using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.AspNetCore.Http.Json;
using Microsoft.AspNetCore.HttpLogging;
using Microsoft.Identity.Web;
using Microsoft.OpenApi.Models;
using Shogi.Api.Managers;
using Shogi.Api.Repositories;
using Shogi.Api.Services;

namespace Shogi.Api
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            var allowedOrigins = builder.Configuration.GetSection("Cors:AllowedOrigins").Get<string[]>() ?? throw new InvalidOperationException("Configuration for allowed origins is missing.");
            builder.Services.AddCors(options =>
            {
                options.AddDefaultPolicy(policy =>
                {
                    policy
                    .WithOrigins(allowedOrigins)
                    .SetIsOriginAllowedToAllowWildcardSubdomains()
                    .WithExposedHeaders("Set-Cookie")
                    .AllowAnyHeader()
                    .AllowAnyMethod()
                    .AllowCredentials();
                });
            });
            ConfigureAuthentication(builder);
            ConfigureControllers(builder);
            ConfigureSwagger(builder);
            ConfigureDependencyInjection(builder);
            ConfigureLogging(builder);

            var app = builder.Build();

            app.UseWhen(
                // Log anything that isn't related to swagger.
                context => IsNotSwaggerUI(context),
                appBuilder => appBuilder.UseHttpLogging());

            // Configure the HTTP request pipeline.
            if (app.Environment.IsDevelopment())
            {
                app.UseHttpsRedirection(); // Apache handles HTTPS in production.
            }

            app.UseSwagger();
            app.UseSwaggerUI(options =>
            {
                options.OAuthScopes("api://c1e94676-cab0-42ba-8b6c-9532b8486fff/DefaultScope");
                options.OAuthConfigObject.ClientId = builder.Configuration["AzureAd:SwaggerUIClientId"];
                options.OAuthConfigObject.UsePkceWithAuthorizationCodeGrant = true;
            });

            UseCorsAndWebSockets(app, allowedOrigins);

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

            app.Map("/", () => "OK");
            app.MapControllers();

            app.Run();

            static bool IsNotSwaggerUI(HttpContext context)
            {
                var path = context.Request.GetEncodedPathAndQuery();

                return !path.Contains("swagger")
                    && !path.Equals("/", StringComparison.Ordinal);
            }
        }

        private static void UseCorsAndWebSockets(WebApplication app, string[] allowedOrigins)
        {

            // TODO: Figure out how to make a middleware for sockets?
            var socketService = app.Services.GetRequiredService<ISocketService>();
            var socketOptions = new WebSocketOptions();
            foreach (var origin in allowedOrigins)
                socketOptions.AllowedOrigins.Add(origin);

            app.UseCors();
            app.UseWebSockets(socketOptions);
            app.Use(async (context, next) =>
            {
                if (context.WebSockets.IsWebSocketRequest)
                {
                    await socketService.HandleSocketRequest(context);
                }
                await next();
            });
        }

        private static void ConfigureLogging(WebApplicationBuilder builder)
        {
            builder.Services.AddHttpLogging(options =>
            {
                options.LoggingFields = HttpLoggingFields.RequestProperties
                | HttpLoggingFields.RequestBody
                | HttpLoggingFields.ResponseStatusCode
                | HttpLoggingFields.ResponseBody;
            });
        }

        private static void ConfigureAuthentication(WebApplicationBuilder builder)
        {
            AddJwtAuth(builder);
            AddCookieAuth(builder);
            SetupAuthSwitch(builder);

            static void AddJwtAuth(WebApplicationBuilder builder)
            {
                builder.Services
                    .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                    .AddMicrosoftIdentityWebApi(builder.Configuration.GetSection("AzureAd"));
            }

            static void AddCookieAuth(WebApplicationBuilder builder)
            {
                builder.Services
                    .AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
                    .AddCookie(options =>
                    {
                        options.Cookie.Name = "session-id";
                        options.Cookie.SameSite = SameSiteMode.None;
                        options.Cookie.SecurePolicy = CookieSecurePolicy.Always;
                        options.SlidingExpiration = true;
                        options.LoginPath = new PathString("/User/LoginAsGuest");
                    });
            }

            static void SetupAuthSwitch(WebApplicationBuilder builder)
            {
                var defaultScheme = "CookieOrJwt";
                builder.Services
                    .AddAuthentication(defaultScheme)
                    .AddPolicyScheme("CookieOrJwt", "Either cookie or jwt", options =>
                    {
                        options.ForwardDefaultSelector = context =>
                        {
                            var bearerAuth = context.Request.Headers["Authorization"].FirstOrDefault()?.StartsWith("Bearer ") ?? false;
                            return bearerAuth
                            ? JwtBearerDefaults.AuthenticationScheme
                            : CookieAuthenticationDefaults.AuthenticationScheme;
                        };
                    });
                builder
                    .Services
                    .AddAuthentication(options =>
                    {
                        options.DefaultAuthenticateScheme = defaultScheme;
                    });
            }
        }

        private static void ConfigureControllers(WebApplicationBuilder builder)
        {
            builder.Services.AddControllers();
            builder.Services.Configure<JsonOptions>(options =>
            {
                options.SerializerOptions.WriteIndented = true;
            });
        }

        private static void ConfigureDependencyInjection(WebApplicationBuilder builder)
        {
            var services = builder.Services;
            services.AddSingleton<ISocketConnectionManager, SocketConnectionManager>();
            services.AddSingleton<ISocketTokenCache, SocketTokenCache>();
            services.AddSingleton<ISocketService, SocketService>();
            services.AddTransient<IClaimsTransformation, ShogiUserClaimsTransformer>();
            services.AddTransient<IShogiUserClaimsTransformer, ShogiUserClaimsTransformer>();
            services.AddTransient<IUserRepository, UserRepository>();
            services.AddTransient<ISessionRepository, SessionRepository>();
            services.AddTransient<IQueryRespository, QueryRepository>();
            services.AddTransient<IModelMapper, ModelMapper>();
        }

        private static void ConfigureSwagger(WebApplicationBuilder builder)
        {
            // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
            builder.Services.AddEndpointsApiExplorer();
            builder.Services.AddSwaggerGen(options =>
            {
                var bearerKey = "Bearer";
                options.AddSecurityDefinition(bearerKey, new OpenApiSecurityScheme
                {
                    Type = SecuritySchemeType.OAuth2,
                    Flows = new OpenApiOAuthFlows
                    {
                        Implicit = new OpenApiOAuthFlow
                        {
                            // These urls might be why only my email can login.
                            // TODO: Try testing with tenantId in the url instead of "common".
                            AuthorizationUrl = new Uri("https://login.microsoftonline.com/common/oauth2/v2.0/authorize"),
                            TokenUrl = new Uri("https://login.microsoftonline.com/common/oauth2/v2.0/token"),
                            Scopes = new Dictionary<string, string>
                            {
                                { "api://c1e94676-cab0-42ba-8b6c-9532b8486fff/DefaultScope", "Default Scope" },
                                { "profile", "profile" },
                                { "openid", "openid" }
                            }
                        }
                    },
                    Scheme = "Bearer",
                    BearerFormat = "JWT",
                    In = ParameterLocation.Header,
                });

                // This adds the lock symbol next to every route in SwaggerUI.
                options.AddSecurityRequirement(new OpenApiSecurityRequirement
                {
                    {
                        new OpenApiSecurityScheme{ Reference = new OpenApiReference{ Type = ReferenceType.SecurityScheme, Id = bearerKey } },
                        Array.Empty<string>()
                    }
                });
            });
        }
    }
}