/**
 * 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.
 */

/**
 * These .proto interfaces are private and unstable.
 * Please see http://wiki.apache.org/hadoop/Compatibility
 * for what changes are allowed for a *unstable* .proto interface.
 */

option java_package = "org.apache.hadoop.hdds.protocol.proto";

option java_outer_classname = "StorageContainerDatanodeProtocolProtos";

option java_generic_services = true;

option java_generate_equals_and_hash = true;

package hadoop.hdds;

import "hdds.proto";

/**
 * Request for version info of the software stack on the server.
 */
message SCMVersionRequestProto {}

/**
* Generic response that is send to a version request. This allows keys to be
* added on the fly and protocol to remain stable.
*/
message SCMVersionResponseProto {
  required uint32 softwareVersion = 1;
  repeated hadoop.hdds.KeyValue keys = 2;
}

message SCMRegisterRequestProto {
  required DatanodeDetailsProto datanodeDetails = 1;
  required NodeReportProto nodeReport = 2;
  required ContainerReportsProto containerReport = 3;
  required PipelineReportsProto pipelineReports = 4;
}

/**
 * Datanode ID returned by the SCM. This is similar to name node
 * registeration of a datanode.
 */
message SCMRegisteredResponseProto {
  enum ErrorCode {
    success = 1;
    errorNodeNotPermitted = 2;
  }
  required ErrorCode errorCode = 1;
  required string datanodeUUID = 2;
  required string clusterID = 3;
  optional SCMNodeAddressList addressList = 4;
  optional string hostname = 5;
  optional string ipAddress = 6;
}

/**
* This message is send by data node to indicate that it is alive or it is
* registering with the node manager.
*/
message SCMHeartbeatRequestProto {
  required DatanodeDetailsProto datanodeDetails = 1;
  optional NodeReportProto nodeReport = 2;
  optional ContainerReportsProto containerReport = 3;
  repeated CommandStatusReportsProto commandStatusReports = 4;
  optional ContainerActionsProto containerActions = 5;
  optional PipelineActionsProto pipelineActions = 6;
  optional PipelineReportsProto pipelineReports = 7;
}

/*
 * A group of commands for the datanode to execute
 */
message SCMHeartbeatResponseProto {
  required string datanodeUUID = 1;
  repeated SCMCommandProto commands = 2;
}

message SCMNodeAddressList {
  repeated string addressList = 1;
}

/**
* This message is send along with the heart beat to report datanode
* storage utilization to SCM.
*/
message NodeReportProto {
  repeated StorageReportProto storageReport = 1;
}

message StorageReportProto {
  required string storageUuid = 1;
  required string storageLocation = 2;
  optional uint64 capacity = 3 [default = 0];
  optional uint64 scmUsed = 4 [default = 0];
  optional uint64 remaining = 5 [default = 0];
  optional StorageTypeProto storageType = 6 [default = DISK];
  optional bool failed = 7 [default = false];
}

/**
 * Types of recognized storage media.
 */
enum StorageTypeProto {
  DISK = 1;
  SSD = 2;
  ARCHIVE = 3;
  RAM_DISK = 4;
  PROVIDED = 5;
}

message ContainerReportsProto {
  repeated ContainerInfo reports = 1;
}

message CommandStatusReportsProto {
  repeated CommandStatus cmdStatus = 1;
}

message CommandStatus {
  enum Status {
    PENDING = 1;
    EXECUTED = 2;
    FAILED = 3;
  }
  required int64 cmdId = 1;
  required Status status = 2 [default = PENDING];
  required SCMCommandProto.Type type = 3;
  optional string msg = 4;
  optional ContainerBlocksDeletionACKProto blockDeletionAck = 5;
}

message ContainerActionsProto {
  repeated ContainerAction containerActions = 1;
}

message ContainerAction {
  enum Action {
    CLOSE = 1;
  }

  enum Reason {
    CONTAINER_FULL = 1;
    CONTAINER_UNHEALTHY = 2;
  }

  required int64 containerID = 1;
  required Action action = 2;
  optional Reason reason = 3;
}

message PipelineReport {
  required PipelineID pipelineID = 1;
}

message PipelineReportsProto {
  repeated PipelineReport pipelineReport = 1;
}

message PipelineActionsProto {
  repeated PipelineAction pipelineActions = 1;
}

message ClosePipelineInfo {
  enum Reason {
    PIPELINE_FAILED = 1;
  }
  required PipelineID pipelineID = 1;
  optional Reason reason = 3;
  optional string detailedReason = 4;
}

message PipelineAction {
  enum Action {
    CLOSE = 1;
  }

  /**
   * Action will be used to identify the correct pipeline action.
   */
  required Action action = 1;
  optional ClosePipelineInfo closePipeline = 2;
}

/**
A container report contains the following information.
*/
message ContainerInfo {
  required int64 containerID = 1;
  optional int64 size = 2;
  optional int64 used = 3;
  optional int64 keyCount = 4;
  // TODO: move the io count to separate message
  optional int64 readCount = 5;
  optional int64 writeCount = 6;
  optional int64 readBytes = 7;
  optional int64 writeBytes = 8;
  optional string finalhash = 9;
  optional hadoop.hdds.LifeCycleState state = 10;
  optional int64 deleteTransactionId = 11;
  optional uint64 blockCommitSequenceId = 12;
}

