using System;
using System.Text;
using System.Threading.Tasks;
using BlueWest.Cryptography;
using BlueWest.Data;
using BlueWest.WebApi.Context.Users;
using BlueWest.WebApi.EF;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;

namespace BlueWest.WebApi
{
    /// <summary>
    /// Startup Extensions
    /// </summary>
    public static class StartupExtensions
    {
        private static MySqlServerVersion GetMySqlServerVersion(int major, int minor, int build) => new (new Version(major, minor, build));
        
        /// <summary>
        /// Get MYSQL Connection String
        /// </summary>
        /// <param name="optionsBuilder"></param>
        /// <param name="configuration"></param>
        /// <param name="environment"></param>
        private static DbContextOptionsBuilder GetMySqlSettings(
            this DbContextOptionsBuilder optionsBuilder,
            IConfiguration configuration,
            IWebHostEnvironment environment)
        {
            var sqlVersion = GetMySqlServerVersion(8, 0, 11);

            optionsBuilder
                .UseMySql(
                    configuration.GetConnectionString("DockerMySQL"), 
                    sqlVersion)
                    .UseMySql(sqlVersion,
                        builder =>
                        {
                            builder.EnableRetryOnFailure(6, TimeSpan.FromSeconds(3), null);
                        });

            // The following three options help with debugging, but should
            // be changed or removed for production.
            if (environment.IsDevelopment())
            {
                optionsBuilder
                    .LogTo(Console.WriteLine, LogLevel.Information)
                    .EnableSensitiveDataLogging()
                    .EnableDetailedErrors();
            }

            return optionsBuilder;
        }

        /// <summary>
        /// Setup database Contexts
        /// </summary>
        /// <param name="serviceCollection"></param>
        /// <param name="configuration"></param>
        /// <param name="environment"></param>
        /// <returns></returns>
        public static IServiceCollection PrepareMySqlDatabasePool(this IServiceCollection serviceCollection,
            IConfiguration configuration, IWebHostEnvironment environment)
        {
            return serviceCollection
                .AddDbContextPool<UserDbContext>(options => options.GetMySqlSettings(configuration, environment))
                .AddDbContextPool<CountryDbContext>(options => options.GetMySqlSettings(configuration, environment))
                .AddDbContextPool<FinanceDbContext>(options => options.GetMySqlSettings(configuration, environment))
                .AddDbContextPool<CompanyDbContext>(options => options.GetMySqlSettings(configuration, environment));
        }
        
        /// <summary>
        /// Setup database Contexts
        /// </summary>
        /// <param name="serviceCollection"></param>
        /// <param name="configuration"></param>
        /// <param name="environment"></param>
        /// <returns></returns>
        public static IServiceCollection PrepareSqlLiteDatabasePool(this IServiceCollection serviceCollection,
            IConfiguration configuration, IWebHostEnvironment environment)
        {
            var sqliteConString = "Data Source=BlueWest.Api.db";
            
            return serviceCollection
                .AddDbContextPool<UserDbContext>(options => options.UseSqlite(sqliteConString))
                .AddDbContextPool<CountryDbContext>(options => options.UseSqlite(sqliteConString))
                .AddDbContextPool<FinanceDbContext>(options => options.UseSqlite(sqliteConString))
                .AddDbContextPool<CompanyDbContext>(options => options.UseSqlite(sqliteConString));
        }
        
        public static void AddAuthServerServices(this IServiceCollection services,  string origins, IConfiguration _configuration)
        {
            services.AddScoped<IJwtTokenHandler, JwtTokenHandler>();
            services.AddScoped<IJwtFactory, JwtFactory>();

            // User management 
            services
                .AddIdentityCore<ApplicationUser>(opt => { opt.User.RequireUniqueEmail = true; })
                .AddEntityFrameworkStores<UserDbContext>()
                .AddUserManager<UserManager>()
                .AddUserStore<UserRepository>();
            // Database Context and Swagger

            services.TryAddSingleton<ISystemClock, SystemClock>();
            // Registering 'services' and Authentication, Cookies, JWT
            services
                .AddScoped<IUsersRepo, UserRepository>()
                .AddScoped<IUserManager, UserManager>() // So it gets successfully registered in UserManager
                .AddScoped<IAuthManager, AuthManager>()
                .AddScoped<IHasher, Hasher>();


            // Register the ConfigurationBuilder instance of AuthSettings
            var authSettings = _configuration.GetSection(nameof(AuthSettings));
            services.Configure<AuthSettings>(authSettings);
            var signingKey = new SymmetricSecurityKey
                (Encoding.ASCII.GetBytes(authSettings[nameof(AuthSettings.SecretKey)]));

            // jwt wire up
            // Get options from app settings
            var jwtAppSettingOptions = _configuration
                .GetSection(nameof(JwtIssuerOptions));

            // Configure JwtIssuerOptions
            services.Configure<JwtIssuerOptions>(options =>
            {
                options.Issuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
                options.Audience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)];
                options.SigningCredentials = new SigningCredentials
                    (signingKey, SecurityAlgorithms.HmacSha256);
            });

            var tokenValidationParameters = new TokenValidationParameters
            {
                ValidateIssuer = true,
                ValidIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)],

                ValidateAudience = true,
                ValidAudience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)],

                ValidateIssuerSigningKey = true,
                IssuerSigningKey = signingKey,

                RequireExpirationTime = false,
                ValidateLifetime = true,
                ClockSkew = TimeSpan.Zero
            };

            services.AddAuthentication(options =>
                {
                    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                    options.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
                    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
                })
                .AddCookie(options =>
                {
                    options.LoginPath = "/api/auth/login2";
                    options.LogoutPath = "/api/auth/logout";
                })
                .AddJwtBearer(configureOptions =>
                {
                    configureOptions.ClaimsIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
                    configureOptions.TokenValidationParameters = tokenValidationParameters;
                    configureOptions.SaveToken = true;

                    configureOptions.Events = new JwtBearerEvents
                    {
                        OnAuthenticationFailed = context =>
                        {
                            if (context.Exception.GetType() == typeof(SecurityTokenExpiredException))
                            {
                                context.Response.Headers.Add("Token-Expired", "true");
                            }

                            return Task.CompletedTask;
                        }
                    };
                });
                

            // api user claim policy
            services.AddAuthorization(options =>
            {
                options.AddPolicy("ApiUser",
                    policy => policy.RequireClaim(Constants.JwtClaimIdentifiers.Rol,
                        Constants.JwtClaims.ApiAccess));
            });

            // add identity
            var identityBuilder = services.AddIdentityCore<User>(o =>
            {
                // configure identity options
                o.Password.RequireDigit = false;
                o.Password.RequireLowercase = false;
                o.Password.RequireUppercase = false;
                o.Password.RequireNonAlphanumeric = false;
                o.Password.RequiredLength = 6;
            });

            identityBuilder = new IdentityBuilder(identityBuilder.UserType, typeof(IdentityRole), identityBuilder.Services);
            identityBuilder.AddEntityFrameworkStores<UserDbContext>().AddDefaultTokenProviders();
        }
        public static void ConfigureApiWithUsers(this IApplicationBuilder app, IWebHostEnvironment env, string origins)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseHsts();
            }

            app.UseSwagger()
                .UseSwaggerUI(config => { config.SwaggerEndpoint("/swagger/v1/swagger.json", "Commands And Snippets API"); })
                .UseRouting()
                .UseAuthentication()
                .UseAuthorization()
                .UseCors(origins)   
                .UseEndpoints(endpoints => endpoints.MapControllers());
        }
        
    }
}