game-tracker/lib/services/data_transfer_service.dart

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

import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:game_tracker/data/db/database.dart';
import 'package:game_tracker/data/dto/game.dart';
import 'package:game_tracker/data/dto/group.dart';
import 'package:game_tracker/data/dto/player.dart';
import 'package:game_tracker/presentation/views/main_menu/settings_view.dart';
import 'package:provider/provider.dart';

class DataTransferService {
  /// Deletes all data from the database.
  static Future<void> deleteAllData(BuildContext context) async {
    final db = Provider.of<AppDatabase>(context, listen: false);
    await db.gameDao.deleteAllGames();
    await db.groupDao.deleteAllGroups();
    await db.playerDao.deleteAllPlayers();
    print('[deleteAllData] All data deleted');
  }

  static Future<String> getAppDataAsJson(BuildContext context) async {
    final db = Provider.of<AppDatabase>(context, listen: false);
    final games = await db.gameDao.getAllGames();
    final groups = await db.groupDao.getAllGroups();
    final players = await db.playerDao.getAllPlayers();

    // Construct a JSON representation of the data
    final Map<String, dynamic> jsonMap = {
      'games': games.map((game) => game.toJson()).toList(),
      'groups': groups.map((group) => group.toJson()).toList(),
      'players': players.map((player) => player.toJson()).toList(),
    };

    return json.encode(jsonMap);
  }

  /// Exports the given JSON string to a file with the specified name.
  static Future<bool> exportData(String jsonString, String fileName) async {
    try {
      final bytes = Uint8List.fromList(utf8.encode(jsonString));
      await FilePicker.platform.saveFile(
        fileName: '$fileName.json',
        bytes: bytes,
      );
      return true;
    } catch (e, stack) {
      print('[exportData] $e');
      print(stack);
      return false;
    }
  }

  /// Imports data from a selected JSON file into the database.
  static Future<void> importData(BuildContext context) async {
    final db = Provider.of<AppDatabase>(context, listen: false);

    final path = await FilePicker.platform.pickFiles(
      type: FileType.custom,
      allowedExtensions: ['json'],
    );

    if (path == null) {
      print('[importData] No file selected');
      return;
    }

    try {
      final jsonString = await _readFileContent(path.files.single);

      if (await SettingsView.validateJsonSchema(jsonString)) {
        final Map<String, dynamic> jsonData =
            json.decode(jsonString) as Map<String, dynamic>;

        final List<dynamic>? gamesJson = jsonData['games'] as List<dynamic>?;
        final List<dynamic>? groupsJson = jsonData['groups'] as List<dynamic>?;
        final List<dynamic>? playersJson =
            jsonData['players'] as List<dynamic>?;

        final List<Game> importedGames =
            gamesJson
                ?.map((g) => Game.fromJson(g as Map<String, dynamic>))
                .toList() ??
            [];
        final List<Group> importedGroups =
            groupsJson
                ?.map((g) => Group.fromJson(g as Map<String, dynamic>))
                .toList() ??
            [];
        final List<Player> importedPlayers =
            playersJson
                ?.map((p) => Player.fromJson(p as Map<String, dynamic>))
                .toList() ??
            [];

        for (Player player in importedPlayers) {
          await db.playerDao.addPlayer(player: player);
        }

        for (Group group in importedGroups) {
          await db.groupDao.addGroup(group: group);
        }

        for (Game game in importedGames) {
          await db.gameDao.addGame(game: game);
        }
      } else {
        print('[importData] Invalid JSON schema');
        return;
      }
      print('[importData] Data imported successfully');
      return;
    } on FormatException catch (e, stack) {
      print('[importData] FormatException');
      print('[importData] $e');
      print(stack);
      return;
    } on Exception catch (e, stack) {
      print('[importData] Exception');
      print('[importData] $e');
      print(stack);
      return;
    }
  }

  /// Helper method to read file content from either bytes or path
  static Future<String> _readFileContent(PlatformFile file) async {
    if (file.bytes != null) return utf8.decode(file.bytes!);
    if (file.path != null) return await File(file.path!).readAsString();

    throw Exception('Die Datei hat keinen lesbaren Inhalt');
  }
}