//
// Copyright (C) 2019  NetDEF, Inc.
//                     Renato Westphal
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; see the file COPYING; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//

syntax = "proto3";

package frr;

// Service specification for the FRR northbound interface.
service Northbound {
  // Retrieve the capabilities supported by the target.
  rpc GetCapabilities(GetCapabilitiesRequest) returns (GetCapabilitiesResponse) {}

  // Retrieve configuration data, state data or both from the target.
  rpc Get(GetRequest) returns (stream GetResponse) {}

  // Create a new candidate configuration and return a reference to it. The
  // created candidate is a copy of the running configuration.
  rpc CreateCandidate(CreateCandidateRequest) returns (CreateCandidateResponse) {}

  // Delete a candidate configuration.
  rpc DeleteCandidate(DeleteCandidateRequest) returns (DeleteCandidateResponse) {}

  // Update a candidate configuration by rebasing the changes on top of the
  // latest running configuration. Resolve conflicts automatically by giving
  // preference to the changes done in the candidate configuration.
  rpc UpdateCandidate(UpdateCandidateRequest) returns (UpdateCandidateResponse) {}

  // Edit a candidate configuration. All changes are discarded if any error
  // happens.
  rpc EditCandidate(EditCandidateRequest) returns (EditCandidateResponse) {}

  // Load configuration data into a candidate configuration. Both merge and
  // replace semantics are supported.
  rpc LoadToCandidate(LoadToCandidateRequest) returns (LoadToCandidateResponse) {}

  // Create a new configuration transaction using a two-phase commit protocol.
  rpc Commit(CommitRequest) returns (CommitResponse) {}

  // List the metadata of all configuration transactions recorded in the
  // transactions database.
  rpc ListTransactions(ListTransactionsRequest) returns (stream ListTransactionsResponse) {}

  // Fetch a configuration (identified by its transaction ID) from the
  // transactions database.
  rpc GetTransaction(GetTransactionRequest) returns (GetTransactionResponse) {}

  // Lock the running configuration, preventing other users from changing it.
  rpc LockConfig(LockConfigRequest) returns (LockConfigResponse) {}

  // Unlock the running configuration.
  rpc UnlockConfig(UnlockConfigRequest) returns (UnlockConfigResponse) {}

  // Execute a YANG RPC.
  rpc Execute(ExecuteRequest) returns (ExecuteResponse) {}
}

// ----------------------- Parameters and return types -------------------------

//
// RPC: GetCapabilities()
//
message GetCapabilitiesRequest {
  // Empty.
}

message GetCapabilitiesResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.

  // FRR version.
  string frr_version = 1;

  // Indicates whether FRR was compiled with support for configuration
  // rollbacks or not (--enable-config-rollbacks).
  bool rollback_support = 2;

  // Supported schema modules.
  repeated ModuleData supported_modules = 3;

  // Supported encodings.
  repeated Encoding supported_encodings = 4;
}

//
// RPC: Get()
//
message GetRequest {
  // Type of elements within the data tree.
  enum DataType {
    // All data elements.
    ALL = 0;

    // Config elements.
    CONFIG = 1;

    // State elements.
    STATE = 2;
  }

  // The type of data being requested.
  DataType type = 1;

  // Encoding to be used.
  Encoding encoding = 2;

  // Include implicit default nodes.
  bool with_defaults = 3;

  // Paths requested by the client.
  repeated string path = 4;
}

message GetResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::INVALID_ARGUMENT: Invalid YANG data path.

  // Timestamp in nanoseconds since Epoch.
  int64 timestamp = 1;

  // The requested data.
  DataTree data = 2;
}

//
// RPC: CreateCandidate()
//
message CreateCandidateRequest {
  // Empty.
}

message CreateCandidateResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::RESOURCE_EXHAUSTED: can't create candidate
  //   configuration.

