/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.url;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import javax.servlet.http.HttpServletRequest;
import org.apereo.portal.security.mvc.LoginController;
import org.springframework.beans.factory.annotation.Required;

/**
 * Encode the originally requested URL for use as a RefUrl parameter for the CAS login use case.
 * This handles the additional encoding needed to encode the originally-requested URL since the
 * originally requested URL will be decoded twice (decoded once when the browser sends it to CAS,
 * then again when the browser sends it back to uPortal after coming from CAS).
 *
 */
public class CasLoginRefUrlEncoder implements LoginRefUrlEncoder {

    private String casLoginUrl;

    @Required
    public void setCasLoginUrl(String casLoginUrl) {
        this.casLoginUrl = casLoginUrl;
    }

    public String getCasLoginUrl() {
        return casLoginUrl;
    }

    @Override
    public String encodeLoginAndRefUrl(HttpServletRequest request)
            throws UnsupportedEncodingException {
        final String requestEncoding = request.getCharacterEncoding();
        final StringBuilder loginRedirect = new StringBuilder();

        loginRedirect.append(casLoginUrl);
        loginRedirect.append(URLEncoder.encode("?", requestEncoding));
        loginRedirect.append(
                URLEncoder.encode(LoginController.REFERER_URL_PARAM + "=", requestEncoding));

        loginRedirect.append(URLEncoder.encode(request.getRequestURI(), requestEncoding));

        final String queryString = request.getQueryString();
        if (queryString != null) {
            String firstEncoding = URLEncoder.encode("?" + queryString, requestEncoding);
            loginRedirect.append(URLEncoder.encode(firstEncoding, requestEncoding));
        }

        return loginRedirect.toString();
    }
}