using Microsoft.Extensions.Logging;

namespace ZB.MOM.WW.MxGateway.Tests.TestSupport;

/// <summary>
///     <see cref="ILogger{TCategoryName}"/> that records every entry's level and formatted message,
///     so a test can assert that a path logs (or does not log) at a given level.
/// </summary>
/// <typeparam name="T">The logger category type.</typeparam>
public sealed class RecordingLogger<T> : ILogger<T>
{
    private readonly object _syncRoot = new();
    private readonly List<(LogLevel Level, string Message, Exception? Exception)> _entries = [];

    /// <summary>Gets a snapshot of the recorded entries, in order.</summary>
    public IReadOnlyList<(LogLevel Level, string Message, Exception? Exception)> Entries
    {
        get
        {
            lock (_syncRoot)
            {
                return _entries.ToArray();
            }
        }
    }

    /// <inheritdoc />
    public IDisposable? BeginScope<TState>(TState state)
        where TState : notnull => null;

    /// <inheritdoc />
    public bool IsEnabled(LogLevel logLevel) => true;

    /// <inheritdoc />
    public void Log<TState>(
        LogLevel logLevel,
        EventId eventId,
        TState state,
        Exception? exception,
        Func<TState, Exception?, string> formatter)
    {
        ArgumentNullException.ThrowIfNull(formatter);
        lock (_syncRoot)
        {
            _entries.Add((logLevel, formatter(state, exception), exception));
        }
    }
}