/*
 * Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 * See https://github.com/openiddict/openiddict-core for more information concerning
 * the license and the contributors participating to this project.
 */

using System.ComponentModel;
using System.Security.Cryptography.X509Certificates;
using Microsoft.Extensions.Http;
using Microsoft.Extensions.Options;
using OpenIddict.Client.SystemNetHttp;
using static OpenIddict.Client.WebIntegration.OpenIddictClientWebIntegrationConstants;

namespace OpenIddict.Client.WebIntegration;

/// <summary>
/// Contains the methods required to ensure that the OpenIddict client Web integration configuration is valid.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Advanced)]
public sealed partial class OpenIddictClientWebIntegrationConfiguration : IConfigureOptions<OpenIddictClientOptions>,
                                                                          IConfigureOptions<OpenIddictClientSystemNetHttpOptions>,
                                                                          IConfigureNamedOptions<HttpClientFactoryOptions>,
                                                                          IPostConfigureOptions<OpenIddictClientOptions>
{
    /// <summary>
    /// Creates a new instance of the <see cref="OpenIddictClientWebIntegrationConfiguration"/> class.
    /// </summary>
    public OpenIddictClientWebIntegrationConfiguration()
    {
    }

    /// <summary>
    /// Creates a new instance of the <see cref="OpenIddictClientWebIntegrationConfiguration"/> class.
    /// </summary>
    /// <param name="provider">The service provider.</param>
    [Obsolete("This constructor is no longer supported and will be removed in a future version.")]
    public OpenIddictClientWebIntegrationConfiguration(IServiceProvider provider)
    {
    }

    /// <inheritdoc/>
    public void Configure(OpenIddictClientOptions options)
    {
        if (options is null)
        {
            throw new ArgumentNullException(nameof(options));
        }

        // Register the built-in event handlers used by the OpenIddict client Web components.
        options.Handlers.AddRange(OpenIddictClientWebIntegrationHandlers.DefaultHandlers);
    }

    /// <inheritdoc/>
    public void Configure(OpenIddictClientSystemNetHttpOptions options)
    {
        if (options is null)
        {
            throw new ArgumentNullException(nameof(options));
        }

        options.UnfilteredHttpClientHandlerActions.Add(static (registration, handler) =>
        {
            // Note: while not enforced yet, Pro Santé Connect's specification requires sending a TLS
            // client certificate when communicating with its backchannel OpenID Connect endpoints.
            //
            // For that, the primary HTTP handler must be altered or replaced by an instance that
            // includes the client certificate set in the options in its certificate collection.
            //
            // For more information, see EXI PSC 24 in the annex part of
            // https://www.legifrance.gouv.fr/jorf/id/JORFTEXT000045551195.
            if (registration.ProviderType is ProviderTypes.ProSantéConnect &&
                registration.GetProSantéConnectSettings() is { ClientCertificate: X509Certificate2 certificate })
            {
                handler.ClientCertificates.Add(certificate);
                handler.ClientCertificateOptions = ClientCertificateOption.Manual;
            }
        });
    }

    /// <inheritdoc/>
    [Obsolete("This method is no longer supported and will be removed in a future version.", error: true)]
    public void Configure(HttpClientFactoryOptions options)
        => throw new NotSupportedException(SR.GetResourceString(SR.ID0403));

    /// <inheritdoc/>
    [Obsolete("This method is no longer supported and will be removed in a future version.", error: true)]
    public void Configure(string? name, HttpClientFactoryOptions options)
        => throw new NotSupportedException(SR.GetResourceString(SR.ID0403));

    /// <inheritdoc/>
    public void PostConfigure(string? name, OpenIddictClientOptions options)
    {
        if (options is null)
        {
            throw new ArgumentNullException(nameof(options));
        }

        options.Registrations.ForEach(static registration =>
        {
            // If the client registration has a provider type attached, apply
            // the configuration logic corresponding to the specified provider.
            if (!string.IsNullOrEmpty(registration.ProviderType))
            {
                ConfigureProvider(registration);
            }
        });
    }

    /// <summary>
    /// Amends the registration with the provider-specific configuration logic.
    /// </summary>
    /// <param name="registration">The client registration.</param>
    // Note: the implementation of this method is automatically generated by the source generator.
    static partial void ConfigureProvider(OpenIddictClientRegistration registration);
}