<%#
 Copyright 2013-2018 the original author or authors from the JHipster project.

 This file is part of the JHipster project, see http://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

      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.jhipster.config.JHipsterProperties;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.oauth2.config.annotation.configurers.ClientDetailsServiceConfigurer;
import org.springframework.security.oauth2.config.annotation.web.configuration.AuthorizationServerConfigurerAdapter;
import org.springframework.security.oauth2.config.annotation.web.configuration.EnableAuthorizationServer;
import org.springframework.security.oauth2.config.annotation.web.configuration.EnableResourceServer;
import org.springframework.security.oauth2.config.annotation.web.configuration.ResourceServerConfigurerAdapter;
import org.springframework.security.oauth2.config.annotation.web.configurers.AuthorizationServerEndpointsConfigurer;
import org.springframework.security.oauth2.config.annotation.web.configurers.AuthorizationServerSecurityConfigurer;
import org.springframework.security.oauth2.config.annotation.web.configurers.ResourceServerSecurityConfigurer;
import org.springframework.security.oauth2.provider.token.TokenEnhancer;
import org.springframework.security.oauth2.provider.token.TokenEnhancerChain;
import org.springframework.security.oauth2.provider.token.TokenStore;
import org.springframework.security.oauth2.provider.token.store.JwtAccessTokenConverter;
import org.springframework.security.oauth2.provider.token.store.JwtTokenStore;
import org.springframework.security.oauth2.provider.token.store.KeyStoreKeyFactory;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
import org.springframework.web.filter.CorsFilter;

import javax.servlet.http.HttpServletResponse;
import java.security.KeyPair;
import java.util.ArrayList;
import java.util.Collection;

@Configuration
@EnableAuthorizationServer
public class UaaConfiguration extends AuthorizationServerConfigurerAdapter implements ApplicationContextAware {
    /**
     * Access tokens will not expire any earlier than this.
     */
    private static final int MIN_ACCESS_TOKEN_VALDITIY_SECS = 60;

    private ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    @EnableResourceServer
    public static class ResourceServerConfiguration extends ResourceServerConfigurerAdapter {

        private final TokenStore tokenStore;

        private final JHipsterProperties jHipsterProperties;

        private final CorsFilter corsFilter;

        public ResourceServerConfiguration(TokenStore tokenStore, JHipsterProperties jHipsterProperties, CorsFilter corsFilter) {
            this.tokenStore = tokenStore;
            this.jHipsterProperties = jHipsterProperties;
            this.corsFilter = corsFilter;
        }

        @Override
        public void configure(HttpSecurity http) throws Exception {
            http
                .exceptionHandling()
                .authenticationEntryPoint((request, response, authException) -> response.sendError(HttpServletResponse.SC_UNAUTHORIZED))
            .and()
                .csrf()
                .disable()
                .addFilterBefore(corsFilter, UsernamePasswordAuthenticationFilter.class)
                .headers()
                .frameOptions()
                .disable()
            .and()
                .sessionManagement()
                .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
            .and()
                .authorizeRequests()
                .antMatchers("/api/register").permitAll()
                .antMatchers("/api/activate").permitAll()
                .antMatchers("/api/authenticate").permitAll()
                .antMatchers("/api/account/reset-password/init").permitAll()
                .antMatchers("/api/account/reset-password/finish").permitAll()
                .antMatchers("/api/profile-info").permitAll()
                .antMatchers("/api/**").authenticated()<% if (websocket === 'spring-websocket') { %>
                .antMatchers("/websocket/tracker").hasAuthority(AuthoritiesConstants.ADMIN)
                .antMatchers("/websocket/**").permitAll()<% } %>
                .antMatchers("/management/health").permitAll()
                .antMatchers("/management/**").hasAuthority(AuthoritiesConstants.ADMIN)
                .antMatchers("/v2/api-docs/**").permitAll()
                .antMatchers("/swagger-resources/configuration/ui").permitAll()
                .antMatchers("/swagger-ui/index.html").hasAuthority(AuthoritiesConstants.ADMIN);
        }

