// Copyright (c) The Libra Core Contributors
// SPDX-License-Identifier: Apache-2.0

syntax = "proto3";

package mempool;

import "transaction.proto";
import "mempool_status.proto";

// -----------------------------------------------------------------------------
// ---------------- Mempool Service Definition
// -----------------------------------------------------------------------------
service Mempool {
  // Adds a new transaction to the mempool with validation against existing
  // transactions in the mempool.  Note that this function performs additional
  // validation that AC is unable to perform. (because AC knows only about a
  // single transaction, but mempool potentially knows about multiple pending
  // transactions)
  rpc AddTransactionWithValidation(AddTransactionWithValidationRequest)
      returns (AddTransactionWithValidationResponse) {}

  // Fetch ordered block of transactions
  rpc GetBlock(GetBlockRequest) returns (GetBlockResponse) {}

  // Remove committed transactions from Mempool
  rpc CommitTransactions(CommitTransactionsRequest)
      returns (CommitTransactionsResponse) {}

  // Check the health of mempool
  rpc HealthCheck(HealthCheckRequest)
      returns (HealthCheckResponse) {}
}

// -----------------------------------------------------------------------------
// ---------------- AddTransactionWithValidation
// -----------------------------------------------------------------------------

message AddTransactionWithValidationRequest {
  // Transaction from a wallet
  types.SignedTransaction signed_txn = 1;
  // Max amount of gas required to execute the transaction
  // Without running the program, it is very difficult to determine this number,
  // so we use the max gas specified by the signed transaction.
  // This field is still included separately from the signed transaction so that
  // if we have a better methodology in the future, we can more accurately
  // specify the max gas.
  uint64 max_gas_cost = 2;
  // Latest sequence number of the involved account from state db.
  uint64 latest_sequence_number = 3;
  // Latest account balance of the involved account from state db.
  uint64 account_balance = 4;
}

message AddTransactionWithValidationResponse {
  // The ledger version at the time of the transaction submitted. The submitted
  // transaction will have version bigger than this 'current_version'
  uint64 current_version = 1;
  // The result of the transaction submission
  MempoolAddTransactionStatus status = 2;
}

// -----------------------------------------------------------------------------
// ---------------- GetBlock
// -----------------------------------------------------------------------------
message GetBlockRequest {
  uint64 max_block_size = 1;
  repeated TransactionExclusion transactions = 2;
}

message GetBlockResponse { types.SignedTransactionsBlock block = 1; }

message TransactionExclusion {
  bytes sender = 1;
  uint64 sequence_number = 2;
}

// -----------------------------------------------------------------------------
// ---------------- CommitTransactions
// -----------------------------------------------------------------------------
message CommitTransactionsRequest {
  repeated CommittedTransaction transactions = 1;
  // agreed monotonic timestamp microseconds since the epoch for a committed block
  // used by Mempool to GC expired transactions
  uint64 block_timestamp_usecs = 2;
}

message CommitTransactionsResponse {}

message CommittedTransaction {
  bytes sender = 1;
  uint64 sequence_number = 2;
  bool is_rejected = 3;
}

// -----------------------------------------------------------------------------
// ---------------- HealthCheck
// -----------------------------------------------------------------------------
message HealthCheckRequest {
}

message HealthCheckResponse {
  // Indicate whether Mempool is in healthy condition.
  bool is_healthy = 1;
}