Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using BookStore.Data;
using BookStore.Interfaces;
using BookStore.Repository;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;

namespace BookStore
{
    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)
        {
            services.AddControllers();
            // Add Swagger 
            services.AddSwaggerGen(conf =>
            {
                conf.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme()
                {
                    // Location of token definition
                    In = ParameterLocation.Header,
                    Description = "Please insert jwt token here",
                    Name = "Authorization",
                    Type = SecuritySchemeType.Http,
                    BearerFormat = "JWT",
                    Scheme = "bearer"
                });
                conf.AddSecurityRequirement(new OpenApiSecurityRequirement
                {
                    {
                    new OpenApiSecurityScheme
                    {
                        Reference = new OpenApiReference
                        {
                            Type = ReferenceType.SecurityScheme,
                            Id = "Bearer"
                        }
                    },
                    Array.Empty<string>()
                    }
                });
            });

            // Add DbContext and Set ConnectionString
            services.AddDbContext<BookStoreContext>(options =>
            options.UseNpgsql(Configuration.GetConnectionString("BookStoreConnectionString")));

            services.AddTransient<IBookRepository, BookRepository>();
            services.AddTransient<IAccountRepository, AccountRepository>();

            // Registration of Identity Service
            services.AddIdentity<ApplicationUser, IdentityRole>()
                    .AddEntityFrameworkStores<BookStoreContext>()
                    .AddDefaultTokenProviders();

            // Add Authentication & JWT Configurations
            services.AddAuthentication(option =>
            {
                option.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                option.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                option.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
            }).AddJwtBearer(opt =>
            {
                opt.SaveToken = true;
                opt.RequireHttpsMetadata = false;
                opt.TokenValidationParameters = new TokenValidationParameters()
                {
                    ValidateIssuer = true,
                    ValidateAudience = true,
                    ValidIssuer = Configuration["JWT:ValidIssuer"],
                    ValidAudience = Configuration["JWT:ValidAudiance"],
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["JWT:Secret"]))
                };

            });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseSwagger();
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("v1/swagger.json", "My API V1");
            });

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseAuthentication();
            app.UseAuthorization();

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