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 Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Bus;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Helpers;
using Sarand.Net.Standard.Base.Utils;
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Web;

namespace Sacs.Web.Components
{
	//=======================================================================
	public class SaController : Controller
	{
		//-------------------------------------------------------------------
		/// <summary>
		///  Protected construction - use derived objects.
		/// </summary>
		protected SaController()
		{
		}
		protected override void Dispose(bool disposing)
		{
			if (disposing)
			{
			}
			base.Dispose(disposing);
		}

		//-------------------------------------------------------------------
		// Properties.
		public DateTime CreatedAt { get; } = DateTime.Now;
		public bool DebugMode { get; } = SacsSystem.DebugMode;
		/// <summary>
		/// Indicate whether session data should be stored by action.
		/// <para>Any action that might modify the session data must store it.</para>
		/// <para>Some actions such as scoring a password's complexity don't need to.</para>
		/// </summary>
		public virtual bool StoreSessionData { get; protected set; } = true;

		//-------------------------------------------------------------------
		// Culture.
		private CultureInfo sessionCulture;
		private CultureInfo RequestCulture { get { return Request.HttpContext.Features.Get<IRequestCultureFeature>()?.RequestCulture?.Culture ?? CultureInfo.InvariantCulture; } }
		public CultureInfo SessionCulture
		{
			get
			{
				if (sessionCulture == null)
				{
					sessionCulture = RequestCulture;
					// ToDo Adjust culture if needed.
				}
				return sessionCulture;
			}
		}
		private string LanguageIso2
		{
			get
			{
				var feature = HttpContext.Features.Get<IRequestCultureFeature>();
				return feature.RequestCulture.UICulture.TwoLetterISOLanguageName.ToLower();
			}
		}

		//-------------------------------------------------------------------
		// Redirection locations.
		//-------------------------------------------------------------------
		public static readonly String ParamName_SessionExpired = "SessionExpired";
		public enum RedirectLocation
		{
			WebAppBase,
			WebAppHome,
			WebAppHome_SessionExpired,
		}
		[NonAction]
		public String GetRedirectLocation(RedirectLocation redirectLocation)
		{
			string protocol = Request.Scheme;
			var parameters = new RouteValueDictionary();
			String homeAction = Url.Action("Index", "Home", parameters, protocol);
			switch (redirectLocation)
			{
				case RedirectLocation.WebAppBase:
					return Regex.Replace(homeAction, "\\/$", "") + "/";
				case RedirectLocation.WebAppHome:
					return homeAction;
				case RedirectLocation.WebAppHome_SessionExpired:
					// Set the session expired parameter so that the page can report it.
					// NB Parameter must have a value to be included in the URL query string.
					parameters.Add(ParamName_SessionExpired, "1");
					return homeAction;
			}
			return "";
		}

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

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

			base.OnActionExecuted(filterContext);
		}

		//-------------------------------------------------------------------
		public static String EncryptParameters(NameValueCollection parameters, String base64IV, String base64Key)
		{
			try
			{
				// Copy the list of parameters and sort the keys.
				NameValueCollection parametersToEncrypt = new NameValueCollection(parameters);
				String[] paramKeys = parametersToEncrypt.AllKeys;
				Array.Sort(paramKeys);

				// Serialise parameters as if in a URL query string - so that they can be deserialised in DecryptParameters() below.
				// Start with a random length parameter name at start of list to obscure the encryption.
				string queryString = SacsRandomHelper.getRandomLengthNumber(4) + "&";
				queryString += String.Join("&", paramKeys.Select(a => a + "=" + HttpUtility.UrlEncode(parametersToEncrypt[a])));

