/*
 * 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 java.io.IOException;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;

import org.apache.geode.cache.LowMemoryException;
import org.apache.geode.cache.execute.Function;
import org.apache.geode.cache.execute.FunctionContext;
import org.apache.geode.cache.execute.FunctionException;
import org.apache.geode.cache.execute.FunctionService;
import org.apache.geode.cache.execute.ResultSender;
import org.apache.geode.cache.operations.ExecuteFunctionOperationContext;
import org.apache.geode.distributed.DistributedMember;
import org.apache.geode.distributed.internal.membership.InternalDistributedMember;
import org.apache.geode.internal.cache.InternalCache;
import org.apache.geode.internal.cache.control.HeapMemoryMonitor;
import org.apache.geode.internal.cache.control.InternalResourceManager;
import org.apache.geode.internal.cache.control.MemoryThresholds;
import org.apache.geode.internal.cache.execute.FunctionContextImpl;
import org.apache.geode.internal.cache.execute.FunctionStats;
import org.apache.geode.internal.cache.execute.InternalFunctionInvocationTargetException;
import org.apache.geode.internal.cache.execute.MemberMappedArgument;
import org.apache.geode.internal.cache.execute.ServerToClientFunctionResultSender;
import org.apache.geode.internal.cache.tier.Command;
import org.apache.geode.internal.cache.tier.MessageType;
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.HandShake;
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.i18n.LocalizedStrings;
import org.apache.geode.internal.logging.log4j.LocalizedMessage;
import org.apache.geode.internal.security.AuthorizeRequest;
import org.apache.geode.internal.security.SecurityService;

/**
 * This is the base command which read the parts for the MessageType.EXECUTE_FUNCTION.<br>
 * If the hasResult byte is 1, then this command send back the result after the execution to the
 * client else do not send the reply back to the client
 * 
 * @since GemFire 5.8Beta
 */
public class ExecuteFunction extends BaseCommand {

  private final static ExecuteFunction singleton = new ExecuteFunction();

  public static Command getCommand() {
    return singleton;
  }

  @Override
  public void cmdExecute(final Message clientMessage, final ServerConnection serverConnection,
      final SecurityService securityService, long start) throws IOException {
    Object function = null;
    Object args = null;
    MemberMappedArgument memberMappedArg = null;
    byte hasResult = 0;
    try {
      hasResult = clientMessage.getPart(0).getSerializedForm()[0];
      if (hasResult == 1) {
        serverConnection.setAsTrue(REQUIRES_RESPONSE);
        serverConnection.setAsTrue(REQUIRES_CHUNKED_RESPONSE);
      }
      function = clientMessage.getPart(1).getStringOrObject();
      args = clientMessage.getPart(2).getObject();

      Part part = clientMessage.getPart(3);
      if (part != null) {
        memberMappedArg = (MemberMappedArgument) part.getObject();
      }
    } catch (ClassNotFoundException exception) {
      logger.warn(LocalizedMessage.create(
          LocalizedStrings.ExecuteFunction_EXCEPTION_ON_SERVER_WHILE_EXECUTIONG_FUNCTION_0,
          function), exception);
      if (hasResult == 1) {
        writeChunkedException(clientMessage, exception, serverConnection);
        serverConnection.setAsTrue(RESPONDED);
        return;
      }
    }
    if (function == null) {
      final String message =
          LocalizedStrings.ExecuteFunction_THE_INPUT_FUNCTION_FOR_THE_EXECUTE_FUNCTION_REQUEST_IS_NULL
              .toLocalizedString();
      logger.warn("{}: {}", serverConnection.getName(), message);
      sendError(hasResult, clientMessage, message, serverConnection);
      return;
    }

    // Execute function on the cache
    try {
      Function<?> functionObject = null;
      if (function instanceof String) {
        functionObject = FunctionService.getFunction((String) function);
        if (functionObject == null) {
          final String message = LocalizedStrings.ExecuteFunction_FUNCTION_NAMED_0_IS_NOT_REGISTERED
              .toLocalizedString(function);
          logger.warn("{}: {}", serverConnection.getName(), message);
          sendError(hasResult, clientMessage, message, serverConnection);
          return;
        }
      } else {
        functionObject = (Function) function;
      }

      FunctionStats stats = FunctionStats.getFunctionStats(functionObject.getId());

      // check if the caller is authorized to do this operation on server
      functionObject.getRequiredPermissions(null).forEach(securityService::authorize);

