using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Localization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Routing;
using Microsoft.Net.Http.Headers;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using Sacs.Web.Components;
using Sarand.BusinessMgr.Net.Core.Web.App;
using Sarand.BusinessMgr.Net.Core.Web.Models;
using Sarand.BusinessMgr.Net.Standard.Base.App;
using Sarand.BusinessMgr.Net.Standard.Base.Bus;
using Sarand.BusinessMgr.Net.Standard.Base.Consoles;
using Sarand.BusinessMgr.Net.Standard.Base.Core;
using Sarand.BusinessMgr.Net.Standard.Base.Mgr;
using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.CodeTypes;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Dbas;
using Sarand.Net.Standard.Base.Diary;
using Sarand.Net.Standard.Base.Email;
using Sarand.Net.Standard.Base.Helpers;
using Sarand.Net.Standard.Base.Interfaces;
using Sarand.Net.Standard.Base.ItemData;
using Sarand.Net.Standard.Base.ItemDocs;
using Sarand.Net.Standard.Base.ItemOptions;
using Sarand.Net.Standard.Base.ReferenceData;
using Sarand.Net.Standard.Base.Security;
using Sarand.Net.Standard.Base.UpdateLog;
using Sarand.Net.Standard.Base.Utils;
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;

namespace Sarand.BusinessMgr.Net.Core.Web.Controllers
{
	//=======================================================================
	public abstract class SbmController_Web : SbmController_Base
	{
		//-------------------------------------------------------------------
		// Data members.

		//-------------------------------------------------------------------
		// Protected construction.
		protected SbmController_Web(SbmLocaliser localiser) : base(localiser)
		{
			// Initialise console (debug) logging listener.
			//if (Directory.Exists(App.LoggingRootFolder) && SbmSystem.DebugMode)
			//	SbmConsoleListener.ConfigureDebugListener(App.LoggingRootFolder);
			if (DebugMode) SaLogger.Trace($"{GetType().Name}.CTR");
		}
		protected override void Dispose(bool disposing)
		{
			if (disposing)
			{
			}
			base.Dispose(disposing);
		}

		//-------------------------------------------------------------------
		// Properties.
		public override SbmSessionContext SessionContext { get { return SessionData?.SessionContext ?? null; } }

		//-------------------------------------------------------------------
		// Action execution events.
		//-------------------------------------------------------------------
		public override void OnActionExecuting(ActionExecutingContext filterContext)
		{
			//if (DebugMode) SaLogger.Debug($"{SysUtil.Fn}" + (ViewData.Model != null ? " Model: " + ViewData.Model : ""));

			// Refreh model properties.
			SbmModel_Base baseModel = ViewData.Model as SbmModel_Base;
			RefreshModel(baseModel);

			base.OnActionExecuting(filterContext);
		}
		public override void OnActionExecuted(ActionExecutedContext filterContext)
		{
			//if (DebugMode) SaLogger.Debug($"{SysUtil.Fn}" + (ViewData.Model != null ? " Model: " + ViewData.Model : ""));

			// Refreh model properties.
			SbmModel_Base baseModel = ViewData.Model as SbmModel_Base;
			RefreshModel(baseModel);

			// Store session data if present - as potentially modfied.
			if (SessionData != null)
			{
				// Most actions will store the session data in case it's been modified.
				// Some actions (eg. score password) don't need to.
				if (StoreSessionData)
				{
					String sessionDataJson = JsonConvert.SerializeObject(SessionData);
					HttpContext.Session.Set(SessionStorage.SessionKey_SessionData, SessionStorage.sessionDataEncoding.GetBytes(sessionDataJson));
				}
			}
			else HttpContext.Session.Remove(SessionStorage.SessionKey_SessionData);

			// Response headers.
			if (baseModel != null && baseModel.ProhibitCache)
			{
				if (Response.Headers.ContainsKey(HeaderNames.CacheControl))
					Response.Headers.Remove(HeaderNames.CacheControl);
				Response.Headers.Add(HeaderNames.CacheControl, "no-cache, no-store, must-revalidate");
				Response.Headers.Add(HeaderNames.Pragma, "no-cache");
				Response.Headers.Add(HeaderNames.Expires, "0");
			}


			base.OnActionExecuted(filterContext);
		}

		//-------------------------------------------------------------------
		// Model.
		//-------------------------------------------------------------------
		protected void RefreshModel(SbmModel_Base model)
		{
			if (model == null) return;

			// Session data.
			model.Controller = this;
			model.SessionData_Web = SessionData;

