using System;
using System.Linq;
using Microsoft.AspNetCore.Builder;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using xCommons.Extensions;
using xCommons.Helpers;
using xDataService.Configuration;
using xDataService.Constants;
using xDataService.Extensions;
using xDataService.Helpers;
using xDataService.Interfaces;
using xDataService.Models;
using xExceptions.Constants;

namespace xDataService.DI
{
    public static partial class XDIHelperExtension
    {
        /// <summary>
        /// Retrive XDataService Configurations
        /// </summary>
        /// <param name="source"></param>
        /// <param name="connectionName"></param>
        /// <returns></returns>
        public static XDataServiceConfiguration GetXDataServiceConfiguration(
            this IConfiguration source
        )
        {
            //
            var xDataServiceConfigSection = source
                .GetSection(ConfigurationNodeNames.DATA_SERVICE_NODE);
            var result = xDataServiceConfigSection.Get<XDataServiceConfiguration>();

            //
            return result;
        }

        /// <summary>
        /// Register XDataService Configuration ... 
        /// </summary>
        /// <param name="source"></param>
        /// <param name="configuration"></param>
        public static void AddXDataServiceConfiguration(
            this IServiceCollection source,
            IConfiguration configuration
        )
        {
            //
            var config = configuration.GetXDataServiceConfiguration();
            if (config.IsNullOrDefault())
            {
                //
                Log("Configurations Not Founded ...");
                XException.NotFound.Throw();
            }

            //
            source.AddSingleton(config);
        }

        /// <summary>
        /// Register XDataService Configuration ... 
        /// </summary>
        /// <param name="source"></param>
        /// <param name="configuration"></param>
        public static void AddXDataServiceConfiguration(
            this IServiceCollection source,
            XDataServiceConfiguration configuration
        )
        {
            //
            if (configuration.IsNullOrDefault())
            {
                //
                Log("Configurations Not Founded ...");
                XException.NotFound.Throw();
            }

            //
            source.AddSingleton(configuration);
        }

        /// <summary>
        /// Register a Data Base using Descriptor ...
        /// </summary>
        /// <param name="source"></param>
        /// <param name="configuration"></param>
        /// <param name="descriptor"></param>
        /// <param name="lifetime"></param>
        public static void AddXDatabase(
            this IServiceCollection source,
            IConfiguration configuration,
            XDatabaseDescriptor descriptor,
            ServiceLifetime lifetime = ServiceLifetime.Scoped
        )
        {
            //
            // Validate Database Descriptor ...
            var isValid =
                !descriptor.IsNullOrDefault() &&
                !descriptor.Name.IsNullOrEmpty();
            if (!isValid)
            {
                //
                Log("Invalid Database Descriptor ...");
                return;
            }

            //
            // Check Service Collection Validation ...
            isValid =
                !source.IsNull() &&
                !configuration.IsNull();
            if (!isValid)
            {
                //
                Log("Invalid Service Provider or Configuration ...");
                return;
            }

            //
            // Get Registere Data Service Configuration ...
            var xDataServiceConfiguration = source
                .GetRegisteredService<XDataServiceConfiguration>();
            isValid = !xDataServiceConfiguration.IsNullOrDefault();
            if (!isValid)
            {
                //
                // Extract Configuration from Configuration ...
                xDataServiceConfiguration = configuration.GetXDataServiceConfiguration();
                isValid = !xDataServiceConfiguration.IsNullOrDefault();
                if (!isValid)
                {
                    //
                    Log("DataService Configuration notProvided ...");
                    return;
                }

                //
                // Register Configuration in DI ... 
                source.AddSingleton(xDataServiceConfiguration);
            }

            //
            // Check Data Service Configuration has Database ...
            isValid =
                !xDataServiceConfiguration.Databases.IsNullOrDefault() &&
                xDataServiceConfiguration.Databases.HasChild() &&
                xDataServiceConfiguration.Databases.Keys.Contains(descriptor.Name);
            if (!isValid)
            {
                //
                Log("Invalid Database Descriptor ...");
                return;
            }

            //
            // Configure Database Descriptor ...
            descriptor.Configure(source);

            //
            // Register Context ...
            if (!descriptor.Context.IsNull() &&
                descriptor.Provider != XDbProviders.None &&
                !descriptor.ConnectionString.IsNullOrEmpty())
            {
                //
                try
                {
                    //
                    typeof(XDataServiceHelper).InvokeGenericMethod(
                        methodName: "AddXDbContext",
                        runtimeType: descriptor.Context,
                        args: [
                            source,
                        descriptor.Provider,
                        descriptor.ConnectionString,
                        lifetime,
                        descriptor.OptionsBuilder
                        ]
                    );

                    //
                    Log($"DbContext: {descriptor.Name} Registered Successfully ...");
                }
                catch (Exception ex)
                {
                    Log($"DbContext: {descriptor.Name} Registration failed due {ex.Message} ...");
                }
            }

