namespace Sunfish.Log;

public enum LogLevel { Detail, Info, Warning, Error }

public sealed record LogEntry(DateTime Time, LogLevel Level, string Message);

/// <summary>
/// Registro del servidor: guarda las ultimas entradas en memoria (para las interfaces)
/// y avisa de cada entrada nueva con <see cref="Written"/>.
/// </summary>
public sealed class ServerLog
{
    private readonly object _lock = new();
    private readonly Queue<LogEntry> _recent = new();
    private readonly int _capacity;

    public ServerLog(int capacity = 1000) => _capacity = capacity;

    /// <summary>Se dispara en el hilo que escribe; las interfaces deben pasar a su propio hilo.</summary>
    public event Action<LogEntry>? Written;

    public LogLevel MinimumLevel { get; set; } = LogLevel.Info;

    public void Detail(string message) => Write(LogLevel.Detail, message);
    public void Info(string message) => Write(LogLevel.Info, message);
    public void Warning(string message) => Write(LogLevel.Warning, message);
    public void Error(string message) => Write(LogLevel.Error, message);

    public void Write(LogLevel level, string message)
    {
        if (level < MinimumLevel)
            return;
        var entry = new LogEntry(DateTime.Now, level, message);
        lock (_lock)
        {
            _recent.Enqueue(entry);
            while (_recent.Count > _capacity)
                _recent.Dequeue();
        }
        Written?.Invoke(entry);
    }

    public LogEntry[] Recent()
    {
        lock (_lock)
            return _recent.ToArray();
    }
}