				// Encrypt data.
				String encrypted = SacsEncryptionHelper.Encrypt(queryString, base64IV, base64Key);
				//if (SacsSystem.DebugMode) SaLogger.Debug(SysUtil.Fn + "\n\tData:      " + queryString + " \n\tEncrypted: " + encrypted);
				return encrypted;
			}
			catch (Exception exc) { SaLogger.Warn($"{SysUtil.Fn} {ExceptionUtil.GetErrorStateMessage(exc)}"); }
			return "";
		}
		public static NameValueCollection DecryptParameters(String encrypted, String base64IV, String base64Key)
		{
			try
			{
				String queryString = SacsEncryptionHelper.Decrypt(encrypted, base64IV, base64Key);
				//if (SacsSystem.DebugMode) SaLogger.Debug(SysUtil.Fn + " \n\tEncrypted: " + encrypted + "\n\tData:      " + queryString);
				return HttpUtility.ParseQueryString(queryString);
			}
			catch (Exception exc) { SaLogger.Warn(SysUtil.Fn + " " + ExceptionUtil.GetErrorStateMessage(exc)); }
			return new NameValueCollection();
		}

		//-------------------------------------------------------------------
		// Cookies.
		//-------------------------------------------------------------------
		[NonAction]
		/// <summary>Retrieve the value from the named request cookie.</summary>
		public String GetRequestCookie(String key)
		{
			if (Request.Cookies.ContainsKey(key))
				return Request.Cookies[key];
			return null;
		}
		[NonAction]
		/// <summary>Set the value against the named response cookie.</summary>
		public void SetResponseCookie(string key, string value, DateTime? expiresAt = null, bool isEssential = false)
		{
			CookieOptions options = new CookieOptions();
			options.HttpOnly = true;
			options.Secure = true;
			options.SameSite = Microsoft.AspNetCore.Http.SameSiteMode.Strict;
			if (expiresAt.HasValue)
				options.Expires = expiresAt;
			if (isEssential)
				options.IsEssential = true;
			Response.Cookies.Append(key, value, options);
		}

		//-------------------------------------------------------------------
		// Error State
		//-------------------------------------------------------------------
		private SacsErrorState errorState = null;
		public bool HasErrorState()
		{
			return errorState != null;
		}
		public SacsErrorState ErrorState
		{
			get { return errorState; }
		}
		public String ErrorStateMessage
		{
			get { return (errorState != null ? errorState.Message : String.Empty); }
		}
		/// <summary>
		/// Record the error state message.
		/// <para>Blank message does not set the error state - leaves previous state intact.</para>
		/// <para>Return value is fale unless the message is blank.</para>
		/// </summary>
		public bool SetErrorState(String message)
		{
			if (StringUtil.IsEmpty(message)) return true;
			this.errorState = new SacsErrorState(message);
			return false;
		}
		/// <summary>Clear the error state.</summary>
		public void ClearErrorState()
		{
			errorState = null;
		}

		//-------------------------------------------------------------------
		// Ajax actions.
		//-------------------------------------------------------------------
		protected static readonly Encoding ajaxResponseEncoding = Encoding.UTF8;
		protected IActionResult GetAjaxResult_GoHome(AjaxResponse_Base responseData)
		{
			responseData.SetGoHome();
			return Json(responseData);
		}
		protected IActionResult GetAjaxResult_InvalidSession(AjaxResponse_Base responseData)
		{
			responseData.SetGoHome();
			return Json(responseData);
		}

