<%#
 Copyright 2013-2017 the original author or authors from the JBooter project.

 This file is part of the JBooter project, see https://jbooter.github.io/
 for more information.

 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 <%=packageName%>.config;

import <%=packageName%>.security.AuthoritiesConstants;
import io.github.jbooter.config.JBooterProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.security.authentication.AnonymousAuthenticationToken;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.server.HandshakeInterceptor;
import org.springframework.web.socket.server.support.DefaultHandshakeHandler;

import java.security.Principal;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import java.util.Optional;

@Configuration
@EnableWebSocketMessageBroker
public class WebsocketConfiguration extends AbstractWebSocketMessageBrokerConfigurer {

    private final Logger log = LoggerFactory.getLogger(WebsocketConfiguration.class);

    public static final String IP_ADDRESS = "IP_ADDRESS";

    private final JBooterProperties jBooterProperties;

    public WebsocketConfiguration(JBooterProperties jBooterProperties) {
        this.jBooterProperties = jBooterProperties;
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.enableSimpleBroker("/topic");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        String[] allowedOrigins = Optional.ofNullable(jBooterProperties.getCors().getAllowedOrigins()).map(origins -> origins.toArray(new String[0])).orElse(new String[0]);
        registry.addEndpoint("/websocket/tracker")
            .setHandshakeHandler(new DefaultHandshakeHandler() {
                @Override
                protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map<String, Object> attributes) {
                    Principal principal = request.getPrincipal();
                    if (principal == null) {
                        Collection<SimpleGrantedAuthority> authorities = new ArrayList<>();
                        authorities.add(new SimpleGrantedAuthority(AuthoritiesConstants.ANONYMOUS));
                        principal = new AnonymousAuthenticationToken("WebsocketConfiguration", "anonymous", authorities);
                    }
                    return principal;
                }
            })
            .setAllowedOrigins(allowedOrigins)
            .withSockJS()
            .setInterceptors(httpSessionHandshakeInterceptor());
    }

    @Bean
    public HandshakeInterceptor httpSessionHandshakeInterceptor() {
        return new HandshakeInterceptor() {

            @Override
            public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
                if (request instanceof ServletServerHttpRequest) {
                    ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
                    attributes.put(IP_ADDRESS, servletRequest.getRemoteAddress());
                }
                return true;
            }

            @Override
            public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {

            }
        };
    }
}