syntax = "proto3";

package centrifugal.centrifuge.protocol;

option go_package = "github.com/centrifugal/protocol";

message Error {
  uint32 code = 1;
  string message = 2;
  bool temporary = 3;
}

message EmulationRequest {
  string node = 1;
  string session = 2;
  bytes data = 3;
}

// Command sent from a client to a server.
message Command {
  // Id of command to let client match replies to commands.
  uint32 id = 1;

  reserved 2, 3;

  // Client can send one of the following requests. Server will
  // only take the first non-null request out of these and may return an error if
  // client passed more than one request. We are not using oneof here due to JSON
  // interoperability concerns.
  ConnectRequest connect = 4;
  SubscribeRequest subscribe = 5;
  UnsubscribeRequest unsubscribe = 6;
  PublishRequest publish = 7;
  PresenceRequest presence = 8;
  PresenceStatsRequest presence_stats = 9;
  HistoryRequest history = 10;
  PingRequest ping = 11;
  SendRequest send = 12;
  RPCRequest rpc = 13;
  RefreshRequest refresh = 14;
  SubRefreshRequest sub_refresh = 15;
}

// Reply is sent from a server to a client is sent as a response to Command or
// can be an async server-to-client Push.
message Reply {
  // Id will only be set to a value > 0 for replies to commands. For pushes
  // coming from server to client it has zero value.
  uint32 id = 1;
  // Error can only be set in replies to commands. For pushes it is never set.
  Error error = 2;

  reserved 3;

  // ProtocolVersion2 server can send one of the following fields. We are not using
  // oneof here due to JSON interoperability concerns.
  Push push = 4;
  ConnectResult connect = 5;
  SubscribeResult subscribe = 6;
  UnsubscribeResult unsubscribe = 7;
  PublishResult publish = 8;
  PresenceResult presence = 9;
  PresenceStatsResult presence_stats = 10;
  HistoryResult history = 11;
  PingResult ping = 12;
  RPCResult rpc = 13;
  RefreshResult refresh = 14;
  SubRefreshResult sub_refresh = 15;
}

// Push can be sent to a client as part of Reply in case of bidirectional transport or
// without additional wrapping in case of unidirectional transports.
message Push {
  reserved 3;
  int64 id = 1; // Optional numeric channel ID to avoid sending string channel in Push (bandwidth optimization).
  string channel = 2;

  // Server can push one of the following fields to the client. We are
  // not using oneof here due to JSON interoperability concerns.
  Publication pub = 4;
  Join join = 5;
  Leave leave = 6;
  Unsubscribe unsubscribe = 7;
  Message message = 8;
  Subscribe subscribe = 9;
  Connect connect = 10;
  Disconnect disconnect = 11;
  Refresh refresh = 12;
}

// ClientInfo contains information about client connection.
message ClientInfo {
  string user = 1;
  string client = 2;
  bytes conn_info = 3;
  bytes chan_info = 4;
}

// Publication in channel.
message Publication {
  reserved 1, 2, 3;
  bytes data = 4; // Data contains publication payload.
  ClientInfo info = 5; // Info contains optional information about publisher. Usually it is set only if publication goes from the client side.
  uint64 offset = 6; // Offset is a stream offset of the publication. Epoch is given in SubscribeResult.
  map<string, string> tags = 7; // Optional tags associated with publication.
  bool delta = 8;  // When set indicates that data in Publication is a delta from previous data.
  int64 time = 9;  // Optional time of publication as Unix timestamp milliseconds.
  string channel = 10; // Optional channel name if Publication relates to wildcard subscription.
}

// Join to channel.
message Join {
  ClientInfo info = 1;
}

// Leave from channel.
message Leave {
  ClientInfo info = 1;
}

// Unsubscribe from channel.
message Unsubscribe {
  reserved 1;
  uint32 code = 2;
  string reason = 3;
}

// Subscribe to channel, used for server-side subscriptions.
message Subscribe {
  bool recoverable = 1;
  reserved 2, 3;
  string epoch = 4;
  uint64 offset = 5;
  bool positioned = 6;
  bytes data = 7;
}