		//-------------------------------------------------------------------
		// Response data.
		// Null values are ignored by JSON serialisation.
		// - See Saxonite.Net.Core.Web.Base.App.SaxStartup.ConfigureServices()
		// - Ref. config.services.AddMvc(...).AddJsonOptions(options => { options.JsonSerializerOptions.IgnoreNullValues = true; });
		//-------------------------------------------------------------------
		// Base response data - for simple responses.
		public class AjaxResponse_Base
		{
			// Response status.
			public bool? Success { get; set; } = null;
			public bool? Error { get; set; } = null;
			public bool? SessionExpired { get; protected set; } = null;
			public bool? GoHome { get; protected set; } = null;
			public AjaxResponse_Base SetSessionExpired(String title, String text)
			{
				SessionExpired = true;
				return SetMessage(title, text);
			}
			public AjaxResponse_Base SetGoHome()
			{
				GoHome = true;
				return this;
			}
			public AjaxResponse_Base SetGoHome(String title, String text)
			{
				GoHome = true;
				return SetMessage(title, text);
			}
			// Message - displays alert popup.
			public class MessageData
			{
				public String Title { get; set; }
				public String Text { get; set; }
			}
			public MessageData Message { get; private set; }
			public AjaxResponse_Base SetMessage(String title, String text)
			{
				if (!StringUtil.IsBlank(text))
					Message = new MessageData() { Title = title, Text = text };
				return this;
			}
			// Confirmation message - to query user.
			public class ConfirmMessageData : MessageData
			{
				public SaConfirmActions Actions { get; set; }
			}
			public ConfirmMessageData ConfirmMessage { get; private set; }
			public AjaxResponse_Base SetConfirmMessage(String title, String text, SaConfirmActions actions = SaConfirmActions.YesNo)
			{
				if (!StringUtil.IsBlank(text))
					ConfirmMessage = new ConfirmMessageData() { Title = title, Text = text, Actions = actions };
				return this;
			}
			public bool HasConfirmMessage { get { return ConfirmMessage != null; } }
		}

		//-------------------------------------------------------------------
		public class AjaxResponse_Data : AjaxResponse_Base
		{
			//---------------------------------------------------------------
			// Construction.
			protected AjaxResponse_Data(SaModel model)
			{
			}

			//---------------------------------------------------------------
			/// <summary>Item data - Common properties for data items.</summary>
			public class ItemData_Base
			{
				// Common item properties.
				public String Id { get; set; } = null;
				private String notes;
				public String Notes { get { return StringUtil.IsBlank(notes) ? null : notes; } set { notes = StringUtil.EmptyOnNull(value).Trim(); } }
				public String StatusCode { get; set; } = null;
				public String StatusDesc { get; set; } = null;
				// Flags for common status values.
				// Return true or null so that property is not serialised when false.
				public bool? Awaiting { get { return StatusCode.EqualsCI(SacsSystem.GetStatusCode(SaStatus.Awaiting)) ? true : (bool?)null; } }
				public bool? Active { get { return StatusCode.EqualsCI(SacsSystem.GetStatusCode(SaStatus.Active)) ? true : (bool?)null; } }
				public bool? Inactive { get { return StatusCode.EqualsCI(SacsSystem.GetStatusCode(SaStatus.Inactive)) ? true : (bool?)null; } }
				public bool? Deleted { get { return StatusCode.EqualsCI(SacsSystem.GetStatusCode(SaStatus.Deleted)) ? true : (bool?)null; } }
				/// <summary>Created on date - YYYYMMDD</summary>
				public String CreatedOn { get; set; }
				/// <summary>Created on date - formatted per locale</summary>
				public String CreatedOnFmt { get; set; }
				/// <summary>Updated on date - YYYYMMDD</summary>
				public String UpdatedOn { get; set; }
				/// <summary>Updated on date - formatted per locale</summary>
				public String UpdatedOnFmt { get; set; }
			}
			/// <summary>Contact Method properties.</summary>
			public class ContactMethodData
			{
				public String Method { get; set; }
				public String MethodCaption { get; set; }
				public String Value { get; set; }
			}
			/// <summary>Address properties.</summary>
			public class AddressData : ItemData_Base
			{
				public String Line1 { get; set; }
				public String Line2 { get; set; }
				public String Line3 { get; set; }
				public String Town { get; set; }
				public String RegionIdProvince { get; set; }
				public String RegionNameProvince { get; set; }
				public String RegionIdCountry { get; set; }
				public String RegionNameCountry { get; set; }
				public String PostalCode { get; set; }
			}
			/// <summary>
			/// Item data with label and value.
			/// </summary>
			public class ItemLabelValue
			{
				public String Label { get; set; }
				public String Value { get; set; }
			}
			/// <summary>
			/// Item data with just Id and name.
			/// <para>- Id is String to allow for obfuscated values.</para>
			/// </summary>
			public class ItemIdName
			{
				public String Id { get; set; }
				public String Name { get; set; }
			}
			/// <summary>Item code and desc values.</summary>
			public class ItemCodeDesc
			{
				public ItemCodeDesc() { }
				public ItemCodeDesc(String code, String desc)
				{
					this.Code = code;
					this.Desc = desc;
				}
				public String Code { get; set; }
				public String Desc { get; set; }
			}
			/// <summary>Statistics Caption/Value pair.</summary>
			public class StatData : AjaxResponse_Base
			{
				public String Caption { get; set; }
				public String Value { get; set; }
			}
			/// <summary>Statistics Group.</summary>
			public class StatsGroupData : AjaxResponse_Base
			{
				public String Caption { get; set; }
				public List<StatData> Stats { get; } = new List<StatData>();
			}

