// Copyright 2016 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 arc.mojom;

import "arc_camera3_metadata.mojom";

[Extensible]
enum HalPixelFormat {
  HAL_PIXEL_FORMAT_RGBA_8888 = 0x1,
  HAL_PIXEL_FORMAT_RGBX_8888 = 0x2,
  HAL_PIXEL_FORMAT_BGRA_8888 = 0x5,
  HAL_PIXEL_FORMAT_YCrCb_420_SP = 0x11,
  HAL_PIXEL_FORMAT_YCbCr_422_I = 0x14,
  HAL_PIXEL_FORMAT_BLOB = 0x21,
  HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED = 0x22,
  HAL_PIXEL_FORMAT_YCbCr_420_888 = 0x23,
  HAL_PIXEL_FORMAT_YV12 = 0x32315659,
};

// The following enums are from Android's camera HAL v3 API header
// (https://goo.gl/jciSjC).

enum CameraFacing {
  CAMERA_FACING_BACK = 0,
  CAMERA_FACING_FRONT = 1,
  CAMERA_FACING_EXTERNAL = 2,
};

enum Camera3StreamType {
  CAMERA3_STREAM_OUTPUT = 0,
  CAMERA3_STREAM_INPUT = 1,
  CAMERA3_STREAM_BIDIRECTIONAL = 2,
  CAMERA3_NUM_STREAM_TYPES,
};

enum Camera3StreamRotation {
  CAMERA3_STREAM_ROTATION_0 = 0,
  CAMERA3_STREAM_ROTATION_90 = 1,
  CAMERA3_STREAM_ROTATION_180 = 2,
  CAMERA3_STREAM_ROTATION_270 = 3,
};

enum Camera3StreamConfigurationMode {
  CAMERA3_STREAM_CONFIGURATION_NORMAL_MODE = 0,
  CAMERA3_STREAM_CONFIGURATION_CONSTRAINED_HIGH_SPEED_MODE =1,
};

enum Camera3RequestTemplate {
  CAMERA3_TEMPLATE_PREVIEW = 1,
  CAMERA3_TEMPLATE_STILL_CAPTURE = 2,
  CAMERA3_TEMPLATE_VIDEO_RECORD = 3,
  CAMERA3_TEMPLATE_VIDEO_SNAPSHOT = 4,
  CAMERA3_TEMPLATE_ZERO_SHUTTER_LAG = 5,
  CAMERA3_TEMPLATE_MANUAL = 6,
  CAMERA3_TEMPLATE_COUNT,
};

enum Camera3BufferStatus {
  CAMERA3_BUFFER_STATUS_OK = 0,
  CAMERA3_BUFFER_STATUS_ERROR = 1,
};

enum Camera3MsgType {
  CAMERA3_MSG_ERROR = 1,
  CAMERA3_MSG_SHUTTER = 2,
  CAMERA3_NUM_MESSAGES,
};

struct Camera3Stream {
  uint64 id;
  Camera3StreamType stream_type;
  uint32 width;
  uint32 height;
  HalPixelFormat format;
  uint32 usage;
  uint32 max_buffers;
  uint32 data_space;
  Camera3StreamRotation rotation;
};

struct Camera3StreamConfiguration {
  array<Camera3Stream> streams;
  Camera3StreamConfigurationMode operation_mode;
};

struct Camera3StreamBuffer {
  uint64 stream_id;
  uint64 buffer_id;
  Camera3BufferStatus status;
  handle? acquire_fence;
  handle? release_fence;
};

struct Camera3CaptureRequest {
  uint32 frame_number;
  CameraMetadata settings;
  Camera3StreamBuffer? input_buffer;
  array<Camera3StreamBuffer> output_buffers;
};

