syntax = "proto3";

package api;

option go_package = "github.com/psviderski/uncloud/internal/machine/api/pb";

import "google/protobuf/duration.proto";

// Lease provides atomic operations for time-bound ownership of resources on a single machine.
service Lease {
  // Acquire creates a lease when the resource has no unexpired lease.
  rpc Acquire(AcquireLeaseRequest) returns (AcquireLeaseResponse);
  // Renew extends an unexpired lease when its ownership token matches.
  rpc Renew(RenewLeaseRequest) returns (RenewLeaseResponse);
  // Release removes an unexpired lease when its ownership token matches.
  rpc Release(ReleaseLeaseRequest) returns (ReleaseLeaseResponse);
}

message AcquireLeaseRequest {
  string resource = 1;
  // Token uniquely identifies the lease owner.
  bytes token = 2;
  // TTL sets how long the lease remains valid without renewal.
  google.protobuf.Duration ttl = 3;
}

message AcquireLeaseResponse {
  // Acquired is true when this request successfully created the lease.
  bool acquired = 1;
}

message RenewLeaseRequest {
  string resource = 1;
  // Token identifies the owner of the existing lease.
  bytes token = 2;
  // TTL sets how long the renewed lease remains valid.
  google.protobuf.Duration ttl = 3;
}

message RenewLeaseResponse {
  // Renewed is true when an unexpired lease matched the ownership token and was successfully renewed.
  bool renewed = 1;
}

message ReleaseLeaseRequest {
  string resource = 1;
  // Token identifies the owner of the existing lease.
  bytes token = 2;
}

message ReleaseLeaseResponse {
  // Released is true when an unexpired lease existed, matched the ownership token, and was successfully released.
  bool released = 1;
}