// main.dart
  
import 'package:flutter/material.dart';

void main() {
  debugPrint("1313");
  // runApp(const MyApp());

  debugPrint("--------1----------");
  debugPrint(RegUtil.convert1('# abcd'));
  debugPrint(RegUtil.convert1('## abcd'));
  // debugPrint(RegUtil.convert1('# abcd\n## efgh'));

  debugPrint("--------2----------");
  debugPrint(RegUtil.convert2("# [[abcd]]"));
  debugPrint(RegUtil.convert2("## [[abcd]]"));
  debugPrint(RegUtil.convert2("### [[lmn]]"));

  debugPrint("--------3----------");
  debugPrint(RegUtil.convert3("abcd\"*lmn")); // todo

  debugPrint("--------4----------");
  debugPrint(RegUtil.convert4(
      "Introducing ChatGPT We've trained (a model) called #ChatGPT which interacts in a  (conversational way). The # dialogue format makes it possible for ChatGPT to answer followup questions, admit its mistakes, challenge incorrect premises, and reject inappropriate requests."));

  debugPrint("--------5----------");
  debugPrint(
      RegUtil.convert5("你的好朋友\$张三\$发来⼀个地址\$https://www.google.com\$，你想要打开吗？")
          .toString());
  debugPrint(
      RegUtil.convert5("你的好朋友\$李四\$发来⼀个地址\$http://www.google.com\$，你想要打开吗？")
          .toString());
}

class RegUtil {
  // convert "# abcd" to "# [[abcd]]"
  // convert "## abcd" to "## [[abcd]]"
  static String convert1(String text) {
    final pattern = RegExp(r'^(#+) (.+)$', multiLine: true);
    return pattern.allMatches(text).fold('', (result, match) {
      final level = match.group(1);
      final content = match.group(2)?.trim();
      return '$result$level [[$content]]\n';
    });
  }

  // convert "# [[abcd]]" to "# abcd"
  // convert "## [[abcd]]" to "# abcd"
  // convert "### [[lmn]]" to "# lmn
  static String convert2(String text) {
    final pattern = RegExp(r'^#+ \[\[(.+)\]\]$', multiLine: true);
    return pattern.allMatches(text).fold('', (result, match) {
      if (match.group(0) == null) {
        return '';
      }
      // final level = '#' * match.group(0)!.indexOf(' ');
      const level = '#';
      final content = match.group(1);
      return '$result$level $content\n';
    });
  }

  // convert `abcd"*lmn` to `abcd'lmn.com`
  static String convert3(String text) {
    text = 'abcd"*lmn';

    String output = text.replaceAll(RegExp('"'), "'");
    output = output.replaceAll(RegExp(r'\*'), "");
    output += ".com";
    return output;
  }

  static String convert32(String input) {
    RegExp pattern = RegExp(r'"\*([\w]+)');
    String? output = pattern.stringMatch(input);
    if (output == null) {
      return input;
    }
    output = output.replaceAll('"', '\''); // 将双引号替换为单引号
    output = output.replaceAll('*', ''); // 去掉星号
    output += '.com'; // 添加 .com 后缀
    return input.replaceAll(pattern, output);
  }

  // 输出 "a model"
  // 怎么获取 trained (a model) in a  (conversational way). The 中的a model，但不会获取到conversational way，用dart语言和正则。
  // 即我希望获取()中的字符，但如果这些字符所在的()的前面有多个空格就不要(提取的是括号中的内容，但只想要获取前面没有多个空格的内容)
  static String convert4_1(String text) {
    // RegExp regex = RegExp(r'(?:\(|#)\s*(\w+(?:\s+\w+)*)\)');
    // RegExp regex = RegExp(r'(?:\()\s*(\w+(?:\s+\w+)*)\)');
    // Iterable<Match> matches = regex.allMatches(text);
    // List<String?> results = matches.map((match) {
    //   final level = match.group(1);
    //   // final content = match.group(2)?.trim();
    //   return '$level';
    // }).toList();

    String text = "trained (a model) in a  (conversational way). The";
    RegExp regExp = RegExp(r"\(\s*(?<!\s{2,}).*?\s*\)");
    Iterable<Match> matches = regExp.allMatches(text);
    String word = "";
    for (Match match in matches) {
      String matchWord = match.group(0) ?? '';
      word = matchWord.trim().substring(1, matchWord.length - 1);
      break;
    }
    debugPrint(word);
    return word;
  }

  // 输出 "ChatGPT"
  // 怎么获取 The # dialogue format makes #ChatGPT it 中的ChatGPT，但不会获取到dialogue，用dart语言和正则。
  // 即我希望获取#后的单词，但如果这个单词和#号之间有空格，就不要
  static String convert4_2(String text) {
    // String text = "The # dialogue format makes #ChatGPT it";
    RegExp regExp = RegExp(r"#\s*(\w+)\b");
    Iterable<Match> matches = regExp.allMatches(text);
    String word = "";
    for (Match match in matches) {
      String matchWord = match.group(1) ?? '';
      if (!matchWord.contains(" ")) {
        word = matchWord;
        break;
      }
    }
    debugPrint(word);
    return word;
  }

// conversational way is invalid since there are more than 1 space before it, dialogure is invalid since there is a space after #
  static String convert4(String text) {
    // String text = "trained (a model) in a  (conversational way). The # dialogue format makes #ChatGPT it";
    RegExp regExp = RegExp(r"\((\s*(?<!\s{2,}).*?\s*)\)|#\s*(\w+)\b");
    List<String> array = [];
    Iterable<Match> matches = regExp.allMatches(text);
    for (Match match in matches) {
      if (match.group(1) != null) {
        String model = match.group(1)!.trim();
        array.add(model);
      }
      if (match.group(2) != null) {
        String word = match.group(2) ?? '';
        array.add(word);
        break;
      }
    }

    return array.toString();
  }

  static String convert5(String text) {
    RegExp nameRegex = RegExp(r'\$(.*?)\$');
    RegExp urlRegex = RegExp(r'https?://(?:[-\w.]|(?:%[\da-fA-F]{2}))+');
    String? name = nameRegex.stringMatch(text)?.replaceAll('\$', '');
    String? url = urlRegex.stringMatch(text);

