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 * 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.
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package org.apache.iotdb.confignode.procedure.impl.schema;

import org.apache.iotdb.common.rpc.thrift.TConsensusGroupId;
import org.apache.iotdb.common.rpc.thrift.TDataNodeLocation;
import org.apache.iotdb.common.rpc.thrift.TRegionReplicaSet;
import org.apache.iotdb.common.rpc.thrift.TSStatus;
import org.apache.iotdb.commons.exception.MetadataException;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.commons.path.PathPatternTree;
import org.apache.iotdb.confignode.client.async.CnToDnAsyncRequestType;
import org.apache.iotdb.confignode.client.async.CnToDnInternalServiceAsyncRequestManager;
import org.apache.iotdb.confignode.client.async.handlers.DataNodeAsyncRequestContext;
import org.apache.iotdb.confignode.consensus.request.write.pipe.payload.PipeDeleteLogicalViewPlan;
import org.apache.iotdb.confignode.consensus.request.write.pipe.payload.PipeEnrichedPlan;
import org.apache.iotdb.confignode.procedure.env.ConfigNodeProcedureEnv;
import org.apache.iotdb.confignode.procedure.exception.ProcedureException;
import org.apache.iotdb.confignode.procedure.impl.StateMachineProcedure;
import org.apache.iotdb.confignode.procedure.state.schema.DeleteLogicalViewState;
import org.apache.iotdb.confignode.procedure.store.ProcedureType;
import org.apache.iotdb.consensus.exception.ConsensusException;
import org.apache.iotdb.db.exception.metadata.view.ViewNotExistException;
import org.apache.iotdb.mpp.rpc.thrift.TConstructViewSchemaBlackListReq;
import org.apache.iotdb.mpp.rpc.thrift.TDeleteViewSchemaReq;
import org.apache.iotdb.mpp.rpc.thrift.TInvalidateMatchedSchemaCacheReq;
import org.apache.iotdb.mpp.rpc.thrift.TRollbackViewSchemaBlackListReq;
import org.apache.iotdb.pipe.api.exception.PipeException;
import org.apache.iotdb.rpc.TSStatusCode;

import org.apache.tsfile.utils.ReadWriteIOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.BiFunction;
import java.util.stream.Collectors;

public class DeleteLogicalViewProcedure
    extends StateMachineProcedure<ConfigNodeProcedureEnv, DeleteLogicalViewState> {

  private static final Logger LOGGER = LoggerFactory.getLogger(DeleteLogicalViewProcedure.class);

  private String queryId;

  private PathPatternTree patternTree;
  private transient ByteBuffer patternTreeBytes;

  private transient String requestMessage;

  private static final String CONSENSUS_WRITE_ERROR =
      "Failed in the write API executing the consensus layer due to: ";

  public DeleteLogicalViewProcedure(final boolean isGeneratedByPipe) {
    super(isGeneratedByPipe);
  }

  public DeleteLogicalViewProcedure(
      final String queryId, final PathPatternTree patternTree, final boolean isGeneratedByPipe) {
    super(isGeneratedByPipe);
    this.queryId = queryId;
    setPatternTree(patternTree);
  }

  @Override
  protected Flow executeFromState(
      final ConfigNodeProcedureEnv env, final DeleteLogicalViewState state)
      throws InterruptedException {
    long startTime = System.currentTimeMillis();
    try {
      switch (state) {
        case CONSTRUCT_BLACK_LIST:
          LOGGER.info("Construct view schemaengine black list of view {}", requestMessage);
          if (constructBlackList(env) > 0) {
            setNextState(DeleteLogicalViewState.CLEAN_DATANODE_SCHEMA_CACHE);
            break;
          } else {
            setFailure(
                new ProcedureException(
                    new ViewNotExistException(
                        patternTree.getAllPathPatterns().stream()
                            .map(PartialPath::getFullPath)
                            .collect(Collectors.toList()))));
            return Flow.NO_MORE_STATE;
          }
        case CLEAN_DATANODE_SCHEMA_CACHE:
          LOGGER.info("Invalidate cache of view {}", requestMessage);
          invalidateCache(env);
          break;
        case DELETE_VIEW_SCHEMA:
          LOGGER.info("Delete view schemaengine of {}", requestMessage);
          deleteViewSchema(env);
          collectPayload4Pipe(env);
          return Flow.NO_MORE_STATE;
        default:
          setFailure(new ProcedureException("Unrecognized state " + state));
          return Flow.NO_MORE_STATE;
      }
      return Flow.HAS_MORE_STATE;
    } finally {
      LOGGER.info(
          "DeleteLogicalView-[{}] costs {}ms", state, (System.currentTimeMillis() - startTime));
    }
  }

