/********************** 自定義 授權攔截註解***********************************/

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface AuthToken {
    boolean required() default true;
}

/********************** 自定義 授權資訊註解***********************************/

@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ApiIgnore
public @interface AuthUser {
}

/****************************** 使用者授權登入攔截 *************************************/

@Component
@Slf4j
public class AuthUserInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws AuthorizationException {
        if (!(handler instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        Method method = handlerMethod.getMethod();
        // 如果不是對映到方法檢視controller層註解
        if (method.isAnnotationPresent(AuthToken.class) || handlerMethod.getBeanType().isAnnotationPresent(AuthToken.class)) {
            //登入驗證
            AuthToken authToken = method.isAnnotationPresent(AuthToken.class) ?
                    method.getAnnotation(AuthToken.class) : handlerMethod.getBeanType().getAnnotation(AuthToken.class);
            if (authToken.required()) {
                // 從 http 請求頭中取出 token
                String token = request.getHeader(IAuthConst.KEY_AUTHORIZATION);
                // token認證
                if (null == token) {
                    throw new AuthorizationException(IAuthConst.KEY_AUTHORIZATION + "不能為空");
                }
                // 在此根據token獲取到使用者授權資訊，然後寫入到request
                request.setAttribute(IAuthConst.KEY_USER_ID, 1);
                request.setAttribute(IAuthConst.KEY_USER_NAME, "admin");
            }
        }
        return true;
    }
}

/***********************************使用者資訊欄位 Resolver*****************************************/

@Component
public class AuthUserMethodArgumentResolver implements HandlerMethodArgumentResolver {
    /**
     * 此方法攔截加了註解的引數 方法
     *
     * @param parameter
     * @return
     */
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        if (parameter.hasParameterAnnotation(AuthUser.class)) {
            return true;
        }
        return false;
    }

    /**
     * 對加了自定義註解的方法進行業務操做
     *
     * @return
     * @throws Exception
     */
    @Override
    public Object resolveArgument(MethodParameter parameter,
                                  ModelAndViewContainer mavContainer,
                                  NativeWebRequest webRequest,
                                  WebDataBinderFactory binderFactory) {
        if (parameter.hasParameterAnnotation(AuthUser.class)) {
            HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
            Object userIdObj = servletRequest.getAttribute(IAuthConst.KEY_USER_ID);
            Object userNameObj = servletRequest.getAttribute(IAuthConst.KEY_USER_NAME);
            if (userIdObj != null && userNameObj != null && userIdObj instanceof Integer) {
                return new UserBase(Integer.parseInt(userIdObj.toString())
                        , userNameObj.toString());
            }
        }
        return null;
    }
}

/***************************  新增攔截器到spring*****************************************/

@Configuration
public class MyWebMvcConfigurerAdapter extends WebMvcConfigurerAdapter {
    //註冊到spring容器中
    @Resource
    private AuthUserMethodArgumentResolver handlerParameterResolver;

    //新增對方法的攔截
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
        argumentResolvers.add(handlerParameterResolver);
        super.addArgumentResolvers(argumentResolvers);
    }

    /**
     * 新增對使用者授權的攔截器
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 可新增多個
        registry.addInterceptor(new AuthUserInterceptor()).addPathPatterns("/**");
    }
}