namespace anjianjingling.Common
{
    /// <summary>
    /// 线程安全日志总线：后台线程产生日志，UI 线程定时消费。
    /// </summary>
    public sealed class LogBus
    {
        private readonly Queue<string> _queue = new();
        private readonly object _lock = new();

        public event Action<string>? OnLog;

        public void Write(string message)
        {
            var line = $"[{DateTime.Now:HH:mm:ss}] {message}";
            lock (_lock)
            {
                _queue.Enqueue(line);
                if (_queue.Count > 2000)
                {
                    // 防止异常情况下无限增长
                    while (_queue.Count > 1000) _queue.Dequeue();
                }
            }
            OnLog?.Invoke(line);
        }

        /// <summary>取出当前所有缓冲日志（UI 定时器调用）。</summary>
        public List<string> Drain()
        {
            lock (_lock)
            {
                var list = new List<string>(_queue.Count);
                while (_queue.Count > 0) list.Add(_queue.Dequeue());
                return list;
            }
        }
    }
}