  // return the total num of timeseries in schemaengine black list
  private long constructBlackList(ConfigNodeProcedureEnv env) {
    final Map<TConsensusGroupId, TRegionReplicaSet> targetSchemaRegionGroup =
        env.getConfigManager().getRelatedSchemaRegionGroup(patternTree);
    if (targetSchemaRegionGroup.isEmpty()) {
      return 0;
    }
    List<TSStatus> successResult = new ArrayList<>();
    DeleteLogicalViewRegionTaskExecutor<TConstructViewSchemaBlackListReq> constructBlackListTask =
        new DeleteLogicalViewRegionTaskExecutor<TConstructViewSchemaBlackListReq>(
            "construct view schema engine black list",
            env,
            targetSchemaRegionGroup,
            CnToDnAsyncRequestType.CONSTRUCT_VIEW_SCHEMA_BLACK_LIST,
            ((dataNodeLocation, consensusGroupIdList) ->
                new TConstructViewSchemaBlackListReq(consensusGroupIdList, patternTreeBytes))) {
          @Override
          protected List<TConsensusGroupId> processResponseOfOneDataNode(
              TDataNodeLocation dataNodeLocation,
              List<TConsensusGroupId> consensusGroupIdList,
              TSStatus response) {
            List<TConsensusGroupId> failedRegionList = new ArrayList<>();
            if (response.getCode() == TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
              successResult.add(response);
            } else if (response.getCode() == TSStatusCode.MULTIPLE_ERROR.getStatusCode()) {
              List<TSStatus> subStatusList = response.getSubStatus();
              for (int i = 0; i < subStatusList.size(); i++) {
                if (subStatusList.get(i).getCode() == TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
                  successResult.add(subStatusList.get(i));
                } else {
                  failedRegionList.add(consensusGroupIdList.get(i));
                }
              }
            } else {
              failedRegionList.addAll(consensusGroupIdList);
            }
            return failedRegionList;
          }
        };
    constructBlackListTask.execute();

    if (isFailed()) {
      return 0;
    }

    return successResult.stream()
        .mapToLong(resp -> Long.parseLong(resp.getMessage()))
        .reduce(0L, Long::sum);
  }

  private void invalidateCache(final ConfigNodeProcedureEnv env) {
    final Map<Integer, TDataNodeLocation> dataNodeLocationMap =
        env.getConfigManager().getNodeManager().getRegisteredDataNodeLocations();
    final DataNodeAsyncRequestContext<TInvalidateMatchedSchemaCacheReq, TSStatus> clientHandler =
        new DataNodeAsyncRequestContext<>(
            CnToDnAsyncRequestType.INVALIDATE_MATCHED_SCHEMA_CACHE,
            new TInvalidateMatchedSchemaCacheReq(patternTreeBytes),
            dataNodeLocationMap);
    CnToDnInternalServiceAsyncRequestManager.getInstance().sendAsyncRequestWithRetry(clientHandler);
    final Map<Integer, TSStatus> statusMap = clientHandler.getResponseMap();
    for (final TSStatus status : statusMap.values()) {
      // all dataNodes must clear the related schemaengine cache
      if (status.getCode() != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
        LOGGER.error("Failed to invalidate schemaengine cache of view {}", requestMessage);
        setFailure(
            new ProcedureException(
                new MetadataException("Invalidate view schemaengine cache failed")));
        return;
      }
    }

    setNextState(DeleteLogicalViewState.DELETE_VIEW_SCHEMA);
  }

  private void deleteViewSchema(final ConfigNodeProcedureEnv env) {
    final DeleteLogicalViewRegionTaskExecutor<TDeleteViewSchemaReq> deleteTimeSeriesTask =
        new DeleteLogicalViewRegionTaskExecutor<>(
            "delete view in schema engine",
            env,
            env.getConfigManager().getRelatedSchemaRegionGroup(patternTree),
            CnToDnAsyncRequestType.DELETE_VIEW,
            ((dataNodeLocation, consensusGroupIdList) ->
                new TDeleteViewSchemaReq(consensusGroupIdList, patternTreeBytes)
                    .setIsGeneratedByPipe(isGeneratedByPipe)));
    deleteTimeSeriesTask.execute();
  }

  private void collectPayload4Pipe(final ConfigNodeProcedureEnv env) {
    TSStatus result;
    try {
      result =
          env.getConfigManager()
              .getConsensusManager()
              .write(
                  isGeneratedByPipe
                      ? new PipeEnrichedPlan(new PipeDeleteLogicalViewPlan(patternTreeBytes))
                      : new PipeDeleteLogicalViewPlan(patternTreeBytes));
    } catch (final ConsensusException e) {
      LOGGER.warn(CONSENSUS_WRITE_ERROR, e);
      result = new TSStatus(TSStatusCode.EXECUTE_STATEMENT_ERROR.getStatusCode());
      result.setMessage(e.getMessage());
    }
    if (result.getCode() != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
      throw new PipeException(result.getMessage());
    }
  }

