperties.getXslBasePath(contextPath + "/xsl");

                String replace = "\r\n<?xml-stylesheet type=\"text/xsl\" href=\"" + basepath + "/" + xsl + "\"?>\r\n";

                xml = xml.replaceFirst("\r\n", replace);

            }

            writer.append(xml);

        } else {

            // assuming json

            if(jsonpCallback != null){

                writer.append(jsonpCallback).append("(").append(jsonObj.toString()).append(")");

            } else {

                writer.append(jsonObj.toString());

            }

        }

        //TODO resp.setContentType(type);

        } else {

            writer.append("SkipJSON mode detected, this is for debugging only! Please contact the adminitrator.");

            // END SkipJSON

        }

        writer.flush();

    }

    /*

     * (non-Javadoc)

     * @see org.springframework.web.servlet.View#render(java.util.Map, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

     */

    @Override

    public void render(Map model, HttpServletRequest request, HttpServletResponse response) throws Exception {

        // Retrieve data from model

        Object entity = getResponseData(model);

        // set content type

        response.setContentType(type.getContentType());

        PrintWriter writer = response.getWriter();

        // read jsonp parameter from query string

        String jsonpCallback = extractJsonpCallback(request);

        // render

        render(entity, writer, jsonpCallback, request, response);

    }

    /**

     * @param request

     * @return

     */

    private String extractJsonpCallback(HttpServletRequest request) {

        String jsonpCallback= null;

        String queryString = request.getQueryString();

        if(queryString != null){

            String[] tokens = request.getQueryString().split("&", 0);

            String jsonpParamName = "callback";

            for (int i = 0; i < tokens.length; i++) {

                if(tokens[i].startsWith(jsonpParamName)){

                    jsonpCallback = tokens[i].substring(jsonpParamName.length() + 1);

                    break;

                }

            }

        }

        return jsonpCallback;

    }

}