// Copyright 2025 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

package google.cloud.retail.v2alpha;

import "google/api/annotations.proto";
import "google/api/client.proto";
import "google/api/field_behavior.proto";
import "google/api/resource.proto";
import "google/cloud/retail/v2alpha/user_event.proto";
import "google/protobuf/struct.proto";

option csharp_namespace = "Google.Cloud.Retail.V2Alpha";
option go_package = "cloud.google.com/go/retail/apiv2alpha/retailpb;retailpb";
option java_multiple_files = true;
option java_outer_classname = "PredictionServiceProto";
option java_package = "com.google.cloud.retail.v2alpha";
option objc_class_prefix = "RETAIL";
option php_namespace = "Google\\Cloud\\Retail\\V2alpha";
option ruby_package = "Google::Cloud::Retail::V2alpha";

// Service for making recommendation prediction.
service PredictionService {
  option (google.api.default_host) = "retail.googleapis.com";
  option (google.api.oauth_scopes) =
      "https://www.googleapis.com/auth/cloud-platform";

  // Makes a recommendation prediction.
  rpc Predict(PredictRequest) returns (PredictResponse) {
    option (google.api.http) = {
      post: "/v2alpha/{placement=projects/*/locations/*/catalogs/*/placements/*}:predict"
      body: "*"
      additional_bindings {
        post: "/v2alpha/{placement=projects/*/locations/*/catalogs/*/servingConfigs/*}:predict"
        body: "*"
      }
    };
  }
}

// Request message for Predict method.
message PredictRequest {
  // Required. Full resource name of the format:
  // `{placement=projects/*/locations/global/catalogs/default_catalog/servingConfigs/*}`
  // or
  // `{placement=projects/*/locations/global/catalogs/default_catalog/placements/*}`.
  // We recommend using the `servingConfigs` resource. `placements` is a legacy
  // resource.
  // The ID of the Recommendations AI serving config or placement.
  // Before you can request predictions from your model, you must create at
  // least one serving config or placement for it. For more information, see
  // [Manage serving configs]
  // (https://cloud.google.com/retail/docs/manage-configs).
  //
  // The full list of available serving configs can be seen at
  // https://console.cloud.google.com/ai/retail/catalogs/default_catalog/configs
  string placement = 1 [(google.api.field_behavior) = REQUIRED];

  // Required. Context about the user, what they are looking at and what action
  // they took to trigger the predict request. Note that this user event detail
  // won't be ingested to userEvent logs. Thus, a separate userEvent write
  // request is required for event logging.
  //
  // Don't set
  // [UserEvent.visitor_id][google.cloud.retail.v2alpha.UserEvent.visitor_id] or
  // [UserInfo.user_id][google.cloud.retail.v2alpha.UserInfo.user_id] to the
  // same fixed ID for different users. If you are trying to receive
  // non-personalized recommendations (not recommended; this can negatively
  // impact model performance), instead set
  // [UserEvent.visitor_id][google.cloud.retail.v2alpha.UserEvent.visitor_id] to
  // a random unique ID and leave
  // [UserInfo.user_id][google.cloud.retail.v2alpha.UserInfo.user_id] unset.
  UserEvent user_event = 2 [(google.api.field_behavior) = REQUIRED];

  // Maximum number of results to return. Set this property to the number of
  // prediction results needed. If zero, the service will choose a reasonable
  // default. The maximum allowed value is 100. Values above 100 will be coerced
  // to 100.
  int32 page_size = 3;

  // This field is not used; leave it unset.
  string page_token = 4 [deprecated = true];

  // Filter for restricting prediction results with a length limit of 5,000
  // characters. Accepts values for tags and the `filterOutOfStockItems` flag.
  //
  //  * Tag expressions. Restricts predictions to products that match all of the
  //    specified tags. Boolean operators `OR` and `NOT` are supported if the
  //    expression is enclosed in parentheses, and must be separated from the
  //    tag values by a space. `-"tagA"` is also supported and is equivalent to
  //    `NOT "tagA"`. Tag values must be double quoted UTF-8 encoded strings
  //    with a size limit of 1,000 characters.
  //
  //    Note: "Recently viewed" models don't support tag filtering at the
  //    moment.
  //
  //  * filterOutOfStockItems. Restricts predictions to products that do not
  //  have a
  //    stockState value of OUT_OF_STOCK.
  //
  // Examples:
  //
  //  * tag=("Red" OR "Blue") tag="New-Arrival" tag=(NOT "promotional")
  //  * filterOutOfStockItems  tag=(-"promotional")
  //  * filterOutOfStockItems
  //
  // If your filter blocks all prediction results, the API will return *no*
  // results. If instead you want empty result sets to return generic
  // (unfiltered) popular products, set `strictFiltering` to False in
  // `PredictRequest.params`. Note that the API will never return items with
  // storageStatus of "EXPIRED" or "DELETED" regardless of filter choices.
  //
  // If `filterSyntaxV2` is set to true under the `params` field, then
  // attribute-based expressions are expected instead of the above described
  // tag-based syntax. Examples:
  //
  //  * (colors: ANY("Red", "Blue")) AND NOT (categories: ANY("Phones"))
  //  * (availability: ANY("IN_STOCK")) AND
  //    (colors: ANY("Red") OR categories: ANY("Phones"))
  //
  // For more information, see
  // [Filter recommendations](https://cloud.google.com/retail/docs/filter-recs).
  string filter = 5;

