using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using xCommons.Extensions;
using xExceptions.Constants;
using xPushService.Configurations;
using xPushService.Constants;
using xPushService.Helpers;
using xPushService.Providers;

namespace xPushService.DI
{
    public static partial class XDIHelperExtension
    {
        /// <summary>
        /// Extract Module Configuration from provided IConfiguration
        /// </summary>
        /// <param name="config"></param>
        /// <returns>an instance of XPushServiceConfiguration</returns>
        public static XPushServiceConfiguration GetXPushServiceConfiguration(this IConfiguration config)
        {
            //
            var xPushConfigSection = config.GetSection(XPushServiceConstants.XConfigurationNodes.XPushServiceConfiguration);
            return xPushConfigSection.Get<XPushServiceConfiguration>();
        }

        /// <summary>
        /// Register XPushServiceHelper ...
        /// </summary>
        /// <param name="services"></param>
        /// <param name="helper"></param>
        public static void AddXPushServiceHelper(
            this IServiceCollection services,
            XPushServiceHelper helper
        )
        {
            //
            // Validate Args ...
            if (helper.IsNull())
            {
                //
                Log("AddXPushServiceHelper failed, helper not provided ...");
                throw XException.InvalidArgs.ToException();
            }

            //
            // Register Helper ...
            services.AddSingleton(helper);
        }

        /// <summary>
        /// Register Module Provided Service on DI
        /// </summary>
        /// <param name="services"></param>
        /// <param name="config"></param>
        /// <param name="lifeTime"></param>
        public static void AddXPushService(
            this IServiceCollection services,
            IConfiguration config,
            ServiceLifetime lifeTime = ServiceLifetime.Scoped
        )
        {
            //
            AddPushService(
                services,
                config.GetXPushServiceConfiguration(),
                lifeTime
            );
        }

        /// <summary>
        /// Register Module Provided Service on DI
        /// </summary>
        /// <param name="services"></param>
        /// <param name="config"></param>
        /// <param name="lifeTime"></param>
        public static void AddXPushService(
            this IServiceCollection services,
            XPushServiceConfiguration config,
            ServiceLifetime lifeTime = ServiceLifetime.Scoped
        )
        {
            //
            AddPushService(
                services,
                config,
                lifeTime
            );
        }

        /// <summary>
        /// Use Module Middlewares on Application Builder
        /// </summary>
        /// <param name="app"></param>
        /// <param name="helper"></param>
        public static void UseXPushService(
            this IApplicationBuilder app,
            XPushServiceHelper helper
        )
        {
            //
            // Validate Args ...
            var isHelperExists = !helper.IsNull();
            if (!isHelperExists)
            {
                //
                Log("AddXPushServiceHelper failed, helper not provided ...");
                throw XException.InvalidArgs.ToException();
            }

            //
            // Create an Scope for Accessing Registered Services ...
            using (var scope = app.ApplicationServices.CreateScope())
            {
                //
                // try to Retrieve Configuration ....
                var config = scope.ServiceProvider.GetService<XPushServiceConfiguration>();
                if (
                    config.IsNull() ||
                    config.BaseRoute.IsNullOrEmpty() ||
                    config.BaseRoute.Trim().IsNullOrEmpty()
                )
                {
                    //
                    Log("AddXPushServiceHelper failed, Configuration not provided ...");
                    throw XException.InvalidConfiguration.ToException();
                }

                //
                #region Normalize Routes ...
                //
                // Base Reoute ...
                config.BaseRoute = config.BaseRoute.ToNormalString();
                if (!config.BaseRoute.StartsWith("/"))
                {
                    config.BaseRoute = "/" + config.BaseRoute;
                }
                #endregion

                //
                // add XPushService Hub to Helper ...
                //
                var hubRoutes = new List<string>();

                //
                // Try to Register Hubs ...
                //
                // Use SignalR in App ...
                app.UseSignalR(routes =>
                {
                    //
                    helper.GetHubs().ForEach(hubDescriptor =>
                    {
                        //
                        var hubRoute = config.BaseRoute + "/" + hubDescriptor.Route;
                        hubRoutes.Add(hubRoute);

                        //
                        try
                        {
                            //
                            Type routesType = routes.GetType();
                            MethodInfo mapHubMethod = routesType
                                .GetMethods()
                                .SingleOrDefault(m =>
                                    m.Name == "MapHub" &&
                                    m.GetParameters().Length == 1
                                );
                            if (mapHubMethod.IsNull())
                            {
                                throw XException.ActionFailed.ToException();
                            }

                            //
                            object[] genericMapHubMethodArgs = { new PathString(hubRoute) };
                            MethodInfo genericMapHubMethod = mapHubMethod.MakeGenericMethod(hubDescriptor.Hub);
                            genericMapHubMethod.Invoke(routes, genericMapHubMethodArgs);

                            //
                            Log($"Register {hubDescriptor.Hub} Hub: {hubRoute}");
                        }
                        catch
                        {
                            throw;
                        }
                    });
                });
            }
        }

        //
        #region Private ...
        /// <summary>
        /// a LogTag for XPushService ...
        /// </summary>
        private static string XLogTag = "XPushService";

        /// <summary>
        /// print a log in Console ...
        /// </summary>
        /// <param name="message"></param>
        private static void Log(string message)
        {
            Console.WriteLine($"{XLogTag} => {message}");
        }

        /// <summary>
        /// Register Push Service ...
        /// </summary>
        /// <param name="services"></param>
        /// <param name="config"></param>
        /// <param name="lifeTime"></param>
        private static void AddPushService(
            IServiceCollection services,
            XPushServiceConfiguration config,
            ServiceLifetime lifeTime
        )
        {
            //
            #region Validate Args ...
            //
            var exception = XException.InvalidArgs.ToException(); ;

            //
            // Services ...
            var isServicesExists = !services.IsNull();
            if (!isServicesExists)
            {
                //
                Log("AddXPushServiceHelper failed, services not provided ...");
                throw exception;
            }

            //
            // Config ...
            var isConfigExists = !config.IsNull();
            if (!isConfigExists)
            {
                //
                Log("AddXPushServiceHelper failed, configuration not provided ...");
                throw exception;
            }

            //
            // Lifetime ...
            var isLifetimeExists = !lifeTime.IsNull();
            if (!isLifetimeExists)
            {
                //
                Log("AddXPushServiceHelper failed, lifetime not provided ...");
                throw exception;
            }
            #endregion

            //
            // Register XPushService Configuration ...
            services.AddSingleton(config);

            //
            // Register SignalR ...
            var builder = services.AddSignalR(options =>
            {
                options.KeepAliveInterval = TimeSpan.FromSeconds(10);
                options.ClientTimeoutInterval = TimeSpan.FromSeconds(10);
            });

            //
            // Add NewtonSoftJson Protocol ...
            builder.AddNewtonsoftJsonProtocol(x =>
            {
                x.PayloadSerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                x.PayloadSerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            });
            
            //
            // Register XPushServiceUserNameProvider ...
            services.AddSingleton<IUserIdProvider, XPushServiceUserNameProvider>();

            //
            // add Message Protocol Support ...
            if (config.AddSupportMessageProtocol)
            {
                builder.AddMessagePackProtocol();
            }
        }
        #endregion
    }
}