syntax = "proto3";

package worker_pb;

option go_package = "github.com/seaweedfs/seaweedfs/weed/pb/worker_pb";

// WorkerService provides bidirectional communication between admin and worker
service WorkerService {
  // WorkerStream maintains a bidirectional stream for worker communication
  rpc WorkerStream(stream WorkerMessage) returns (stream AdminMessage);
}

// WorkerMessage represents messages from worker to admin
message WorkerMessage {
  string worker_id = 1;
  int64 timestamp = 2;
  
  oneof message {
    WorkerRegistration registration = 3;
    WorkerHeartbeat heartbeat = 4;
    TaskRequest task_request = 5;
    TaskUpdate task_update = 6;
    TaskComplete task_complete = 7;
    WorkerShutdown shutdown = 8;
  }
}

// AdminMessage represents messages from admin to worker
message AdminMessage {
  string admin_id = 1;
  int64 timestamp = 2;
  
  oneof message {
    RegistrationResponse registration_response = 3;
    HeartbeatResponse heartbeat_response = 4;
    TaskAssignment task_assignment = 5;
    TaskCancellation task_cancellation = 6;
    AdminShutdown admin_shutdown = 7;
  }
}

// WorkerRegistration message when worker connects
message WorkerRegistration {
  string worker_id = 1;
  string address = 2;
  repeated string capabilities = 3;
  int32 max_concurrent = 4;
  map<string, string> metadata = 5;
}

// RegistrationResponse confirms worker registration
message RegistrationResponse {
  bool success = 1;
  string message = 2;
  string assigned_worker_id = 3;
}

// WorkerHeartbeat sent periodically by worker
message WorkerHeartbeat {
  string worker_id = 1;
  string status = 2;
  int32 current_load = 3;
  int32 max_concurrent = 4;
  repeated string current_task_ids = 5;
  int32 tasks_completed = 6;
  int32 tasks_failed = 7;
  int64 uptime_seconds = 8;
}

// HeartbeatResponse acknowledges heartbeat
message HeartbeatResponse {
  bool success = 1;
  string message = 2;
}

// TaskRequest from worker asking for new tasks
message TaskRequest {
  string worker_id = 1;
  repeated string capabilities = 2;
  int32 available_slots = 3;
}

// TaskAssignment from admin to worker
message TaskAssignment {
  string task_id = 1;
  string task_type = 2;
  TaskParams params = 3;
  int32 priority = 4;
  int64 created_time = 5;
  map<string, string> metadata = 6;
}

// TaskParams contains task-specific parameters
message TaskParams {
  uint32 volume_id = 1;
  string server = 2;
  string collection = 3;
  string data_center = 4;
  string rack = 5;
  repeated string replicas = 6;
  map<string, string> parameters = 7;
}

// TaskUpdate reports task progress
message TaskUpdate {
  string task_id = 1;
  string worker_id = 2;
  string status = 3;
  float progress = 4;
  string message = 5;
  map<string, string> metadata = 6;
}

// TaskComplete reports task completion
message TaskComplete {
  string task_id = 1;
  string worker_id = 2;
  bool success = 3;
  string error_message = 4;
  int64 completion_time = 5;
  map<string, string> result_metadata = 6;
}

// TaskCancellation from admin to cancel a task
message TaskCancellation {
  string task_id = 1;
  string reason = 2;
  bool force = 3;
}

// WorkerShutdown notifies admin that worker is shutting down
message WorkerShutdown {
  string worker_id = 1;
  string reason = 2;
  repeated string pending_task_ids = 3;
}

// AdminShutdown notifies worker that admin is shutting down
message AdminShutdown {
  string reason = 1;
  int32 graceful_shutdown_seconds = 2;
}