import 'dart:io';

import 'package:flutter/foundation.dart' show Uint8List;
import 'package:http/http.dart' as http;
import 'package:image_gallery_saver/image_gallery_saver.dart';

// I would like to orgnize the project structure and the code more
// but here I don't want to change too much since that is a community project

RegExp _base64 = RegExp(
  r'^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=|[A-Za-z0-9+\/]{4})$',
);

bool isBase64(String str) {
  return _base64.hasMatch(str);
}

bool isImageBase64(String imageUrl) {
  return !imageUrl.startsWith('http') && isBase64(imageUrl);
}

enum SaveImageResultMethod { network, localStorage }

class _SaveImageResult {
  const _SaveImageResult({required this.isSuccess, required this.method});

  final bool isSuccess;
  final SaveImageResultMethod method;
}

Future<_SaveImageResult> saveImage(String imageUrl) async {
  final imageFile = File(imageUrl);
  final imageExistsLocally = await imageFile.exists();
  if (!imageExistsLocally) {
    final success = await _saveNetworkImageToLocal(imageUrl);
    return _SaveImageResult(
      isSuccess: success,
      method: SaveImageResultMethod.network,
    );
  }
  final success = await _saveImageLocally(imageFile);
  return _SaveImageResult(
    isSuccess: success,
    method: SaveImageResultMethod.localStorage,
  );
}

Future<bool> _saveNetworkImageToLocal(String imageUrl) async {
  try {
    final response = await http.get(
      Uri.parse(imageUrl),
    );
    if (response.statusCode != 200) {
      return false;
    }
    final imageBytes = response.bodyBytes;
    final result = await ImageGallerySaver.saveImage(
      Uint8List.fromList(imageBytes),
    );
    return result['isSuccess'];
  } catch (e) {
    return false;
  }
}

Future<Uint8List> _convertFileToUint8List(File file) async {
  try {
    final uint8list = await file.readAsBytes();
    return uint8list;
  } catch (e) {
    return Uint8List(0);
  }
}

Future<bool> _saveImageLocally(File imageFile) async {
  try {
    final imageBytes = await _convertFileToUint8List(imageFile);
    final result = await ImageGallerySaver.saveImage(imageBytes);

    return result['isSuccess'];
  } catch (e) {
    return false;
  }
}