// 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.Authentication;
using Microsoft.AspNetCore.Authentication.OAuth;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Options;

namespace Microsoft.Extensions.DependencyInjection
{
    /// <summary>
    /// Extension methods to add OAuth authentication.
    /// </summary>
    public static class OAuthExtensions
    {
        /// <summary>
        /// Adds OAuth 2.0 based authentication to <see cref="AuthenticationBuilder"/> using the specified authentication scheme.
        /// </summary>
        /// <param name="builder">The <see cref="AuthenticationBuilder"/>.</param>
        /// <param name="authenticationScheme">The authentication scheme.</param>
        /// <param name="configureOptions">A delegate to configure <see cref="OAuthOptions"/>.</param>
        /// <returns>A reference to <paramref name="builder"/> after the operation has completed.</returns>
        public static AuthenticationBuilder AddOAuth(this AuthenticationBuilder builder, string authenticationScheme, Action<OAuthOptions> configureOptions)
            => builder.AddOAuth<OAuthOptions, OAuthHandler<OAuthOptions>>(authenticationScheme, configureOptions);

        /// <summary>
        /// Adds OAuth 2.0 based authentication to <see cref="AuthenticationBuilder"/> using the specified authentication scheme.
        /// </summary>
        /// <param name="builder">The <see cref="AuthenticationBuilder"/>.</param>
        /// <param name="authenticationScheme">The authentication scheme.</param>
        /// <param name="displayName">A display name for the authentication handler.</param>
        /// <param name="configureOptions">A delegate to configure <see cref="OAuthOptions"/>.</param>
        /// <returns>A reference to <paramref name="builder"/> after the operation has completed.</returns>
        public static AuthenticationBuilder AddOAuth(this AuthenticationBuilder builder, string authenticationScheme, string displayName, Action<OAuthOptions> configureOptions)
            => builder.AddOAuth<OAuthOptions, OAuthHandler<OAuthOptions>>(authenticationScheme, displayName, configureOptions);

        /// <summary>
        /// Adds OAuth 2.0 based authentication to <see cref="AuthenticationBuilder"/> using the specified authentication scheme.
        /// </summary>
        /// <param name="builder">The <see cref="AuthenticationBuilder"/>.</param>
        /// <param name="authenticationScheme">The authentication scheme.</param>
        /// <param name="configureOptions">A delegate to configure the handler specific options.</param>
        /// <returns>A reference to <paramref name="builder"/> after the operation has completed.</returns>
        public static AuthenticationBuilder AddOAuth<TOptions, [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]THandler>(this AuthenticationBuilder builder, string authenticationScheme, Action<TOptions> configureOptions)
            where TOptions : OAuthOptions, new()
            where THandler : OAuthHandler<TOptions>
            => builder.AddOAuth<TOptions, THandler>(authenticationScheme, OAuthDefaults.DisplayName, configureOptions);

        /// <summary>
        /// Adds OAuth 2.0 based authentication to <see cref="AuthenticationBuilder"/> using the specified authentication scheme.
        /// </summary>
        /// <param name="builder">The <see cref="AuthenticationBuilder"/>.</param>
        /// <param name="authenticationScheme">The authentication scheme.</param>
        /// <param name="displayName">A display name for the authentication handler.</param>
        /// <param name="configureOptions">A delegate to configure the handler specific options.</param>
        /// <returns>A reference to <paramref name="builder"/> after the operation has completed.</returns>
        public static AuthenticationBuilder AddOAuth<TOptions, [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]THandler>(this AuthenticationBuilder builder, string authenticationScheme, string displayName, Action<TOptions> configureOptions)
            where TOptions : OAuthOptions, new()
            where THandler : OAuthHandler<TOptions>
        {
            builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IPostConfigureOptions<TOptions>, OAuthPostConfigureOptions<TOptions, THandler>>());
            return builder.AddRemoteScheme<TOptions, THandler>(authenticationScheme, displayName, configureOptions);
        }
    }
}
