/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

include protocol PSpeechRecognition;

using mozilla::dom::ContentParentId from "mozilla/dom/ipc/IdType.h";
using mozilla::hwinference::ModelInstallResult from "mozilla/hwinference/HWInferenceTypes.h";

namespace mozilla {

namespace hwinference {

struct GetModelFileSuccess
{
  FileDescriptor fd;
};

struct GetModelError
{
  nsresult errorCode;
};

union GetModelFileResult
{
  GetModelFileSuccess;
  GetModelError;
};

[ChildProc=Utility]
protocol PHWInference
{
  parent:
    // id is an abstract, task-defined model id. HWInference looks up the
    // resolver registered for task (contract id
    // "@mozilla.org/ml/model-resolver;1?task=<task>", see
    // nsIMLModelResolver) to validate id and expand it to a concrete
    // artifact; an unknown id is rejected.
    async IsModelAvailable(nsCString task,
                           nsCString id) returns (bool available);

    // Whether the model is already downloaded to the local cache (no
    // network involved), as opposed to IsModelAvailable which also reports
    // true for a model that is merely downloadable.
    async IsModelInstalled(nsCString task,
                           nsCString id) returns (bool installed);

    // Install (download) a model for a specific task, on behalf of a
    // requesting content process. innerWindowId and contentId identify the
    // requester generically; contentId is supplied by the utility (the trusted
    // id of the content process that owns this connection), never supplied by
    // content. For requests originating from privileged chrome rather than a
    // content document, both are 0 (no content to validate; trusted origin).
    // Whether the download actually happens is decided by the resolver
    // registered for task (nsIMLModelResolver::authorizeDownload), which also
    // gets the progress token the parent created for this install. A resolver
    // that refuses is reported as Denied rather than Failed, so a caller can
    // tell a refusal from a download that did not work.
    async InstallModel(nsCString task,
                       nsCString id,
                       uint64_t innerWindowId,
                       ContentParentId contentId) returns (ModelInstallResult result);

    // Get the model as a file descriptor. This provides direct access to the
    // model file from the HWInference process for use with libraries that
    // require a FILE* handle.
    async GetModelFile(nsCString task,
                       nsCString id) returns (GetModelFileResult result);

  child:
    async NewContentSpeechRecognition(Endpoint<PSpeechRecognitionParent> endpoint,
                                      ContentParentId contentId);
};

} // namespace hwinference

} // namespace mozilla