package at.gv.egovernment.moa.id.auth.builder;

import at.gv.egovernment.moa.id.auth.servlet.AuthServlet;

/**
 * Builds a DataURL parameter meant for the security layer implementation
 * to respond to.
 * 
 * @author Paul Ivancsics
 * @version $Id$
 */
public class DataURLBuilder {
	
  /**
   * Constructor for DataURLBuilder.
   */
  public DataURLBuilder() {
    super();
  }

  /**
   * Constructs a data URL for <code>VerifyIdentityLink</code> or <code>VerifyAuthenticationBlock</code>, 
   * including the <code>MOASessionID</code> as a parameter.
   * 
   * @param authBaseURL base URL (context path) of the MOA ID Authentication component,
   * 				 including a trailing <code>'/'</code>
   * @param authServletName request part of the data URL
   * @param sessionID sessionID to be included in the dataURL
   * @return String
   */
  public String buildDataURL(String authBaseURL, String authServletName, String sessionID) {
    String dataURL = authBaseURL + authServletName;
    dataURL = addParameter(dataURL, AuthServlet.PARAM_SESSIONID, sessionID);
  	return dataURL;
  }

  /**
   * Method addParameter.
   * @param urlString represents the url 
   * @param paramname is the parameter to be added
   * @param value is the value of that parameter
   * @return String
   */
  private String addParameter(String urlString, String paramname, String value) {
    String url = urlString;
    if (paramname != null) {
      if (url.indexOf("?") < 0)
        url += "?";
      else
        url += "&";
      url += paramname + "=" + value;
    }
    return url;
  }
}