// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

syntax = "proto3";
option optimize_for = LITE_RUNTIME;

// This file defines messages used for interacting with the document scanner
// utility, lorgnette.
package lorgnette;

// Describes possible types of sources that can be supported by a scanner.
enum SourceType {
  SOURCE_UNSPECIFIED = 0;
  SOURCE_PLATEN = 1;
  SOURCE_ADF_SIMPLEX = 2;
  SOURCE_ADF_DUPLEX = 3;

  // SourceType used for the implicit default source on devices that do not
  // expose a source option.
  SOURCE_DEFAULT = 4;
}

// Dimensions of the scannable area, in mm.
message ScannableArea {
  double width = 1;
  double height = 2;
}

// A source that can be scanned from for a scanner.
message DocumentSource {
  // The type of this source.
  SourceType type = 1;

  // The name for this source used by the scanner backend.
  string name = 2;

  // The dimensions of the scannable area for this source.
  ScannableArea area = 3;
}

// The color modes that may be supported for a particular scanner.
enum ColorMode {
  MODE_UNSPECIFIED = 0;
  MODE_LINEART = 1;
  MODE_GRAYSCALE = 2;
  MODE_COLOR = 3;
}

// An object representing one scanner.
message ScannerInfo {
  // The name of the scanner, as reported by SANE.
  string name = 1;

  // The manufacturer of the scanner.
  string manufacturer = 2;

  // The particular model of scanner.
  string model = 3;

  // The type of the scanner, e.g. "video camera", "flatbed scanner".
  string type = 4;
}

// Information returned from a ListScanners dbus request.
message ListScannersResponse {
  repeated ScannerInfo scanners = 1;
}

// Information returned from a GetScannerCapabilities dbus request.
message ScannerCapabilities {
  // Discrete scanning resolutions.
  repeated uint32 resolutions = 1;

  // Sources to scan a document from.
  repeated DocumentSource sources = 2;

  // Color modes to use for a document.
  repeated ColorMode color_modes = 3;
}

// Specifies a region to be scanned.
message ScanRegion {
  // The coordinates of the top-left corner of the scan region, in mm.
  double top_left_x = 1;
  double top_left_y = 2;

  // The coordinates of the bottom-right corner of the scan region, in mm.
  double bottom_right_x = 3;
  double bottom_right_y = 4;
}

// Settings for how lorgnette should perform a scan.
message ScanSettings {
  // The resolution, in DPI, to use for the scan.
  uint32 resolution = 1;

  reserved "source";
  reserved 2;

  // The color mode to use for the scan.
  ColorMode color_mode = 3;

  // The name of the source to scan the document from.
  string source_name = 4;
  //
  // The region to be scanned.
  ScanRegion scan_region = 5;
}

// The status of a scan job.
enum ScanState {
  // Unknown state.
  SCAN_STATE_UNSPECIFIED = 0;

  // The scan job is currently running.
  SCAN_STATE_IN_PROGRESS = 1;

  // The scan job has completed successfully.
  SCAN_STATE_COMPLETED = 2;

  // The scan job failed.
  SCAN_STATE_FAILED = 3;

  // Scanning of the current page completed successfully.
  SCAN_STATE_PAGE_COMPLETED = 4;

  // The scan job was cancelled via a call to CancelScan.
  SCAN_STATE_CANCELLED = 5;
}

// Information passed to a StartScan D-Bus request.
// Used by lorgnette to initialize a new scan job.
message StartScanRequest {
  // The name of the device to scan from.
  string device_name = 1;

  // The settings to use for this scan.
  ScanSettings settings = 2;
}

// Information returned from a StartScan D-Bus request.
message StartScanResponse {
  // The status of the scan.
  ScanState state = 1;

  // The failure reason if state is SCAN_STATE_FAILED.
  string failure_reason = 2;

  // A UUID identifying the scan job.
  string scan_uuid = 3;
}

// Information passed to a GetNextImage D-Bus request.
// Used by lorgnette to read image data for a scan job.
message GetNextImageRequest {
  // A UUID identifying the scan job.
  string scan_uuid = 1;
}

// Information returned from a GetNextImage D-Bus request;
message GetNextImageResponse {
  // True if initiating this image fetch was successful.
  bool success = 1;

  // The failure reason if success is false.
  string failure_reason = 2;
}

// Information passed to a CancelScan D-Bus request.
// Used by lorgnette to find the scan job to cancel.
message CancelScanRequest {
  // A UUID identifying the scan job.
  string scan_uuid = 1;
}

// Information returned from a CancelScan D-Bus request;
message CancelScanResponse {
  // True if requesting scan cancellation was successful.
  bool success = 1;

  // The failure reason if success is false.
  string failure_reason = 2;
}

// Information sent with ScanStatus D-Bus signal.
message ScanStatusChangedSignal {
  // A UUID identifying the scan job.
  string scan_uuid = 1;

  // The status of the scan.
  ScanState state = 2;

  // The failure reason if state is SCAN_STATE_FAILED.
  string failure_reason = 3;

  // Scan progress from 0 to 100%.
  uint32 progress = 4;

  // The page field will be set to the page currently being scanned for
  // SCAN_STATE_IN_PROGRESS, or the page that has just been completed for
  // SCAN_STATE_PAGE_COMPLETED.
  // Pages are 1-indexed.
  uint32 page = 5;

  // If state is SCAN_STATE_PAGE_COMPLETED and more_pages is true, the client
  // should send another GetNextImage request in order to fetch the next page.
  bool more_pages = 6;
}