// Camera3DeviceOps is mostly a translation of the camera3_device_ops_t API from
// Android camera HAL v3, with the additional RegisterBuffer() function to pass
// buffer handles across processes.  This is the interface to interact with a
// camera device in the camera HAL.
//
// The work flow of the Camera3DeviceOps is:
//
//   1. Call Initialize() to register the Camera3CallbackOps interface with the
//      camera HAL.
//
//   2. Call ConfigureStreams() to negotiate the set of usable video streams
//      with the camera HAL.
//
//   3. After the video streams are successfully configured, call
//      ConstructDefaultRequestSettings() to get the capture settings for each
//      stream.  The capture settings of a stream will be associated with the
//      capture requests of the stream.
//
//   4. Start the capture loop. The capture loop is composed of a series of
//      capture requests and results.
//
//      For each capture request:
//        a. Call RegisterBuffer() for each buffer associated with the request
//           to register the buffers which will later be filled by the camera
//           HAL with capture result.  For example, the client may register one
//           small buffer for the low-resolution preview stream and one large
//           buffer for the high-resolution still capture stream.
//        b. Call ProcessCaptureRequest() to request capturing one frame.  A
//           request may contain multiple streams and the camera HAL would fill
//           the buffers of each streams per requirements specified in
//           ConfigureStreams() and RegisterBuffer().  For example, the camera
//           HAL may fill a frame to a still capture buffer with the native
//           capture resolution, and down-scale the same frame to a lower
//           resolution for the preview buffer.
//      The client may continue with RegisterBuffer() -> ProcessCaptureRequest()
//      up to the pipe-line depth configured in ConfigureStreams().
//
//      When the camera HAL is done with a capture request, the capture result
//      is sent back to the client through the callbacks in Camera3CallbackOps.
//
//      For each capture result:
//        a. The camera HAL notifies the client through Notify() of the shutter
//           time of the captured frame.  If an error happens while capturing a
//           frame or filling a buffer, the camera HAL notifies the client
//           through Notify() of the error.
//        b. The camera HAL returns the capture result with various result
//           metadata and the filled buffers to the client in
//           ProcessCaptureResult().  The result metadata may be sent partially
//           in multiple stages, and the client must wait until all the partial
//           metadata are received before handing the capture result to upper
//           layer.
//
//    5. Dump() can be used to dump various information of the camera HAL for
//       debug purpose.
//
//    6. Flush() tells the camera HAL to finish processing or discard the
//       current on-going capture requests and return to the state where
//       ConfigureStreams() can be called again to set up new streams.
//
//    7. Close() closes the camera device.

interface Camera3DeviceOps {
  // Initialize() is called once after the camera device is opened to register
  // the Camera3CallbackOps handle.
  Initialize@0(Camera3CallbackOps callback_ops) => (int32 result);

  // ConfigureStreams() is called every time the client needs to set up new set
  // of streams.
  ConfigureStreams@1(Camera3StreamConfiguration config) =>
      (int32 result, Camera3StreamConfiguration? updated_config);

  // ConstructDefaultRequestSettings() is called to get the request settings for
  // common use cases, e.g. preview, still capture, video recording...etc.
  ConstructDefaultRequestSettings@2(Camera3RequestTemplate type) =>
      (CameraMetadata? settings);

  // ProcessCaptureRequest() is the core method and is called for every captured
  // frame to provide the camera HAL with the capture settings and the
  // associated buffers to fill.
  ProcessCaptureRequest@3(Camera3CaptureRequest request) => (int32 result);

  // Dump() is called to gather various states and information about the camera
  // HAL; it is mainly for debug purpose.
  Dump@4(handle fd);

  // Flush() is called to clear out any in-progress captures and return the
  // camera HAL to idle state.
  Flush@5() => (int32 result);

  // The type of buffers the ARC++ camera service currently supports.
  // GRALLOC is for the platform-specific gralloc buffer allocated by Android.
  // SHM is for the shared memory buffer allocated by Chrome.
  enum BufferType {
    GRALLOC = 0,  // gralloc buffer. Needs to be imported through GBM.
    SHM = 1,      // shared memory buffer. Can be mmapped directly.
    // Add DMABUF when needed.
  };

  // RegisterBuffer() is called to register a buffer with the camera HAL.  The
  // registered buffer can then be specified in ProcessCaptureRequest() for the
  // camera HAL to fill captured frame.  RegisterBuffer() is not part of the
  // Android camera HAL v3 API; it is added for ARC++ camera service to pass
  // buffer handles across different processes.
  RegisterBuffer@6(uint64 buffer_id, BufferType type, array<handle> fds,
                   uint32 drm_format, HalPixelFormat hal_pixel_format,
                   uint32 width, uint32 height, array<uint32> strides,
                   array<uint32> offsets) =>
      (int32 result);

