// Copyright 2017 Google LLC
//
// Licensed 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.

#ifndef FIREBASE_FUNCTIONS_SRC_INCLUDE_FIREBASE_FUNCTIONS_COMMON_H_
#define FIREBASE_FUNCTIONS_SRC_INCLUDE_FIREBASE_FUNCTIONS_COMMON_H_

#include "firebase/variant.h"

namespace firebase {
namespace functions {

/// Error code returned by Cloud Functions C++ functions.
/// Standard gRPC error codes, as defined in:
/// https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
enum Error {
#ifdef INTERNAL_EXPERIMENTAL
// LINT.IfChange
#endif  // INTERNAL_EXPERIMENTAL

  // Not an error; returned on success
  //
  // HTTP Mapping: 200 OK
  kErrorNone = 0,

  // The operation was cancelled, typically by the caller.
  //
  // HTTP Mapping: 499 Client Closed Request
  kErrorCancelled = 1,

  // Unknown error.  For example, this error may be returned when
  // a `Status` value received from another address space belongs to
  // an error space that is not known in this address space.  Also
  // errors raised by APIs that do not return enough error information
  // may be converted to this error.
  //
  // HTTP Mapping: 500 Internal Server Error
  kErrorUnknown = 2,

  // The client specified an invalid argument.  Note that this differs
  // from `FAILED_PRECONDITION`.  `INVALID_ARGUMENT` indicates arguments
  // that are problematic regardless of the state of the system
  // (e.g., a malformed file name).
  //
  // HTTP Mapping: 400 Bad Request
  kErrorInvalidArgument = 3,

  // The deadline expired before the operation could complete. For operations
  // that change the state of the system, this error may be returned
  // even if the operation has completed successfully.  For example, a
  // successful response from a server could have been delayed long
  // enough for the deadline to expire.
  //
  // HTTP Mapping: 504 Gateway Timeout
  kErrorDeadlineExceeded = 4,

  // Some requested entity (e.g., file or directory) was not found.
  //
  // Note to server developers: if a request is denied for an entire class
  // of users, such as gradual feature rollout or undocumented whitelist,
  // `NOT_FOUND` may be used. If a request is denied for some users within
  // a class of users, such as user-based access control, `PERMISSION_DENIED`
  // must be used.
  //
  // HTTP Mapping: 404 Not Found
  kErrorNotFound = 5,

  // The entity that a client attempted to create (e.g., file or directory)
  // already exists.
  //
  // HTTP Mapping: 409 Conflict
  kErrorAlreadyExists = 6,

  // The caller does not have permission to execute the specified
  // operation. `PERMISSION_DENIED` must not be used for rejections
  // caused by exhausting some resource (use `RESOURCE_EXHAUSTED`
  // instead for those errors). `PERMISSION_DENIED` must not be
  // used if the caller can not be identified (use `UNAUTHENTICATED`
  // instead for those errors). This error code does not imply the
  // request is valid or the requested entity exists or satisfies
  // other pre-conditions.
  //
  // HTTP Mapping: 403 Forbidden
  kErrorPermissionDenied = 7,

  // The request does not have valid authentication credentials for the
  // operation.
  //
  // HTTP Mapping: 401 Unauthorized
  kErrorUnauthenticated = 16,

  // Some resource has been exhausted, perhaps a per-user quota, or
  // perhaps the entire file system is out of space.
  //
  // HTTP Mapping: 429 Too Many Requests
  kErrorResourceExhausted = 8,

  // The operation was rejected because the system is not in a state
  // required for the operation's execution.  For example, the directory
  // to be deleted is non-empty, an rmdir operation is applied to
  // a non-directory, etc.
  //
  // Service implementors can use the following guidelines to decide
  // between `FAILED_PRECONDITION`, `ABORTED`, and `UNAVAILABLE`:
  //  (a) Use `UNAVAILABLE` if the client can retry just the failing call.
  //  (b) Use `ABORTED` if the client should retry at a higher level
  //      (e.g., when a client-specified test-and-set fails, indicating the
  //      client should restart a read-modify-write sequence).
  //  (c) Use `FAILED_PRECONDITION` if the client should not retry until
  //      the system state has been explicitly fixed.  E.g., if an "rmdir"
  //      fails because the directory is non-empty, `FAILED_PRECONDITION`
  //      should be returned since the client should not retry unless
  //      the files are deleted from the directory.
  //
  // HTTP Mapping: 400 Bad Request
  kErrorFailedPrecondition = 9,

  // The operation was aborted, typically due to a concurrency issue such as
  // a sequencer check failure or transaction abort.
  //
  // See the guidelines above for deciding between `FAILED_PRECONDITION`,
  // `ABORTED`, and `UNAVAILABLE`.
  //
  // HTTP Mapping: 409 Conflict
  kErrorAborted = 10,

  // The operation was attempted past the valid range.  E.g., seeking or
  // reading past end-of-file.
  //
  // Unlike `INVALID_ARGUMENT`, this error indicates a problem that may
  // be fixed if the system state changes. For example, a 32-bit file
  // system will generate `INVALID_ARGUMENT` if asked to read at an
  // offset that is not in the range [0,2^32-1], but it will generate
  // `OUT_OF_RANGE` if asked to read from an offset past the current
  // file size.
  //
  // There is a fair bit of overlap between `FAILED_PRECONDITION` and
  // `OUT_OF_RANGE`.  We recommend using `OUT_OF_RANGE` (the more specific
  // error) when it applies so that callers who are iterating through
  // a space can easily look for an `OUT_OF_RANGE` error to detect when
  // they are done.
  //
  // HTTP Mapping: 400 Bad Request
  kErrorOutOfRange = 11,

  // The operation is not implemented or is not supported/enabled in this
  // service.
  //
  // HTTP Mapping: 501 Not Implemented
  kErrorUnimplemented = 12,

  // Internal errors.  This means that some invariants expected by the
  // underlying system have been broken.  This error code is reserved
  // for serious errors.
  //
  // HTTP Mapping: 500 Internal Server Error
  kErrorInternal = 13,

  // The service is currently unavailable.  This is most likely a
  // transient condition, which can be corrected by retrying with
  // a backoff.
  //
  // See the guidelines above for deciding between `FAILED_PRECONDITION`,
  // `ABORTED`, and `UNAVAILABLE`.
  //
  // HTTP Mapping: 503 Service Unavailable
  kErrorUnavailable = 14,

  // Unrecoverable data loss or corruption.
  //
  // HTTP Mapping: 500 Internal Server Error
  kErrorDataLoss = 15,

};

#ifdef INTERNAL_EXPERIMENTAL
/// @cond FIREBASE_APP_INTERNAL
namespace internal {

// Get the human-readable error message corresponding to an error code.
//
// Returns a statically-allocated string describing the error code you pass in.
const char* GetErrorMessage(Error error);

}  // namespace internal
/// @endcond
#endif  // INTERNAL_EXPERIMENTAL

}  // namespace functions
}  // namespace firebase

#endif  // FIREBASE_FUNCTIONS_SRC_INCLUDE_FIREBASE_FUNCTIONS_COMMON_H_