/*
 * Copyright 2004-present 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
 *
 *      https://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.web.header.writers.frameoptions;

import jakarta.servlet.http.HttpServletRequest;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.core.log.LogMessage;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * Base class for AllowFromStrategy implementations which use a request parameter to
 * retrieve the origin. By default the parameter named <code>x-frames-allow-from</code> is
 * read from the request.
 *
 * @author Marten Deinum
 * @since 3.2
 * @deprecated ALLOW-FROM is an obsolete directive that no longer works in modern
 * browsers. Instead use Content-Security-Policy with the <a href=
 * "https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/frame-ancestors">frame-ancestors</a>
 * directive.
 */
@Deprecated
public abstract class AbstractRequestParameterAllowFromStrategy implements AllowFromStrategy {

	private static final String DEFAULT_ORIGIN_REQUEST_PARAMETER = "x-frames-allow-from";

	private String allowFromParameterName = DEFAULT_ORIGIN_REQUEST_PARAMETER;

	/** Logger for use by subclasses */
	protected final Log log = LogFactory.getLog(getClass());

	AbstractRequestParameterAllowFromStrategy() {
	}

	@Override
	public String getAllowFromValue(HttpServletRequest request) {
		String allowFromOrigin = request.getParameter(this.allowFromParameterName);
		this.log.debug(LogMessage.format("Supplied origin '%s'", allowFromOrigin));
		if (StringUtils.hasText(allowFromOrigin) && allowed(allowFromOrigin)) {
			return allowFromOrigin;
		}
		return "DENY";
	}

	/**
	 * Sets the HTTP parameter used to retrieve the value for the origin that is allowed
	 * from. The value of the parameter should be a valid URL. The default parameter name
	 * is "x-frames-allow-from".
	 * @param allowFromParameterName the name of the HTTP parameter to
	 */
	public void setAllowFromParameterName(String allowFromParameterName) {
		Assert.notNull(allowFromParameterName, "allowFromParameterName cannot be null");
		this.allowFromParameterName = allowFromParameterName;
	}

	/**
	 * Method to be implemented by base classes, used to determine if the supplied origin
	 * is allowed.
	 * @param allowFromOrigin the supplied origin
	 * @return <code>true</code> if the supplied origin is allowed.
	 */
	protected abstract boolean allowed(String allowFromOrigin);

}
