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package com.eduworks.cruncher.rdf;

import com.eduworks.lang.util.EwJson;
import com.eduworks.resolver.Context;
import com.eduworks.resolver.Cruncher;
import com.github.jsonldjava.core.JsonLdConsts;
import com.github.jsonldjava.core.JsonLdError;
import com.github.jsonldjava.core.JsonLdOptions;
import com.github.jsonldjava.core.JsonLdProcessor;
import com.github.jsonldjava.utils.JsonUtils;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

/**
 *
 * @author fray
 */
public class CruncherNQuadsToJsonLd extends Cruncher
{
    
    @Override
    public Object resolve(Context c, Map parameters, Map dataStreams) throws JSONException
    {
        try
        {
            String obj = getObjAsString(c, parameters, dataStreams);
            if (obj == null) return null;
            
           
            
            JsonLdOptions options = new JsonLdOptions();
            options.outputForm=JsonLdConsts.COMPACTED;
            Object output =  JsonLdProcessor.fromRDF(obj, options);
            if(!((Map)output).containsKey("@context")){
            	Object context;
            	String ctxString = optAsString("context", null, c, parameters, dataStreams);
            	JSONObject ctxObj;
            	if (ctxString != null){
            		try{
            			ctxObj = new JSONObject(ctxString);
                 		context = new HashMap();
                        for (String s : EwJson.getKeys(ctxObj))
                        {
                        	if (ctxObj.isNull(s))continue;
                             
                            ((Map)context).put(s, ctxObj.get(s));
                        }
                 	}catch(JSONException e){
                 		try{
                 			JSONArray arr = new JSONArray(ctxString);
                 			
                 			context = new ArrayList();
                 			for(int i = 0; i < arr.length(); i++){
                 				((ArrayList)context).add(arr.get(i));
                 			}
                 		}catch(JSONException e2){
                 			context = ctxString;
                 		}
                 	}
                 } else {
                     context = obj;
             	 }
                 
                 output = JsonLdProcessor.compact(output, context, options);
                 if(!((Map)output).containsKey("@context")){
                	 ((Map)output).put("@context", context);
                 }
            }
            	
            
            return new JSONObject(JsonUtils.toString(output));
        }
        catch (IOException ex)
        {
            Logger.getLogger(CruncherJsonLdExpand.class.getName()).log(Level.SEVERE, null, ex);
        }
        catch (JsonLdError ex)
        {
            Logger.getLogger(CruncherJsonLdExpand.class.getName()).log(Level.SEVERE, null, ex);
        }
        return null;
    }
    
    @Override
    public String getDescription()
    {
        return "Performs a JSON-LD Expand algorithm on the obj.";
    }
    
    @Override
    public String getReturn()
    {
        return "JSON-LD";
    }
    
    @Override
    public String getAttribution()
    {
        return ATTRIB_NONE;
    }
    
    @Override
    public JSONObject getParameters() throws JSONException
    {
        return jo("obj", "JSONObject|JSONArray");
    }
    
}