/*
 * Copyright 2002-2023 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.server.util.matcher;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.core.publisher.Mono;

import org.springframework.http.HttpMethod;
import org.springframework.http.server.PathContainer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.Assert;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.util.pattern.PathPattern;
import org.springframework.web.util.pattern.PathPatternParser;

/**
 * Matches if the {@link PathPattern} matches the path within the application.
 *
 * @author Rob Winch
 * @author Mathieu Ouellet
 * @since 5.0
 */
public final class PathPatternParserServerWebExchangeMatcher implements ServerWebExchangeMatcher {

	private static final Log logger = LogFactory.getLog(PathPatternParserServerWebExchangeMatcher.class);

	private final PathPattern pattern;

	private final HttpMethod method;

	public PathPatternParserServerWebExchangeMatcher(PathPattern pattern) {
		this(pattern, null);
	}

	public PathPatternParserServerWebExchangeMatcher(PathPattern pattern, HttpMethod method) {
		Assert.notNull(pattern, "pattern cannot be null");
		this.pattern = pattern;
		this.method = method;
	}

	public PathPatternParserServerWebExchangeMatcher(String pattern, HttpMethod method) {
		Assert.notNull(pattern, "pattern cannot be null");
		this.pattern = parse(pattern);
		this.method = method;
	}

	public PathPatternParserServerWebExchangeMatcher(String pattern) {
		this(pattern, null);
	}

	private PathPattern parse(String pattern) {
		PathPatternParser parser = PathPatternParser.defaultInstance;
		pattern = parser.initFullPathPattern(pattern);
		return parser.parse(pattern);
	}

	@Override
	public Mono<MatchResult> matches(ServerWebExchange exchange) {
		ServerHttpRequest request = exchange.getRequest();
		PathContainer path = request.getPath().pathWithinApplication();
		if (this.method != null && !this.method.equals(request.getMethod())) {
			return MatchResult.notMatch().doOnNext((result) -> {
				if (logger.isDebugEnabled()) {
					logger.debug("Request '" + request.getMethod() + " " + path + "' doesn't match '" + this.method
							+ " " + this.pattern.getPatternString() + "'");
				}
			});
		}
		boolean match = this.pattern.matches(path);
		if (!match) {
			return MatchResult.notMatch().doOnNext((result) -> {
				if (logger.isDebugEnabled()) {
					logger.debug("Request '" + request.getMethod() + " " + path + "' doesn't match '" + this.method
							+ " " + this.pattern.getPatternString() + "'");
				}
			});
		}
		Map<String, String> pathVariables = this.pattern.matchAndExtract(path).getUriVariables();
		Map<String, Object> variables = new HashMap<>(pathVariables);
		if (logger.isDebugEnabled()) {
			logger.debug(
					"Checking match of request : '" + path + "'; against '" + this.pattern.getPatternString() + "'");
		}
		return MatchResult.match(variables);
	}

	@Override
	public String toString() {
		return "PathMatcherServerWebExchangeMatcher{" + "pattern='" + this.pattern + '\'' + ", method=" + this.method
				+ '}';
	}

}
