// 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.Diagnostics.CodeAnalysis;
using Microsoft.AspNetCore.Mvc.Razor.Compilation;

namespace Microsoft.AspNetCore.Mvc.Razor
{
    /// <summary>
    /// Result of <see cref="IRazorPageFactoryProvider.CreateFactory(string)"/>.
    /// </summary>
    public readonly struct RazorPageFactoryResult
    {
        /// <summary>
        /// Initializes a new instance of <see cref="RazorPageFactoryResult"/> with the
        /// specified <see cref="IRazorPage"/> factory.
        /// </summary>
        /// <param name="razorPageFactory">The <see cref="IRazorPage"/> factory.</param>
        /// <param name="viewDescriptor">The <see cref="CompiledViewDescriptor"/>.</param>
        public RazorPageFactoryResult(
            CompiledViewDescriptor viewDescriptor,
            Func<IRazorPage>? razorPageFactory)
        {
            ViewDescriptor = viewDescriptor ?? throw new ArgumentNullException(nameof(viewDescriptor));
            RazorPageFactory = razorPageFactory;
        }

        /// <summary>
        /// The <see cref="IRazorPage"/> factory.
        /// </summary>
        /// <remarks>This property is <c>null</c> when <see cref="Success"/> is <c>false</c>.</remarks>
        public Func<IRazorPage>? RazorPageFactory { get; }

        /// <summary>
        /// Gets the <see cref="CompiledViewDescriptor"/>.
        /// </summary>
        public CompiledViewDescriptor? ViewDescriptor { get; }

        /// <summary>
        /// Gets a value that determines if the page was successfully located.
        /// </summary>
        [MemberNotNullWhen(true, nameof(RazorPageFactory))]
        public bool Success => RazorPageFactory != null;
    }
}
