import 'package:comunic/helpers/websocket_helper.dart';
import 'package:comunic/lists/forez_presences_set.dart';
import 'package:comunic/models/forez_presence.dart';

/// Presence helper
///
/// @author Pierre Hubert

int? _cachedGroup;
PresenceSet? _cache;

class ForezPresenceHelper {
  /// Refresh presence cache
  ///
  /// Throws in case of failure
  static Future<void> refreshCache(int groupID) async {
    final response = await ws("forez_presence/list", {"group": groupID});

    final list = response
        .cast<String>()
        .map((element) {
          final cut = element.split(",").map((e) => int.parse(e)).toList();
          assert(cut.length == 4);

          return Presence(
              userID: cut[0], year: cut[1], month: cut[2], day: cut[3]);
        })
        .toList()
        .cast<Presence>();

    _cachedGroup = groupID;
    _cache = PresenceSet()..addAll(list);
  }

  /// Initialize cache if required
  static Future<void> _checkCache(int groupID) async {
    if (_cache == null || _cachedGroup != groupID) await refreshCache(groupID);
  }

  /// Get the presences of a given user
  ///
  /// Throws in case of failure
  static Future<PresenceSet> getForUser(int groupID, int? userID) async {
    await _checkCache(groupID);

    return _cache!.getForUser(userID);
  }

  /// Get all the available presences
  ///
  /// Throws in case of failure
  static Future<PresenceSet?> getAll(int groupID) async {
    await _checkCache(groupID);
    return _cache;
  }

  /// Add a new day of presence
  ///
  /// Throws in case of failure
  static Future<void> addDay(int groupID, DateTime dt) async =>
      await ws("forez_presence/add_day", {
        "group": groupID,
        "year": dt.year,
        "month": dt.month,
        "day": dt.day,
      });

  /// Remove a new day of presence
  ///
  /// Throws in case of failure
  static Future<void> delDay(int groupID, DateTime dt) async =>
      await ws("forez_presence/del_day", {
        "group": groupID,
        "year": dt.year,
        "month": dt.month,
        "day": dt.day,
      });
}