// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Mvc.Core;
using Microsoft.Extensions.Internal;

namespace Microsoft.AspNetCore.Mvc.Controllers
{
    internal sealed class DefaultControllerPropertyActivator : IControllerPropertyActivator
    {
        private static readonly Func<Type, PropertyActivator<ControllerContext>[]> _getPropertiesToActivate =
            GetPropertiesToActivate;
        private readonly ConcurrentDictionary<Type, PropertyActivator<ControllerContext>[]> _activateActions = new();

        public void Activate(ControllerContext context, object controller)
        {
            var controllerType = controller.GetType();
            var propertiesToActivate = _activateActions!.GetOrAdd(
                controllerType,
                _getPropertiesToActivate);

            for (var i = 0; i < propertiesToActivate.Length; i++)
            {
                var activateInfo = propertiesToActivate[i];
                activateInfo.Activate(controller, context);
            }
        }

        public void ClearCache() => _activateActions.Clear();

        public Action<ControllerContext, object> GetActivatorDelegate(ControllerActionDescriptor actionDescriptor)
        {
            if (actionDescriptor == null)
            {
                throw new ArgumentNullException(nameof(actionDescriptor));
            }

            var controllerType = actionDescriptor.ControllerTypeInfo?.AsType();
            if (controllerType == null)
            {
                throw new ArgumentException(Resources.FormatPropertyOfTypeCannotBeNull(
                    nameof(actionDescriptor.ControllerTypeInfo),
                    nameof(actionDescriptor)),
                    nameof(actionDescriptor));
            }

            var propertiesToActivate = GetPropertiesToActivate(controllerType);
            void Activate(ControllerContext controllerContext, object controller)
            {
                for (var i = 0; i < propertiesToActivate.Length; i++)
                {
                    var activateInfo = propertiesToActivate[i];
                    activateInfo.Activate(controller, controllerContext);
                }
            }

            return Activate;
        }

        private static PropertyActivator<ControllerContext>[] GetPropertiesToActivate(Type type)
        {
            IEnumerable<PropertyActivator<ControllerContext>> activators;
            activators = PropertyActivator<ControllerContext>.GetPropertiesToActivate(
                type,
                typeof(ActionContextAttribute),
                p => new PropertyActivator<ControllerContext>(p, c => c));

            activators = activators.Concat(PropertyActivator<ControllerContext>.GetPropertiesToActivate(
                type,
                typeof(ControllerContextAttribute),
                p => new PropertyActivator<ControllerContext>(p, c => c)));

            return activators.ToArray();
        }
    }
}
