using Autofac;
using Autofac.Extensions.DependencyInjection;
using Devspaces.Support;
using HealthChecks.UI.Client;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Diagnostics.HealthChecks;
using Microsoft.AspNetCore.Http;
using Microsoft.Azure.ServiceBus;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBus;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBusServiceBus;
using Microsoft.eShopOnContainers.BuildingBlocks.IntegrationEventLogEF.Services;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Diagnostics.HealthChecks;
using Microsoft.Extensions.Logging;
using Microsoft.OpenApi.Models;
using RabbitMQ.Client;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.IdentityModel.Tokens.Jwt;
using System.Reflection;
using System.Threading;
using Webhooks.API.Infrastructure;
using Webhooks.API.IntegrationEvents;
using Webhooks.API.Services;

namespace Webhooks.API
{
    public class Startup
    {
        public IConfiguration Configuration { get; }

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }


        public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services
                .AddAppInsight(Configuration)
                .AddCustomRouting(Configuration)
                .AddCustomDbContext(Configuration)
                .AddSwagger(Configuration)
                .AddCustomHealthCheck(Configuration)
                .AddDevspaces()
                .AddHttpClientServices(Configuration)
                .AddIntegrationServices(Configuration)
                .AddEventBus(Configuration)
                .AddCustomAuthentication(Configuration)
                .AddSingleton<IHttpContextAccessor, HttpContextAccessor>()
                .AddTransient<IIdentityService, IdentityService>()
                .AddTransient<IGrantUrlTesterService, GrantUrlTesterService>()
                .AddTransient<IWebhooksRetriever, WebhooksRetriever>()
                .AddTransient<IWebhooksSender, WebhooksSender>();

            var container = new ContainerBuilder();
            container.Populate(services);
            return new AutofacServiceProvider(container.Build());
        }

        public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddApplicationInsights(app.ApplicationServices, LogLevel.Trace);

            var pathBase = Configuration["PATH_BASE"];

            if (!string.IsNullOrEmpty(pathBase))
            {
                loggerFactory.CreateLogger("init").LogDebug($"Using PATH BASE '{pathBase}'");
                app.UsePathBase(pathBase);
            }

            app.UseCors("CorsPolicy");

            ConfigureAuth(app);

            app.UseRouting();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapDefaultControllerRoute();
                endpoints.MapControllers();
                endpoints.MapHealthChecks("/hc", new HealthCheckOptions()
                {
                    Predicate = _ => true,
                    ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
                });
                endpoints.MapHealthChecks("/liveness", new HealthCheckOptions
                {
                    Predicate = r => r.Name.Contains("self")
                });
            });

            app.UseSwagger()
              .UseSwaggerUI(c =>
              {
                  c.SwaggerEndpoint($"{ (!string.IsNullOrEmpty(pathBase) ? pathBase : string.Empty) }/swagger/v1/swagger.json", "Webhooks.API V1");
                  c.OAuthClientId("webhooksswaggerui");
                  c.OAuthAppName("WebHooks Service Swagger UI");
              });

            ConfigureEventBus(app);
        }

        protected virtual void ConfigureAuth(IApplicationBuilder app)
        {
            /*
            if (Configuration.GetValue<bool>("UseLoadTest"))
            {
                app.UseMiddleware<ByPassAuthMiddleware>();
            }
            */

            app.UseAuthentication();
        }

        protected virtual void ConfigureEventBus(IApplicationBuilder app)
        {
            var eventBus = app.ApplicationServices.GetRequiredService<IEventBus>();
            eventBus.Subscribe<ProductPriceChangedIntegrationEvent, ProductPriceChangedIntegrationEventHandler>();
            eventBus.Subscribe<OrderStatusChangedToShippedIntegrationEvent, OrderStatusChangedToShippedIntegrationEventHandler>();
            eventBus.Subscribe<OrderStatusChangedToPaidIntegrationEvent, OrderStatusChangedToPaidIntegrationEventHandler>();
        }
    }

    static class CustomExtensionMethods
    {
        public static IServiceCollection AddAppInsight(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddApplicationInsightsTelemetry(configuration);
            services.AddApplicationInsightsKubernetesEnricher();

            return services;
        }

        public static IServiceCollection AddCustomRouting(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddControllers(options =>
            {
                options.Filters.Add(typeof(HttpGlobalExceptionFilter));
            });

            services.AddCors(options =>
            {
                options.AddPolicy("CorsPolicy",
                    builder => builder
                    .SetIsOriginAllowed((host) => true)
                    .AllowAnyMethod()
                    .AllowAnyHeader()
                    .AllowCredentials());
            });

            return services;
        }

        public static IServiceCollection AddCustomDbContext(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddEntityFrameworkSqlServer()
                .AddDbContext<WebhooksContext>(options =>
            {
                options.UseSqlServer(configuration["ConnectionString"],
                                     sqlServerOptionsAction: sqlOptions =>
                                     {
                                         sqlOptions.MigrationsAssembly(typeof(Startup).GetTypeInfo().Assembly.GetName().Name);
                                         //Configuring Connection Resiliency: https://docs.microsoft.com/en-us/ef/core/miscellaneous/connection-resiliency 
                                         sqlOptions.EnableRetryOnFailure(maxRetryCount: 15, maxRetryDelay: TimeSpan.FromSeconds(30), errorNumbersToAdd: null);
                                     });

