Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.OpenApi.Models;

using VSC_TweetsApi.DAL;
using Microsoft.EntityFrameworkCore;
using VSC_TweetsApi.Repositoies;

namespace VSC_TweetsApi
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            //let's add our datacontext service 
            services.AddDbContext<DataContext>(options => options.UseNpgsql(Configuration.GetConnectionString("DefaultConnection")));
            services.AddScoped<IDataContext>(provider => provider.GetService<DataContext>());
            services.AddScoped<ITweetsRepository, TweetRepository>();
            services.AddScoped<IReTweetsRepository, ReTweetRepository>();
            services.AddScoped<ILikesRepository, LikeRepository>();
            services.AddScoped<IUsersRepository, UserRepository>();

            services.AddControllers();
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = "VSC_TweetsApi", Version = "v1" });
            });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseSwagger();
                app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "VSC_TweetsApi v1"));
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}