syntax = "proto3";
package object;

option go_package = "./;object";

message GRN {
  // the tenant/org id
  int64 tenant_id = 1;

  // mabybe "namespace"?  valid values include
  // * entity
  // * drive
  // * service/xyz
  string scope = 2;

  // Identify the object kind.  This kind will be used to apply a schema to the body and
  // will trigger additional indexing behavior.
  string kind = 3;

  // Unique ID
  string UID = 4;
}

// The canonical object/document data -- this represents the raw bytes and storage level metadata
message RawObject {
  // Object identifier
  GRN GRN = 1;

  // Time in epoch milliseconds that the object was created
  int64 created_at = 2;

  // Time in epoch milliseconds that the object was updated
  int64 updated_at = 3;

  // Who created the object
  string created_by = 4;

  // Who updated the object
  string updated_by = 5;

  // Content Length
  int64 size = 6;

  // MD5 digest of the body
  string ETag = 7;

  // Raw bytes of the storage object.  The kind will determine what is a valid payload
  bytes body = 8;

  // The version will change when the object is saved. It is not necessarily sortable
  //
  // NOTE: currently managed by the dashboard+dashboard_version tables
  string version = 9;

  // External location info
  ObjectOriginInfo origin = 10;
}

message ObjectOriginInfo {
  // NOTE: currently managed by the dashboard_provisioning table
  string source = 1;

  // Time in epoch milliseconds that the object was last synced with an external system (provisioning/git)
  int64 time = 2;
}

// Report error while working with objects
// NOTE: real systems at scale will contain errors.
message ObjectErrorInfo {
  // Match an error code registry?
  int64 code = 1;

  // Simple error display
  string message = 2;

  // Details encoded in JSON
  bytes details_json = 3;
}

// This is a subset of RawObject that does not include body or sync info
message ObjectVersionInfo {
  // The version will change when the object is saved. It is not necessarily sortable
  string version = 1;

  // Time in epoch milliseconds that the object was updated
  int64 updated_at = 2;

  // Who updated the object
  string updated_by = 3;

  // Content Length
  int64 size = 4;

  // MD5 digest of the body
  string ETag = 5;

  // optional "save" or "commit" message
  //
  // NOTE: currently managed by the dashboard_version table, and will be returned from a "history" command
  string comment = 6;
}

//-----------------------------------------------
// Get request/response
//-----------------------------------------------

message ReadObjectRequest {
  // Object identifier
  GRN GRN = 1;

  // Fetch an explicit version
  string version = 2;

  // Include the full body bytes
  bool with_body = 3;

  // Include derived summary metadata
  bool with_summary = 4;
}

message ReadObjectResponse {
  // Object details with the body removed
  RawObject object = 1; 

  // Object summary as JSON
  bytes summary_json = 2;
}

//------------------------------------------------------
// Make many read requests at once (by Kind+ID+version)
//------------------------------------------------------

message BatchReadObjectRequest {
  repeated ReadObjectRequest batch = 1;
}

message BatchReadObjectResponse {
  repeated ReadObjectResponse results = 1;
}

//-----------------------------------------------
// Write request/response
//-----------------------------------------------

message WriteObjectRequest {
  // Object identifier
  GRN GRN = 1;

  // The raw object body
  bytes body = 2;

  // Message that can be seen when exploring object history
  string comment = 3;

  // Used for optimistic locking.  If missing, the previous version will be replaced regardless
  string previous_version = 4;
}

// This operation is useful when syncing a resource from external sources
// that have more accurate metadata information (git, or an archive).
// This process can bypass the forced checks that 
message AdminWriteObjectRequest {
  // Object identifier
  GRN GRN = 1;

  // The raw object body
  bytes body = 2;

  // Message that can be seen when exploring object history
  string comment = 3;

  // Time in epoch milliseconds that the object was created
  // Optional, if 0 it will use the current time
  int64 created_at = 4;

  // Time in epoch milliseconds that the object was updated
  // Optional, if empty it will use the current user
  int64 updated_at = 5;

  // Who created the object
  // Optional, if 0 it will use the current time
  string created_by = 6;

  // Who updated the object
  // Optional, if empty it will use the current user
  string updated_by = 7;

  // An explicit version identifier
  // Optional, if set, this will overwrite/define an explicit version
  string version = 8;

  // Used for optimistic locking.  If missing, the previous version will be replaced regardless
  // This may not be used along with an explicit version in the request
  string previous_version = 9;