/*
 * These are commands returned by SCM for to the datanode to execute.
 */
message SCMCommandProto {
  enum Type {
    reregisterCommand = 1;
    deleteBlocksCommand = 2;
    closeContainerCommand = 3;
    deleteContainerCommand = 4;
    replicateContainerCommand = 5;
  }
  // TODO: once we start using protoc 3.x, refactor this message using "oneof"
  required Type commandType = 1;
  optional ReregisterCommandProto reregisterCommandProto = 2;
  optional DeleteBlocksCommandProto deleteBlocksCommandProto = 3;
  optional CloseContainerCommandProto closeContainerCommandProto = 4;
  optional DeleteContainerCommandProto deleteContainerCommandProto = 5;
  optional ReplicateContainerCommandProto replicateContainerCommandProto = 6;
}

/**
 * SCM informs a datanode to register itself again.
 * With recieving this command, datanode will transit to REGISTER state.
 */
message ReregisterCommandProto {}


// HB response from SCM, contains a list of block deletion transactions.
message DeleteBlocksCommandProto {
  repeated DeletedBlocksTransaction deletedBlocksTransactions = 1;
  required int64 cmdId = 3;
}

// The deleted blocks which are stored in deletedBlock.db of scm.
// We don't use BlockID because this only contians multiple localIDs
// of the same containerID.
message DeletedBlocksTransaction {
  required int64 txID = 1;
  required int64 containerID = 2;
  repeated int64 localID = 3;
  // the retry time of sending deleting command to datanode.
  required int32 count = 4;
}

// ACK message datanode sent to SCM, contains the result of
// block deletion transactions.
message ContainerBlocksDeletionACKProto {
  message DeleteBlockTransactionResult {
    required int64 txID = 1;
    required int64 containerID = 2;
    required bool success = 3;
  }
  repeated DeleteBlockTransactionResult results = 1;
  required string dnId = 2;
}

/**
This command asks the datanode to close a specific container.
*/
message CloseContainerCommandProto {
  required int64 containerID = 1;
  required hadoop.hdds.ReplicationType replicationType = 2;
  required int64 cmdId = 3;
  required PipelineID pipelineID = 4;
}

/**
This command asks the datanode to delete a specific container.
*/
message DeleteContainerCommandProto {
  required int64 containerID = 1;
  required int64 cmdId = 2;
}

/**
This command asks the datanode to replicate a container from specific sources.
*/
message ReplicateContainerCommandProto {
  required int64 containerID = 1;
  repeated DatanodeDetailsProto sources = 2;
  required int64 cmdId = 3;
}

/**
 * Protocol used from a datanode to StorageContainerManager.
 *
 * Please see the request and response messages for details of the RPC calls.
 *
 * Here is a simple state diagram that shows how a datanode would boot up and
 * communicate with SCM.
 *
 *           -----------------------
 *          |         Start         |
 *           ---------- ------------
 *                     |
 *                     |
 *                     |
 *                     |
 *                     |
 *                     |
 *                     |
 *           ----------v-------------
 *          |   Searching for  SCM    ------------
 *           ---------- -------------             |
 *                     |                          |
 *                     |                          |
 *                     |                ----------v-------------
 *                     |               | Register if needed     |
 *                     |                ----------- ------------
 *                     |                           |
 *                     v                           |
 *            ----------- ----------------         |
 *  ---------   Heartbeat state           <--------
 * |          --------^-------------------
 * |                  |
 * |                  |
 * |                  |
 * |                  |
 * |                  |
 * |                  |
 * |                  |
 *  ------------------
 *
 *
 *
 * Here is how this protocol is used by the datanode. When a datanode boots up
 * it moves into a stated called SEARCHING_SCM. In this state datanode is
 * trying to establish communication with the SCM. The address of the SCMs are
 * retrieved from the configuration information.
 *
 * In the SEARCHING_SCM state, only rpc call made by datanode is a getVersion
 * call to SCM. Once any of the SCMs reply, datanode checks if it has a local
 * persisted datanode ID. If it has this means that this datanode is already
 * registered with some SCM. If this file is not found, datanode assumes that
 * it needs to do a registration.
 *
 * If registration is need datanode moves into REGISTER state. It will
 * send a register call with DatanodeDetailsProto data structure and presist
 * that info.
 *
 * The response to the command contains clusterID. This information is
 * also persisted by the datanode and moves into heartbeat state.
 *
 * Once in the heartbeat state, datanode sends heartbeats and container reports
 * to SCM and process commands issued by SCM until it is shutdown.
 *
 */
service StorageContainerDatanodeProtocolService {

  /**
  * Gets the version information from the SCM.
  */
  rpc getVersion (SCMVersionRequestProto) returns (SCMVersionResponseProto);

  /**
  * Registers a data node with SCM.
  */
  rpc register (SCMRegisterRequestProto) returns (SCMRegisteredResponseProto);

  /**
   * Send heartbeat from datanode to SCM. HB's under SCM looks more
   * like life line protocol than HB's under HDFS. In other words, it is
   * extremely light weight and contains no data payload.
   */
  rpc sendHeartbeat (SCMHeartbeatRequestProto) returns (SCMHeartbeatResponseProto);

}