package com.digag.config.security;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpMethod;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

/**
 * Created by Yuicon on 2017/5/14.
 * https://segmentfault.com/u/yuicon
 */
@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private JwtAuthenticationEntryPoint unauthorizedHandler;

    // Spring会自动寻找同样类型的具体类注入，这里就是JwtUserDetailsServiceImpl了
    @Autowired
    private UserDetailsService userDetailsService;

    @Autowired
    public void configureAuthentication(AuthenticationManagerBuilder authenticationManagerBuilder) throws Exception {
        authenticationManagerBuilder
                // 设置UserDetailsService
                .userDetailsService(this.userDetailsService)
                // 使用BCrypt进行密码的hash
                .passwordEncoder(passwordEncoder());
    }

    // 装载BCrypt密码编码器
    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    public JwtAuthenticationTokenFilter authenticationTokenFilterBean() throws Exception {
        return new JwtAuthenticationTokenFilter();
    }

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**").allowedOrigins("*")
                        .allowedMethods("GET", "HEAD", "POST","PUT", "DELETE", "OPTIONS")
                        .allowCredentials(false).maxAge(3600);
            }
        };
    }

    @Override
    protected void configure(HttpSecurity httpSecurity) throws Exception {
        httpSecurity
                // 由于使用的是JWT，我们这里不需要csrf
                .csrf().disable()

                .exceptionHandling().authenticationEntryPoint(unauthorizedHandler).and()

                // 基于token，所以不需要session
                .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()

                .authorizeRequests()
                .antMatchers(HttpMethod.OPTIONS, "/**").permitAll()

                // 允许对于网站静态资源的无授权访问
                .antMatchers(
                        HttpMethod.GET,
                        "/",
                        "/*.html",
                        "/favicon.ico",
                        "/**/*.html",
                        "/**/*.css",
                        "/**/*.js",
                        "/webjars/**",
                        "/swagger-resources/**",
                        "/*/api-docs"
                ).permitAll()
                // 对于获取token的rest api要允许匿名访问
                .antMatchers("/auth/**").permitAll()
                .antMatchers("/druid/**").permitAll()
                .antMatchers(HttpMethod.GET, "/entries/**", "/articles/**").permitAll()
                // 除上面外的所有请求全部需要鉴权认证
                .anyRequest().authenticated();

        // 添加JWT filter
        httpSecurity
                .addFilterBefore(authenticationTokenFilterBean(), UsernamePasswordAuthenticationFilter.class);

        // 禁用缓存
        httpSecurity.headers().cacheControl();
    }
}