using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ApplicationModels;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using System.Collections.Generic;
using System.Linq;
using Umbraco.Core;
using Umbraco.Web.Common.Attributes;
using Umbraco.Web.Common.ModelBinding;

namespace Umbraco.Web.Common.ApplicationModels
{
    public class NewtonsoftJsonModelBinderConvention : IActionModelConvention
    {
        public void Apply(ActionModel action)
        {
            foreach(var p in action.Parameters)
            {
                if (p.BindingInfo?.BindingSource == BindingSource.Body)
                {
                    p.BindingInfo.BinderType = typeof(UmbracoJsonModelBinder);
                }
            }
        }
    }

    /// <summary>
    /// A custom application model provider for Umbraco controllers
    /// </summary>
    /// <remarks>
    /// <para>
    /// Conventions will be applied to controllers attributed with <see cref="UmbracoApiControllerAttribute"/>
    /// </para>
    /// <para>
    /// This is nearly a copy of aspnetcore's ApiBehaviorApplicationModelProvider which supplies a convention for the
    /// [ApiController] attribute, however that convention is too strict for our purposes so we will have our own.
    /// </para>
    /// </remarks>
    public class UmbracoApiBehaviorApplicationModelProvider : IApplicationModelProvider
    {
        public UmbracoApiBehaviorApplicationModelProvider(IModelMetadataProvider modelMetadataProvider)
        {
            // see see https://docs.microsoft.com/en-us/aspnet/core/web-api/?view=aspnetcore-3.1#apicontroller-attribute
            // for what these things actually do
            // NOTE: we don't have attribute routing requirements and we cannot use ApiVisibilityConvention without attribute routing

            ActionModelConventions = new List<IActionModelConvention>()
            {
                new ClientErrorResultFilterConvention(), // TODO: Need to determine exactly how this affects errors
                new InvalidModelStateFilterConvention(), // automatically 400 responses if ModelState is invalid before hitting the controller
                new ConsumesConstraintForFormFileParameterConvention(), // If an controller accepts files, it must accept multipart/form-data.
                new InferParameterBindingInfoConvention(modelMetadataProvider), // no need for [FromBody] everywhere, A complex type parameter is assigned to FromBody

                new NewtonsoftJsonModelBinderConvention()
            };

            // TODO: Need to determine exactly how this affects errors
            var defaultErrorType = typeof(ProblemDetails);
            var defaultErrorTypeAttribute = new ProducesErrorResponseTypeAttribute(defaultErrorType);
            ActionModelConventions.Add(new ApiConventionApplicationModelConvention(defaultErrorTypeAttribute));
        }

        /// <summary>
        /// Will execute after <see cref="DefaultApplicationModelProvider"/>
        /// </summary>
        public int Order => 0;

        public List<IActionModelConvention> ActionModelConventions { get; }

        public void OnProvidersExecuted(ApplicationModelProviderContext context)
        {
        }

        public void OnProvidersExecuting(ApplicationModelProviderContext context)
        {
            foreach (var controller in context.Result.Controllers)
            {
                if (!IsUmbracoApiController(controller))
                    continue;

                foreach (var action in controller.Actions)
                {
                    foreach (var convention in ActionModelConventions)
                    {
                        convention.Apply(action);
                    }   
                }
                    
            }
        }

        private bool IsUmbracoApiController(ControllerModel controller) => controller.Attributes.OfType<UmbracoApiControllerAttribute>().Any();
    }
}