package org.webcat.core.webapi;

import java.io.IOException;
import java.io.Writer;
import org.webcat.core.Application;
import com.webobjects.appserver.WOApplication;
import com.webobjects.foundation.NSMutableDictionary;

//-------------------------------------------------------------------------
/**
 * The base class for result formatters in the web API. Web-CAT currently
 * provides two fixed formatters: JSON ({@link JSONResponseFormatter}, the
 * default), and XML ({@link XmlResponseFormatter}).
 *
 * @author  Tony Allevato
 * @author  Last changed by $Author: aallowat $
 * @version $Revision: 1.1 $, $Date: 2012/06/22 16:23:17 $
 */
public abstract class ResponseFormatter
{
    //~ Methods ...............................................................

    // ----------------------------------------------------------
    /**
     * Takes the session identifier and the result of the action for
     * formatting.
     *
     * @param sessionId the session identifier
     * @param result the result of the action
     */
    public void setResult(Object sessionId, Object result)
    {
        root = new NSMutableDictionary<String, Object>();

        root.setObjectForKey(sessionId, SESSION_ID_KEY);

        if (result instanceof WebAPIError)
        {
            root.setObjectForKey(result, "error");
        }
        else if (result != null)
        {
            root.setObjectForKey(result, "result");
        }
    }


    // ----------------------------------------------------------
    /**
     * Formats the stored result to the specified writer.
     *
     * @param writer the writer
     * @throws IOException if an I/O error occurs
     */
    public void formatToWriter(Writer writer) throws IOException
    {
        format(root);
    }


    // ----------------------------------------------------------
    /**
     * Gets the MIME type of the response generated by this formatter.
     *
     * @return the MIME type of the response
     */
    public abstract String mimeType();


    // ----------------------------------------------------------
    /**
     * Subclasses should override this method to provide the logic for
     * formatting an object.
     *
     * @param object the object to format
     * @throws IOException if an I/O error occurs
     */
    protected abstract void format(Object object)
        throws IOException;


    //~ Instance/static variables .............................................

    private static final String SESSION_ID_KEY = "sessionId";

    private NSMutableDictionary<String, Object> root;
}