import 'dart:convert';
import 'dart:io';

import 'package:file_selector/file_selector.dart';
import 'package:flutter/services.dart';

import '../model/bookmark.dart';
import '../model/collection.dart';
import '../assets/constants.dart' as constants;

class JsonFileService {
  static Future<bool> exportToJson({
    required List<Collection> collections,
    required List<Bookmark> bookmarks,
  }) async {
    try {
      final dir = await _directoryPath;
      if (dir.isEmpty) return false;

      final data = {
        'collections': collections.map((c) => c.toJson()).toList(),
        'bookmarks': bookmarks.map((b) => b.toJson()).toList(),
      };
      final json = jsonEncode(data).codeUnits;
      final file = XFile.fromData(
        Uint8List.fromList(json),
        mimeType: 'application/json',
        name: constants.jsonFileName,
      );

      file.saveTo('$dir/${constants.jsonFileName}');
    } catch (e) {
      return false;
    }
    return true;
  }

  static Future<({List<Collection> collections, List<Bookmark> bookmarks})>
  importFromJson() async {
    try {
      const typeGroup = XTypeGroup(label: 'json', extensions: <String>['json']);
      final XFile? file = await openFile(
        acceptedTypeGroups: <XTypeGroup>[typeGroup],
      );

      if (file == null) {
        return (collections: <Collection>[], bookmarks: <Bookmark>[]);
      }

      final jsonString = await file.readAsString();

      final data = jsonDecode(jsonString) as Map<String, dynamic>;

      final collections = (data['collections'] as List<dynamic>? ?? [])
          .map((json) => Collection.fromJson(json as Map<String, dynamic>))
          .toList();

      final bookmarks = (data['bookmarks'] as List<dynamic>? ?? [])
          .map((json) => Bookmark.fromJson(json as Map<String, dynamic>))
          .toList();

      return (collections: collections, bookmarks: bookmarks);
    } catch (e) {
      return (collections: <Collection>[], bookmarks: <Bookmark>[]);
    }
  }

  static Future<String> get _directoryPath async {
    if (Platform.isAndroid) {
      return await getDirectoryPath(
            initialDirectory: constants.defaultAndroidExportDirectory,
          ) ??
          '';
    }
    return await getDirectoryPath() ?? '';
  }
}