                // Changing default behavior when client evaluation occurs to throw. 
                // Default in EF Core would be to log a warning when client evaluation is performed.
                options.ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));
                //Check Client vs. Server evaluation: https://docs.microsoft.com/en-us/ef/core/querying/client-eval
            });

            return services;
        }

        public static IServiceCollection AddSwagger(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddSwaggerGen(options =>
            {
                options.DescribeAllEnumsAsStrings();
                options.SwaggerDoc("v1", new OpenApiInfo
                {
                    Title = "eShopOnContainers - Webhooks HTTP API",
                    Version = "v1",
                    Description = "The Webhooks Microservice HTTP API. This is a simple webhooks CRUD registration entrypoint"
                });

                options.AddSecurityDefinition("oauth2", new OpenApiSecurityScheme
                {
                    Type = SecuritySchemeType.OAuth2,
                    Flows = new OpenApiOAuthFlows()
                    {
                        Implicit = new OpenApiOAuthFlow()
                        {
                            AuthorizationUrl = new Uri($"{configuration.GetValue<string>("IdentityUrlExternal")}/connect/authorize"),
                            TokenUrl = new Uri($"{configuration.GetValue<string>("IdentityUrlExternal")}/connect/token"),
                            Scopes = new Dictionary<string, string>()
                            {
                                {  "webhooks", "Webhooks API" }
                            }
                        }
                    }
                });

                options.OperationFilter<AuthorizeCheckOperationFilter>();
            });

            return services;
        }
        public static IServiceCollection AddEventBus(this IServiceCollection services, IConfiguration configuration)
        {
            var subscriptionClientName = configuration["SubscriptionClientName"];

            if (configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IEventBus, EventBusServiceBus>(sp =>
                {
                    var serviceBusPersisterConnection = sp.GetRequiredService<IServiceBusPersisterConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusServiceBus>>();
                    var eventBusSubcriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();

                    return new EventBusServiceBus(serviceBusPersisterConnection, logger,
                        eventBusSubcriptionsManager, subscriptionClientName, iLifetimeScope);
                });

            }
            else
            {
                services.AddSingleton<IEventBus, EventBusRabbitMQ>(sp =>
                {
                    var rabbitMQPersistentConnection = sp.GetRequiredService<IRabbitMQPersistentConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusRabbitMQ>>();
                    var eventBusSubcriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(configuration["EventBusRetryCount"]);
                    }

                    return new EventBusRabbitMQ(rabbitMQPersistentConnection, logger, iLifetimeScope, eventBusSubcriptionsManager, subscriptionClientName, retryCount);
                });
            }

            services.AddSingleton<IEventBusSubscriptionsManager, InMemoryEventBusSubscriptionsManager>();
            services.AddTransient<ProductPriceChangedIntegrationEventHandler>();
            services.AddTransient<OrderStatusChangedToShippedIntegrationEventHandler>();
            services.AddTransient<OrderStatusChangedToPaidIntegrationEventHandler>();
            return services;
        }

        public static IServiceCollection AddCustomHealthCheck(this IServiceCollection services, IConfiguration configuration)
        {
            var accountName = configuration.GetValue<string>("AzureStorageAccountName");
            var accountKey = configuration.GetValue<string>("AzureStorageAccountKey");

            var hcBuilder = services.AddHealthChecks();

            hcBuilder
                .AddCheck("self", () => HealthCheckResult.Healthy())
                .AddSqlServer(
                    configuration["ConnectionString"],
                    name: "WebhooksApiDb-check",
                    tags: new string[] { "webhooksdb" });

            return services;
        }

        public static IServiceCollection AddHttpClientServices(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddHttpClient("extendedhandlerlifetime").SetHandlerLifetime(Timeout.InfiniteTimeSpan);
            //add http client services
            services.AddHttpClient("GrantClient")
                   .SetHandlerLifetime(TimeSpan.FromMinutes(5))
                   .AddDevspacesSupport();
            return services;
        }

        public static IServiceCollection AddIntegrationServices(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddTransient<Func<DbConnection, IIntegrationEventLogService>>(
                sp => (DbConnection c) => new IntegrationEventLogService(c, sp.GetService<ILogger<IntegrationEventLogService>>()));

            if (configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IServiceBusPersisterConnection>(sp =>
                {
                    var logger = sp.GetRequiredService<ILogger<DefaultServiceBusPersisterConnection>>();
                    var serviceBusConnection = new ServiceBusConnectionStringBuilder(configuration["EventBusConnection"]);
                    return new DefaultServiceBusPersisterConnection(serviceBusConnection, logger);
                });
            }
            else
            {
                services.AddSingleton<IRabbitMQPersistentConnection>(sp =>
                {
                    var logger = sp.GetRequiredService<ILogger<DefaultRabbitMQPersistentConnection>>();

                    var factory = new ConnectionFactory()
                    {
                        HostName = configuration["EventBusConnection"],
                        DispatchConsumersAsync = true
                    };

                    if (!string.IsNullOrEmpty(configuration["EventBusUserName"]))
                    {
                        factory.UserName = configuration["EventBusUserName"];
                    }

                    if (!string.IsNullOrEmpty(configuration["EventBusPassword"]))
                    {
                        factory.Password = configuration["EventBusPassword"];
                    }

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(configuration["EventBusRetryCount"]);
                    }

                    return new DefaultRabbitMQPersistentConnection(factory, logger, retryCount);
                });
            }

            return services;
        }

        public static IServiceCollection AddCustomAuthentication(this IServiceCollection services, IConfiguration configuration)
        {
            // prevent from mapping "sub" claim to nameidentifier.
            JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Remove("sub");

            var identityUrl = configuration.GetValue<string>("IdentityUrl");

            services.AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

            }).AddJwtBearer(options =>
            {
                options.Authority = identityUrl;
                options.RequireHttpsMetadata = false;
                options.Audience = "webhooks";
            });

            return services;
        }
    }
}