<%#
 Copyright 2013-2021 the original author or authors from the JHipster project.

 This file is part of the JHipster project, see https://www.jhipster.tech/
 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

      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 <%= packageName %>.config;

import <%= packageName %>.security.AuthoritiesConstants;

import java.security.Principal;
import java.util.*;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.server.*;
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.*;
import org.springframework.web.socket.server.HandshakeInterceptor;
import org.springframework.web.socket.server.support.DefaultHandshakeHandler;

import tech.jhipster.config.JHipsterProperties;

@Configuration
@EnableWebSocketMessageBroker
public class WebsocketConfiguration implements WebSocketMessageBrokerConfigurer {

    public static final String IP_ADDRESS = "IP_ADDRESS";

    private final JHipsterProperties jHipsterProperties;

    public WebsocketConfiguration(JHipsterProperties jHipsterProperties) {
        this.jHipsterProperties = jHipsterProperties;
    }

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

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        String[] allowedOrigins = Optional.ofNullable(jHipsterProperties.getCors().getAllowedOrigins()).map(origins -> origins.toArray(new String[0])).orElse(new String[0]);
        registry.addEndpoint("/websocket/tracker")
            .setHandshakeHandler(defaultHandshakeHandler())
            .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) {

            }
        };
    }

    private DefaultHandshakeHandler defaultHandshakeHandler() {
        return 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;
            }
        };
    }
}