/*
 * Copyright (c) 2023 - present Dromara, All rights reserved.
 *
 *   https://visor.dromara.org
 *   https://visor.dromara.org.cn
 *   https://visor.orionsec.cn
 *
 * Members:
 *   Jiahang Li - ljh1553488six@139.com - author
 *
 * 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.dromara.visor.framework.security.core.context;

import cn.orionsec.kit.lang.utils.Valid;
import com.alibaba.ttl.TransmittableThreadLocal;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolderStrategy;
import org.springframework.security.core.context.SecurityContextImpl;

/**
 * 使用 TransmittableThreadLocal 实现 Security Context 持有者策略
 * 避免异步执行时 ThreadLocal 的丢失问题
 *
 * @author Jiahang Li
 * @version 1.0.0
 * @since 2023/7/6 15:55
 */
public class TransmittableThreadLocalSecurityContextHolderStrategy implements SecurityContextHolderStrategy {

    /**
     * 使用 TransmittableThreadLocal 作为上下文
     */
    private static final ThreadLocal<SecurityContext> CONTEXT_HOLDER = new TransmittableThreadLocal<>();

    @Override
    public void clearContext() {
        CONTEXT_HOLDER.remove();
    }

    @Override
    public SecurityContext getContext() {
        SecurityContext ctx = CONTEXT_HOLDER.get();
        if (ctx == null) {
            ctx = this.createEmptyContext();
            CONTEXT_HOLDER.set(ctx);
        }
        return ctx;
    }

    @Override
    public void setContext(SecurityContext context) {
        Valid.notNull(context, "only non-null SecurityContext instances are permitted");
        CONTEXT_HOLDER.set(context);
    }

    @Override
    public SecurityContext createEmptyContext() {
        return new SecurityContextImpl();
    }

}