      AuthorizeRequest authzRequest = serverConnection.getAuthzRequest();
      ExecuteFunctionOperationContext executeContext = null;
      if (authzRequest != null) {
        executeContext = authzRequest.executeFunctionAuthorize(functionObject.getId(), null, null,
            args, functionObject.optimizeForWrite());
      }

      ChunkedMessage m = serverConnection.getFunctionResponseMessage();
      m.setTransactionId(clientMessage.getTransactionId());
      ResultSender resultSender = new ServerToClientFunctionResultSender(m,
          MessageType.EXECUTE_FUNCTION_RESULT, serverConnection, functionObject, executeContext);

      FunctionContext context = null;
      InternalCache cache = serverConnection.getCache();
      InternalDistributedMember localVM =
          (InternalDistributedMember) cache.getDistributedSystem().getDistributedMember();

      if (memberMappedArg != null) {
        context = new FunctionContextImpl(cache, functionObject.getId(),
            memberMappedArg.getArgumentsForMember(localVM.getId()), resultSender);
      } else {
        context = new FunctionContextImpl(cache, functionObject.getId(), args, resultSender);
      }

      HandShake handShake = (HandShake) serverConnection.getHandshake();
      int earlierClientReadTimeout = handShake.getClientReadTimeout();
      handShake.setClientReadTimeout(0);
      try {
        long startExecution = stats.startTime();
        stats.startFunctionExecution(functionObject.hasResult());
        if (logger.isDebugEnabled()) {
          logger.debug("Executing Function on Server: " + serverConnection.toString()
              + "with context :" + context.toString());
        }

        HeapMemoryMonitor hmm =
            ((InternalResourceManager) cache.getResourceManager()).getHeapMonitor();
        if (functionObject.optimizeForWrite() && cache != null && hmm.getState().isCritical()
            && !MemoryThresholds.isLowMemoryExceptionDisabled()) {
          Set<DistributedMember> sm = Collections.<DistributedMember>singleton(cache.getMyId());
          throw new LowMemoryException(
              LocalizedStrings.ResourceManager_LOW_MEMORY_FOR_0_FUNCEXEC_MEMBERS_1
                  .toLocalizedString(new Object[] {functionObject.getId(), sm}),
              sm);
        }
        functionObject.execute(context);
        stats.endFunctionExecution(startExecution, functionObject.hasResult());
      } catch (FunctionException functionException) {
        stats.endFunctionExecutionWithException(functionObject.hasResult());
        throw functionException;
      } catch (Exception exception) {
        stats.endFunctionExecutionWithException(functionObject.hasResult());
        throw new FunctionException(exception);
      } finally {
        handShake.setClientReadTimeout(earlierClientReadTimeout);
      }
    } catch (IOException ioException) {
      logger.warn(LocalizedMessage.create(
          LocalizedStrings.ExecuteFunction_EXCEPTION_ON_SERVER_WHILE_EXECUTIONG_FUNCTION_0,
          function), ioException);
      String message =
          LocalizedStrings.ExecuteFunction_SERVER_COULD_NOT_SEND_THE_REPLY.toLocalizedString();
      sendException(hasResult, clientMessage, message, serverConnection, ioException);
    } catch (InternalFunctionInvocationTargetException internalfunctionException) {
      // Fix for #44709: User should not be aware of
      // InternalFunctionInvocationTargetException. No instance of
      // InternalFunctionInvocationTargetException is giving useful
      // information to user to take any corrective action hence logging
      // this at fine level logging
      // 1> When bucket is moved
      // 2> Incase of HA FucntionInvocationTargetException thrown. Since
      // it is HA, fucntion will be reexecuted on right node
      // 3> Multiple target nodes found for single hop operation
      // 4> in case of HA member departed
      if (logger.isDebugEnabled()) {
        logger.debug(LocalizedMessage.create(
            LocalizedStrings.ExecuteFunction_EXCEPTION_ON_SERVER_WHILE_EXECUTIONG_FUNCTION_0,
            new Object[] {function}), internalfunctionException);
      }
      final String message = internalfunctionException.getMessage();
      sendException(hasResult, clientMessage, message, serverConnection, internalfunctionException);
    } catch (Exception e) {
      logger.warn(LocalizedMessage.create(
          LocalizedStrings.ExecuteFunction_EXCEPTION_ON_SERVER_WHILE_EXECUTIONG_FUNCTION_0,
          function), e);
      final String message = e.getMessage();
      sendException(hasResult, clientMessage, message, serverConnection, e);
    }
  }

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

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

}
