/*
 * 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.geode.internal.cache.tier.sockets.command;

import static org.apache.geode.internal.cache.execute.ServerFunctionExecutor.DEFAULT_CLIENT_FUNCTION_TIMEOUT;

import java.io.IOException;
import java.util.HashSet;
import java.util.NoSuchElementException;
import java.util.Set;

import org.apache.geode.annotations.Immutable;
import org.apache.geode.cache.Region;
import org.apache.geode.cache.execute.Function;
import org.apache.geode.cache.execute.FunctionException;
import org.apache.geode.cache.execute.FunctionInvocationTargetException;
import org.apache.geode.cache.execute.FunctionService;
import org.apache.geode.cache.operations.ExecuteFunctionOperationContext;
import org.apache.geode.internal.cache.PartitionedRegion;
import org.apache.geode.internal.cache.execute.AbstractExecution;
import org.apache.geode.internal.cache.execute.InternalFunctionInvocationTargetException;
import org.apache.geode.internal.cache.execute.MemberMappedArgument;
import org.apache.geode.internal.cache.execute.PartitionedRegionFunctionExecutor;
import org.apache.geode.internal.cache.execute.ServerToClientFunctionResultSender;
import org.apache.geode.internal.cache.execute.ServerToClientFunctionResultSender65;
import org.apache.geode.internal.cache.tier.CachedRegionHelper;
import org.apache.geode.internal.cache.tier.Command;
import org.apache.geode.internal.cache.tier.MessageType;
import org.apache.geode.internal.cache.tier.ServerSideHandshake;
import org.apache.geode.internal.cache.tier.sockets.BaseCommand;
import org.apache.geode.internal.cache.tier.sockets.ChunkedMessage;
import org.apache.geode.internal.cache.tier.sockets.Message;
import org.apache.geode.internal.cache.tier.sockets.Part;
import org.apache.geode.internal.cache.tier.sockets.ServerConnection;
import org.apache.geode.internal.security.AuthorizeRequest;
import org.apache.geode.internal.security.SecurityService;
import org.apache.geode.internal.serialization.Version;

/**
 * @since GemFire 6.5
 */
public class ExecuteRegionFunctionSingleHop extends BaseCommand {

  @Immutable
  private static final ExecuteRegionFunctionSingleHop singleton =
      new ExecuteRegionFunctionSingleHop();

  public static Command getCommand() {
    return singleton;
  }

  private ExecuteRegionFunctionSingleHop() {}

  @Override
  public void cmdExecute(final Message clientMessage, final ServerConnection serverConnection,
      final SecurityService securityService, long start) throws IOException {

    String regionName = null;
    Object function = null;
    Object args = null;
    MemberMappedArgument memberMappedArg = null;
    byte isExecuteOnAllBuckets = 0;
    Set<Object> filter = null;
    Set<Integer> buckets = null;
    byte hasResult = 0;
    byte functionState = 0;
    int removedNodesSize = 0;
    Set<Object> removedNodesSet = null;
    int filterSize = 0, bucketIdsSize = 0, partNumber = 0;
    CachedRegionHelper crHelper = serverConnection.getCachedRegionHelper();
    int functionTimeout = DEFAULT_CLIENT_FUNCTION_TIMEOUT;
    try {
      byte[] bytes = clientMessage.getPart(0).getSerializedForm();
      functionState = bytes[0];
      if (bytes.length >= 5
          && serverConnection.getClientVersion().ordinal() >= Version.GFE_8009.ordinal()) {
        functionTimeout = Part.decodeInt(bytes, 1);
      }
      if (functionState != 1) {
        hasResult = (byte) ((functionState & 2) - 1);
      } else {
        hasResult = functionState;
      }
      if (hasResult == 1) {
        serverConnection.setAsTrue(REQUIRES_RESPONSE);
        serverConnection.setAsTrue(REQUIRES_CHUNKED_RESPONSE);
      }
      regionName = clientMessage.getPart(1).getCachedString();
      function = clientMessage.getPart(2).getStringOrObject();
      args = clientMessage.getPart(3).getObject();
      Part part = clientMessage.getPart(4);
      if (part != null) {
        Object obj = part.getObject();
        if (obj instanceof MemberMappedArgument) {
          memberMappedArg = (MemberMappedArgument) obj;
        }
      }
      isExecuteOnAllBuckets = clientMessage.getPart(5).getSerializedForm()[0];
      if (isExecuteOnAllBuckets == 1) {
        filter = new HashSet();
        bucketIdsSize = clientMessage.getPart(6).getInt();
        if (bucketIdsSize != 0) {
          buckets = new HashSet<Integer>();
          partNumber = 7;
          for (int i = 0; i < bucketIdsSize; i++) {
            buckets.add(clientMessage.getPart(partNumber + i).getInt());
          }
        }
        partNumber = 7 + bucketIdsSize;
      } else {
        filterSize = clientMessage.getPart(6).getInt();
        if (filterSize != 0) {
          filter = new HashSet<Object>();
          partNumber = 7;
          for (int i = 0; i < filterSize; i++) {
            filter.add(clientMessage.getPart(partNumber + i).getStringOrObject());
          }
        }
        partNumber = 7 + filterSize;
      }