  // Handle to the new created candidate configuration.
  uint32 candidate_id = 1;
}

//
// RPC: DeleteCandidate()
//
message DeleteCandidateRequest {
  // Candidate configuration to delete.
  uint32 candidate_id = 1;
}

message DeleteCandidateResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::NOT_FOUND: Candidate wasn't found.
}

//
// RPC: UpdateCandidate()
//
message UpdateCandidateRequest {
  // Candidate configuration to update.
  uint32 candidate_id = 1;
}

message UpdateCandidateResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::NOT_FOUND: Candidate wasn't found.
}

//
// RPC: EditCandidate()
//
message EditCandidateRequest {
  // Candidate configuration that is going to be edited.
  uint32 candidate_id = 1;

  // Data elements to be created or updated.
  repeated PathValue update = 2;

  // Paths to be deleted from the data tree.
  repeated PathValue delete = 3;
}

message EditCandidateResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::NOT_FOUND: Candidate wasn't found.
  // - grpc::StatusCode::INVALID_ARGUMENT: An error occurred while editing the
  //   candidate configuration.
}

//
// RPC: LoadToCandidate()
//
message LoadToCandidateRequest {
  enum LoadType {
    // Merge the data tree into the candidate configuration.
    MERGE = 0;

    // Replace the candidate configuration by the provided data tree.
    REPLACE = 1;
  }

  // Candidate configuration that is going to be edited.
  uint32 candidate_id = 1;

  // Load operation to apply.
  LoadType type = 2;

  // Configuration data.
  DataTree config = 3;
}

message LoadToCandidateResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::INVALID_ARGUMENT: An error occurred while performing
  //   the load operation.
}

//
// RPC: Commit()
//
message CommitRequest {
  enum Phase {
    // Validate if the configuration changes are valid (phase 0).
    VALIDATE = 0;

    // Prepare resources to apply the configuration changes (phase 1).
    PREPARE = 1;

    // Release previously allocated resources (phase 2).
    ABORT = 2;

    // Apply the configuration changes (phase 2).
    APPLY = 3;

    // All of the above (VALIDATE + PREPARE + ABORT/APPLY).
    //
    // This option can't be used to implement network-wide transactions,
    // since they require the manager entity to take into account the results
    // of the preparation phase of multiple managed devices.
    ALL = 4;
  }

  // Candidate configuration that is going to be committed.
  uint32 candidate_id = 1;

  // Transaction phase.
  Phase phase = 2;

  // Assign a comment to this commit.
  string comment = 3;
}

message CommitResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::FAILED_PRECONDITION: misuse of the two-phase commit
  //   protocol.
  // - grpc::StatusCode::INVALID_ARGUMENT: Validation error.
  // - grpc::StatusCode::RESOURCE_EXHAUSTED: Failure to allocate resource.

  // ID of the created configuration transaction (when the phase is APPLY
  // or ALL).
  uint32 transaction_id = 1;
}

//
// RPC: ListTransactions()
//
message ListTransactionsRequest {
  // Empty.
}

message ListTransactionsResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.

  // Transaction ID.
  uint32 id = 1;

  // Client that committed the transaction.
  string client = 2;

  // Date and time the transaction was committed.
  string date = 3;

  // Comment assigned to the transaction.
  string comment = 4;
}

//
// RPC: GetTransaction()
//
message GetTransactionRequest {
  // Transaction to retrieve.
  uint32 transaction_id = 1;

  // Encoding to be used.
  Encoding encoding = 2;

  // Include implicit default nodes.
  bool with_defaults = 3;
}

message GetTransactionResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::NOT_FOUND: Transaction wasn't found in the transactions
  //   database.

  DataTree config = 1;
}

//
// RPC: LockConfig()
//
message LockConfigRequest {
  // Empty.
}

message LockConfigResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::FAILED_PRECONDITION: Running configuration is
  //   locked already.
}

//
// RPC: UnlockConfig()
//
message UnlockConfigRequest {
  // Empty.
}

message UnlockConfigResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.
  // - grpc::StatusCode::FAILED_PRECONDITION: Running configuration isn't
  //   locked.
}

//
// RPC: Execute()
//
message ExecuteRequest {
  // Path of the YANG RPC or YANG Action.
  string path = 1;

  // Input parameters.
  repeated PathValue input = 2;
}

message ExecuteResponse {
  // Return values:
  // - grpc::StatusCode::OK: Success.

  // Output parameters.
  repeated PathValue output = 1;
}

// -------------------------------- Definitions --------------------------------

// YANG module.
message ModuleData {
  // Name of the YANG module;
  string name = 1;

  // Organization publishing the module.
  string organization = 2;

  // Latest revision of the module;
  string revision = 3;
}

// Supported encodings for YANG instance data.
enum Encoding {
  JSON = 0;
  XML = 1;
}

// Path-value pair representing a data element.
message PathValue {
  // YANG data path.
  string path = 1;

  // Data value.
  string value = 2;
}

// YANG instance data.
message DataTree {
  Encoding encoding = 1;
  string data = 2;
}