// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module device.mojom;

enum HidBusType {
  kHIDBusTypeUSB = 0,
  kHIDBusTypeBluetooth = 1,
};

struct HidUsageAndPage {
  uint16 usage;
  uint16 usage_page;
};

struct HidCollectionInfo {
  HidUsageAndPage usage;
  array<int32> report_ids;
};

struct HidDeviceInfo {
  string guid;
  uint16 vendor_id;
  uint16 product_id;
  string product_name;
  string serial_number;
  HidBusType bus_type;
  array<uint8> report_descriptor;
  array<HidCollectionInfo> collections;
  bool has_report_id;
  uint64 max_input_report_size;
  uint64 max_output_report_size;
  uint64 max_feature_report_size;
  string device_node;
};

interface HidManagerClient {
  // Notifies the client that a device is added.
  DeviceAdded(HidDeviceInfo device_info);

  // Notifies the client that a device is being removed, called before
  // removing the device from HidService.
  DeviceRemoved(HidDeviceInfo device_info);
};

interface HidManager {
  // Enumerates available devices and set as a client of HidManager.
  // The implementation of HidManager guarantees that the returned callback
  // will always be posted earlier than DeviceAdded() and DeviceRemoved().
  GetDevicesAndSetClient(associated HidManagerClient client) =>
                       (array<HidDeviceInfo> devices);

  // Enumerates available devices only.
  GetDevices() => (array<HidDeviceInfo> devices);

  // Opens a connection to a device by given guid. The callback will be run
  // with null on failure.
  Connect(string device_guid) => (HidConnection? connection);
};

interface HidConnection {
  // The report_id is returned as 0 if not supported by the device.
  Read() => (bool success, uint8 report_id, array<uint8>? buffer);

  // Pass the report_id as 0 if not supported by the device.
  Write(uint8 report_id, array<uint8> buffer) => (bool success);

  // The buffer will contain whatever report data was received from the device.
  // This may include the report ID. The report ID is not stripped because a
  // device may respond with other data in place of the report ID.
  GetFeatureReport(uint8 report_id) => (bool success, array<uint8>? buffer);

  // Pass the report_id as 0 if not supported by the device.
  SendFeatureReport(uint8 report_id, array<uint8> buffer) => (bool success);
};