      removedNodesSize = clientMessage.getPart(partNumber).getInt();

      if (removedNodesSize != 0) {
        removedNodesSet = new HashSet<Object>();
        partNumber = partNumber + 1;

        for (int i = 0; i < removedNodesSize; i++) {
          removedNodesSet.add(clientMessage.getPart(partNumber + i).getStringOrObject());
        }
      }

    } catch (ClassNotFoundException exception) {
      logger.warn(String.format("Exception on server while executing function : %s",
          function),
          exception);
      if (hasResult == 1) {
        writeChunkedException(clientMessage, exception, serverConnection);
        serverConnection.setAsTrue(RESPONDED);
        return;
      }
    }
    if (function == null || regionName == null) {
      String message = null;
      if (function == null) {
        message =
            String.format("The input %s for the execute function request is null",
                "function");
      }
      if (regionName == null) {
        message =
            String.format("The input %s for the execute function request is null",
                "region");
      }
      logger.warn("{}: {}", serverConnection.getName(), message);
      sendError(hasResult, clientMessage, message, serverConnection);
      return;
    }

    Region region = crHelper.getRegion(regionName);
    if (region == null) {
      String message =
          String.format("The region named %s was not found during execute Function request.",
              regionName);
      logger.warn("{}: {}", serverConnection.getName(), message);
      sendError(hasResult, clientMessage, message, serverConnection);
      return;
    }
    ServerSideHandshake handshake = serverConnection.getHandshake();
    int earlierClientReadTimeout = handshake.getClientReadTimeout();
    handshake.setClientReadTimeout(functionTimeout);
    ServerToClientFunctionResultSender resultSender = null;
    Function<?> functionObject = null;
    try {
      if (function instanceof String) {
        functionObject = FunctionService.getFunction((String) function);
        if (functionObject == null) {
          String message =
              String.format("The function, %s, has not been registered",
                  function);
          logger.warn("{}: {}", serverConnection.getName(), message);
          sendError(hasResult, clientMessage, message, serverConnection);
          return;
        } else {
          byte functionStateOnServer = AbstractExecution.getFunctionState(functionObject.isHA(),
              functionObject.hasResult(), functionObject.optimizeForWrite());
          if (functionStateOnServer != functionState) {
            String message =
                String.format("Function attributes at client and server don't match: %s",
                    function);
            logger.warn("{}: {}", serverConnection.getName(), message);
            sendError(hasResult, clientMessage, message, serverConnection);
            return;
          }
        }
      } else {
        functionObject = (Function) function;
      }

