import 'dart:math';
import 'package:pokedex/pokemon.dart';
import 'package:shared_preferences/shared_preferences.dart';

class Callbacks {
  Function()? mainPage;
  Function()? filtersPage;
  Function()? dexDisplay;
  Function()? updateCheckPage;

  Future<void> dispatch() async {
    if (mainPage != null) mainPage!.call();
    if (filtersPage != null) filtersPage!.call();
    if (dexDisplay != null) dexDisplay!.call();
    if (updateCheckPage != null) updateCheckPage!.call();
  }
}

class SessionData {
  static Future<void> initialize() async {
    SharedPreferencesAsync spa = SharedPreferencesAsync();
    darkMode = await spa.getBool("dark") ?? false;
  }

  static Future<void> finalize() async {
    SharedPreferencesAsync spa = SharedPreferencesAsync();
    await spa.setBool("dark", darkMode);
  }

  static Callbacks callbacks = Callbacks();
  static bool isUpdateAvailable = false;
  static bool enableDescription = true;
  static bool darkMode = false;
  static int highest = 9;
  static int _cachedHighest = -1;
  static final List<String> ALPHABET = [
    "A",
    "B",
    "C",
    "D",
    "E",
    "F",
    "G",
    "H",
    "I",
    "J",
    "K",
    "L",
    "M",
    "N",
    "O",
    "P",
    "Q",
    "R",
    "S",
    "T",
    "U",
    "V",
    "W",
    "X",
    "Y",
    "Z",
    "EM",
    "QM",
  ];

  static int _lastMaxID = 0;

  static void resetHighestGenCache() {
    _cachedHighest = -1;
  }

  static String getRandomUnownSprite() {
    int index = Random().nextInt(ALPHABET.length);
    var digit = ALPHABET[index];

    return "assets/sprites/unown-${digit.toLowerCase()}.png";
  }

  static int highestGenID() {
    if (_lastMaxID != Pokemon.values.length) resetHighestGenCache();
    if (_cachedHighest != -1) return _cachedHighest;
    List<Generation> gens = [];

    if (highest >= 9) gens.add(Generation.Nine);
    if (highest >= 8) gens.add(Generation.Eight);
    if (highest >= 7) gens.add(Generation.Seven);
    if (highest >= 6) gens.add(Generation.Six);
    if (highest >= 5) gens.add(Generation.Five);
    if (highest >= 4) gens.add(Generation.Four);
    if (highest >= 3) gens.add(Generation.Three);
    if (highest >= 2) gens.add(Generation.Two);
    if (highest >= 1) gens.add(Generation.One);

    int max = 0;
    // Iterate over the list, and get the count of all pokemon from a specific generation
    for (var gen in gens) {
      for (var pokemon in Pokemon.values) {
        if (pokemon.generation == gen) max++;
      }
    }

    _cachedHighest = max;
    _lastMaxID = Pokemon.values.length;

    return max;
  }
}