// 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.Authorization;
using Microsoft.AspNetCore.Authorization.Policy;
using Microsoft.Extensions.DependencyInjection.Extensions;

namespace Microsoft.Extensions.DependencyInjection
{
    /// <summary>
    /// Extension methods for setting up authorization services in an <see cref="IServiceCollection" />.
    /// </summary>
    public static class PolicyServiceCollectionExtensions
    {
        /// <summary>
        /// Adds the authorization policy evaluator service to the specified <see cref="IServiceCollection" />.
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
        /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
        public static IServiceCollection AddAuthorizationPolicyEvaluator(this IServiceCollection services)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            services.TryAddSingleton<AuthorizationPolicyMarkerService>();
            services.TryAddTransient<IPolicyEvaluator, PolicyEvaluator>();
            services.TryAddTransient<IAuthorizationMiddlewareResultHandler, AuthorizationMiddlewareResultHandler>();
            return services;
        }

        /// <summary>
        /// Adds authorization policy services to the specified <see cref="IServiceCollection" />.
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
        /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
        public static IServiceCollection AddAuthorization(this IServiceCollection services)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            services.AddAuthorizationCore();
            services.AddAuthorizationPolicyEvaluator();
            return services;
        }

        /// <summary>
        /// Adds authorization policy services to the specified <see cref="IServiceCollection" />.
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
        /// <param name="configure">An action delegate to configure the provided <see cref="AuthorizationOptions"/>.</param>
        /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
        public static IServiceCollection AddAuthorization(this IServiceCollection services, Action<AuthorizationOptions> configure)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            services.AddAuthorizationCore(configure);
            services.AddAuthorizationPolicyEvaluator();
            return services;
        }
    }
}
