/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed 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
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.springframework.security.config.http;

import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.security.web.util.UrlUtils;
import org.springframework.util.StringUtils;

/**
 * Utility methods used internally by the Spring Security http namespace configuration code.
 *
 * @author Luke Taylor
 * @author Ben Alex
 */
abstract class WebConfigUtils {

    public static int countNonEmpty(String[] objects) {
        int nonNulls = 0;

        for (String object : objects) {
            if (StringUtils.hasText(object)) {
                nonNulls++;
            }
        }

        return nonNulls;
    }

    /**
     * Checks the value of an XML attribute which represents a redirect URL.
     * If not empty or starting with "$" (potential placeholder), or starting with "#" (potential SpEL), "/" or "http" it will raise an error.
     */
    static void validateHttpRedirect(String url, ParserContext pc, Object source) {
        if (!StringUtils.hasText(url) || UrlUtils.isValidRedirectUrl(url) || url.startsWith("$") || url.startsWith("#")) {
            return;
        }
        pc.getReaderContext().warning(url + " is not a valid redirect URL (must start with '/' or http(s))", source);
    }

}