        @Override
        public void configure(ResourceServerSecurityConfigurer resources) throws Exception {
            resources.resourceId("jhipster-uaa").tokenStore(tokenStore);
        }
    }

    private final JHipsterProperties jHipsterProperties;

    private final UaaProperties uaaProperties;

    public UaaConfiguration(JHipsterProperties jHipsterProperties, UaaProperties uaaProperties) {
        this.jHipsterProperties = jHipsterProperties;
        this.uaaProperties = uaaProperties;
    }

    @Override
    public void configure(ClientDetailsServiceConfigurer clients) throws Exception {
        int accessTokenValidity = uaaProperties.getWebClientConfiguration().getAccessTokenValidityInSeconds();
        accessTokenValidity = Math.max(accessTokenValidity, MIN_ACCESS_TOKEN_VALDITIY_SECS);
        int refreshTokenValidity = uaaProperties.getWebClientConfiguration().getRefreshTokenValidityInSecondsForRememberMe();
        refreshTokenValidity = Math.max(refreshTokenValidity, accessTokenValidity);
        /*
        For a better client design, this should be done by a ClientDetailsService (similar to UserDetailsService).
         */
        clients.inMemory()
            .withClient(uaaProperties.getWebClientConfiguration().getClientId())
            .secret(uaaProperties.getWebClientConfiguration().getSecret())
            .scopes("openid")
            .autoApprove(true)
            .authorizedGrantTypes("implicit","refresh_token", "password", "authorization_code")
            .accessTokenValiditySeconds(accessTokenValidity)
            .refreshTokenValiditySeconds(refreshTokenValidity)
            .and()
            .withClient(jHipsterProperties.getSecurity().getClientAuthorization().getClientId())
            .secret(jHipsterProperties.getSecurity().getClientAuthorization().getClientSecret())
            .scopes("web-app")
            .autoApprove(true)
            .authorizedGrantTypes("client_credentials")
            .accessTokenValiditySeconds((int) jHipsterProperties.getSecurity().getAuthentication().getJwt().getTokenValidityInSeconds())
            .refreshTokenValiditySeconds((int) jHipsterProperties.getSecurity().getAuthentication().getJwt().getTokenValidityInSecondsForRememberMe());
    }

    @Override
    public void configure(AuthorizationServerEndpointsConfigurer endpoints) throws Exception {
        //pick up all  TokenEnhancers incl. those defined in the application
        //this avoids changes to this class if an application wants to add its own to the chain
        Collection<TokenEnhancer> tokenEnhancers = applicationContext.getBeansOfType(TokenEnhancer.class).values();
        TokenEnhancerChain tokenEnhancerChain=new TokenEnhancerChain();
        tokenEnhancerChain.setTokenEnhancers(new ArrayList<>(tokenEnhancers));
        endpoints
            .authenticationManager(authenticationManager)
            .tokenStore(tokenStore())
            .tokenEnhancer(tokenEnhancerChain)
            .reuseRefreshTokens(false);             //don't reuse or we will run into session inactivity timeouts
    }

    @Autowired
    @Qualifier("authenticationManagerBean")
    private AuthenticationManager authenticationManager;

    /**
     * Apply the token converter (and enhancer) for token store.
     * @return the JwtTokenStore managing the tokens.
     */
    @Bean
    public JwtTokenStore tokenStore() {
        return new JwtTokenStore(jwtAccessTokenConverter());
    }

    /**
     * This bean generates an token enhancer, which manages the exchange between JWT acces tokens and Authentication
     * in both directions.
     *
     * @return an access token converter configured with the authorization server's public/private keys
     */
    @Bean
    public JwtAccessTokenConverter jwtAccessTokenConverter() {
        JwtAccessTokenConverter converter = new JwtAccessTokenConverter();
        KeyPair keyPair = new KeyStoreKeyFactory(
             new ClassPathResource(uaaProperties.getKeyStore().getName()), uaaProperties.getKeyStore().getPassword().toCharArray())
             .getKeyPair(uaaProperties.getKeyStore().getAlias());
        converter.setKeyPair(keyPair);
        return converter;
    }

    @Override
    public void configure(AuthorizationServerSecurityConfigurer oauthServer) throws Exception {
        oauthServer.tokenKeyAccess("permitAll()").checkTokenAccess(
                "isAuthenticated()");
    }
}