calorimeter/lib/storage/storage.dart

import 'dart:io';

import 'package:kalodings/food_entry_bloc.dart';
import 'package:path_provider/path_provider.dart';

class FoodStorage {
  static late FoodStorage _instance;
  late String path;
  FoodStorage._create();

  static Future<FoodStorage> create() async {
    var storage = FoodStorage._create();
    var directory = await getApplicationCacheDirectory();
    storage.path = directory.path;
    _instance = storage;

    return _instance;
  }

  static FoodStorage getInstance() => _instance;

  Future<List<FoodEntry>> getEntriesForDate(DateTime date) async {
    List<FoodEntry> entries = [];
    var filePath = '$path/${date.year}/${date.month}/${date.day}';

    var file = File(filePath);
    var exists = await file.exists();

    if (!exists) return [];

    var lines = await file.readAsLines();

    for (var line in lines) {
      var fields = line.split(',');
      var entry = FoodEntry(
          name: fields[1],
          mass: double.parse(fields[2]),
          kcalPerMass: double.parse(fields[3]));
      entries.add(entry);
    }

    return entries;
  }

  Future<void> writeEntriesForDate(
      DateTime date, List<FoodEntry> foodEntries) async {
    var filePath = '$path/${date.year}/${date.month}/${date.day}';
    var file = File(filePath);

    var exists = await file.exists();

    if (!exists) {
      await file.create(recursive: true);
    }

    String fullString = '';
    for (var entry in foodEntries) {
      fullString += '${entry.toString()}\n';
    }

    await file.writeAsString(fullString);
  }

  Future<void> updateLimit(double limit) async {
    var filePath = '$path/limit';
    var file = File(filePath);

    var exists = await file.exists();
    if (!exists) {
      await file.create();
    }

    await file.writeAsString(limit.toString());
  }

  Future<double> readLimit() async {
    var filePath = '$path/limit';
    var file = File(filePath);
    var exists = await file.exists();

    if (!exists) {
      return 2000;
    }

    var line = await file.readAsLines();

    double limit;
    try {
      limit = double.parse(line[0]);
    } catch (e) {
      limit = 2000;
    }

    return limit;
  }
}