/*
 * SPDX-FileCopyrightText: 2023 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 * 
 * This program and the accompanying materials are made available under
 * the terms of the Apache License Version 2.0 which is available at
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * SPDX-FileType: SOURCE
 * SPDX-License-Identifier: Apache-2.0
 */
syntax = "proto3";

package uprotocol.v1;

option java_package = "org.eclipse.uprotocol.v1";
option java_outer_classname = "UCodeProto";
option java_multiple_files = true;

// Canonical Error codes for uProtocol APIs
enum UCode {
  // Completes successfully
  OK = 0;

  // Operation has been cancelled by the caller
  CANCELLED = 1;

  // An unknown (but not critical) error has occurred
  UNKNOWN = 2;

  // Passed arguments are invalid (ex. improperly formatted)
  INVALID_ARGUMENT = 3;

  // Operation has expired (timeout)
  DEADLINE_EXCEEDED = 4;

  // Operation cannot be completed because the requested entity was not
  // found (ex. database lookup and the data is not found)
  // Calling uE *MAY* retry the operation with back-off
  NOT_FOUND = 5;

  // The calling uE requested to add/create something that already exists
  // (ex. add to a database something that is already there)
  ALREADY_EXISTS = 6;

  // The calling uE is authenticated but not permitted to call the API
  PERMISSION_DENIED = 7;

  // The calling uE does not have valid authentication credentials for the API
  UNAUTHENTICATED = 16;

  // The resource being accessed has been exhausted (ex. out of disk space, etc...)
  RESOURCE_EXHAUSTED = 8;

  // The system (service) is in a state that it cannot handle the request
  // Calling uEs *SHOULD NOT* retry till the system state has been corrected
  FAILED_PRECONDITION = 9;

  // The operation was aborted, typically due to a concurrency issue such as
  // a sequencer check failure or transaction abort
  // Calling uEs *MAY* retry but at a higher frequency than UNAVAILABLE
  ABORTED = 10;

  // A caller would typically iterating through the results from said API
  // and can is expected to detect the end of the results (out of range)
  OUT_OF_RANGE = 11;

  // Part or all of the requested operation has not been implemented yet
  UNIMPLEMENTED = 12;

  // A serious internal error has not described by a known error code
  INTERNAL = 13;

  // The operation is currently unavailable
  // Calling uEs *MAY* retry with back-off
  UNAVAILABLE = 14;

  // When an unrecoverable data loss or corruption has occurred
  DATA_LOSS = 15;
}