/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.hadoop.hdds.scm.safemode;

import org.apache.hadoop.hdds.scm.events.SCMEvents;
import org.apache.hadoop.hdds.scm.ha.SCMStateMachine;
import org.apache.hadoop.hdds.server.events.EventQueue;
import org.apache.hadoop.hdds.server.events.TypedEvent;

/**
 * Class defining Safe mode exit when SCM State Machine is ready, ie all transaction is applied.
 */
public class StateMachineReadyRule extends SafeModeExitRule<Boolean> {
  private SCMStateMachine scmStateMachine = null;

  public StateMachineReadyRule(EventQueue eventQueue, SCMSafeModeManager manager, SCMStateMachine scmStateMachine) {
    super(manager, eventQueue);
    this.scmStateMachine = scmStateMachine;
  }

  @Override
  protected TypedEvent<Boolean> getEventType() {
    return SCMEvents.STATEMACHINE_READY;
  }

  @Override
  protected boolean validate() {
    if (null != scmStateMachine) {
      return scmStateMachine.getIsStateMachineReady();
    }
    // if no HA, always return true.
    return true;
  }

  @Override
  protected void process(Boolean ignored) {
  }

  @Override
  protected void cleanup() {
  }

  @Override
  public String getStatusText() {
    return String.format("Refreshed SCM State Machine after leader ready: %s",
        scmStateMachine != null ? scmStateMachine.getIsStateMachineReady() : "NA");
  }

  @Override
  public void refresh(boolean forceRefresh) {
    // Do nothing.
  }
}
