/*
 *      Copyright (c) 2018-2028, Chill Zhuang All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer.
 *  Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *  Neither the name of the dreamlu.net developer nor the names of its
 *  contributors may be used to endorse or promote products derived from
 *  this software without specific prior written permission.
 *  Author: Chill 庄骞 (smallchill@163.com)
 */
package org.springblade.core.secure.interceptor;

import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springblade.core.secure.auth.AuthFun;
import org.springblade.core.secure.props.AuthSecure;
import org.springblade.core.secure.provider.HttpMethod;
import org.springblade.core.secure.provider.ResponseProvider;
import org.springblade.core.tool.jackson.JsonUtil;
import org.springblade.core.tool.utils.WebUtil;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;
import org.springframework.lang.NonNull;
import org.springframework.util.AntPathMatcher;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;

/**
 * 自定义授权拦截器校验
 *
 * @author Chill
 */
@Slf4j
@AllArgsConstructor
public class AuthInterceptor extends HandlerInterceptorAdapter {

	/**
	 * 表达式处理
	 */
	private static final ExpressionParser EXPRESSION_PARSER = new SpelExpressionParser();
	private static final EvaluationContext EVALUATION_CONTEXT = new StandardEvaluationContext(new AuthFun());
	private static final AntPathMatcher ANT_PATH_MATCHER = new AntPathMatcher();

	/**
	 * 授权集合
	 */
	private final List<AuthSecure> authSecures;

	@Override
	public boolean preHandle(@NonNull HttpServletRequest request, @NonNull HttpServletResponse response, @NonNull Object handler) {
		boolean check = authSecures.stream().filter(authSecure -> checkAuth(request, authSecure)).findFirst().map(
			authSecure -> checkExpression(authSecure.getExpression())
		).orElse(Boolean.TRUE);
		if (!check) {
			log.warn("授权认证失败，请求接口：{}，请求IP：{}，请求参数：{}", request.getRequestURI(), WebUtil.getIP(request), JsonUtil.toJson(request.getParameterMap()));
			ResponseProvider.write(response);
			return false;
		}
		return true;
	}

	/**
	 * 检测授权
	 */
	private boolean checkAuth(HttpServletRequest request, AuthSecure authSecure) {
		return checkMethod(request, authSecure.getMethod()) && checkPath(request, authSecure.getPattern());
	}

	/**
	 * 检测请求方法
	 */
	private boolean checkMethod(HttpServletRequest request, HttpMethod method) {
		return method == HttpMethod.ALL || (
			method != null && method == HttpMethod.of(request.getMethod())
		);
	}

	/**
	 * 检测路径匹配
	 */
	private boolean checkPath(HttpServletRequest request, String pattern) {
		String servletPath = request.getServletPath();
		String pathInfo = request.getPathInfo();
		if (pathInfo != null && pathInfo.length() > 0) {
			servletPath = servletPath + pathInfo;
		}
		return ANT_PATH_MATCHER.match(pattern, servletPath);
	}

	/**
	 * 检测表达式
	 */
	private boolean checkExpression(String expression) {
		Boolean result = EXPRESSION_PARSER.parseExpression(expression).getValue(EVALUATION_CONTEXT, Boolean.class);
		return result != null ? result : false;
	}

}