			//---------------------------------------------------------------
			// Form data.
			public class FormControlValue
			{
				public FormControlValue(String controlName, String value, String error)
				{
					ControlName = controlName;
					Value = value;
					Error = error;
				}
				public String ControlName { get; }
				public String Value { get; set; }
				public String Error { get; set; }
			}
			private readonly Dictionary<String, FormControlValue> controlValues = new Dictionary<String, FormControlValue>();
			public List<FormControlValue> ControlValues { get { return controlValues.Count > 0 ? controlValues.Values.ToList() : null; } }
			public void SetControlValue(String controlName, String value, String error = null)
			{
				if (controlValues.ContainsKey(controlName))
				{
					// Modify existing entry in the list.
					FormControlValue controlValue = controlValues[controlName];
					if (value != null) controlValue.Value = value;
					if (error != null) controlValue.Error = error;
				}
				else
				{
					// Add new control to list.
					controlValues.Add(controlName, new FormControlValue(controlName, value, error));
				}
			}
			/// <summary>Assign the error to the control by name and return this response data.</summary>
			public AjaxResponse_Data SetControlError(String controlName, String error)
			{
				return SetControlError(controlName, error, this);
			}
			/// <summary>
			/// Assign the error to the control by name and return the specified value.
			/// <para>- Allows alternative return values to be specified (eg. 'false') to avoid separate return statement in calling routine.</para>
			/// </summary>
			public T SetControlError<T>(String controlName, String error, T returnValue)
			{
				SetControlValue(controlName, null, error);
				return returnValue;
			}
			public bool HasControlErrors()
			{
				foreach (FormControlValue controlValue in controlValues.Values)
				{
					if (!StringUtil.IsBlank(controlValue.Error)) return true;
				}
				return false;
			}

			//---------------------------------------------------------------
			// Notification - briefly displays after response received.
			public class NotificationData
			{
				public String Title { get; set; }
				public String Message { get; set; }
			}
			public NotificationData Notification { get; private set; }
			public AjaxResponse_Data SetNotification(String title, String message)
			{
				Notification = new NotificationData() { Title = title, Message = message };
				return this;
			}

			//---------------------------------------------------------------
			// Paged data.
			public class PagingData
			{
				public PagingData(SaModel model) :
					this(model.Paging.PageNo, model.Paging.PageLength, model.Paging.ItemCount, model.Paging.ItemTotal)
				{ }
				public PagingData(uint pageNo, ushort pageLength, ushort itemCount, ulong itemTotal)
				{
					PageNo = pageNo;
					PageLength = pageLength;
					ItemCount = itemCount;
					ItemTotal = itemTotal;
				}
				public bool Paged { get { return (PageNo > 0 && PageLength > 0 && ItemTotal > PageLength); } }
				public uint PageNo { get; } = 0;
				public ushort PageLength { get; } = 0;
				public uint PageCount { get { return (PageLength > 0 ? (uint)Math.Ceiling((decimal)ItemTotal / PageLength) : 0); } }
				public ushort ItemCount { get; } = 0;
				public ulong ItemTotal { get; } = 0;
			}
			public PagingData Paging { get; private set; }
			public void SetPaging(SaModel model)
			{
				Paging = new PagingData(model);
			}

			//---------------------------------------------------------------
		}

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