      // check if the caller is authorized to do this operation on server
      functionObject.getRequiredPermissions(regionName, args).forEach(securityService::authorize);
      AuthorizeRequest authzRequest = serverConnection.getAuthzRequest();
      final String functionName = functionObject.getId();
      final String regionPath = region.getFullPath();
      ExecuteFunctionOperationContext executeContext = null;
      if (authzRequest != null) {
        executeContext = authzRequest.executeFunctionAuthorize(functionName, regionPath, filter,
            args, functionObject.optimizeForWrite());
      }

      // Construct execution
      AbstractExecution execution = (AbstractExecution) FunctionService.onRegion(region);
      ChunkedMessage m = serverConnection.getFunctionResponseMessage();
      m.setTransactionId(clientMessage.getTransactionId());
      resultSender =
          new ServerToClientFunctionResultSender65(m, MessageType.EXECUTE_REGION_FUNCTION_RESULT,
              serverConnection, functionObject, executeContext);

      if (isExecuteOnAllBuckets == 1) {
        PartitionedRegion pr = (PartitionedRegion) region;
        Set<Integer> actualBucketSet = pr.getRegionAdvisor().getBucketSet();
        try {
          buckets.retainAll(actualBucketSet);
        } catch (NoSuchElementException done) {
        }
        if (buckets.isEmpty()) {
          throw new FunctionException("Buckets are null");
        }
        execution = new PartitionedRegionFunctionExecutor((PartitionedRegion) region, buckets, args,
            memberMappedArg, resultSender, removedNodesSet, true, true);
      } else {
        execution = new PartitionedRegionFunctionExecutor((PartitionedRegion) region, filter, args,
            memberMappedArg, resultSender, removedNodesSet, false, true);
      }

      if ((hasResult == 1) && filter != null && filter.size() == 1) {
        ServerConnection.executeFunctionOnLocalNodeOnly((byte) 1);
      }

      if (logger.isDebugEnabled()) {
        logger.debug("Executing Function: {} on Server: {} with Execution: {}",
            functionObject.getId(), serverConnection, execution);
      }
      if (hasResult == 1) {
        if (function instanceof String) {
          switch (functionState) {
            case AbstractExecution.NO_HA_HASRESULT_NO_OPTIMIZEFORWRITE:
              execution.execute((String) function).getResult();
              break;
            case AbstractExecution.HA_HASRESULT_NO_OPTIMIZEFORWRITE:
              execution.execute((String) function).getResult();
              break;
            case AbstractExecution.HA_HASRESULT_OPTIMIZEFORWRITE:
              execution.execute((String) function).getResult();
              break;
            case AbstractExecution.NO_HA_HASRESULT_OPTIMIZEFORWRITE:
              execution.execute((String) function).getResult();
              break;
          }
        } else {
          execution.execute(functionObject).getResult();
        }
      } else {
        if (function instanceof String) {
          switch (functionState) {
            case AbstractExecution.NO_HA_NO_HASRESULT_NO_OPTIMIZEFORWRITE:
              execution.execute((String) function);
              break;
            case AbstractExecution.NO_HA_NO_HASRESULT_OPTIMIZEFORWRITE:
              execution.execute((String) function);
              break;
          }
        } else {
          execution.execute(functionObject);
        }
      }
    } catch (IOException ioe) {
      logger.warn(String.format("Exception on server while executing function : %s",
          function),
          ioe);
      final String message = "Server could not send the reply";
      sendException(hasResult, clientMessage, message, serverConnection, ioe);
    } catch (FunctionException fe) {
      String message = fe.getMessage();

      if (fe.getCause() instanceof FunctionInvocationTargetException) {
        if (functionObject.isHA() && logger.isDebugEnabled()) {
          logger.debug("Exception on server while executing function: {}: {}", function, message);
        } else if (logger.isDebugEnabled()) {
          logger.debug("Exception on server while executing function: {}: {}", function, message,
              fe);
        }
        synchronized (clientMessage) {
          resultSender.setException(fe);
        }
      } else {
        if (logger.isDebugEnabled()) {
          logger.debug(String.format("Exception on server while executing function : %s",
              function),
              fe);
        }
        sendException(hasResult, clientMessage, message, serverConnection, fe);
      }
    } catch (Exception e) {
      logger.warn(String.format("Exception on server while executing function : %s",
          function),
          e);
      String message = e.getMessage();
      sendException(hasResult, clientMessage, message, serverConnection, e);
    } finally {
      handshake.setClientReadTimeout(earlierClientReadTimeout);
      ServerConnection.executeFunctionOnLocalNodeOnly((byte) 0);
    }
  }

