// Copyright 2020 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.dataqna.v1alpha;

import "google/api/annotations.proto";
import "google/api/field_behavior.proto";
import "google/api/resource.proto";
import "google/cloud/dataqna/v1alpha/annotated_string.proto";
import "google/api/client.proto";

option csharp_namespace = "Google.Cloud.DataQnA.V1Alpha";
option go_package = "cloud.google.com/go/dataqna/apiv1alpha/dataqnapb;dataqnapb";
option java_multiple_files = true;
option java_outer_classname = "AutoSuggestionServiceProto";
option java_package = "com.google.cloud.dataqna.v1alpha";
option php_namespace = "Google\\Cloud\\DataQnA\\V1alpha";
option ruby_package = "Google::Cloud::DataQnA::V1alpha";

// This stateless API provides automatic suggestions for natural language
// queries for the data sources in the provided project and location.
//
// The service provides a resourceless operation `suggestQueries` that can be
// called to get a list of suggestions for a given incomplete query and scope
// (or list of scopes) under which the query is to be interpreted.
//
// There are two types of suggestions, ENTITY for single entity suggestions
// and TEMPLATE for full sentences. By default, both types are returned.
//
// Example Request:
// ```
// GetSuggestions({
//   parent: "locations/us/projects/my-project"
//   scopes:
//   "//bigquery.googleapis.com/projects/my-project/datasets/my-dataset/tables/my-table"
//   query: "top it"
// })
// ```
//
// The service will retrieve information based on the given scope(s) and give
// suggestions based on that (e.g. "top item" for "top it" if "item" is a known
// dimension for the provided scope).
// ```
// suggestions {
//   suggestion_info {
//     annotated_suggestion {
//       text_formatted: "top item by sum of usd_revenue_net"
//       markups {
//         type: DIMENSION
//         start_char_index: 4
//         length: 4
//       }
//       markups {
//         type: METRIC
//         start_char_index: 19
//         length: 15
//       }
//     }
//     query_matches {
//       start_char_index: 0
//       length: 6
//     }
//   }
//   suggestion_type: TEMPLATE
//   ranking_score: 0.9
// }
// suggestions {
//   suggestion_info {
//     annotated_suggestion {
//       text_formatted: "item"
//       markups {
//         type: DIMENSION
//         start_char_index: 4
//         length: 2
//       }
//     }
//     query_matches {
//       start_char_index: 0
//       length: 6
//     }
//   }
//   suggestion_type: ENTITY
//   ranking_score: 0.8
// }
// ```
service AutoSuggestionService {
  option (google.api.default_host) = "dataqna.googleapis.com";
  option (google.api.oauth_scopes) = "https://www.googleapis.com/auth/cloud-platform";

  // Gets a list of suggestions based on a prefix string.
  // AutoSuggestion tolerance should be less than 1 second.
  rpc SuggestQueries(SuggestQueriesRequest) returns (SuggestQueriesResponse) {
    option (google.api.http) = {
      post: "/v1alpha/{parent=projects/*/locations/*}:suggestQueries"
      body: "*"
    };
  }
}

// Request for query suggestions.
message SuggestQueriesRequest {
  // Required. The parent of the suggestion query is the resource denoting the project and
  // location.
  string parent = 1 [
    (google.api.field_behavior) = REQUIRED,
    (google.api.resource_reference) = {
      type: "locations.googleapis.com/Location"
    }
  ];

  // The scopes to which this search is restricted. The only supported scope
  // pattern is
  // `//bigquery.googleapis.com/projects/{GCP-PROJECT-ID}/datasets/{DATASET-ID}/tables/{TABLE-ID}`.
  repeated string scopes = 2;

  // User query for which to generate suggestions. If the query is empty, zero
  // state suggestions are returned. This allows UIs to display suggestions
  // right away, helping the user to get a sense of what a query might look
  // like.
  string query = 3;

  // The requested suggestion type. Multiple suggestion types can be
  // requested, but there is no guarantee that the service will return
  // suggestions for each type. Suggestions for a requested type might rank
  // lower than suggestions for other types and the service may decide to cut
  // these suggestions off.
  repeated SuggestionType suggestion_types = 4;
}

// A suggestion for a query with a ranking score.
message Suggestion {
  // Detailed information about the suggestion.
  SuggestionInfo suggestion_info = 1;

  // The score of the suggestion. This can be used to define ordering in UI.
  // The score represents confidence in the suggestion where higher is better.
  // All score values must be in the range [0, 1).
  double ranking_score = 2;

  // The type of the suggestion.
  SuggestionType suggestion_type = 3;
}

// Detailed information about the suggestion.
message SuggestionInfo {
  // MatchInfo describes which part of suggestion matched with data in user
  // typed query. This can be used to highlight matching parts in the UI. This
  // is different from the annotations provided in annotated_suggestion. The
  // annotated_suggestion provides information about the semantic meaning, while
  // this provides information about how it relates to the input.
  //
  // Example:
  // user query: `top products`
  //
  // ```
  // annotated_suggestion {
  //  text_formatted = "top product_group"
  //  html_formatted = "top <b>product_group</b>"
  //  markups {
  //   {type: TEXT, start_char_index: 0, length: 3}
  //   {type: DIMENSION, start_char_index: 4, length: 13}
  //  }
  // }
  //
  // query_matches {
  //  { start_char_index: 0, length: 3 }
  //  { start_char_index: 4, length: 7}
  // }
  // ```
  message MatchInfo {
    // Unicode character index of the string annotation.
    int32 start_char_index = 1;

    // Count of unicode characters of this substring.
    int32 length = 2;
  }

  // Annotations for the suggestion. This provides information about which part
  // of the suggestion corresponds to what semantic meaning (e.g. a metric).
  AnnotatedString annotated_suggestion = 1;

  // Matches between user query and the annotated string.
  repeated MatchInfo query_matches = 2;
}

// Response to SuggestQueries.
message SuggestQueriesResponse {
  // A list of suggestions.
  repeated Suggestion suggestions = 1;
}

// The type of suggestion.
enum SuggestionType {
  // No suggestiont type is specified.
  SUGGESTION_TYPE_UNSPECIFIED = 0;

  // Entity suggestion type. Suggestions are for single entities.
  ENTITY = 1;

  // Template suggestion type. Suggestions are for full sentences.
  TEMPLATE = 2;
}