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

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

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

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

        public async Task<Messages.MessagesResponse> GetMessages(Messages.MessagesRequest request)
        {
            using var broCtx = this.brokerDbContextFactory.CreateDbContext();

            var brokerMessageIdCollection = broCtx.Messages
                .Where(x => x.BrokerId == request.OwnerBrokerId)
                .Select(x => x.Id)
                .Take(1000)
                .ToArray();

            using var apiCtx = this.messengerDbContextFactory.CreateDbContext();

            var messages = apiCtx.Messages
                .Where(x => x.CreatedUtc >= request.SinceUtc && brokerMessageIdCollection.Contains(x.Id))
                .ToArray();

            var response = new Messages.MessagesResponse
            {
                Messages = messages
            };

            return response;
        }
    }
}