comunicmobile/lib/helpers/users_helper.dart

import 'package:comunic/enums/user_page_visibility.dart';
import 'package:comunic/helpers/database/users_database_helper.dart';
import 'package:comunic/lists/users_list.dart';
import 'package:comunic/models/api_request.dart';
import 'package:comunic/models/user.dart';

/// User helper
///
/// Helper used to get information about the users of Comunic
///
/// @author Pierre HUBERT

class UsersHelper {
  final UsersDatabaseHelper _usersDatabaseHelper = UsersDatabaseHelper();

  /// Download information about some given users ID
  ///
  /// Return the list of users information in case of success, null in case of
  /// failure
  Future<UsersList> _downloadInfo(List<int> users) async {
    // Execute the request
    final response = await APIRequest(
        uri: "user/getInfoMultiple", args: {"usersID": users.join(",")}).exec();

    // Check if the request did not execute correctly
    if (response.code != 200) return null;

    final list = UsersList();
    response.getObject().forEach(
          (k, v) => list.add(
                User(
                  id: v["userID"],
                  firstName: v["firstName"],
                  lastName: v["lastName"],
                  pageVisibility: v["publicPage"] == "false"
                      ? UserPageVisibility.PRIVATE
                      : (v["openPage"] == "false"
                          ? UserPageVisibility.PRIVATE
                          : UserPageVisibility.OPEN),
                  virtualDirectory: v["virtualDirectory"] == ""
                      ? null
                      : v["virtualDirectory"],
                  accountImageURL: v["accountImage"],
                ),
              ),
        );

    // Save the list
    _usersDatabaseHelper.insertOrUpdateAll(list);

    return list;
  }

  /// Get users information from a given [Set]
  Future<UsersList> getList(Set<int> users,
      {bool forceDownload = false}) async {
    return await getUsersInfo(users.toList());
  }

  /// Get users information
  ///
  /// If [forceDownload] is set to true, the data will always be retrieved from
  /// the server, otherwise cached data will be used if available
  Future<UsersList> getUsersInfo(List<int> users,
      {bool forceDownload = false}) async {

    List<int> toDownload = List();
    UsersList list = UsersList();

    // Check cache
    for(int userID in users){
      if(!forceDownload && await _usersDatabaseHelper.has(userID))
        list.add(await _usersDatabaseHelper.get(userID));
      else
        toDownload.add(userID);
    }

    // Process download if required
    if(toDownload.length > 0) {
      final downloadedList = await _downloadInfo(toDownload);

      if(downloadedList == null)
        return null;

      list.addAll(downloadedList);
    }

    return list;
  }
}