package org.onap.sdc.dcae.catalog.commons; 
 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.io.OutputStreamWriter; 
import java.io.Reader; 
import java.io.Writer; 
import java.lang.reflect.Type; 
import java.nio.charset.Charset; 
 
import org.springframework.http.HttpHeaders; 
import org.springframework.http.HttpInputMessage; 
import org.springframework.http.HttpOutputMessage; 
import org.springframework.http.MediaType; 
import org.springframework.http.converter.AbstractHttpMessageConverter; 
import org.springframework.http.converter.HttpMessageNotReadableException; 
import org.springframework.http.converter.HttpMessageNotWritableException; 
 
import org.json.JSONObject; 
import org.json.JSONArray; 
import org.json.JSONTokener; 
import org.json.JSONException; 
 
/**
 */ 
public class JSONHttpMessageConverter extends AbstractHttpMessageConverter<Object> { 
 
	public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8"); 

	/** */ 
	public JSONHttpMessageConverter() { 
  	super(new MediaType("application", "json", DEFAULT_CHARSET)); 
 	} 
 /* 
 	@Override 
 	public boolean canRead(Class<?> theClazz, MediaType theMediaType) { 
  	return canRead(theMediaType); 
 	} 
 
 	@Override 
	public boolean canWrite(Class<?> theClazz, MediaType theMediaType) { 
  	return canWrite(theMediaType); 
 	} 
 */
 	@Override 
 	protected boolean supports(Class<?> theClazz) {
		return theClazz.equals(JSONObject.class) ||
					 theClazz.equals(JSONArray.class);
 	} 
 
	@Override 
 	protected Object readInternal(Class<?> theClazz, HttpInputMessage theInputMessage) 
  																								 throws IOException, HttpMessageNotReadableException { 
   
  	Reader json = new InputStreamReader(theInputMessage.getBody(), getCharset(theInputMessage.getHeaders())); 
   
		try {
			if (theClazz.equals(JSONObject.class))
				return new JSONObject(new JSONTokener(json));
			if (theClazz.equals(JSONArray.class))
				return new JSONArray(new JSONTokener(json));
 			
			throw new HttpMessageNotReadableException("Could not process input, cannot handle " + theClazz); 
		}
		catch (JSONException jsonx) { 
 			throw new HttpMessageNotReadableException("Could not read JSON: " + jsonx.getMessage(), jsonx); 
 		} 
	} 
 
	@Override 
 	protected void writeInternal(Object theObject, HttpOutputMessage theOutputMessage) 
  																								 throws IOException, HttpMessageNotWritableException { 
   
  	Writer writer = new OutputStreamWriter(theOutputMessage.getBody(), getCharset(theOutputMessage.getHeaders())); 
 
		try {
			if (theObject instanceof JSONObject) {
				((JSONObject)theObject).write(writer);
			}
			else if (theObject instanceof JSONArray) {
				((JSONArray)theObject).write(writer);
			}

			writer.close();
  	}
		catch(JSONException jsonx) { 
   		throw new HttpMessageNotWritableException("Could not write JSON: " + jsonx.getMessage(), jsonx); 
  	}  
	} 
  
	private Charset getCharset(HttpHeaders theHeaders) { 
  	if (theHeaders != null &&
				theHeaders.getContentType() != null &&
				theHeaders.getContentType().getCharSet() != null) { 
   		return theHeaders.getContentType().getCharSet(); 
  	} 
  	return DEFAULT_CHARSET; 
	} 
 
}