  // Use validate only mode for this prediction query. If set to true, a
  // dummy model will be used that returns arbitrary products.
  // Note that the validate only mode should only be used for testing the API,
  // or if the model is not ready.
  bool validate_only = 6;

  // Additional domain specific parameters for the predictions.
  //
  // Allowed values:
  //
  // * `returnProduct`: Boolean. If set to true, the associated product
  //    object will be returned in the `results.metadata` field in the
  //    prediction response.
  // * `returnScore`: Boolean. If set to true, the prediction 'score'
  //    corresponding to each returned product will be set in the
  //    `results.metadata` field in the prediction response. The given
  //    'score' indicates the probability of a product being clicked/purchased
  //    given the user's context and history.
  // * `strictFiltering`: Boolean. True by default. If set to false, the service
  //    will return generic (unfiltered) popular products instead of empty if
  //    your filter blocks all prediction results.
  // * `priceRerankLevel`: String. Default empty. If set to be non-empty, then
  //    it needs to be one of {'no-price-reranking', 'low-price-reranking',
  //    'medium-price-reranking', 'high-price-reranking'}. This gives
  //    request-level control and adjusts prediction results based on product
  //    price.
  // * `diversityLevel`: String. Default empty. If set to be non-empty, then
  //    it needs to be one of {'no-diversity', 'low-diversity',
  //    'medium-diversity', 'high-diversity', 'auto-diversity'}. This gives
  //    request-level control and adjusts prediction results based on product
  //    category.
  // * `filterSyntaxV2`: Boolean. False by default. If set to true, the `filter`
  //   field is interpreteted according to the new, attribute-based syntax.
  map<string, google.protobuf.Value> params = 7;

  // The labels applied to a resource must meet the following requirements:
  //
  // * Each resource can have multiple labels, up to a maximum of 64.
  // * Each label must be a key-value pair.
  // * Keys have a minimum length of 1 character and a maximum length of 63
  //   characters and cannot be empty. Values can be empty and have a maximum
  //   length of 63 characters.
  // * Keys and values can contain only lowercase letters, numeric characters,
  //   underscores, and dashes. All characters must use UTF-8 encoding, and
  //   international characters are allowed.
  // * The key portion of a label must be unique. However, you can use the same
  //   key with multiple resources.
  // * Keys must start with a lowercase letter or international character.
  //
  // See [Google Cloud
  // Document](https://cloud.google.com/resource-manager/docs/creating-managing-labels#requirements)
  // for more details.
  map<string, string> labels = 8;
}

// Response message for predict method.
message PredictResponse {
  // PredictionResult represents the recommendation prediction results.
  message PredictionResult {
    // ID of the recommended product
    string id = 1;

    // Additional product metadata / annotations.
    //
    // Possible values:
    //
    // * `product`: JSON representation of the product. Is set if
    //   `returnProduct` is set to true in `PredictRequest.params`.
    // * `score`: Prediction score in double value. Is set if
    //   `returnScore` is set to true in `PredictRequest.params`.
    map<string, google.protobuf.Value> metadata = 2;
  }

  // A list of recommended products. The order represents the ranking (from the
  // most relevant product to the least).
  repeated PredictionResult results = 1;

  // A unique attribution token. This should be included in the
  // [UserEvent][google.cloud.retail.v2alpha.UserEvent] logs resulting from this
  // recommendation, which enables accurate attribution of recommendation model
  // performance.
  string attribution_token = 2;

  // IDs of products in the request that were missing from the inventory.
  repeated string missing_ids = 3;

  // True if the validateOnly property was set in the request.
  bool validate_only = 4;
}
