// 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.Antiforgery;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.Logging;
 
namespace Microsoft.AspNetCore.Mvc.ViewFeatures.Filters;
 
internal partial class ValidateAntiforgeryTokenAuthorizationFilter : IAsyncAuthorizationFilter, IAntiforgeryPolicy
{
    private readonly IAntiforgery _antiforgery;
    private readonly ILogger _logger;
 
    public ValidateAntiforgeryTokenAuthorizationFilter(IAntiforgery antiforgery, ILoggerFactory loggerFactory)
    {
        ArgumentNullException.ThrowIfNull(antiforgery);
 
        _antiforgery = antiforgery;
        _logger = loggerFactory.CreateLogger(GetType());
    }
 
    public async Task OnAuthorizationAsync(AuthorizationFilterContext context)
    {
        ArgumentNullException.ThrowIfNull(context);
 
        if (!context.IsEffectivePolicy<IAntiforgeryPolicy>(this))
        {
            Log.NotMostEffectiveFilter(_logger, typeof(IAntiforgeryPolicy));
            return;
        }
 
        if (ShouldValidate(context))
        {
            try
            {
                await _antiforgery.ValidateRequestAsync(context.HttpContext);
            }
            catch (AntiforgeryValidationException exception)
            {
                Log.AntiforgeryTokenInvalid(_logger, exception.Message, exception);
                context.Result = new AntiforgeryValidationFailedResult();
            }
        }
    }
 
    protected virtual bool ShouldValidate(AuthorizationFilterContext context)
    {
        ArgumentNullException.ThrowIfNull(context);
 
        return true;
    }
 
    private static partial class Log
    {
        [LoggerMessage(1, LogLevel.Information, "Antiforgery token validation failed. {Message}", EventName = "AntiforgeryTokenInvalid")]
        public static partial void AntiforgeryTokenInvalid(ILogger logger, string message, Exception exception);
 
        [LoggerMessage(2, LogLevel.Trace, "Skipping the execution of current filter as its not the most effective filter implementing the policy {FilterPolicy}.", EventName = "NotMostEffectiveFilter")]
        public static partial void NotMostEffectiveFilter(ILogger logger, Type filterPolicy);
    }
}