// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module blink.mojom;

import "third_party/blink/public/mojom/ai/ai_common.mojom";
import "third_party/blink/public/mojom/ai/model_streaming_responder.mojom";

// The enumerations and struct follows the explainer in
// https://github.com/explainers-by-googlers/writing-assistance-apis/blob/main/README.md

// The output tone of the rewriter.
enum AIRewriterTone {
  kAsIs,
  kMoreFormal,
  kMoreCasual,
};

// The output format of the rewriter.
enum AIRewriterFormat {
  kAsIs,
  kPlainText,
  kMarkdown,
};

// The output length of the rewriter.
enum AIRewriterLength {
  kAsIs,
  kShorter,
  kLonger,
};

// This is used when creating a new AIRewriter.
struct AIRewriterCreateOptions {
  string? shared_context;
  AIRewriterTone tone;
  AIRewriterFormat format;
  AIRewriterLength length;

  // Creation fails if a model is not available for specified languages.
  array<AILanguageCode> expected_input_languages;
  array<AILanguageCode> expected_context_languages;
  AILanguageCode output_language;
};

// Interface for AIRewriter that can stream the output string.
interface AIRewriter {
  // Rewrite the input string. The shared context string, tone option and length
  // option can be set when creating the AIRewriter.
  // `input` is a string that is set when the JS API `rewriter.rewrite()` is
  // called.
  // `context` is a optional string that is set in the AIRewriterRewriteOptions
  // when the JS API `rewriter.rewrite()` is called.
  Rewrite(
    string input,
    string? context,
    pending_remote<ModelStreamingResponder> pending_responder);

  // Returns the usage size of `input` and `context`, or null if unable to
  // retrieve the usage.
  MeasureUsage(string input, string context) => (uint32? number_of_tokens);
};