/*
 * Copyright 2014 Federal Chancellery Austria MOA-ID has been developed in a cooperation between
 * BRZ, the Federal Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by the European
 * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
 * compliance with the Licence. You may obtain a copy of the Licence at: http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the Licence
 * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the Licence for the specific language governing permissions and limitations under
 * the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text file for details on the
 * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
 * works that you distribute must include a readable copy of the "NOTICE" text file.
 */

package at.gv.egiz.eaaf.core.impl.utils;

import org.apache.commons.lang3.StringUtils;

import at.gv.egiz.eaaf.core.api.data.EaafConstants;

/**
 * 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 pendingReqId    sessionID to be included in the dataURL
   * @return String
   */
  public String buildDataUrl(String authBaseUrl, String authServletName,
      final String pendingReqId) {
    String dataUrl;
    if (!authBaseUrl.endsWith("/")) {
      authBaseUrl += "/";
    }

    if (authServletName.startsWith("/")) {
      authServletName = authServletName.substring(1);
    }

    dataUrl = authBaseUrl + authServletName;

    if (StringUtils.isNotEmpty(pendingReqId)) {
      dataUrl =
          addParameter(dataUrl, EaafConstants.PARAM_HTTP_TARGET_PENDINGREQUESTID, pendingReqId);
    }

    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(final String urlString, final String paramname, final String value) {
    String url = urlString;
    if (paramname != null) {
      if (url.indexOf("?") < 0) {
        url += "?";
      } else {
        url += "&";
      }
      url += paramname + "=" + value;
    }
    return url;
  }
}