  // Close() is called to close the camera device.
  Close@7() => (int32 result);
};

struct Camera3CaptureResult {
  uint32 frame_number;
  CameraMetadata result;
  array<Camera3StreamBuffer>? output_buffers;
  Camera3StreamBuffer? input_buffer;
  uint32 partial_result;
};

enum Camera3ErrorMsgCode {
  CAMERA3_MSG_ERROR_DEVICE = 1,
  CAMERA3_MSG_ERROR_REQUEST = 2,
  CAMERA3_MSG_ERROR_RESULT = 3,
  CAMERA3_MSG_ERROR_BUFFER = 4,
  CAMERA3_MSG_NUM_ERRORS,
};

struct Camera3ErrorMsg {
  uint32 frame_number;
  uint64 error_stream_id;
  Camera3ErrorMsgCode error_code;
};

struct Camera3ShutterMsg {
  uint32 frame_number;
  uint64 timestamp;
};

union Camera3NotifyMsgMessage {
  Camera3ErrorMsg error;
  Camera3ShutterMsg shutter;
  array<uint8> generic;
};

struct Camera3NotifyMsg {
  Camera3MsgType type;
  Camera3NotifyMsgMessage message;
};

// Camera3CallbackOps is a translation of the camera3_callback_ops_t API
// in Android camera HAL v3.  For the work flow of the functions in
// Camera3CallbackOps, see the comments about Camera3DeviceOps above.
interface Camera3CallbackOps {
  // ProcessCaptureResult() is called by the camera HAL to send result metadata
  // and filled buffer to the client.
  ProcessCaptureResult@0(Camera3CaptureResult result);

  // Notify() is called by the camera HAL to notify the client of the start of
  // each capture, and of errors encountered.
  Notify@1(Camera3NotifyMsg msg);
};

struct CameraInfo {
  CameraFacing facing;
  int32 orientation;
  uint32 device_version;
  CameraMetadata static_camera_characteristics;
  // resource cost is not valid in CAMERA_MODULE_API_VERSION_2_3 or lower.
  // conflicting_devices is not valid in CAMERA_MODULE_API_VERSION_2_3 or lower.
  // conflicting_devices_length is not valid in CAMERA_MODULE_API_VERSION_2_3 or
  // lower.
};

// CameraModule is a translation of the camera_module_t API
// (https://goo.gl/8Hf8S8).  CameraModule is the interface to interact with a
// camera HAL to query device info and open camera devices.
interface CameraModule {
  // Opens the camera device specified by |camera_id|.  On success, the camera
  // device is accessible through the |device_ops| returned.
  OpenDevice@0(int32 camera_id, Camera3DeviceOps& device_ops_request)
      => (int32 result);

  // Gets the number of cameras currently present on the system.
  GetNumberOfCameras@1() => (int32 result);

  // Gets various info about the camera specified by |camera_id|.
  GetCameraInfo@2(int32 camera_id) => (int32 result, CameraInfo? camera_info);

  // Registers the CameraModuleCallbacks interface with the camera HAL.
  SetCallbacks@3(CameraModuleCallbacks callbacks) => (int32 result);
};

enum CameraDeviceStatus {
  CAMERA_DEVICE_STATUS_NOT_PRESENT = 0,
  CAMERA_DEVICE_STATUS_PRESENT = 1,
  CAMERA_DEVICE_STATUS_ENUMERATING = 2,
};

// CameraModuleCallbacks is a translation of the camera_module_callbacks_t API
// (https://goo.gl/8Hf8S8).  CameraModuleCallbacks is used by the camera HAL to
// inform the client of the various status change of a camera.
interface CameraModuleCallbacks {
  // CameraDeviceStatusChange() is called by the camera HAL to notify the client
  // of the new status of the camera device specified by |camera_id|.
  CameraDeviceStatusChange@0(int32 camera_id, CameraDeviceStatus new_status);
};