/*
    * 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.shardingsphere.proxy.backend.handler.distsql.ral.updatable;
  
  import org.apache.shardingsphere.distsql.handler.engine.update.DistSQLUpdateExecutor;
  import org.apache.shardingsphere.distsql.handler.required.DistSQLExecutorClusterModeRequired;
  import org.apache.shardingsphere.distsql.statement.ral.updatable.UnlockClusterStatement;
  import org.apache.shardingsphere.infra.exception.core.ShardingSpherePreconditions;
  import org.apache.shardingsphere.infra.lock.GlobalLockNames;
  import org.apache.shardingsphere.infra.lock.LockContext;
  import org.apache.shardingsphere.infra.state.cluster.ClusterState;
  import org.apache.shardingsphere.mode.lock.GlobalLockDefinition;
  import org.apache.shardingsphere.mode.manager.ContextManager;
  import org.apache.shardingsphere.mode.manager.cluster.coordinator.registry.status.cluster.event.ClusterStatusChangedEvent;
  
  /**
   * Unlock cluster executor.
   */
  @DistSQLExecutorClusterModeRequired
  public final class UnlockClusterExecutor implements DistSQLUpdateExecutor<UnlockClusterStatement> {
      
      @Override
      @SuppressWarnings({"unchecked", "rawtypes"})
      public void executeUpdate(final UnlockClusterStatement sqlStatement, final ContextManager contextManager) {
          checkState(contextManager);
          LockContext lockContext = contextManager.getInstanceContext().getLockContext();
          GlobalLockDefinition lockDefinition = new GlobalLockDefinition(GlobalLockNames.CLUSTER_LOCK.getLockName());
          if (lockContext.tryLock(lockDefinition, 3000L)) {
              try {
                  checkState(contextManager);
                  contextManager.getInstanceContext().getEventBusContext().post(new ClusterStatusChangedEvent(ClusterState.OK));
                  // TODO unlock snapshot info if locked
              } finally {
                  lockContext.unlock(lockDefinition);
              }
          }
      }
      
      private void checkState(final ContextManager contextManager) {
          ShardingSpherePreconditions.checkState(ClusterState.OK != contextManager.getClusterStateContext().getCurrentState(), () -> new IllegalStateException("Cluster is not locked"));
      }
      
      @Override
      public Class<UnlockClusterStatement> getType() {
          return UnlockClusterStatement.class;
      }
  }