/*
 * Copyright 2013-2020 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.cloud.gateway.config;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.cloud.gateway.support.MvcFoundOnClasspathException;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
@AutoConfigureBefore(GatewayAutoConfiguration.class)
@ConditionalOnProperty(name = "spring.cloud.gateway.enabled", matchIfMissing = true)
public class GatewayClassPathWarningAutoConfiguration {

	private static final Log log = LogFactory.getLog(GatewayClassPathWarningAutoConfiguration.class);

	private static final String BORDER = "\n\n**********************************************************\n\n";

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(name = "org.springframework.web.servlet.DispatcherServlet")
	@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.SERVLET)
	protected static class SpringMvcFoundOnClasspathConfiguration {

		public SpringMvcFoundOnClasspathConfiguration() {
			throw new MvcFoundOnClasspathException();
		}

	}

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnMissingClass("org.springframework.web.reactive.DispatcherHandler")
	protected static class WebfluxMissingFromClasspathConfiguration {

		public WebfluxMissingFromClasspathConfiguration() {
			log.warn(BORDER + "Spring Webflux is missing from the classpath, "
					+ "which is required for Spring Cloud Gateway at this time. "
					+ "Please add spring-boot-starter-webflux dependency." + BORDER);
		}

	}

}