            //
            // Register Repositories ...
            if (!descriptor.Repositories.IsNull() &&
                descriptor.Repositories.HasChild())
            {
                //
                descriptor.Repositories.ToList().ForEach(r =>
                {
                    //
                    // Preparing Runtime Types ...
                    Type[] runtimeTypes = r.GetType().GenericTypeArguments;

                    //
                    try
                    {
                        //
                        typeof(XDataServiceHelper).InvokeGenericMethod(
                            methodName: "AddXRepository",
                            runtimeTypes: runtimeTypes,
                            args: [
                                source,
                            r,
                            lifetime
                            ]
                        );

                        //
                        Log($"Repository of: {runtimeTypes[0]}, Registered Successfully ...");
                    }
                    catch (Exception ex)
                    {
                        Log($"Repository of: {runtimeTypes[0]}, Registration failed due {ex.Message} ...");
                    }
                });
            }
        }

        public static void UseXDatabase(
            this IApplicationBuilder source,
            XDatabaseDescriptor descriptor
        )
        {
            //
            // Validate ...
            var isValid =
                !source.IsNull() &&
                descriptor.IsValid();
            if (!isValid)
            {
                //
                Log("Invalid Database Configuration ...");
                XException.InvalidArgs.Throw();
            }

            //
            // Check Repositories Exists ...
            isValid = descriptor.HasRepositories();
            if (isValid)
            {
                //
                // Create an Scope for Services Acces ...
                using (var scope = source.ApplicationServices.CreateScope())
                {
                    //
                    // Inject XDataServiceConfiguration ForMake Sure DataService Registration ...
                    var dataServiceConfiguration = scope.ServiceProvider.GetService<XDataServiceConfiguration>();
                    isValid = !dataServiceConfiguration.IsNullOrDefault();
                    if (isValid)
                    {
                        //
                        // Loop through Repositories ...
                        descriptor.Repositories
                            .ToList()
                            .ForEach(r =>
                            {
                                //
                                // Check GraphQL Support ...
                                isValid = r.HasGraphSupport();
                                if (isValid)
                                {
                                    //
                                    // Inject GraphQL Type Helper ...
                                    var helper = scope.ServiceProvider.GetService(r.GraphTypeHelperService);
                                    isValid = !helper.IsNullOrDefault();
                                    if (!isValid)
                                    {
                                        //
                                        Log($"unable to find GraphQLTypeHelper for Entiy: {r.Entity}");
                                        XException.NotFound.Throw();
                                    }

                                    //
                                    var methods = source.GetType().GetMethods();
                                    isValid =
                                        !methods.IsNull() &&
                                        methods.HasChild();
                                    if (isValid)
                                    {
                                        //
                                        try
                                        {
                                            //
                                            // UseGraphQL ...
                                            var method = methods.First(m =>
                                                m.IsGenericMethod &&
                                                m.Name == "UseGraphQL" &&
                                                m.GetGenericArguments().Length == 1 &&
                                                m.GetParameters().Length == 1
                                            );
                                            var genericMethod = method.MakeGenericMethod(r.GraphSchema);
                                            genericMethod.Invoke(null, ((dynamic)helper).GetGraphQLPath());

                                            //
                                            // UseGraphQLWebSockets ...
                                            method = methods.First(m =>
                                                m.IsGenericMethod &&
                                                m.Name == "UseGraphQLWebSockets" &&
                                                m.GetGenericArguments().Length == 1 &&
                                                m.GetParameters().Length == 0
                                            );
                                            genericMethod = method.MakeGenericMethod(r.GraphSchema);
                                            genericMethod.Invoke(null, null);

                                            //
                                            Log($"Register GraphQL Middleware for Entity {r.Entity} Successfully ...");
                                        }
                                        catch (Exception ex)
                                        {
                                            Log($"Registration GraphQL Middleware for Entity {r.Entity} failed due {ex.Message} ...");
                                        }
                                    }
                                }
                            });
                    }
                }
            }
        }

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

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

        /// <summary>
        /// Do Seeding Initialization Data on DbContext
        /// </summary>
        /// <param name="app"></param>
        private static void SeedData(
            this IApplicationBuilder app
        )
        {
            //
            using (var scope = app.ApplicationServices.CreateScope())
            {
                //
                var dbSeeder = scope.ServiceProvider.GetService<IXDbSeeder>();
                Console.WriteLine($"XDataService: dbSeeder retrieved from DI is => {!dbSeeder.IsNull()}");

                //
                if (!dbSeeder.IsNull())
                {
                    try
                    {
                        //
                        dbSeeder.Seed()
                            .GetAwaiter()
                            .GetResult();
                    }
                    catch (Exception ex)
                    {
                        //
                        Console.WriteLine(" ");
                        Console.WriteLine($"XDataService: Seeding Error: {ex.Message}");
                        XException.InvalidConfiguration.Throw();
                    }
                }
            }
        }
        #endregion
    }
}