import 'dart:typed_data';
import 'dart:ui';

import 'package:flutter/cupertino.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:jdenticon_dart/jdenticon_dart.dart';
import 'package:random_string/random_string.dart';

/// Identicon utilities
///
/// @author Pierre Hubert


// Based on https://stackoverflow.com/a/63215502/3781411
Future<Uint8List> svgToPng(BuildContext context, String svgString,
    {int svgWidth, int svgHeight}) async {
  DrawableRoot svgDrawableRoot = await svg.fromSvgString(svgString, null);

  // to have a nice rendering it is important to have the exact original height and width,
  // the easier way to retrieve it is directly from the svg string
  // but be careful, this is an ugly fix for a flutter_svg problem that works
  // with my images
  String temp = svgString.substring(svgString.indexOf('height="') + 8);
  int originalHeight =
      svgHeight ?? int.parse(temp.substring(0, temp.indexOf('p')));
  temp = svgString.substring(svgString.indexOf('width="') + 7);
  int originalWidth =
      svgWidth ?? int.parse(temp.substring(0, temp.indexOf('p')));

  // toPicture() and toImage() don't seem to be pixel ratio aware, so we calculate the actual sizes here
  double devicePixelRatio = MediaQuery.of(context).devicePixelRatio;

  double width = originalHeight *
      devicePixelRatio; // where 32 is your SVG's original width
  double height = originalWidth * devicePixelRatio; // same thing

  // Convert to ui.Picture
  final picture = svgDrawableRoot.toPicture(size: Size(width, height));

  // Convert to ui.Image. toImage() takes width and height as parameters
  // you need to find the best size to suit your needs and take into account the screen DPI
  final image = await picture.toImage(width.toInt(), height.toInt());
  ByteData bytes = await image.toByteData(format: ImageByteFormat.png);

  return bytes.buffer.asUint8List();
}

Future<Uint8List> genIdenticon(BuildContext context, {int size: 100}) async {
  final identicon = Jdenticon.toSvg(randomString(25), size: size);

  return svgToPng(context, identicon, svgHeight: size, svgWidth: size);
}