  // Request that all previous versions are removed from the history
  // This will make sense for systems that manage history explicitly externallay
  bool clear_history = 10;

  // Optionally define where the object came from
  string origin = 11;
}

message WriteObjectResponse {
  // Error info -- if exists, the save did not happen
  ObjectErrorInfo error = 1;

  // Object identifier
  GRN GRN = 2;

  // Object details with the body removed
  ObjectVersionInfo object = 3; 

  // Object summary as JSON
  bytes summary_json = 4;

  // Status code
  Status status = 5;

  // Status enumeration
  enum Status {
    ERROR = 0;
    CREATED = 1;
    UPDATED = 2;
    UNCHANGED = 3;
  }
}

//-----------------------------------------------
// Delete request/response
//-----------------------------------------------

message DeleteObjectRequest {
  // Object identifier
  GRN GRN = 1;

  // Used for optimistic locking.  If missing, the previous version will be replaced regardless
  string previous_version = 3;
}

message DeleteObjectResponse {
  bool OK = 1;
}

//-----------------------------------------------
// History request/response
//-----------------------------------------------

message ObjectHistoryRequest {
  // Object identifier
  GRN GRN = 1;

  // Maximum number of items to return
  int64 limit = 3; 

  // Starting from the requested page
  string next_page_token = 5;
}

message ObjectHistoryResponse {
  // Object identifier
  GRN GRN = 1;

  // Object metadata without the raw bytes
  repeated ObjectVersionInfo versions = 2;

  // More results exist... pass this in the next request
  string next_page_token = 3;
}


//-----------------------------------------------
// List request/response
//-----------------------------------------------

message ObjectSearchRequest {
  // Starting from the requested page (other query parameters must match!)
  string next_page_token = 1;

  // Maximum number of items to return
  int64 limit = 2; 

  // Free text query string -- mileage may vary :)
  string query = 3;

  // limit to a specific kind (empty is all)
  repeated string kind = 4;

  // Limit results to items in a specific folder
  string folder = 5;

  // Must match all labels
  map<string,string> labels = 6;

  // Sorting instructions `field ASC/DESC`
  repeated string sort = 7;

  // Return the full body in each payload
  bool with_body = 8;

  // Return the full body in each payload
  bool with_labels = 9;

  // Return the full body in each payload
  bool with_fields = 10;
}

// Search result metadata for each object
message ObjectSearchResult {
  // Object identifier
  GRN GRN = 1;

  // The current veresion of this object
  string version = 2;

  // Content Length
  int64 size = 3;

  // Time in epoch milliseconds that the object was updated
  int64 updated_at = 4;

  // Who updated the object
  string updated_by = 5;

  // Optionally include the full object body
  bytes body = 6;

  //----------------------------------------
  // Derived from body in the summary
  //----------------------------------------

  // Always included
  string name = 7;

  // Always included
  string description = 8;

  // The structured labels
  map<string,string> labels = 9;

  // Optionally include extracted JSON
  bytes fields_json = 10;

  // ObjectErrorInfo in json
  bytes error_json = 11;
}

message ObjectSearchResponse {
  repeated ObjectSearchResult results = 1;

  // More results exist... pass this in the next request
  string next_page_token = 2;
}


//-----------------------------------------------
// Storage interface
//-----------------------------------------------

// The object store provides a basic CRUD (+watch eventually) interface for generic objects
service ObjectStore {
  rpc Read(ReadObjectRequest) returns (ReadObjectResponse);
  rpc BatchRead(BatchReadObjectRequest) returns (BatchReadObjectResponse);
  rpc Write(WriteObjectRequest) returns (WriteObjectResponse);
  rpc Delete(DeleteObjectRequest) returns (DeleteObjectResponse);
  rpc History(ObjectHistoryRequest) returns (ObjectHistoryResponse);
  rpc Search(ObjectSearchRequest) returns (ObjectSearchResponse);

// Ideally an additional search endpoint with more flexibility to limit what you actually care about
//  https://github.com/grafana/grafana-plugin-sdk-go/blob/main/proto/backend.proto#L129
//  rpc SearchEX(ObjectSearchRequest) returns (DataResponse);

  // TEMPORARY... while we split this into a new service (see below)
  rpc AdminWrite(AdminWriteObjectRequest) returns (WriteObjectResponse);
}

// The admin service extends the basic object store interface, but provides
// more explicit control that can support bulk operations like efficient git sync
service ObjectStoreAdmin {
  rpc AdminWrite(AdminWriteObjectRequest) returns (WriteObjectResponse);
}