/*
 * Copyright 2008-2026 Async-IO.org
 *
 * 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.atmosphere.checkpoint.coordinator;

import org.atmosphere.coordinator.journal.CoordinationEvent;

/**
 * Common {@link CoordinationStateExtractor} implementations. These are useful
 * defaults; production workflows typically supply their own extractor that
 * captures the domain state at the checkpoint boundary.
 */
public final class CoordinationStateExtractors {

    private CoordinationStateExtractors() {}

    /** Stores the event itself as the snapshot state. */
    public static CoordinationStateExtractor<CoordinationEvent> event() {
        return event -> event;
    }

    /** Stores the event's {@link CoordinationEvent#toLogLine() log line}. */
    public static CoordinationStateExtractor<String> eventSummary() {
        return CoordinationEvent::toLogLine;
    }

    /** Stores only the result text of {@code AgentCompleted}, {@code null} for anything else. */
    public static CoordinationStateExtractor<String> agentResultText() {
        return event -> event instanceof CoordinationEvent.AgentCompleted c ? c.resultText() : null;
    }
}
