/*
 * Copyright 2012-2018 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.boot.actuate.endpoint.web.reactive;

import java.util.Collection;
import java.util.Collections;
import java.util.Map;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.boot.actuate.endpoint.web.EndpointLinksResolver;
import org.springframework.boot.actuate.endpoint.web.EndpointMapping;
import org.springframework.boot.actuate.endpoint.web.EndpointMediaTypes;
import org.springframework.boot.actuate.endpoint.web.ExposableWebEndpoint;
import org.springframework.boot.actuate.endpoint.web.Link;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.reactive.HandlerMapping;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.util.UriComponentsBuilder;

/**
 * A custom {@link HandlerMapping} that makes web endpoints available over HTTP using
 * Spring WebFlux.
 *
 * @author Andy Wilkinson
 * @author Phillip Webb
 * @since 2.0.0
 */
public class WebFluxEndpointHandlerMapping extends AbstractWebFluxEndpointHandlerMapping
		implements InitializingBean {

	private final EndpointLinksResolver linksResolver;

	/**
	 * Creates a new {@code WebFluxEndpointHandlerMapping} instance that provides mappings
	 * for the given endpoints.
	 * @param endpointMapping the base mapping for all endpoints
	 * @param endpoints the web endpoints
	 * @param endpointMediaTypes media types consumed and produced by the endpoints
	 * @param corsConfiguration the CORS configuration for the endpoints or {@code null}
	 * @param linksResolver resolver for determining links to available endpoints
	 */
	public WebFluxEndpointHandlerMapping(EndpointMapping endpointMapping,
			Collection<ExposableWebEndpoint> endpoints,
			EndpointMediaTypes endpointMediaTypes, CorsConfiguration corsConfiguration,
			EndpointLinksResolver linksResolver) {
		super(endpointMapping, endpoints, endpointMediaTypes, corsConfiguration);
		this.linksResolver = linksResolver;
		setOrder(-100);
	}

	@Override
	@ResponseBody
	protected Map<String, Map<String, Link>> links(ServerWebExchange exchange) {
		String requestUri = UriComponentsBuilder.fromUri(exchange.getRequest().getURI())
				.replaceQuery(null).toUriString();
		return Collections.singletonMap("_links",
				this.linksResolver.resolveLinks(requestUri));
	}

}
