package com.imyeyu.spring.annotation;

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.lang.NonNull;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import java.lang.annotation.Annotation;

/**
 * 抽象验证令牌
 *
 * @param <A> 注解类型
 * @author 夜雨
 * @version 2021-08-16 18:07
 */
public abstract class RequiredTokenAbstractInterceptor<A extends Annotation> implements HandlerInterceptor {

	private final Class<A> annotation;

	/**
	 * 创建 Token 验证拦截器
	 *
	 * @param annotation 注解类型
	 */
	public RequiredTokenAbstractInterceptor(Class<A> annotation) {
		this.annotation = annotation;
	}

	/**
	 * 处理前
	 *
	 * @param req     请求
	 * @param resp    返回
	 * @param handler 处理方法
	 * @return true 为通过
	 */
	@Override
	public boolean preHandle(@NonNull HttpServletRequest req,
	                         @NonNull HttpServletResponse resp,
	                         @NonNull Object handler) {
		// 方法注解
		if (handler instanceof HandlerMethod handlerMethod) {
			A requiredTokenAnnotation = handlerMethod.getMethodAnnotation(annotation);
			if (requiredTokenAnnotation == null) {
				return true;
			}
			return beforeRun(req, resp);
		}
		return true;
	}

	/**
	 * 访问前（通过 Token 限制）
	 *
	 * @param req  请求
	 * @param resp 返回
	 * @return true 为通过
	 */
	protected abstract boolean beforeRun(HttpServletRequest req, HttpServletResponse resp);
}