// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Net.Http;
using Xunit.Abstractions;
 
namespace Microsoft.AspNetCore.Identity.Test;
 
internal class RetryHandler : DelegatingHandler
{
    private readonly ITestOutputHelper _output;
    private readonly int _maxRetries;
    private TimeSpan _waitIntervalBeforeRetry;
 
    public RetryHandler(
        HttpClientHandler httpClientHandler,
        ITestOutputHelper output,
        TimeSpan initialWaitTime,
        int maxAttempts) : base(httpClientHandler)
    {
        _waitIntervalBeforeRetry = initialWaitTime;
        _output = output;
        _maxRetries = maxAttempts;
    }
 
    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        HttpResponseMessage result = null;
        var url = request.RequestUri;
        var method = request.Method;
 
        for (var i = 0; i < _maxRetries; i++)
        {
            try
            {
                _output.WriteLine($"Sending request '{method} - {url}' {i + 1} attempt.");
                result = await base.SendAsync(request, cancellationToken);
                if (result.IsSuccessStatusCode)
                {
                    return result;
                }
                else
                {
                    _output.WriteLine($"Request '{method} - {url}' failed with {result.StatusCode}.");
                }
            }
            catch (Exception e)
            {
                _output.WriteLine($"Request '{method} - {url}' failed with {e.ToString()}");
            }
            finally
            {
                await Task.Delay(_waitIntervalBeforeRetry, cancellationToken);
                _waitIntervalBeforeRetry = _waitIntervalBeforeRetry * 2;
            }
        }
 
        // Try one last time to show the actual error.
        return await base.SendAsync(request, cancellationToken);
    }
}