using System;
using System.Linq;
using System.Reflection;
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.Db;
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);
        }

        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())
            {
                //
                typeof(XDataServiceHelper).InvokeGenericMethod(
                    methodName: "AddXDbContext",
                    runtimeType: descriptor.Context,
                    args: [
                        source,
                        descriptor.Provider,
                        descriptor.ConnectionString,
                        lifetime,
                        descriptor.OptionsBuilder
                    ]
                );

                //
                // source.AddXDbContext<TContext>(
                //     lifetime: lifetime,
                //     provider: descriptor.Provider,
                //     optionsBuilder: descriptor.OptionsBuilder,
                //     connectionString: descriptor.ConnectionString
                // );
            }
        
            //
            // Register Repositories ...
            if (!descriptor.Repositories.IsNull() &&
                descriptor.Repositories.HasChild())
            {
                // source.AddXDataRepositories(

                // );
            }
        }

        //
        #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>
        /// Register DbContext ...
        /// </summary>
        /// <param name="source"></param>
        /// <param name="provider"></param>
        /// <param name="connectionString"></param>
        /// <param name="lifetime"></param>
        /// <param name="optionsBuilder"></param>
        /// <typeparam name="TContext"></typeparam>
        private static void AddXDbContext<TContext>(
            this IServiceCollection source,
            XDbProviders provider,
            string connectionString,
            ServiceLifetime lifetime = ServiceLifetime.Scoped,
            Action<dynamic> optionsBuilder = null
        )
        where TContext : XDbContext
        {
            //
            if (provider == XDbProviders.None)
            {
                //
                Log("Invalid Db Provider ...");
                XException.InvalidArgs.Throw();
            }

            //
            switch (provider)
            {
                //
                // MySQL ...
                case XDbProviders.MySQL:
                    //
                    source.AddDbContext<TContext>(cfg =>
                    {
                        cfg.UseMySQL(connectionString, optionsBuilder);
                    }, lifetime);
                    break;

                //
                // SQLite ...
                case XDbProviders.SQLite:
                    //
                    source.AddDbContext<TContext>(cfg =>
                    {
                        cfg.UseSqlite(connectionString, optionsBuilder);
                    }, lifetime);
                    break;

                //
                // SQLServer ...
                case XDbProviders.SQLServer:
                    //
                    source.AddDbContext<TContext>(cfg =>
                    {
                        cfg.UseSqlServer(connectionString, optionsBuilder);
                    }, lifetime);
                    break;

                //
                case XDbProviders.MongoDB:
                    // There is notRequired to Register DBConext forMongo DB ...
                    break;
            }
        }

        /// <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
    }
}