syntax = "proto3";

package forest.v1;

// RunnerService is exposed by the forest-server. Runners (workers) call these
// RPCs to register for work, fetch release artifacts, stream logs, and report
// completion. Authentication for all post-assignment RPCs uses a release-scoped
// opaque token rather than the regular JWT flow.
service RunnerService {
  // Bidirectional stream used for runner registration and work assignment.
  // The runner sends a RunnerRegister as its first message, then periodic
  // RunnerHeartbeat messages. The server responds with a RegisterAck followed
  // by WorkAssignment messages when releases matching the runner's capabilities
  // become available.
  rpc RegisterRunner(stream RunnerMessage) returns (stream ServerMessage);

  // Fetch the artifact files for a release assigned to this runner.
  // Scoped by the release_token received in the WorkAssignment.
  rpc GetReleaseFiles(GetReleaseFilesRequest) returns (stream ReleaseFile);

  // Stream log lines back to the server for real-time display.
  // Each message must include the release_token for authentication.
  rpc PushLogs(stream PushLogRequest) returns (PushLogResponse);

  // Fetch the original spec files for a release.
  // Scoped by the release_token received in the WorkAssignment.
  rpc GetSpecFiles(GetSpecFilesRequest) returns (stream ReleaseFile);

  // Fetch the annotation (metadata context) for a release.
  rpc GetReleaseAnnotation(GetReleaseAnnotationRequest) returns (ReleaseAnnotationResponse);

  // Fetch project info (organisation + project name) for a release.
  rpc GetProjectInfo(GetProjectInfoRequest) returns (ProjectInfoResponse);

  // Report the final outcome of a release (success or failure).
  // This commits the release status and revokes the token.
  rpc CompleteRelease(CompleteReleaseRequest) returns (CompleteReleaseResponse);
}

// ============================================================================
// Connect stream: Runner → Server
// ============================================================================

message RunnerMessage {
  oneof message {
    RunnerRegister register = 1;
    RunnerHeartbeat heartbeat = 2;
    WorkAck work_ack = 3;
  }
}

// First message a runner sends on the Connect stream.
message RunnerRegister {
  // Runner-chosen unique identifier. If empty, the server assigns one.
  string runner_id = 1;
  // Destination types this runner can handle.
  repeated DestinationCapability capabilities = 2;
  // Maximum number of simultaneous releases this runner can process.
  int32 max_concurrent = 3;
}

// Describes a destination type the runner supports.
message DestinationCapability {
  string organisation = 1;
  string name = 2;
  uint64 version = 3;
}

// Periodic keepalive sent by the runner (recommended every 10s).
message RunnerHeartbeat {
  // Current number of in-progress releases on this runner.
  int32 active_releases = 1;
}

// Runner's response to a WorkAssignment.
message WorkAck {
  string release_token = 1;
  // false = runner rejects the work (e.g., overloaded). The server will
  // reassign or fall back to in-process execution.
  bool accepted = 2;
}

// ============================================================================
// Connect stream: Server → Runner
// ============================================================================

message ServerMessage {
  oneof message {
    RegisterAck register_ack = 1;
    WorkAssignment work_assignment = 2;
  }
}

// Server response to RunnerRegister.
message RegisterAck {
  // Server-confirmed (or server-assigned) runner ID.
  string runner_id = 1;
  bool accepted = 2;
  string reason = 3;
}

// Work assignment pushed to a runner when a matching release is available.
message WorkAssignment {
  // Scoped opaque auth token. Use this for GetReleaseFiles, PushLogs,
  // and CompleteRelease. The token restricts access to only the data
  // associated with this specific release.
  string release_token = 1;
  string release_id = 2;
  string release_intent_id = 3;
  string artifact_id = 4;
  string destination_id = 5;
  // Full destination configuration including metadata.
  DestinationInfo destination = 6;
}

// Destination configuration sent with the work assignment.
message DestinationInfo {
  string name = 1;
  string environment = 2;
  map<string, string> metadata = 3;
  DestinationCapability type = 4;
  string organisation = 5;
}

// ============================================================================
// GetReleaseFiles
// ============================================================================

message GetReleaseFilesRequest {
  string release_token = 1;
}

message ReleaseFile {
  string file_name = 1;
  string file_content = 2;
}

// ============================================================================
// GetSpecFiles
// ============================================================================

message GetSpecFilesRequest {
  string release_token = 1;
}

// ============================================================================
// GetReleaseAnnotation
// ============================================================================

message GetReleaseAnnotationRequest {
  string release_token = 1;
}

message ReleaseAnnotationResponse {
  string slug = 1;
  string source_username = 2;
  string source_email = 3;
  string context_title = 4;
  string context_description = 5;
  string context_web = 6;
  string reference_version = 7;
  string reference_commit_sha = 8;
  string reference_commit_branch = 9;
  string reference_commit_message = 10;
  string created_at = 11;
}

// ============================================================================
// GetProjectInfo
// ============================================================================

message GetProjectInfoRequest {
  string release_token = 1;
}

message ProjectInfoResponse {
  string organisation = 1;
  string project = 2;
}

// ============================================================================
// PushLogs
// ============================================================================

message PushLogRequest {
  string release_token = 1;
  // "stdout" or "stderr"
  string channel = 2;
  string line = 3;
  uint64 timestamp = 4;
}

message PushLogResponse {}

// ============================================================================
// CompleteRelease
// ============================================================================

message CompleteReleaseRequest {
  string release_token = 1;
  ReleaseOutcome outcome = 2;
  // Error description when outcome is FAILURE.
  string error_message = 3;
}

enum ReleaseOutcome {
  RELEASE_OUTCOME_UNSPECIFIED = 0;
  RELEASE_OUTCOME_SUCCESS = 1;
  RELEASE_OUTCOME_FAILURE = 2;
}

message CompleteReleaseResponse {}