// 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.IO;
using System.Text;
using Microsoft.AspNetCore.Server.Kestrel.Core.Internal;
using Microsoft.Extensions.Logging;
using Xunit;
 
namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests;
 
public class LoggingStreamTests
{
    [Theory]
    [InlineData(1, "00                                                 .")]
    [InlineData(2, "00 00                                              ..")]
    [InlineData(3, "00 00 00                                           ...")]
    [InlineData(4, "00 00 00 00                                        ....")]
    [InlineData(5, "00 00 00 00 00                                     .....")]
    [InlineData(6, "00 00 00 00 00 00                                  ......")]
    [InlineData(7, "00 00 00 00 00 00 00                               .......")]
    [InlineData(8, "00 00 00 00 00 00 00 00                            ........ ")]
    [InlineData(9, "00 00 00 00 00 00 00 00  00                        ........ .")]
    [InlineData(10, "00 00 00 00 00 00 00 00  00 00                     ........ ..")]
    [InlineData(11, "00 00 00 00 00 00 00 00  00 00 00                  ........ ...")]
    [InlineData(12, "00 00 00 00 00 00 00 00  00 00 00 00               ........ ....")]
    [InlineData(13, "00 00 00 00 00 00 00 00  00 00 00 00 00            ........ .....")]
    [InlineData(14, "00 00 00 00 00 00 00 00  00 00 00 00 00 00         ........ ......")]
    [InlineData(15, "00 00 00 00 00 00 00 00  00 00 00 00 00 00 00      ........ .......")]
    [InlineData(16, "00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ........ ........")]
    public void CorrectPaddingIsUsedAfterHexValues(int bufferLength, string expectedOutput)
    {
        var mockLogger = new MockLogger();
        var loggingStream = new LoggingStream(Stream.Null, mockLogger);
 
        loggingStream.Write(new byte[bufferLength]);
 
        Assert.Equal($"Write[{bufferLength}]{Environment.NewLine}{expectedOutput}", mockLogger.Logs);
    }
 
    [Fact]
    public void ExtraNewLineIsNotLoggedGivenEmptyBuffer()
    {
        var mockLogger = new MockLogger();
        var loggingStream = new LoggingStream(Stream.Null, mockLogger);
 
        loggingStream.Write(default);
 
        Assert.Equal($"Write[0]", mockLogger.Logs);
    }
 
    private class MockLogger : ILogger
    {
        private readonly StringBuilder _logs = new();
 
        public string Logs => _logs.ToString();
 
        public IDisposable BeginScope<TState>(TState state)
        {
            throw new NotImplementedException();
        }
 
        public bool IsEnabled(LogLevel logLevel) => true;
 
        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
        {
            _logs.Append(formatter(state, exception));
        }
    }
}