// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

syntax = "proto2";

option java_multiple_files = true;
option java_package = "org.chromium.components.sync.protocol";

package sync_pb;

import "google/protobuf/descriptor.proto";

// Configuration for per-field attribution in collaborative Sync data types.
// Attaching this as an option to a field within a Sync entity's proto
// definition (e.g., in a SharedTab or SharedTabGroup) enables the tracking of
// metadata related to cross-user collaboration, such as which user last
// modified that specific field.
message SyncCollaborationAttribution {
  enum AttributionType {
    // Default value. No attribution tracking for this field.
    NONE = 0;
    // Track the user who last modified this field.
    LAST_MODIFIED_BY_USER = 1;
  }

  // Specifies the type of attribution to be applied to the annotated field.
  optional AttributionType attribution_type = 1;

  // A stable identifier for the annotated field, used to distinguish it from
  // other fields within the same Chrome Sync data type message that also
  // have attribution annotations. This identifier is used to associate
  // attribution information (like the last modifier) with this specific field
  // of the Sync Entity.
  //
  // This name is also used in the metadata of SyncEntity that are sent to
  // clients, such that the client code key to find the related attribution
  // data.
  //
  // Because of this, the name MUST be unique across all fields annotated with
  // `sync_collaboration_attribution` within a single EntitySpecifics. For
  // example, all `name` values within `SharedTabGroupData` must be distinct.
  //
  // Recommended format: `lower_snake_case`.
  // Examples: "tab_group_title", "tab_url", "tab_group_color".
  optional string name = 2;
}

extend google.protobuf.FieldOptions {
  // IMPORTANT: the extension number needs to be declared. See
  // go/extension-declaration-reserved-numbers for more information.
  optional SyncCollaborationAttribution sync_collaboration_attribution =
      535801565;
}