using System;
using System.Collections.Concurrent;
using Serilog.Core;
using Serilog.Events;

namespace TINK.Services.Logging
{
	public class MemoryStackSink : ILogEventSink
	{
		private readonly IFormatProvider _formatProvider;

		private static ConcurrentStack<string> _MessageStack = new ConcurrentStack<string>();

		/// <summary>
		/// Reads all messages an clears memory stack.
		/// </summary>
		/// <returns>Array of messages.</returns>
		public static string[] PopAllMessages()
		{
			int countOfMessages = _MessageStack.Count;
			if (countOfMessages <= 0)
				return new string[0];

			string[] messages = new string[countOfMessages];
			if (_MessageStack.TryPopRange(messages) <= 0)
				return new string[0];

			return messages;
		}

		/// <summary>
		/// Clears the message stack.
		/// </summary>
		public static void ClearMessages() => _MessageStack.Clear();

		public MemoryStackSink(IFormatProvider formatProvider)
		{
			_formatProvider = formatProvider;
		}

		public void Emit(LogEvent logEvent)
		{
			var message = logEvent.RenderMessage(_formatProvider);
			_MessageStack.Push(DateTimeOffset.Now.ToString() + " " + message);
		}
	}
}