Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using AutoMapper;
using DatingApp.API.Data;
using DatingApp.API.Helpers;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Diagnostics;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;

namespace DatingApp.API
{
    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)
        {
            var key = Encoding.ASCII.GetBytes(Configuration.GetSection("AppSettings:Token").Value);
            services.AddDbContext<DataContext>( x => x
            .UseSqlite(Configuration.GetConnectionString("DefaultConnection"))
            .ConfigureWarnings(warnings => warnings.Ignore(CoreEventId.IncludeIgnoredWarning)));
            //Populate Dummy Data from json
            services.AddTransient<Seed>();
            // Avoid the reference loop User in Photos Error.
            services.AddMvc().AddJsonOptions(opt =>{
                opt.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
            });
            services.AddCors();
            services.Configure<CloudinarySettings>(Configuration.GetSection("CloudinarySettings"));
            services.AddAutoMapper();
            services.AddScoped<IAuthRepository, AuthRepository>();
            services.AddScoped<IDatingRepository, DatingRepository>();
            services.AddScoped<LogUserActivity>();
            // Security Token JWT.
            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                    .AddJwtBearer(option => {
                        option.TokenValidationParameters = new TokenValidationParameters
                        {
                            ValidateIssuerSigningKey = true,
                            IssuerSigningKey = new SymmetricSecurityKey(key),
                            ValidateIssuer = false,
                            ValidateAudience = false

                        };
                    });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, Seed seeder)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                // Global Error Handling
                app.UseExceptionHandler(builder =>{
                    builder.Run(async context =>{
                        context.Response.StatusCode = (int) HttpStatusCode.InternalServerError;

                        var error = context.Features.Get<IExceptionHandlerFeature>();
                        if(error != null)
                        {
                            context.Response.AddApplicationError(error.Error.Message);
                            await context.Response.WriteAsync(error.Error.Message);
                        }
                    });
                });
            }
            // Feeding Dummy Data from json.
            //seeder.SeedUsers();
            app.UseCors( x => x.AllowAnyHeader().AllowAnyMethod().AllowAnyOrigin(). AllowCredentials());
            app.UseAuthentication();
            app.UseMvc();
        }
    }
}