using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.ModelBinding.Binders;
using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Utils;
using Saxonite.Net.Core.Web.Base.App;
using Saxonite.Net.Standard.Base.App;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace Saxonite.Net.Core.Web.Base.Middleware
{
	//=======================================================================
	/// <summary>
	/// Maps a browser request to a data object. Default class provides a base implementation of a model binder.
	/// <para>Overridden to trim whitespace from input values.</para>
	/// </summary>
	public class SaxModelBinder : ComplexTypeModelBinder
	{
		//-------------------------------------------------------------------
		// Construction.
		public SaxModelBinder(IDictionary<ModelMetadata, IModelBinder> propertyBinders, Microsoft.Extensions.Logging.ILoggerFactory loggerFactory) :
			base(propertyBinders, loggerFactory)
		{
		}

		//-------------------------------------------------------------------
		/// <summary>
		/// Creates the model with one (or more) injected service parameters.
		/// </summary>
		protected override object CreateModel(ModelBindingContext bindingContext)
		{
			var services = bindingContext.HttpContext.RequestServices;
			var modelType = bindingContext.ModelType;
			var ctors = modelType.GetConstructors();
			foreach (var ctor in ctors)
			{
				var paramTypes = ctor.GetParameters().Select(p => p.ParameterType).ToList();
				var parameters = paramTypes.Select(p => services.GetService(p)).ToArray();
				if (parameters.All(p => p != null))
				{
					var model = ctor.Invoke(parameters);
					return model;
				}
			}
			return null;
		}

		//-------------------------------------------------------------------
		/// <summary>
		/// Intercept String properties and trim whitespace.
		/// </summary>
		protected override void SetProperty(ModelBindingContext bindingContext, string modelName, ModelMetadata propertyMetadata, ModelBindingResult result)
		{
			//if (SaxSystem.DebugMode) Logger.Debug(fn + " Form property " + modelName + ": '" + result.Model.ToString() + ".");
			object originalValue = result.Model;
			// Exclude properties that retain leading/trailing whitespace.
			if (result.Model is string)
			{
				if (!modelName.ContainsCI("Password"))
				{
					string value = result.Model as string;

					// Trim leading and trailing whitespace.
					value = StringUtil.TrimAll(value);

					// Check for multi-line.
					if (value.Contains('\n'))
					{
						// Simplify line delimiters.
						value = Regex.Replace(value, "\\r\\n", "\n");
						// Remove white space in front of newlines.
						value = Regex.Replace(value, "\\s+\\n", "\n");
						// Remove multiple newlines.
						value = Regex.Replace(value, "\\n+", "\n");
					}

					// Email addresses must be lowercase to ensure match to encrypted data.
					if (modelName.EqualsCI("EmailAddress") || modelName.EqualsCI("AccountEmailAddress"))
						value = value.ToLower();

					// Uppercase selected values.
					if (modelName.EqualsCI("Postcode") || modelName.EqualsCI("AccountPostcode") || modelName.EqualsCI("RegisteredAddressPostcode"))
						value = value.ToUpper();

					// Assign resulting value.
					result = ModelBindingResult.Success(value);
				}
			}
			// Log property details.
			if (result.Model != null && SaxSystem.DebugMode &&
				// Ignore items that correspond with objects in the model rather than values.
				!result.Model.ToString().Equals(result.Model.GetType().FullName) &&
				// Ignore form files.
				!result.Model.ToString().ContainsCI("Microsoft.AspNetCore.Http.IFormFile"))
				SaLogger.Debug(SysUtil.Fn + " Form property " + modelName + ": '" + result.Model.ToString() + "'." + (originalValue != null && !originalValue.Equals(result.Model) ? " Original value: '" + originalValue.ToString() + "'" : ""));
			base.SetProperty(bindingContext, modelName, propertyMetadata, result);
		}

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