  private void sendException(byte hasResult, Message msg, String message,
      ServerConnection serverConnection, Throwable e) throws IOException {
    synchronized (msg) {
      if (hasResult == 1) {
        writeFunctionResponseException(msg, MessageType.EXCEPTION, message, serverConnection, e);
        serverConnection.setAsTrue(RESPONDED);
      }
    }
  }

  private void sendError(byte hasResult, Message msg, String message,
      ServerConnection serverConnection) throws IOException {
    synchronized (msg) {
      if (hasResult == 1) {
        writeFunctionResponseError(msg, MessageType.EXECUTE_REGION_FUNCTION_ERROR, message,
            serverConnection);
        serverConnection.setAsTrue(RESPONDED);
      }
    }
  }

  protected static void writeFunctionResponseException(Message origMsg, int messageType,
      String message, ServerConnection serverConnection, Throwable e) throws IOException {
    ChunkedMessage functionResponseMsg = serverConnection.getFunctionResponseMessage();
    ChunkedMessage chunkedResponseMsg = serverConnection.getChunkedResponseMessage();
    int numParts = 0;
    if (functionResponseMsg.headerHasBeenSent()) {
      if (e instanceof FunctionException
          && e.getCause() instanceof InternalFunctionInvocationTargetException) {
        functionResponseMsg.setNumberOfParts(3);
        functionResponseMsg.addObjPart(e);
        functionResponseMsg.addStringPart(BaseCommand.getExceptionTrace(e));
        InternalFunctionInvocationTargetException fe =
            (InternalFunctionInvocationTargetException) e.getCause();
        functionResponseMsg.addObjPart(fe.getFailedNodeSet());
        numParts = 3;
      } else {
        functionResponseMsg.setNumberOfParts(2);
        functionResponseMsg.addObjPart(e);
        functionResponseMsg.addStringPart(BaseCommand.getExceptionTrace(e));
        numParts = 2;
      }
      if (logger.isDebugEnabled()) {
        logger.debug("{}: Sending exception chunk while reply in progress: ",
            serverConnection.getName(), e);
      }
      functionResponseMsg.setServerConnection(serverConnection);
      functionResponseMsg.setLastChunkAndNumParts(true, numParts);
      functionResponseMsg.sendChunk(serverConnection);
    } else {
      chunkedResponseMsg.setMessageType(messageType);
      chunkedResponseMsg.setTransactionId(origMsg.getTransactionId());
      chunkedResponseMsg.sendHeader();
      if (e instanceof FunctionException
          && e.getCause() instanceof InternalFunctionInvocationTargetException) {
        chunkedResponseMsg.setNumberOfParts(3);
        chunkedResponseMsg.addObjPart(e);
        chunkedResponseMsg.addStringPart(BaseCommand.getExceptionTrace(e));
        InternalFunctionInvocationTargetException fe =
            (InternalFunctionInvocationTargetException) e.getCause();
        chunkedResponseMsg.addObjPart(fe.getFailedNodeSet());
        numParts = 3;
      } else {
        chunkedResponseMsg.setNumberOfParts(2);
        chunkedResponseMsg.addObjPart(e);
        chunkedResponseMsg.addStringPart(BaseCommand.getExceptionTrace(e));
        numParts = 2;
      }
      if (logger.isDebugEnabled()) {
        logger.debug("{}: Sending exception chunk: ", serverConnection.getName(), e);
      }
      chunkedResponseMsg.setServerConnection(serverConnection);
      chunkedResponseMsg.setLastChunkAndNumParts(true, numParts);
      chunkedResponseMsg.sendChunk(serverConnection);
    }
  }
}