import 'dart:typed_data';
import 'package:vid/us/vid_us_data_reader.dart';
import 'package:vid/us/vid_us_data_writer.dart';
import 'package:vid/us/vid_us_visual.dart';

/// Used for update the image data.
abstract class IImageDataContainer {
  abstract Uint8List imageData;
}

/// This class is used for updating the image data.
class VidUsImageUpdater {
  final IImageDataContainer _imageDataContainer;

  VidUsImageUpdater(this._imageDataContainer);

  /// Update image data
  void update(Uint8List imageData) {
    _imageDataContainer.imageData = imageData;
  }
}

class VidUsImage implements IImageDataContainer {
  @override
  late Uint8List imageData;

  late int _index;
  late int _width;
  late int _height;
  late List<VidUsVisual> _visuals;

  /// Gets the index of this image.
  int get index => _index;

  /// Gets the width of this image data.
  int get width => _width;

  /// Gets the height of this image data.
  int get height => _height;

  /// Gets all visuals of this image.
  List<VidUsVisual> get visuals => _visuals;

  VidUsImage(int index, int width, int height, Uint8List data) {
    _visuals = [];
    _index = index;
    _width = width;
    _height = height;
    imageData = data;
  }

  /// VidUsImage image to binary data.
  Uint8List toBytes() {
    var writer = new VidUsDataWriter();
    writer.writeInt(_index);
    writer.writeByte(_visuals.length);
    _visuals.forEach((visual) {
      var visualData = visual.toBytes();
      writer.writeBytes(visualData);
    });
    writer.writeInt16(_width);
    writer.writeInt16(_height);
    writer.writeBytes(imageData);
    return writer.data;
  }

  /// Convert binary data to VidUsImage
  static VidUsImage fromBytes(Uint8List bytes) {
    var reader = new VidUsDataReader(bytes);
    var index = reader.readInt();
    var visualCount = reader.readByte();
    List<VidUsVisual> visuals = [];
    for (int i = 0; i < visualCount; i++) {
      var visual = VidUsVisual.fromBytes(reader.readBytes());
      visuals.add(visual);
    }
    var width = reader.readInt16();
    var height = reader.readInt16();
    var imageData = reader.readBytes();
    var result = new VidUsImage(index, width, height, imageData);
    visuals.forEach((visual) {
      result._visuals.add(visual);
    });

    return result;
  }
}