  @Override
  protected void rollbackState(
      final ConfigNodeProcedureEnv env, final DeleteLogicalViewState deleteLogicalViewState)
      throws IOException, InterruptedException, ProcedureException {
    DeleteLogicalViewRegionTaskExecutor<TRollbackViewSchemaBlackListReq> rollbackStateTask =
        new DeleteLogicalViewRegionTaskExecutor<>(
            "roll back view schema engine black list",
            env,
            env.getConfigManager().getRelatedSchemaRegionGroup(patternTree),
            CnToDnAsyncRequestType.ROLLBACK_VIEW_SCHEMA_BLACK_LIST,
            (dataNodeLocation, consensusGroupIdList) ->
                new TRollbackViewSchemaBlackListReq(consensusGroupIdList, patternTreeBytes));
    rollbackStateTask.execute();
  }

  @Override
  protected boolean isRollbackSupported(final DeleteLogicalViewState deleteLogicalViewState) {
    return true;
  }

  @Override
  protected DeleteLogicalViewState getState(final int stateId) {
    return DeleteLogicalViewState.values()[stateId];
  }

  @Override
  protected int getStateId(final DeleteLogicalViewState deleteLogicalViewState) {
    return deleteLogicalViewState.ordinal();
  }

  @Override
  protected DeleteLogicalViewState getInitialState() {
    return DeleteLogicalViewState.CONSTRUCT_BLACK_LIST;
  }

  public String getQueryId() {
    return queryId;
  }

  public PathPatternTree getPatternTree() {
    return patternTree;
  }

  public void setPatternTree(final PathPatternTree patternTree) {
    this.patternTree = patternTree;
    requestMessage = patternTree.getAllPathPatterns().toString();
    patternTreeBytes = preparePatternTreeBytesData(patternTree);
  }

  private ByteBuffer preparePatternTreeBytesData(final PathPatternTree patternTree) {
    final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    final DataOutputStream dataOutputStream = new DataOutputStream(byteArrayOutputStream);
    try {
      patternTree.serialize(dataOutputStream);
    } catch (final IOException ignored) {
      // DataOutputStream won't throw IOException
    }
    return ByteBuffer.wrap(byteArrayOutputStream.toByteArray());
  }

  @Override
  public void serialize(final DataOutputStream stream) throws IOException {
    stream.writeShort(
        isGeneratedByPipe
            ? ProcedureType.PIPE_ENRICHED_DELETE_LOGICAL_VIEW_PROCEDURE.getTypeCode()
            : ProcedureType.DELETE_LOGICAL_VIEW_PROCEDURE.getTypeCode());
    super.serialize(stream);
    ReadWriteIOUtils.write(queryId, stream);
    patternTree.serialize(stream);
  }

  @Override
  public void deserialize(final ByteBuffer byteBuffer) {
    super.deserialize(byteBuffer);
    queryId = ReadWriteIOUtils.readString(byteBuffer);
    setPatternTree(PathPatternTree.deserialize(byteBuffer));
  }

  @Override
  public boolean equals(final Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    final DeleteLogicalViewProcedure that = (DeleteLogicalViewProcedure) o;
    return this.getProcId() == that.getProcId()
        && this.getCurrentState().equals(that.getCurrentState())
        && this.getCycles() == that.getCycles()
        && isGeneratedByPipe == that.isGeneratedByPipe
        && patternTree.equals(that.patternTree);
  }

  @Override
  public int hashCode() {
    return Objects.hash(
        getProcId(), getCurrentState(), getCycles(), isGeneratedByPipe, patternTree);
  }

  private class DeleteLogicalViewRegionTaskExecutor<Q> extends DataNodeTSStatusTaskExecutor<Q> {

    private final String taskName;

    DeleteLogicalViewRegionTaskExecutor(
        final String taskName,
        final ConfigNodeProcedureEnv env,
        final Map<TConsensusGroupId, TRegionReplicaSet> targetSchemaRegionGroup,
        final CnToDnAsyncRequestType dataNodeRequestType,
        final BiFunction<TDataNodeLocation, List<TConsensusGroupId>, Q> dataNodeRequestGenerator) {
      super(env, targetSchemaRegionGroup, false, dataNodeRequestType, dataNodeRequestGenerator);
      this.taskName = taskName;
    }

    @Override
    protected void onAllReplicasetFailure(
        final TConsensusGroupId consensusGroupId,
        final Set<TDataNodeLocation> dataNodeLocationSet) {
      setFailure(
          new ProcedureException(
              new MetadataException(
                  String.format(
                      "Delete view %s failed when [%s] because failed to execute in all replicaset of schemaRegion %s. Failure nodes: %s",
                      requestMessage, taskName, consensusGroupId.id, dataNodeLocationSet))));
      interruptTask();
    }
  }
}
