// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Core;
using Microsoft.AspNetCore.Mvc.ModelBinding;
 
namespace Microsoft.AspNetCore.Mvc;
 
/// <summary>
/// An attribute that can specify a model name or type of <see cref="IModelBinder"/> to use for binding the
/// associated property.
/// </summary>
/// <remarks>
/// Similar to <see cref="ModelBinderAttribute"/>. Unlike that attribute, <see cref="BindPropertyAttribute"/>
/// applies only to properties and adds an <see cref="IRequestPredicateProvider"/> implementation that by default
/// indicates the property should not be bound for HTTP GET requests (see also <see cref="SupportsGet"/>).
/// </remarks>
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public class BindPropertyAttribute : Attribute, IModelNameProvider, IBinderTypeProviderMetadata, IRequestPredicateProvider
{
    private static readonly Func<ActionContext, bool> _supportsAllRequests = (c) => true;
    private static readonly Func<ActionContext, bool> _supportsNonGetRequests = IsNonGetRequest;
 
    private BindingSource? _bindingSource;
    private Type? _binderType;
 
    /// <summary>
    /// Gets or sets an indication the associated property should be bound in HTTP GET requests. If
    /// <see langword="true"/>, the property should be bound in all requests. Otherwise, the property should not be
    /// bound in HTTP GET requests.
    /// </summary>
    /// <value>Defaults to <see langword="false"/>.</value>
    public bool SupportsGet { get; set; }
 
    /// <inheritdoc />
    /// <remarks>
    /// Subclass this attribute and set <see cref="BindingSource"/> if <see cref="BindingSource.Custom"/> is not
    /// correct for the specified (non-<see langword="null"/>) <see cref="IModelBinder"/> implementation.
    /// </remarks>
    public Type? BinderType
    {
        get => _binderType;
        set
        {
            if (value != null && !typeof(IModelBinder).IsAssignableFrom(value))
            {
                throw new ArgumentException(
                    Resources.FormatBinderType_MustBeIModelBinder(
                        value.FullName,
                        typeof(IModelBinder).FullName),
                    nameof(value));
            }
 
            _binderType = value;
        }
    }
 
    /// <inheritdoc />
    /// <value>
    /// If <see cref="BinderType"/> is <see langword="null"/>, defaults to <see langword="null"/>. Otherwise,
    /// defaults to <see cref="BindingSource.Custom"/>. May be overridden in a subclass.
    /// </value>
    public virtual BindingSource? BindingSource
    {
        get
        {
            if (_bindingSource == null && BinderType != null)
            {
                return BindingSource.Custom;
            }
 
            return _bindingSource;
        }
        protected set => _bindingSource = value;
    }
 
    /// <inheritdoc />
    public string? Name { get; set; }
 
    Func<ActionContext, bool> IRequestPredicateProvider.RequestPredicate
        => SupportsGet ? _supportsAllRequests : _supportsNonGetRequests;
 
    private static bool IsNonGetRequest(ActionContext context)
    {
        return !HttpMethods.IsGet(context.HttpContext.Request.Method);
    }
}