// 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 Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.DependencyInjection.Extensions;
 
namespace Microsoft.Extensions.DependencyInjection;
 
/// <summary>
/// Contains extension methods to <see cref="IServiceCollection"/> for configuring identity services.
/// </summary>
public static class IdentityServiceCollectionExtensions
{
    /// <summary>
    /// Adds and configures the identity system for the specified User type. Role services are not added
    /// by default but can be added with <see cref="IdentityBuilder.AddRoles{TRole}"/>.
    /// </summary>
    /// <typeparam name="TUser">The type representing a User in the system.</typeparam>
    /// <param name="services">The services available in the application.</param>
    /// <returns>An <see cref="IdentityBuilder"/> for creating and configuring the identity system.</returns>
    public static IdentityBuilder AddIdentityCore<TUser>(this IServiceCollection services) where TUser : class
        => services.AddIdentityCore<TUser>(o => { });
 
    /// <summary>
    /// Adds and configures the identity system for the specified User type. Role services are not added by default
    /// but can be added with <see cref="IdentityBuilder.AddRoles{TRole}"/>.
    /// </summary>
    /// <typeparam name="TUser">The type representing a User in the system.</typeparam>
    /// <param name="services">The services available in the application.</param>
    /// <param name="setupAction">An action to configure the <see cref="IdentityOptions"/>.</param>
    /// <returns>An <see cref="IdentityBuilder"/> for creating and configuring the identity system.</returns>
    public static IdentityBuilder AddIdentityCore<TUser>(this IServiceCollection services, Action<IdentityOptions> setupAction)
        where TUser : class
    {
        // Services identity depends on
        services.AddOptions().AddLogging();
        services.AddMetrics();
 
        // Services used by identity
        services.TryAddScoped<IUserValidator<TUser>, UserValidator<TUser>>();
        services.TryAddScoped<IPasswordValidator<TUser>, PasswordValidator<TUser>>();
        services.TryAddScoped<IPasswordHasher<TUser>, PasswordHasher<TUser>>();
        services.TryAddScoped<ILookupNormalizer, UpperInvariantLookupNormalizer>();
        services.TryAddScoped<IUserConfirmation<TUser>, DefaultUserConfirmation<TUser>>();
        // No interface for the error describer so we can add errors without rev'ing the interface
        services.TryAddScoped<IdentityErrorDescriber>();
        services.TryAddScoped<IUserClaimsPrincipalFactory<TUser>, UserClaimsPrincipalFactory<TUser>>();
        services.TryAddScoped<UserManager<TUser>>();
 
        if (setupAction != null)
        {
            services.Configure(setupAction);
        }
 
        return new IdentityBuilder(typeof(TUser), services);
    }
}