content: /*
   * Copyright 2024-2025 the original author or authors.
   *
   * 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
   *
   *      https://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 com.alibaba.cloud.ai.graph.checkpoint;
  
  import com.alibaba.cloud.ai.graph.KeyStrategy;
  import com.alibaba.cloud.ai.graph.OverAllState;
  import com.fasterxml.jackson.annotation.JsonCreator;
  import com.fasterxml.jackson.annotation.JsonProperty;
  
  import java.util.Map;
  import java.util.UUID;
  
  import static java.lang.String.format;
  import static java.util.Objects.requireNonNull;
  
  public class Checkpoint {
  
  	private final String id;
  
  	private Map<String, Object> state = null;
  
  	private String nodeId = null;
  
  	private String nextNodeId = null;
  
  	public String getId() {
  		return id;
  	}
  
  	public Map<String, Object> getState() {
  		return state;
  	}
  
  	public String getNodeId() {
  		return nodeId;
  	}
  
  	public String getNextNodeId() {
  		return nextNodeId;
  	}
  
  	/**
  	 * create a copy of given checkpoint with a new id
  	 * @param checkpoint value from which copy is created
  	 * @return new copy with different id
  	 */
  	public static Checkpoint copyOf(Checkpoint checkpoint) {
  		requireNonNull(checkpoint, "checkpoint cannot be null");
  		return new Checkpoint(UUID.randomUUID().toString(), checkpoint.state, checkpoint.nodeId, checkpoint.nextNodeId);
  	}
  
  	@JsonCreator
  	private Checkpoint(@JsonProperty("id") String id, @JsonProperty("state") Map<String, Object> state,
  			@JsonProperty("nodeId") String nodeId, @JsonProperty("nextNodeId") String nextNodeId) {
  
  		this.id = requireNonNull(id, "id cannot be null");
  		this.state = requireNonNull(state, "state cannot be null");
  		this.nodeId = requireNonNull(nodeId, "nodeId cannot be null");
  		this.nextNodeId = requireNonNull(nextNodeId, "Checkpoint.nextNodeId cannot be null");
  
  	}
  
  	public static Builder builder() {
  		return new Builder();
  	}
  
  	public static class Builder {
  
  		private String id = UUID.randomUUID().toString();
  
  		private Map<String, Object> state = null;
  
  		private String nodeId = null;
  
  		private String nextNodeId = null;
  
  		public Builder id(String id) {
  			this.id = id;
  			return this;
  		}
  
  		public Builder state(OverAllState state) {
  			this.state = state.data();
  			return this;
  		}
  
  		public Builder state(Map<String, Object> state) {
  			this.state = state;
  			return this;
  		}
  
  		public Builder nodeId(String nodeId) {
  			this.nodeId = nodeId;
  			return this;
  		}
  
  		public Builder nextNodeId(String nextNodeId) {
  			this.nextNodeId = nextNodeId;
  			return this;
  		}
  
  		public Checkpoint build() {
  			return new Checkpoint(id, state, nodeId, nextNodeId);
  		}
  
  	}
  
  	public Checkpoint updateState(Map<String, Object> values, Map<String, KeyStrategy> channels) {
  
  		return new Checkpoint(this.id, OverAllState.updateState(this.state, values, channels), this.nodeId,
  				this.nextNodeId);
  	}
  
  	@Override
  	public String toString() {
  		return format("Checkpoint{ id=%s, nodeId=%s, nextNodeId=%s, state=%s }", id, nodeId, nextNodeId, state);
  	}
  
  }
  