// Message from client to server. No Reply is sent in response to Message.
message Message {
  bytes data = 1;
}

message Connect {
  string client = 1;
  string version = 2;
  bytes data = 3;
  map<string, SubscribeResult> subs = 4;
  bool expires = 5;
  uint32 ttl = 6;
  uint32 ping = 7;
  bool pong = 8;
  string session = 9;
  string node = 10;
  int64 time = 11; // Server time as Unix timestamp in milliseconds (not sent by default).
}

message Disconnect {
  uint32 code = 1;
  string reason = 2;
  bool reconnect = 3;
}

message Refresh {
  bool expires = 1;
  uint32 ttl = 2;
}

message ConnectRequest {
  string token = 1;
  bytes data = 2;
  map<string, SubscribeRequest> subs = 3;
  string name = 4;
  string version = 5;
  map<string, string> headers = 6;
  int64 flag = 7; // Enable connection level features.
}

message ConnectResult {
  string client = 1;
  string version = 2;
  bool expires = 3;
  uint32 ttl = 4;
  bytes data = 5;
  map<string, SubscribeResult> subs = 6;
  uint32 ping = 7;
  bool pong = 8;
  string session = 9;
  string node = 10;
  int64 time = 11; // Server time as Unix timestamp in milliseconds (not sent by default).
}

message RefreshRequest {
  string token = 1;
}

message RefreshResult {
  string client = 1;
  string version = 2;
  bool expires = 3;
  uint32 ttl = 4;
}

message SubscribeRequest {
  string channel = 1;
  string token = 2;
  bool recover = 3;
  reserved 4, 5;
  string epoch = 6;
  uint64 offset = 7;
  bytes data = 8;
  bool positioned = 9;
  bool recoverable = 10;
  bool join_leave = 11;
  string delta = 12;
  FilterNode tf = 13; // Optional server side filter based on publication tags .
  int64 flag = 14; // Enable subscription level features.
}

message SubscribeResult {
  bool expires = 1;
  uint32 ttl = 2;
  bool recoverable = 3;
  reserved 4, 5;
  string epoch = 6;
  repeated Publication publications = 7;
  bool recovered = 8;
  uint64 offset = 9;
  bool positioned = 10;
  bytes data = 11;
  bool was_recovering = 12;
  bool delta = 13;
  int64 id = 14; // Optional numeric channel ID to avoid sending string channel in the following Pushes (bandwidth optimization).
}

message SubRefreshRequest {
  string channel = 1;
  string token = 2;
}

message SubRefreshResult {
  bool expires = 1;
  uint32 ttl = 2;
}

message UnsubscribeRequest {
  string channel = 1;
}

message UnsubscribeResult {}

message PublishRequest {
  string channel = 1;
  bytes data = 2;
}

message PublishResult {}

message PresenceRequest {
  string channel = 1;
}

message PresenceResult {
  map<string, ClientInfo> presence = 1;
}

message PresenceStatsRequest {
  string channel = 1;
}

message PresenceStatsResult {
  uint32 num_clients = 1;
  uint32 num_users = 2;
}

message StreamPosition {
  uint64 offset = 1;
  string epoch = 2;
}

message HistoryRequest {
  string channel = 1;
  reserved 2, 3, 4, 5, 6;
  int32 limit = 7;
  StreamPosition since = 8;
  bool reverse = 9;
}

message HistoryResult {
  repeated Publication publications = 1;
  string epoch = 2;
  uint64 offset = 3;
}

message PingRequest {}

message PingResult {}

message RPCRequest{
  bytes data = 1;
  string method = 2;
}

message RPCResult {
  bytes data = 1 ;
}

message SendRequest{
  bytes data = 1;
}

message FilterNode {
  // Operation type for this node:
  // - "" (empty string) → leaf node (comparison)
  // - "and" → logical AND of child nodes
  // - "or"  → logical OR of child nodes
  // - "not" → logical NOT of a single child node
  string op = 1;
  // Key for comparison (only valid for leaf nodes).
  string key = 2;
  // Comparison operator for leaf nodes.
  // Only meaningful if op == "".
  // Supported values:
  //   "eq"   → equal
  //   "neq"  → not equal
  //   "in"   → value is in vals
  //   "nin"  → value is not in vals
  //   "ex"   → key exists in tags
  //   "nex"  → key does not exist
  //   "sw"   → string starts with val
  //   "ew"   → string ends with val
  //   "ct"   → string contains val
  //   "lt"   → numeric less than val
  //   "lte"  → numeric less than or equal val
  //   "gt"   → numeric greater than val
  //   "gte"  → numeric greater than or equal val
  string cmp = 3;
  // Single value used in most comparisons (e.g. "eq").
  string val = 4;
  // Multiple values used for set comparisons ("in", "nin").
  repeated string vals = 5;
  // Child nodes.
  // Used for logical operations: "and", "or", "not".
  repeated FilterNode nodes = 6;
}