import 'dart:developer';
import 'dart:io';

import 'package:calorimeter/food_entry/food_entry_bloc.dart';
import 'package:path_provider/path_provider.dart';
import 'package:universal_platform/universal_platform.dart';

class FoodStorage {
  static late FoodStorage _instance;
  late String path;
  final Map<String, double> _foodLookupDatabase = {};

  FoodStorage._create();

  static Future<FoodStorage> create() async {
    var storage = FoodStorage._create();

    Directory dir = Directory('');

    if (UniversalPlatform.isDesktop) {
      dir = await getApplicationCacheDirectory();
    } else if (UniversalPlatform.isAndroid) {
      dir = await getApplicationDocumentsDirectory();
    }

    storage.path = dir.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;
  }

  Future<String> readBrightness() async {
    var filePath = '$path/brightness';
    var file = File(filePath);
    var exists = await file.exists();

    if (!exists) {
      return 'dark';
    }

    var line = await file.readAsLines();

    if (line.isEmpty || (line[0] != 'dark' && line[0] != 'light')) {
      return 'dark';
    }

    return line[0];
  }

  Future<void> writeBrightness(String brightness) async {
    var filePath = '$path/brightness';
    var file = File(filePath);
    var exists = await file.exists();

    if (!exists) {
      file.create();
    }

    await file.writeAsString(brightness);
  }

  Future<void> buildFoodLookupDatabase() async {
    // get a list of dates of the last 365 days
    var dates = List<DateTime>.generate(365, (idx) {
      var pastDay = Duration(days: idx);
      return DateTime.now().subtract(pastDay);
    });

    for (var date in dates) {
      addFoodEntryToLookupDatabaseFor(date);
    }
  }

  Future<void> addFoodEntryToLookupDatabaseFor(DateTime date) async {
    var entriesForDate = await getEntriesForDate(date);

    for (var entry in entriesForDate) {
      _foodLookupDatabase[entry.name] = entry.kcalPerMass;
      log("Added entry: ${entry.name}/${entry.kcalPerMass}");
    }
  }

  void addFoodEntryToLookupDatabase(FoodEntry entry) {
    _foodLookupDatabase[entry.name] = entry.kcalPerMass;
    log("Added entry: ${entry.name}/${entry.kcalPerMass}");
  }

  Map<String, double> get getFoodEntryLookupDatabase => _foodLookupDatabase;
}