// 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 on_device_translation.mojom;

import "components/on_device_translation/public/mojom/translator.mojom";
import "mojo/public/mojom/base/file.mojom";
import "mojo/public/mojom/base/file_path.mojom";
import "sandbox/policy/mojom/context.mojom";
import "sandbox/policy/mojom/sandbox.mojom";

// The language package information of the TranslateKit library.
// Normally, `language1` and `language2` are input from hard-coded dictionary
// information within Chromium, but they can also be specified from the command
// line for testing purposes.
struct OnDeviceTranslationLanguagePackage {
  // The first ISO 639 language code of the language pair (eg:"en"). This can
  // either be both source or target language.
  string language1;
  // The second ISO 639 language code of the language pair (eg:"en"). This can
  // either be both source or target language.
  string language2;
};

// The interface that provides file operations for the OnDeviceTranslation
// service. This interface is implemented in the browser process and its methods
// are called from the OnDeviceTranslation service.
// Note: The translation library performs file operations synchronously,
// necessitating the use of synchronous IPC methods.
interface FileOperationProxy {
  // Returns if the file exists and whether it is a directory.
  // `package_index` is the index of the language package in the config.
  // `relative_path` is the relative path in the language package.
  [Sync]
  FileExists(uint32 package_index, mojo_base.mojom.FilePath relative_path)
      => (bool exists, bool is_directory);

  // Returns the file handle of the file. If the file does not exist, it will
  // return an invalid handle.
  // `package_index` is the index of the language package in the config.
  // `relative_path` is the relative path in the language package.
  [Sync]
  Open(uint32 package_index, mojo_base.mojom.FilePath relative_path)
      => (mojo_base.mojom.ReadOnlyFile? file);
};

// The list of language package information.
struct OnDeviceTranslationServiceConfig {
  // The list of language packages.
  array<OnDeviceTranslationLanguagePackage> packages;
  // The file operation proxy used by the service.
  pending_remote<FileOperationProxy> file_operation_proxy;
};

// The result of creating a translator.
enum CreateTranslatorResult {
  // The translator is created successfully.
  kSuccess = 0,

  // The translator cannot be created because the library binary failed to
  // loaded.
  kErrorInvalidBinary = 1,

  // The translator cannot be created because the function pointer of the
  // library is invalid.
  kErrorInvalidFunctionPointer = 2,

  // The translator cannot be created because the library failed to initialize.
  kErrorFailedToInitialize = 3,

  // The translator cannot be created because the library failed to create the
  // translator.
  kErrorFailedToCreateTranslator = 4,

  // The translator cannot be created because the library version is invalid.
  kErrorInvalidVersion= 5,
};

// Currently the sandboxing of the On Device Translation service is supported
// only on macOS, Linux and ChromeOS.
[EnableIf=is_linux|is_mac|is_chromeos]
const sandbox.mojom.Sandbox kOnDeviceTranslationSandbox =
    sandbox.mojom.Sandbox.kOnDeviceTranslation;

[EnableIf=is_win]
const sandbox.mojom.Sandbox kOnDeviceTranslationSandbox =
    sandbox.mojom.Sandbox.kService;

[EnableIfNot=is_linux|is_mac|is_win|is_chromeos]
const sandbox.mojom.Sandbox kOnDeviceTranslationSandbox =
    sandbox.mojom.Sandbox.kNoSandbox;

// The service that provides translation capabilities through
// various implementation.
[ServiceSandbox=kOnDeviceTranslationSandbox,
    RequireContext=sandbox.mojom.Context.kBrowser]
interface OnDeviceTranslationService {
  // This must be called soon after creating the service. Also this can be used
  // when the binary or the language packages are updated (or uninstalled).
  SetServiceConfig(OnDeviceTranslationServiceConfig config);

  // Creates a `OnDeviceTranslator` that could do translation from `source_lang`
  // to `target_lang`. When succeeds, the result callback will be called with a
  // true `kSuccess`. Otherwise, the result callback will be called with one of
  // the other error codes.
  // To detect the idle state of the service, this IPC is passing a
  // pending_receiver instead of returning a pending_remote. See
  // https://crrev.com/c/5992971/comment/ca3edf7c_2ae4ca1a/ for more details.
  CreateTranslator(string source_lang,
                   string target_lang,
                   pending_receiver<OnDeviceTranslator> receiver)
      => (CreateTranslatorResult result);

  // Returns if the service could translate text from `source_lang` to
  // `target_lang`.
  CanTranslate(string source_lang, string target_lang)
      => (bool can_stranslate);
};