/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * 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.keycloak.adapters.springsecurity.config;

import org.keycloak.adapters.AdapterDeploymentContext;
import org.keycloak.adapters.KeycloakConfigResolver;
import org.keycloak.adapters.springsecurity.AdapterDeploymentContextFactoryBean;
import org.keycloak.adapters.springsecurity.authentication.KeycloakAuthenticationEntryPoint;
import org.keycloak.adapters.springsecurity.authentication.KeycloakAuthenticationProvider;
import org.keycloak.adapters.springsecurity.authentication.KeycloakLogoutHandler;
import org.keycloak.adapters.springsecurity.filter.KeycloakAuthenticationProcessingFilter;
import org.keycloak.adapters.springsecurity.filter.KeycloakCsrfRequestMatcher;
import org.keycloak.adapters.springsecurity.filter.KeycloakPreAuthActionsFilter;
import org.keycloak.adapters.springsecurity.management.HttpSessionManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.core.io.Resource;
import org.springframework.security.config.annotation.web.WebSecurityConfigurer;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.builders.WebSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.config.annotation.web.servlet.configuration.EnableWebMvcSecurity;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.security.web.authentication.logout.LogoutFilter;
import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;

/**
 * Provides a convenient base class for creating a {@link WebSecurityConfigurer}
 * instance secured by Keycloak. This implementation allows customization by overriding methods.
 *
 * @author <a href="mailto:srossillo@smartling.com">Scott Rossillo</a>
 * @version $Revision: 1 $
 * @see EnableWebSecurity
 * @see EnableWebMvcSecurity
 */
public abstract class KeycloakWebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter implements WebSecurityConfigurer<WebSecurity> {

    @Value("${keycloak.configurationFile:WEB-INF/keycloak.json}")
    private Resource keycloakConfigFileResource;
    @Autowired(required = false)
    private KeycloakConfigResolver keycloakConfigResolver;

    @Bean
    protected AdapterDeploymentContext adapterDeploymentContext() throws Exception {
        AdapterDeploymentContextFactoryBean factoryBean;
        if (keycloakConfigResolver != null) {
             factoryBean = new AdapterDeploymentContextFactoryBean(keycloakConfigResolver);
        }
        else {
            factoryBean = new AdapterDeploymentContextFactoryBean(keycloakConfigFileResource);
        }
        factoryBean.afterPropertiesSet();
        return factoryBean.getObject();
    }

    protected AuthenticationEntryPoint authenticationEntryPoint() throws Exception {
        return new KeycloakAuthenticationEntryPoint(adapterDeploymentContext());
    }

    protected KeycloakAuthenticationProvider keycloakAuthenticationProvider() {
        return new KeycloakAuthenticationProvider();
    }

    @Bean
    protected KeycloakAuthenticationProcessingFilter keycloakAuthenticationProcessingFilter() throws Exception {
        KeycloakAuthenticationProcessingFilter filter = new KeycloakAuthenticationProcessingFilter(authenticationManagerBean());
        filter.setSessionAuthenticationStrategy(sessionAuthenticationStrategy());
        return filter;
    }

    @Bean
    protected KeycloakPreAuthActionsFilter keycloakPreAuthActionsFilter() {
        return new KeycloakPreAuthActionsFilter(httpSessionManager());
    }

    protected KeycloakCsrfRequestMatcher keycloakCsrfRequestMatcher() {
        return new KeycloakCsrfRequestMatcher();
    }

    @Bean
    protected HttpSessionManager httpSessionManager() {
        return new HttpSessionManager();
    }

    protected KeycloakLogoutHandler keycloakLogoutHandler() throws Exception {
        return new KeycloakLogoutHandler(adapterDeploymentContext());
    }

    protected abstract SessionAuthenticationStrategy sessionAuthenticationStrategy();

    @Override
    protected void configure(HttpSecurity http) throws Exception {

        http
                .csrf().requireCsrfProtectionMatcher(keycloakCsrfRequestMatcher())
                .and()
                .sessionManagement()
                .sessionAuthenticationStrategy(sessionAuthenticationStrategy())
                .and()
                .addFilterBefore(keycloakPreAuthActionsFilter(), LogoutFilter.class)
                .addFilterBefore(keycloakAuthenticationProcessingFilter(), BasicAuthenticationFilter.class)
                .exceptionHandling().authenticationEntryPoint(authenticationEntryPoint())
                .and()
                .logout()
                .addLogoutHandler(keycloakLogoutHandler())
                .logoutUrl("/sso/logout").permitAll()
                .logoutSuccessUrl("/");
    }
}