syntax = "proto3";

package gospeak.livedemo.v1;

option go_package = "gospeak-live-sfu-demo/gen";

// LiveSFU 是直播 SFU 分流 Demo 的控制面契约（protobuf / gRPC）。
//
// 媒体面（WebRTC SDP 交换）不在此契约内：浏览器与 Cloudflare Realtime / SRS
// 直连，经本服务反向代理转发（服务端注入 AppSecret / stream token）。
// 本契约只负责房间、后端、发布/订阅拓扑的协调与扇出状态广播。
service LiveSFU {
  rpc GetConfig(GetConfigRequest) returns (GetConfigResponse);
  rpc ListRooms(ListRoomsRequest) returns (ListRoomsResponse);
  rpc Publish(PublishRequest) returns (PublishResponse);
  rpc Subscribe(SubscribeRequest) returns (SubscribeResponse);
  rpc StopStream(StopStreamRequest) returns (StopStreamResponse);
  rpc WatchRoom(WatchRoomRequest) returns (stream RoomEvent);
}

enum BackendKind {
  BACKEND_KIND_UNSPECIFIED = 0;
  BACKEND_KIND_CLOUDFLARE = 1; // Cloudflare Realtime（主 SFU）
  BACKEND_KIND_SRS = 2;        // SRS（次级 / 本地对照）
}

message IceServer {
  repeated string urls = 1;
  string username = 2;
  string credential = 3;
}

message GetConfigRequest {}

message BackendInfo {
  BackendKind kind = 1;
  string name = 2;
  bool configured = 3;
  bool primary = 4;
}

message GetConfigResponse {
  repeated BackendInfo backends = 1;
  string candidate = 2;
  bool token_required = 3;
}

// StreamTarget 表示一个房间在某后端的一条分发目标（SFU 扇出出口）。
message StreamTarget {
  BackendKind backend = 1;
  string session_id = 2;  // Cloudflare: 发布者 sessionId
  string stream = 3;      // SRS: stream 名
  string publish_token = 4;// SRS: 推流 JWT（可选）
  string url = 5;         // 拉流播放地址（SRS WHEP，可选）
  int64 published_at = 6;
}

message Room {
  string name = 1;
  repeated StreamTarget targets = 2;
}

message ListRoomsRequest {}
message ListRoomsResponse {
  repeated Room rooms = 1;
}

message PublishRequest {
  string room = 1;
  BackendKind backend = 2;
  string identity = 3;
}
message PublishResponse {
  string session_id = 1;
  string stream = 2;
  string publish_token = 3;
  repeated IceServer ice_servers = 4;
  StreamTarget target = 5;
}

message SubscribeRequest {
  string room = 1;
  BackendKind backend = 2;
  string identity = 3;
}
message SubscribeResponse {
  string session_id = 1;
  string stream = 2;
  string publisher_session_id = 3;
  repeated IceServer ice_servers = 4;
}

message StopStreamRequest {
  string room = 1;
  BackendKind backend = 2;
}
message StopStreamResponse {
  bool ok = 1;
}

message WatchRoomRequest {
  string room = 1;
}
message RoomEvent {
  string room = 1;
  repeated StreamTarget targets = 2;
}