using Microsoft.Extensions.Logging;
using ZB.MOM.WW.OtOpcUa.Driver.TwinCAT;

namespace ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests;

/// <summary>Collects the driver's Warning-level messages (thread-safe) for once-per-X assertions.</summary>
internal sealed class TwinCATCapturingLogger : ILogger<TwinCATDriver>
{
    private readonly List<string> _warnings = [];

    /// <summary>Gets a snapshot of the formatted Warning messages logged so far.</summary>
    public IReadOnlyList<string> Warnings { get { lock (_warnings) return [.. _warnings]; } }

    /// <summary>
    ///     Optional hook run synchronously on the logging thread for each Warning, after it is captured. A test can
    ///     block in it to hold open the window between the driver's log call and its next statement.
    /// </summary>
    public Action<string>? OnWarning { get; init; }

    /// <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)
    {
        if (logLevel != LogLevel.Warning) return;
        var message = formatter(state, exception);
        lock (_warnings) _warnings.Add(message);
        OnWarning?.Invoke(message);
    }
}