/**
 * Copyright (c) 2025-2026, Michael Yang 杨福海 (fuhai999@gmail.com).
 * <p>
 * Licensed under the GNU Lesser General Public License (LGPL) ,Version 3.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.gnu.org/licenses/lgpl-3.0.txt
 * <p>
 * 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 com.easyagents.flow.core.chain.repository;

import com.easyagents.flow.core.chain.NodeState;

import java.util.EnumSet;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * 进程内节点状态仓储。
 */
public class InMemoryNodeStateRepository implements NodeStateRepository {

    private static final Map<String, NodeState> chainStateMap = new ConcurrentHashMap<>();

    /**
     * {@inheritDoc}
     */
    @Override
    public NodeState load(String instanceId, String nodeId) {
        // 保留进程内仓储原有的惰性初始化语义，避免改变既有直接读取行为。
        return create(instanceId, nodeId, 0L);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public NodeState create(String instanceId, String nodeId, long chainStateVersion) {
        return chainStateMap.computeIfAbsent(key(instanceId, nodeId), ignored -> {
            NodeState nodeState = new NodeState();
            nodeState.setChainInstanceId(instanceId);
            nodeState.setNodeId(nodeId);
            return nodeState;
        });
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean tryUpdate(NodeState newState, EnumSet<NodeStateField> fields, long version) {
        chainStateMap.put(key(newState.getChainInstanceId(), newState.getNodeId()), newState);
        return true;
    }

    /**
     * 构建进程内节点状态键。
     *
     * @param instanceId 工作流实例 ID
     * @param nodeId 节点 ID
     * @return 节点状态键
     */
    private String key(String instanceId, String nodeId) {
        return instanceId + "." + nodeId;
    }
}