			// Redirect locations.
			model.RedirectLocation.Base = GetRedirectLocation(RedirectLocation.WebAppBase);
			model.RedirectLocation.Home = GetRedirectLocation(RedirectLocation.WebAppHome);
			model.RedirectLocation.Home_SessionExpired = GetRedirectLocation(RedirectLocation.WebAppHome_SessionExpired);
		}

		//-------------------------------------------------------------------
		// Online encryption parameters.
		//-------------------------------------------------------------------
		// Portal Request Password encryption parameters (key & IV) are defined in
		// the base Controller so that they can be shared with the Admin application.
		// NB IV value is generated from the key and fixed so that it doesn't change when the application restarts.
		// IV Must be regenerated if key is changed.
		protected static String Base64Key_RequestPassword_Portal { get; } = SacsEncryptionHelper.EncodePlainKey("[5Abus1neSSmGR~Request#Password}", SacsEncryptionHelper.KeyLength);
		//private static String Base64IV_RequestPassword_Generated_Portal = SacsEncryptionHelper.InitSymmetricEncryptionIV(Base64Key_RequestPassword_Portal);
		protected static String Base64IV_RequestPassword_Portal { get; } = "8TRhBayBJZmACQ6pld1F9A==";

		//-------------------------------------------------------------------
		// Session.
		//-------------------------------------------------------------------
		public bool ValidUserSession { get { return SessionData?.ValidUser ?? false; } }
		public DbUpdateInfo DbUpdateInfo { get { return SessionData?.DbUpdateInfo ?? new DbUpdateInfo(null, "", SbmSystem.ComputerName); } }
		// Referrer.
		public String Referer { get { return Request.Headers["Referer"].ToString(); } }
		public bool ValidReferer { get { return !StringUtil.IsEmpty(Referer); } }
		/// <summary>Store session data, eg. to start a new user session on sign-in.</summary>
		protected bool SetSessionData(SbmSessionData_Web sessionData)
		{
			if (sessionStorage.SessionData != null) return false;
			sessionStorage.SessionData = sessionData;
			return true;
		}
		protected void ClearSessionData()
		{
			if (HttpContext.Session.IsAvailable)
				HttpContext.Session.Clear();
			sessionStorage.SessionData = null;
		}

		//-------------------------------------------------------------------
		// Session storage.
		public class SessionStorage
		{
			public SbmSessionData_Web SessionData { get; set; }
			public static String SessionKey_SessionData { get; } = "SbmSessionData";
			public static Encoding sessionDataEncoding { get; } = Encoding.UTF8;
			//JSON Serialisation.
			public class SbmSessionDataContractResolver : DefaultContractResolver
			{
				// To allow private properties to be deserialised.
				// NB Only applies to top level properties in the serialised object.
				protected override List<MemberInfo> GetSerializableMembers(Type objectType)
				{
					var flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
					MemberInfo[] fields = objectType.GetFields(flags);
					return fields
						.Concat(objectType.GetProperties(flags).Where(propInfo => propInfo.CanWrite))
						.ToList();
				}
				protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
				{
					return base.CreateProperties(type, MemberSerialization.Fields);
				}
			};
			public static JsonSerializerSettings JsonDeserialisationSettings = new JsonSerializerSettings
			{
				ContractResolver = new SbmSessionDataContractResolver(),
				// Force all deserialised objects to be replaced - to avoid proxy lists not populating.
				ObjectCreationHandling = ObjectCreationHandling.Replace
			};
		}
		private readonly SessionStorage sessionStorage = new SessionStorage();
		public static JsonSerializerSettings SbmSessionDataJsonSerializerSettings { get { return SessionStorage.JsonDeserialisationSettings; } }

		//-------------------------------------------------------------------
		public SbmSessionData_Web SessionData
		{
			get
			{
				try
				{
					// Retrieve session data if not already in controller.
					if (sessionStorage.SessionData == null)
					{
						byte[] sessionDataBytes = null;
						HttpContext.Session.TryGetValue(SessionStorage.SessionKey_SessionData, out sessionDataBytes);
						if (sessionDataBytes != null)
						{
							String sessionDataJson = SessionStorage.sessionDataEncoding.GetString(sessionDataBytes);
							sessionStorage.SessionData = DeserializeSessionData(sessionDataJson);
						}
					}
					return sessionStorage.SessionData;
				}
				catch (Exception exc)
				{
					SaLogger.Warn($"{SysUtil.Fn} {exc.GetType().Name} - {exc.Message}{exc.GetStackEntries().Concat("", "\n\t")}");
				}
				return null;
			}
		}
		protected abstract SbmSessionData_Web DeserializeSessionData(String sessionDataJson);

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