/*
 * 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.hbase.master.procedure;

import java.io.IOException;
import java.util.Objects;
import org.apache.hadoop.hbase.NamespaceDescriptor;
import org.apache.hadoop.hbase.NamespaceNotFoundException;
import org.apache.hadoop.hbase.procedure2.ProcedureStateSerializer;
import org.apache.hadoop.hbase.rsgroup.RSGroupInfo;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos;
import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.ModifyNamespaceState;

/**
 * The procedure to add a namespace to an existing table.
 */
@InterfaceAudience.Private
public class ModifyNamespaceProcedure
  extends AbstractStateMachineNamespaceProcedure<ModifyNamespaceState> {
  private static final Logger LOG = LoggerFactory.getLogger(ModifyNamespaceProcedure.class);

  private NamespaceDescriptor oldNsDescriptor;
  private NamespaceDescriptor newNsDescriptor;

  public ModifyNamespaceProcedure() {
    this.oldNsDescriptor = null;
  }

  public ModifyNamespaceProcedure(final MasterProcedureEnv env,
    final NamespaceDescriptor newNsDescriptor) {
    this(env, newNsDescriptor, null);
  }

  public ModifyNamespaceProcedure(final MasterProcedureEnv env,
    final NamespaceDescriptor newNsDescriptor, final ProcedurePrepareLatch latch) {
    super(env, latch);
    this.oldNsDescriptor = null;
    this.newNsDescriptor = newNsDescriptor;
  }

  @Override
  protected Flow executeFromState(final MasterProcedureEnv env, final ModifyNamespaceState state)
    throws InterruptedException {
    LOG.trace("{} execute state={}", this, state);
    try {
      switch (state) {
        case MODIFY_NAMESPACE_PREPARE:
          boolean success = prepareModify(env);
          releaseSyncLatch();
          if (!success) {
            assert isFailed() : "Modify namespace should have an exception here";
            return Flow.NO_MORE_STATE;
          }
          setNextState(ModifyNamespaceState.MODIFY_NAMESPACE_UPDATE_NS_TABLE);
          break;
        case MODIFY_NAMESPACE_UPDATE_NS_TABLE:
          addOrUpdateNamespace(env, newNsDescriptor);
          return Flow.NO_MORE_STATE;
        case MODIFY_NAMESPACE_UPDATE_ZK:
          // not used any more
          return Flow.NO_MORE_STATE;
        default:
          throw new UnsupportedOperationException(this + " unhandled state=" + state);
      }
    } catch (IOException e) {
      if (isRollbackSupported(state)) {
        setFailure("master-modify-namespace", e);
      } else {
        LOG.warn("Retriable error trying to modify namespace=" + newNsDescriptor.getName()
          + " (in state=" + state + ")", e);
      }
    }
    return Flow.HAS_MORE_STATE;
  }

  @Override
  protected void rollbackState(final MasterProcedureEnv env, final ModifyNamespaceState state)
    throws IOException {
    if (state == ModifyNamespaceState.MODIFY_NAMESPACE_PREPARE) {
      // nothing to rollback, pre-modify is just checks.
      // TODO: coprocessor rollback semantic is still undefined.
      releaseSyncLatch();
      return;
    }

    // The procedure doesn't have a rollback. The execution will succeed, at some point.
    throw new UnsupportedOperationException("unhandled state=" + state);
  }

  @Override
  protected boolean isRollbackSupported(ModifyNamespaceState state) {
    switch (state) {
      case MODIFY_NAMESPACE_PREPARE:
        return true;
      default:
        return false;
    }
  }

  @Override
  protected ModifyNamespaceState getState(int stateId) {
    return ModifyNamespaceState.forNumber(stateId);
  }

  @Override
  protected int getStateId(ModifyNamespaceState state) {
    return state.getNumber();
  }

  @Override
  protected ModifyNamespaceState getInitialState() {
    return ModifyNamespaceState.MODIFY_NAMESPACE_PREPARE;
  }

  @Override
  protected void serializeStateData(ProcedureStateSerializer serializer) throws IOException {
    super.serializeStateData(serializer);

    MasterProcedureProtos.ModifyNamespaceStateData.Builder modifyNamespaceMsg =
      MasterProcedureProtos.ModifyNamespaceStateData.newBuilder()
        .setNamespaceDescriptor(ProtobufUtil.toProtoNamespaceDescriptor(this.newNsDescriptor));
    if (this.oldNsDescriptor != null) {
      modifyNamespaceMsg.setUnmodifiedNamespaceDescriptor(
        ProtobufUtil.toProtoNamespaceDescriptor(this.oldNsDescriptor));
    }
    serializer.serialize(modifyNamespaceMsg.build());
  }

  @Override
  protected void deserializeStateData(ProcedureStateSerializer serializer) throws IOException {
    super.deserializeStateData(serializer);

    MasterProcedureProtos.ModifyNamespaceStateData modifyNamespaceMsg =
      serializer.deserialize(MasterProcedureProtos.ModifyNamespaceStateData.class);
    newNsDescriptor =
      ProtobufUtil.toNamespaceDescriptor(modifyNamespaceMsg.getNamespaceDescriptor());
    if (modifyNamespaceMsg.hasUnmodifiedNamespaceDescriptor()) {
      oldNsDescriptor =
        ProtobufUtil.toNamespaceDescriptor(modifyNamespaceMsg.getUnmodifiedNamespaceDescriptor());
    }
  }

  @Override
  public TableOperationType getTableOperationType() {
    return TableOperationType.EDIT;
  }

  @Override
  protected String getNamespaceName() {
    return newNsDescriptor.getName();
  }

  /**
   * Action before any real action of adding namespace.
   */
  private boolean prepareModify(final MasterProcedureEnv env) throws IOException {
    if (!getTableNamespaceManager(env).doesNamespaceExist(newNsDescriptor.getName())) {
      setFailure("master-modify-namespace",
        new NamespaceNotFoundException(newNsDescriptor.getName()));
      return false;
    }
    getTableNamespaceManager(env).validateTableAndRegionCount(newNsDescriptor);

    // This is used for rollback
    oldNsDescriptor = getTableNamespaceManager(env).get(newNsDescriptor.getName());
    if (
      !Objects.equals(oldNsDescriptor.getConfigurationValue(RSGroupInfo.NAMESPACE_DESC_PROP_GROUP),
        newNsDescriptor.getConfigurationValue(RSGroupInfo.NAMESPACE_DESC_PROP_GROUP))
    ) {
      checkNamespaceRSGroup(env, newNsDescriptor);
    }
    return true;
  }
}