using System.IO;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using xCommons.Extensions;
using xExceptions.Constants;
using xStorageService.Constants;
using xStorageService.Helpers;
using xStorageService.Interfaces;
using xStorageService.Models;
using xStorageService.Providers;

namespace xStorageService.DI {
    public static partial class XDIHelperExtension {
        /// <summary>
        /// Retrieve XStorage Configuration from AppSettings 
        /// </summary>
        /// <param name="configuration"></param>
        /// <returns></returns>
        public static XStorageConfiguration GetXStorageConfiguration (this IConfiguration configuration) {
            //
            var storageConfigurationSection = configuration.GetSection (ConfigurationNodeNames.STORAGE_SERVICE_NODE_NAME);
            return storageConfigurationSection.Get<XStorageConfiguration> ();
        }

        /// <summary>
        /// Register XStorage Configuration 
        /// </summary>
        /// <param name="services"></param>
        /// <param name="configuration"></param>
        public static void AddXStorageConfiguration (
            this IServiceCollection services,
            IConfiguration configuration
        ) {
            //
            // Check wwwroot Folder ...
            if (!Directory.Exists ("wwwroot")) {
                Directory.CreateDirectory ("wwwroot");
            }

            //
            // Retrieve and Register XStorage Configurations ...
            var xStorageConfiguration = configuration.GetXStorageConfiguration ();
            if (xStorageConfiguration.IsNull ()) {
                XException.InvalidConfiguration.Throw ();
            }

            //
            xStorageConfiguration.BaseFolder = Path.Combine (Directory.GetCurrentDirectory (), "wwwroot");
            xStorageConfiguration.RootFolder = Directory.GetDirectoryRoot (xStorageConfiguration.BaseFolder);

            //
            services.AddSingleton<XStorageConfiguration> (xStorageConfiguration);
        }

        /// <summary>
        /// Register XStorage Service 
        /// </summary>
        /// <param name="services"></param>
        /// <param name="config"></param>
        public static void AddXStorageService (
            this IServiceCollection services,
            IConfiguration configuration
        ) {
            //
            // Register and Retrieve XStorage Configuration
            services.AddXStorageConfiguration (configuration);
            var xStorageConfiguration = services.GetRegisteredService<XStorageConfiguration> ();

            //
            // Add File Provider ...
            services.AddSingleton<IFileProvider> (
                new PhysicalFileProvider (xStorageConfiguration.BaseFolder)
            );

            //
            // Register XStorageHelper Service ...
            services.AddSingleton<XStorageHelper> ();

            //
            // Register ThumbnailHelper ... 
            services.AddSingleton<IXThumbnailProvider, XThumbnailProvider> ();

            //
            // Register Storage Provider ...
            services.AddScoped<IXStorageProvider, XStorageProvider> ();

            //
            // StorageService Preperation...
            var xStorageService = services.GetRegisteredService<IXStorageProvider> ();
            xStorageService.Prepare ();
        }

        /// <summary>
        /// Use XStorage Service 
        /// </summary>
        /// <param name="app"></param>
        public static void UseXStorageService (this IApplicationBuilder app) {
            //
            // Get Instance of Scope and Service and Prepare Folder Structure ...
            using (var scope = app.ApplicationServices.CreateScope ()) {
                //
                var storageProvider = scope.ServiceProvider.GetService<IXStorageProvider> ();

                //
                storageProvider.Prepare ();
            }

            //
            // available Static Files ...
            app.UseStaticFiles ();
        }
    }
}