// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics.CodeAnalysis;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.BearerToken;
using Microsoft.AspNetCore.Http.Json;
using Microsoft.AspNetCore.Identity.UI.Services;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Options;
 
namespace Microsoft.AspNetCore.Identity;
 
/// <summary>
/// Helper functions for configuring identity services.
/// </summary>
public static class IdentityBuilderExtensions
{
    /// <summary>
    /// Adds the default token providers used to generate tokens for reset passwords, change email
    /// and change telephone number operations, and for two factor authentication token generation.
    /// </summary>
    /// <param name="builder">The current <see cref="IdentityBuilder"/> instance.</param>
    /// <returns>The current <see cref="IdentityBuilder"/> instance.</returns>
    [UnconditionalSuppressMessage("AOT", "IL3050", Justification = "MakeGenericType is safe because user type is a reference type.")]
    public static IdentityBuilder AddDefaultTokenProviders(this IdentityBuilder builder)
    {
        var dataProtectionProviderType = typeof(DataProtectorTokenProvider<>).MakeGenericType(builder.UserType);
        var phoneNumberProviderType = typeof(PhoneNumberTokenProvider<>).MakeGenericType(builder.UserType);
        var emailTokenProviderType = typeof(EmailTokenProvider<>).MakeGenericType(builder.UserType);
        var authenticatorProviderType = typeof(AuthenticatorTokenProvider<>).MakeGenericType(builder.UserType);
        return builder.AddTokenProvider(TokenOptions.DefaultProvider, dataProtectionProviderType)
            .AddTokenProvider(TokenOptions.DefaultEmailProvider, emailTokenProviderType)
            .AddTokenProvider(TokenOptions.DefaultPhoneProvider, phoneNumberProviderType)
            .AddTokenProvider(TokenOptions.DefaultAuthenticatorProvider, authenticatorProviderType);
    }
 
    [UnconditionalSuppressMessage("AOT", "IL3050", Justification = "MakeGenericType is safe because user type is a reference type.")]
    private static void AddSignInManagerDeps(this IdentityBuilder builder)
    {
        builder.Services.AddHttpContextAccessor();
        builder.Services.AddScoped(typeof(ISecurityStampValidator), typeof(SecurityStampValidator<>).MakeGenericType(builder.UserType));
        builder.Services.AddScoped(typeof(ITwoFactorSecurityStampValidator), typeof(TwoFactorSecurityStampValidator<>).MakeGenericType(builder.UserType));
        builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IPostConfigureOptions<SecurityStampValidatorOptions>, PostConfigureSecurityStampValidatorOptions>());
    }
 
    /// <summary>
    /// Adds a <see cref="SignInManager{TUser}"/> for the <see cref="IdentityBuilder.UserType"/>.
    /// </summary>
    /// <param name="builder">The current <see cref="IdentityBuilder"/> instance.</param>
    /// <returns>The current <see cref="IdentityBuilder"/> instance.</returns>
    [UnconditionalSuppressMessage("AOT", "IL3050", Justification = "MakeGenericType is safe because user type is a reference type.")]
    public static IdentityBuilder AddSignInManager(this IdentityBuilder builder)
    {
        builder.AddSignInManagerDeps();
        var managerType = typeof(SignInManager<>).MakeGenericType(builder.UserType);
        builder.Services.AddScoped(managerType);
        return builder;
    }
 
    /// <summary>
    /// Adds a <see cref="SignInManager{TUser}"/> for the <see cref="IdentityBuilder.UserType"/>.
    /// </summary>
    /// <typeparam name="TSignInManager">The type of the sign in manager to add.</typeparam>
    /// <param name="builder">The current <see cref="IdentityBuilder"/> instance.</param>
    /// <returns>The current <see cref="IdentityBuilder"/> instance.</returns>
    [UnconditionalSuppressMessage("AOT", "IL3050", Justification = "MakeGenericType is safe because user type is a reference type.")]
    public static IdentityBuilder AddSignInManager<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] TSignInManager>(this IdentityBuilder builder) where TSignInManager : class
    {
        builder.AddSignInManagerDeps();
        var managerType = typeof(SignInManager<>).MakeGenericType(builder.UserType);
        var customType = typeof(TSignInManager);
        if (!managerType.IsAssignableFrom(customType))
        {
            throw new InvalidOperationException(Resources.FormatInvalidManagerType(customType.Name, "SignInManager", builder.UserType.Name));
        }
        if (managerType != customType)
        {
            builder.Services.AddScoped(typeof(TSignInManager), services => services.GetRequiredService(managerType));
        }
        builder.Services.AddScoped(managerType, typeof(TSignInManager));
        return builder;
    }
 
    /// <summary>
    /// Adds configuration and services needed to support <see cref="IdentityApiEndpointRouteBuilderExtensions.MapIdentityApi{TUser}(IEndpointRouteBuilder)"/>
    /// but does not configure authentication. Call <see cref="BearerTokenExtensions.AddBearerToken(AuthenticationBuilder, Action{BearerTokenOptions}?)"/> and/or
    /// <see cref="IdentityCookieAuthenticationBuilderExtensions.AddIdentityCookies(AuthenticationBuilder)"/> to configure authentication separately.
    /// </summary>
    /// <param name="builder">The <see cref="IdentityBuilder"/>.</param>
    /// <returns>The <see cref="IdentityBuilder"/>.</returns>
    public static IdentityBuilder AddApiEndpoints(this IdentityBuilder builder)
    {
        ArgumentNullException.ThrowIfNull(builder);
 
        builder.AddSignInManager();
        builder.AddDefaultTokenProviders();
        builder.Services.TryAddTransient(typeof(IEmailSender<>), typeof(DefaultMessageEmailSender<>));
        builder.Services.TryAddTransient<IEmailSender, NoOpEmailSender>();
        builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<JsonOptions>, IdentityEndpointsJsonOptionsSetup>());
        return builder;
    }
 
    // Set TimeProvider from DI on all options instances, if not already set by tests.
    private sealed class PostConfigureSecurityStampValidatorOptions : IPostConfigureOptions<SecurityStampValidatorOptions>
    {
        public PostConfigureSecurityStampValidatorOptions(TimeProvider? timeProvider = null)
        {
            // We could assign this to "timeProvider ?? TimeProvider.System", but
            // SecurityStampValidator already has system clock fallback logic.
            TimeProvider = timeProvider;
        }
 
        private TimeProvider? TimeProvider { get; }
 
        public void PostConfigure(string? name, SecurityStampValidatorOptions options)
        {
            options.TimeProvider ??= TimeProvider;
        }
    }
}