messengerapi.Broker/code/MessengerBroker/Handlers/Endpoint/UsersEndpointHandler.cs

using MessengerApi.Factories;
using MessengerBroker.Configuration.Model;
using MessengerBroker.Factories;
using MessengerBroker.Model.Http;
using Microsoft.EntityFrameworkCore;

namespace MessengerBroker.Handlers.Endpoint
{
    public class UsersEndpointHandler
    {
        private readonly BrokerConfiguration configuration;
        private readonly BrokerDbContextFactory brokerDbContextFactory;
        private readonly DbContextFactory messengerDbContextFactory;

        public UsersEndpointHandler(
            BrokerConfiguration configuration,
            BrokerDbContextFactory brokerDbContextFactory,
            DbContextFactory messengerDbContextFactory)
        {
            this.configuration = configuration;
            this.brokerDbContextFactory = brokerDbContextFactory;
            this.messengerDbContextFactory = messengerDbContextFactory;
        }

        public Task<Users.UsersResponse> GetUsers()
        {
            var foreignUserIds = (Guid[])null;

            using(var broCtx = this.brokerDbContextFactory.CreateDbContext())
            {
                foreignUserIds = broCtx.Users.Select(x => x.Id).ToArray();
            }

            using (var apiCtx = this.messengerDbContextFactory.CreateDbContext())
            {
                var localUsers = apiCtx.Users
                    .Where(x => !foreignUserIds.Any(f => f == x.Id))
                    .ToArray();

                var localUserIds = localUsers
                    .Select(x => x.Id)
                    .ToArray();

                var localRoutes = apiCtx.UserRoutes
                    .Include(x => x.From)
                    .Include(x => x.To)
                    .Where(x => localUserIds.Contains(x.From.Id) || localUserIds.Contains(x.To.Id))
                    .ToArray();

                return Task.FromResult(new Users.UsersResponse
                {
                    Users = localUsers.Select(x => new Users.UsersResponse.User
                    {
                        Id = x.Id,
                        ApiKey = x.ApiKey,
                        IsEnabled = x.IsEnabled,
                        Name = x.Name
                    }).ToArray(),
                    UserRoutes = localRoutes.Select(x => new Users.UsersResponse.UserRoute
                    {
                        Id = x.Id,
                        FromId = x.From.Id,
                        ToId = x.To.Id
                    }).ToArray()
                });
            }
        }
    }
}