import 'dart:io';
import 'dart:typed_data';
import 'package:fis_common/logger/logger.dart';
import 'package:path_provider/path_provider.dart';
import 'package:fis_common/env/env.dart';
import 'package:idb_shim/idb.dart';
import 'package:idb_shim/idb_browser.dart';

/// 文件存储
abstract class FileStorageNativeAndWeb {
  FileStorageNativeAndWeb({
    required this.directory,
  });

  /// 存储目录
  final String directory;

  Future<Uint8List?> read(String fileName) async {
    try {
      return await _getFile(fileName);
    } catch (e) {
      logger.e("File storage fetch fail, platform: ${FPlatform.current}.", e);
      return null;
    }
  }

  Future<bool> save(String fileName, Uint8List file) async {
    try {
      return await _setFile(fileName, file);
    } catch (e) {
      logger.e("Text storage save fail, platform: ${FPlatform.current}.", e);
      return false;
    }
  }

  Future<bool> delete(String fileName) async {
    try {
      return await _deleteFile(fileName);
    } catch (e) {
      logger.e("Text storage detail fail, platform: ${FPlatform.current}.", e);
      return false;
    }
  }

  Future<bool> deleteDirectory(String directoryPath) async {
    final storagePath = await _getStoragePath();
    final directory = Directory(storagePath);
    final result = await directory.exists();
    if (result) {
      try {
        await directory.delete(recursive: true);
        return true;
      } catch (e) {
        print(e);
        return false;
      }
    }

    return false;
  }

  Future<void> _checkAndCreateDir(String dir) async {
    final directory = Directory(dir);
    final parentDirectory = directory.parent;
    try {
      if (!await parentDirectory.exists()) {
        await parentDirectory.create(recursive: true);
      }
    } catch (e) {
      print(e);
    }
    if (!await directory.exists()) {
      try {
        await directory.create();
      } catch (e) {
        print(e);
      }
    }
  }

  Future<String> _getStoragePath() async {
    Directory? dir;
    if (Platform.isAndroid) {
      dir = await getExternalStorageDirectory();
    }
    dir ??= await getApplicationDocumentsDirectory();
    if (directory.isNotEmpty) {
      return "${dir.path}/$directory";
    }
    return dir.path;
  }

  Future<bool> _setFile(String fileName, Uint8List file);

  Future<Uint8List?> _getFile(String fileName);
  Future<bool> _deleteFile(String fileName);

  /// 创建实例
  ///
  /// [storageName] 文件名
  static FileStorageNativeAndWeb createInstance(String storageName) {
    final platform = FPlatform.current;
    switch (platform) {
      case FPlatformEnum.android:
      case FPlatformEnum.iOS:
        return _FileStorageNative(storageName);
      case FPlatformEnum.webOnMac:
      case FPlatformEnum.webOnWin:
        return _FileStorageShellWeb(storageName);
      case FPlatformEnum.web:
        return _FileStoragePureWeb(storageName);
    }
  }
}

///本地化的文件存储
class _FileStorageNative extends FileStorageNativeAndWeb {
  _FileStorageNative(String directory) : super(directory: directory);

  @override
  Future<Uint8List?> _getFile(String fileName) async {
    final storagePath = await _getStoragePath();
    final filePath = "$storagePath/$fileName";
    final file = File(filePath);
    if (!await file.exists()) return null;
    final text = await file.readAsBytes();
    return text;
  }

  @override
  Future<bool> _setFile(String fileName, Uint8List file) async {
    final storagePath = await _getStoragePath();
    final filePath = "$storagePath/$fileName";
    File fileToSave = File(filePath);

    _checkAndCreateDir(storagePath);

    if (!await fileToSave.exists()) {
      try {
        fileToSave = await fileToSave.create(recursive: true);
      } catch (e) {
        print(e);
      }
    }
    await fileToSave.writeAsBytes(file.toList());
    return true;
  }

  @override
  Future<String> _getStoragePath() async {
    Directory? dir;
    if (Platform.isAndroid) {
      dir = await getExternalStorageDirectory();
    }
    dir ??= await getApplicationDocumentsDirectory();
    return "${dir.path}/$directory";
  }

  @override
  Future<bool> _deleteFile(String fileName) async {
    final storagePath = await _getStoragePath();
    final filePath = "$storagePath/$fileName";
    final file = File(filePath);

    if (await file.exists()) {
      try {
        await file.delete();
        return true;
      } catch (e) {
        print(e);
        return false;
      }
    }

    return false;
  }
}

///壳子下的文件存储
class _FileStorageShellWeb extends FileStorageNativeAndWeb {
  _FileStorageShellWeb(String directory) : super(directory: directory);

  @override
  Future<Uint8List?> _getFile(String fileName) async {
    return null;
  }

  @override
  Future<bool> _setFile(String fileName, Uint8List file) async {
    return true;
  }

  @override
  Future<bool> _deleteFile(String fileName) async {
    return true;
  }
}

///纯web端的文件缓存
class _FileStoragePureWeb extends FileStorageNativeAndWeb {
  _FileStoragePureWeb(String directory) : super(directory: directory);

  static const int _version = 1;
  static const String _dbName = 'files.db';
  static const String _objectStoreName = 'files';
  static const String _propNameFilePath = 'filePath';
  static const String _propNameFileContents = 'contents';

  Future<Database> _openDb() async {
    final idbFactory = getIdbFactory();
    if (idbFactory == null) {
      throw Exception('getIdbFactory() failed');
    }
    return idbFactory.open(
      _dbName,
      version: _version,
      onUpgradeNeeded: (e) => e.database
          .createObjectStore(_objectStoreName, keyPath: _propNameFilePath),
    );
  }

  Future<bool> exists() async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadOnly);
    final store = txn.objectStore(_objectStoreName);
    final object = await store.getObject(directory);
    await txn.completed;
    return object != null;
  }

  Future<Uint8List> readAsBytes() async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadOnly);
    final store = txn.objectStore(_objectStoreName);
    final object = await store.getObject(directory) as Map?;
    await txn.completed;
    if (object == null) {
      throw Exception('file not found: $directory');
    }
    return object['contents'] as Uint8List;
  }

  Future<String> readAsString() async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadOnly);
    final store = txn.objectStore(_objectStoreName);
    final object = await store.getObject(directory) as Map?;
    await txn.completed;
    if (object == null) {
      writeAsBytes(Uint8List(0));
      return "";
    }
    return object['contents'] as String;
  }

  Future<void> writeAsBytes(Uint8List contents) async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadWrite);
    final store = txn.objectStore(_objectStoreName);
    await store.put({
      _propNameFilePath: directory,
      _propNameFileContents: contents
    }); // if the file exists, it will be replaced.
    await txn.completed;
  }

  Future<void> writeAsString(String contents) async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadWrite);
    final store = txn.objectStore(_objectStoreName);
    await store.put({
      _propNameFilePath: directory,
      _propNameFileContents: contents
    }); // if the file exists, it will be replaced.
    await txn.completed;
  }

  @override
  Future<Uint8List?> _getFile(String fileName) async {
    final uint8List = await readAsBytes();
    return uint8List;
  }

  @override
  Future<bool> _setFile(String fileName, Uint8List file) async {
    await writeAsBytes(file);
    return true;
  }

  @override
  Future<bool> _deleteFile(String fileName) async {
    final db = await _openDb();
    final txn = db.transaction(_objectStoreName, idbModeReadWrite);
    final store = txn.objectStore(_objectStoreName);
    await store.delete(directory);
    await txn.completed;
    return true;
  }
}