using System;
using System.Collections.Generic;
using System.Globalization;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Localization;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Sarand.Core.App;
using Sarand.Core.Base;
using Sarand.OperationsMgr.Core.App;
using Sarand.OperationsMgr.Web.System;

namespace Sarand.OperationsMgr.Web.App
{
	//=======================================================================
	public class Startup
	{
		//-------------------------------------------------------------------
		// Data members.
		private SaOperationsMgrWebApp app = null;
		// Localisation.
		private static RequestCulture defaultRequestCulture = new RequestCulture("en-GB", "en-GB");
		private static List<CultureInfo> supportedCultures = new List<CultureInfo>
		{
			new CultureInfo("en-GB"),
			new CultureInfo("en-US"),
			new CultureInfo("en"),
		};

		//-------------------------------------------------------------------
		public Startup (IHostingEnvironment env)
		{
			String fn = "SaOperationsMgrWeb.Startup";

			// Load server configuration.
			String machineName = Environment.MachineName;
			var builder = new ConfigurationBuilder()
				.SetBasePath(env.ContentRootPath)
				.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
				.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
				.AddJsonFile($"appsettings.machine.{machineName}.json", optional: false, reloadOnChange: true)
				.AddEnvironmentVariables();
			Logger.Info(fn + " EnvironmentName: " + env.EnvironmentName + ". MachineName: " + machineName + ".");

			if (env.IsDevelopment())
			{
				// This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
				builder.AddApplicationInsightsSettings(developerMode: true);
			}
			else
			{
				// Staging, Production.
			}
			Configuration = builder.Build();

			// Avoid automatic binding of model properties.
			// Ref. https://stackoverflow.com/questions/2211829/why-does-asp-net-mvc-care-about-my-read-only-properties-during-databinding
			//DataAnnotationsModelValidatorProvider.AddImplicitRequiredAttributeForValueTypes = false;

			// Initialise application:
			app = new SaOperationsMgrWebApp(env, Configuration.GetSection("SessionContexts"), Opn.ApplicationCaption + " Startup");
		}

		//-------------------------------------------------------------------
		public IConfigurationRoot Configuration { get; }

		//-------------------------------------------------------------------
		// This method gets called by the runtime. Use this method to add services to the container.
		public void ConfigureServices (IServiceCollection services)
		{
			// Add framework services.
			services.AddApplicationInsightsTelemetry(Configuration);

			// Aug-2017 Added to support memory caching of sessions.
			services.AddMemoryCache();
			//services.AddDistributedMemoryCache(); - for multiple web servers.
			services.AddSession
				(options =>
				{
					/* Default cookie name: '.AspNetCore.Session' */
					options.CookieName = "SaOperationsMgr.Session";
					options.IdleTimeout = SacsSystem.DebugMode ? TimeSpan.FromMinutes(15) : TimeSpan.FromMinutes(30);
					options.CookieHttpOnly = true;
				}
				);

			// Application localisation.
			services.AddSingleton<OpnLocaliser>();
			// Lovalisation properties folder.
			String resourcesPath = "Localisation";
			services.AddLocalization(opts => { opts.ResourcesPath = resourcesPath; });

			services.AddMvc
				(options =>
				{
					// Model binding - intercepting form values being bound to models.
					options.ModelBinderProviders.Insert(0, new OpnModelBinderProvider());
				}
				)
				// View and data annotation localisations.
				.AddViewLocalization(
					LanguageViewLocationExpanderFormat.Suffix,
					opts => { opts.ResourcesPath = resourcesPath; })
				.AddDataAnnotationsLocalization();

			// Configure localisation middleware.
			services.Configure<RequestLocalizationOptions>
			(opts =>
			{
					// Default culture to use for requests.
					opts.DefaultRequestCulture = defaultRequestCulture;
					// Cultures supported by the application. Formatting numbers, dates, etc.
					opts.SupportedCultures = supportedCultures;
					// UI cultures supported by the application. UI strings that have been localized.
					opts.SupportedUICultures = supportedCultures;
			}
			);

			services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
		}

		//-------------------------------------------------------------------
		// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
		public void Configure (IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
		{
			loggerFactory.AddConsole(Configuration.GetSection("Logging"));
			loggerFactory.AddDebug();

			// Application insights telemetry for requests.
			//app.UseApplicationInsightsRequestTelemetry();
			//app.UseApplicationInsightsExceptionTelemetry();

			if (env.IsDevelopment())
			{
				app.UseDeveloperExceptionPage();
				//app.UseBrowserLink();
			}
			else
			{
				app.UseExceptionHandler("/Home/Error");
			}

			// Enable static file serving.
			app.UseStaticFiles();

			// Localisation.
			var localisationOptions = app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>();
			app.UseRequestLocalization(localisationOptions.Value);

			// Initialise session handling.
			app.UseSession();

			app.UseMvc(routes =>
			{
				routes.MapRoute(
					name: "default",
					template: "{controller=Home}/{action=Index}/{id?}");
			});
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}