// Copyright 2015 gRPC authors.
//
// 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.

syntax = "proto3";

package lws_vfs;

// Filesystem operation types for diagnostics and observability.
enum FsOp {
  FSOP_UNKNOWN = 0;
  FSOP_GETATTR = 1;
  FSOP_SETXATTR = 2;
  FSOP_ACCESS = 3;
  FSOP_READDIR = 4;
  FSOP_READ = 5;
  FSOP_OPEN = 6;
  FSOP_WRITE = 7;
  FSOP_GETXATTR = 8;
  FSOP_TRUNCATE = 9;
  FSOP_UTIMENS = 10;
  FSOP_CHOWN = 11;
  FSOP_RELEASE = 12;
  FSOP_MKDIR = 13;
  FSOP_RMDIR = 14;
  FSOP_FLUSH = 15;
  FSOP_OPENDIR = 16;
  FSOP_RELEASEDIR = 17;
  FSOP_CREATE = 18;
  FSOP_UNLINK = 19;
  FSOP_RENAME = 20;
  FSOP_HELLO = 21;
  FSOP_GET_CONFIG = 22;
}

// Optional chained cause for nested errors.
message ErrorCause {
  int32 code = 1;                  // POSIX errno if available
  string message = 2;              // human-readable message
  string type = 3;                 // error type/category from server implementation
}

// Rich error payload carried by all responses.
message FsError {
  int32 code = 1;                  // POSIX errno (>0)
  string message = 2;              // application error message
  string sys_msg = 3;              // strerror(code) or OS message
  uint32 grpc_code = 4;            // gRPC status code (if applicable)
  string grpc_message = 5;         // gRPC status message
  FsOp operation = 6;              // which fs op failed
  repeated string paths = 7;       // involved paths (e.g. [from, to])
  map<string, string> context = 8; // flags/size/offset/uid/gid ...
  repeated ErrorCause causes = 9;  // nested causes
  string server = 10;              // server id/hostname
  uint64 timestamp_ms = 11;        // server time when error occurred
  bool retriable = 12;             // whether retry may succeed
}

message RpcStatus {
  bool ok = 1;                     // true if the call succeeded
  FsError error = 2;               // populated when ok == false
}

// Common structs
message file_info {
  uint32 flags = 1;
  uint32 fh_old = 2;
  bool direct_io = 3;
  uint64 fh = 10;
  uint64 lock_owner = 11;
}

message fstat {
  uint64 fst_mode = 1;
  uint64 fst_ino = 2;
  uint64 fst_dev = 3;
  uint64 fst_rdev = 4;
  uint64 fst_nlink = 5;
  uint64 fst_uid = 6;
  uint64 fst_gid = 7;
  uint64 fst_size = 8;
  uint64 fst_atime = 9;
  uint64 fst_mtime = 10;
  uint64 fst_ctime = 11;
  uint64 fst_blksize = 12;
  uint64 fst_blocks = 13;
}

message timespec {
  int32 tv_sec = 1;
  int64 tv_nsec = 2;
}

message direntry {
  string name = 1;
  uint32 kind = 2;
}

// Service and RPCs
service LwsVfs {
  rpc SayHello(HelloRequest) returns (HelloReply) {}
  rpc GetConfig(GetConfigRequest) returns (GetConfigResponse) {}

  rpc fgetattr(GetattrRequest) returns (GetattrResponse) {}
  rpc fsetxattr(SetxattrRequest) returns (EmptyResponse) {}
  rpc faccess(AccessRequest) returns (EmptyResponse) {}
  rpc freaddir(ReaddirRequest) returns (ReaddirResponse) {}
  rpc fread(ReadRequest) returns (ReadResponse) {}
  rpc fopen(OpenRequest) returns (OpenResponse) {}
  rpc fwrite(WriteRequest) returns (WriteResponse) {}
  rpc fgetxattr(GetxattrRequest) returns (GetxattrResponse) {}
  rpc ftruncate(TruncateRequest) returns (EmptyResponse) {}
  rpc futimens(UtimensRequest) returns (EmptyResponse) {}
  rpc fchown(ChownRequest) returns (EmptyResponse) {}
  rpc frelease(ReleaseRequest) returns (EmptyResponse) {}
  rpc fmkdir(MkdirRequest) returns (EmptyResponse) {}
  rpc frmdir(RmdirRequest) returns (EmptyResponse) {}
  rpc fflush(FlushRequest) returns (EmptyResponse) {}
  rpc fopendir(OpendirRequest) returns (OpendirResponse) {}
  rpc freleasedir(ReleasedirRequest) returns (EmptyResponse) {}
  rpc fcreate(CreateRequest) returns (CreateResponse) {}
  rpc funlink(UnlinkRequest) returns (EmptyResponse) {}
  rpc frename(RenameRequest) returns (EmptyResponse) {}
}

// Hello
message HelloRequest { string name = 1; }
message HelloReply { string message = 1; RpcStatus status = 2; }

// Config
message GetConfigRequest {}
message GetConfigResponse { string config = 1; RpcStatus status = 2; }

// getattr
message GetattrRequest { string path = 1; file_info fi = 2; }
message GetattrResponse { fstat stat = 1; RpcStatus status = 2; }

// xattr
message SetxattrRequest { string path = 1; string name = 2; bytes value = 3; int64 size = 4; uint32 flags = 5; }
message GetxattrRequest { string path = 1; string name = 2; int64 size = 3; }
message GetxattrResponse { bytes value = 1; RpcStatus status = 2; }

// access
message AccessRequest { string path = 1; uint32 mask = 2; }

// readdir
message ReaddirRequest { string path = 1; uint32 offset = 2; file_info fi = 3; }
message ReaddirResponse { repeated direntry dirs = 1; RpcStatus status = 2; }

// open
message OpenRequest { string path = 1; file_info fi = 2; }
message OpenResponse { file_info fi = 1; RpcStatus status = 2; }

// read
message ReadRequest { string path = 1; uint64 offset = 2; int64 size = 3; file_info fi = 4; }
message ReadResponse { bytes data = 1; RpcStatus status = 2; }

// write
message WriteRequest { string path = 1; uint64 offset = 2; bytes data = 3; file_info fi = 4; }
message WriteResponse { uint64 written = 1; RpcStatus status = 2; }

// truncate
message TruncateRequest { string path = 1; int64 size = 2; }

// utimens
message UtimensRequest { string path = 1; repeated timespec ts = 2; }

// chown
message ChownRequest { string path = 1; int32 uid = 2; int32 gid = 3; }

// release/flush
message ReleaseRequest { string path = 1; file_info fi = 2; uint32 flush = 3; }
message FlushRequest { string path = 1; file_info fi = 2; }

// mkdir/rmdir
message MkdirRequest { string path = 1; uint32 mode = 2; }
message RmdirRequest { string path = 1; }

// opendir/releasedir
message OpendirRequest { string path = 1; }
message OpendirResponse { file_info fi = 1; RpcStatus status = 2; }
message ReleasedirRequest { string path = 1; file_info fi = 2; }

// create
message CreateRequest { string path = 1; uint32 mode = 2; }
message CreateResponse { file_info fi = 1; RpcStatus status = 2; }

// unlink
message UnlinkRequest { string path = 1; }

// rename
message RenameRequest { string path = 1; string new = 2; }

// Empty response with status only
message EmptyResponse { RpcStatus status = 1; }