    Map<String, dynamic> friend = {"name": name, "url": url};

    return friend.toString();
  }
}

class SharedPreferences {
  SharedPreferences._(this._preferenceCache);

  static const String _prefix = 'flutter.';
  static SharedPreferences _instance;
  static Future<SharedPreferences> getInstance() async {
    if (_instance == null) {
      final Map<Object, Object> fromSystem =
          await _kChannel.invokeMethod('getAll');
      assert(fromSystem != null);
      // Strip the flutter. prefix from the returned preferences.
      final Map<String, Object> preferencesMap = <String, Object>{};
      for (String key in fromSystem.keys) {
        assert(key.startsWith(_prefix));
        preferencesMap[key.substring(_prefix.length)] = fromSystem[key];
      }
      _instance = SharedPreferences._(preferencesMap);
    }
    return _instance;
  }

class Manager {
  // 工厂模式
  factory Manager() =>_getInstance();
  static Manager get instance => _getInstance();
  
  static Manager _instance;
  Manager._internal() {
    // 初始化
  }
  static Manager _getInstance() {
    if (_instance == null) {
      _instance = new Manager._internal();
    }
    return _instance;
  }
}

// 无论如何初始化，取到的都是同一个对象
Manager manager = new Manager();
Manager manager2 = Manager.instance;

/// loadBuffer方法用于加载图片数据并返回ImageStreamCompleter对象。
@override
ImageStreamCompleter loadBuffer(
    image_provider.ExtendedNetworkImageProvider key,
    DecoderBufferCallback decode) {
  // Ownership of this controller is handed off to [_loadAsync]; it is that
  // method's responsibility to close the controller's stream when the image
  // has been loaded or an error is thrown.
  final StreamController<ImageChunkEvent> chunkEvents =
      StreamController<ImageChunkEvent>();

  return MultiFrameImageStreamCompleter(
    codec: _loadAsync(
      key as ExtendedNetworkImageProvider,
      chunkEvents,
      decode,
    ),
    scale: key.scale,
    chunkEvents: chunkEvents.stream,
    debugLabel: key.url,
    informationCollector: () {
      return <DiagnosticsNode>[
        DiagnosticsProperty<ImageProvider>('Image provider', this),
        DiagnosticsProperty<image_provider.ExtendedNetworkImageProvider>(
            'Image key', key),
      ];
    },
  );
}

/// _loadAsync方法是实际加载图片数据的核心逻辑。它首先尝试从缓存中加载图片数据，如果缓存中不存在，则从网络加载图片数据。
Future<ui.Codec> _loadAsync(
  ExtendedNetworkImageProvider key,
  StreamController<ImageChunkEvent> chunkEvents,
  DecoderBufferCallback decode,
) async {
  assert(key == this);
  final String md5Key = cacheKey ?? keyToMd5(key.url);
  ui.Codec? result;
  if (cache) {
    try {
      final Uint8List? data = await _loadCache(  /// _loadCache方法用于从缓存中加载图片数据。
        key,
        chunkEvents,
        md5Key,
      );
      if (data != null) {
        result = await instantiateImageCodec(data, decode);
      }
    } catch (e) {
      if (printError) {
        print(e);
      }
    }
  }

  if (result == null) {
    try {
      final Uint8List? data = await _loadNetwork(
        key,
        chunkEvents,
      );
      if (data != null) {
        result = await instantiateImageCodec(data, decode);
      }
    } catch (e) {
      if (printError) {
        print(e);
      }
    }
  }

  //Failed to load
  if (result == null) {
    //result = await ui.instantiateImageCodec(kTransparentImage);
    return Future<ui.Codec>.error(StateError('Failed to load $url.'));
  }

  return result;
}

/// _loadCache方法用于从缓存中加载图片数据。
/// Get the image from cache folder.
Future<Uint8List?> _loadCache(
  ExtendedNetworkImageProvider key,
  StreamController<ImageChunkEvent>? chunkEvents,
  String md5Key,
) async {
  final Directory _cacheImagesDirectory = Directory(
      join((await getTemporaryDirectory()).path, cacheImageFolderName));
  Uint8List? data;
  // exist, try to find cache image file
  if (_cacheImagesDirectory.existsSync()) { /// existsSync是一个同步方法，用于检查具有该路径的文件系统实体是否存在。
    final File cacheFlie = File(join(_cacheImagesDirectory.path, md5Key));
    if (cacheFlie.existsSync()) {  /// existsSync是一个同步方法，用于检查具有该路径的文件系统实体是否存在。
      if (key.cacheMaxAge != null) {
        final DateTime now = DateTime.now();
        final FileStat fs = cacheFlie.statSync();
        if (now.subtract(key.cacheMaxAge!).isAfter(fs.changed)) {
          cacheFlie.deleteSync(recursive: true);
        } else {
          data = await cacheFlie.readAsBytes();
        }
      } else {
        data = await cacheFlie.readAsBytes();
      }
    }
  }
  // create folder
  else {
    await _cacheImagesDirectory.create();
  }
  // load from network
  if (data == null) {
    data = await _loadNetwork(
      key,
      chunkEvents,
    );
    if (data != null) {
      // cache image file
      await File(join(_cacheImagesDirectory.path, md5Key)).writeAsBytes(data);
    }
  }

  return data;
}