AuthenticationHandler.cs

#region License
/* ************************************************************
 *
 *    @author Couchbase <info@couchbase.com>
 *    @copyright 2025 Couchbase, Inc.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *
 * ************************************************************/
#endregion

using System.Net.Http.Headers;
using System.Text;
using Couchbase.AnalyticsClient.HTTP;

namespace Couchbase.AnalyticsClient.Internal.HTTP;

internal class AuthenticationHandler : DelegatingHandler
{
    private const string BasicScheme = "Basic";
    private readonly string? _headerValue;

    public AuthenticationHandler(HttpMessageHandler innerHandler)
        : this(innerHandler, "default", string.Empty)
    {
    }

    public AuthenticationHandler(HttpMessageHandler innerHandler, ICredential credential)
        : this(innerHandler, credential.Username ?? "default", credential.Password ?? string.Empty)
    {
    }

    public AuthenticationHandler(HttpMessageHandler innerHandler, string username, string password)
        : base(innerHandler)
    {
        if (!string.IsNullOrEmpty(username))
        {
            // Just build once for speed
            _headerValue = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Concat(username, ":", password)));
        }
    }

    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        if (_headerValue != null)
        {
            request.Headers.Authorization = new AuthenticationHeaderValue(BasicScheme, _headerValue);
        }

        return base.SendAsync(request, cancellationToken);
    }
}