// Copyright Epic Games, Inc. All Rights Reserved.

using System.Text.RegularExpressions;
using EpicGames.Core;
using Microsoft.Extensions.Logging;

#nullable enable

namespace AutomationUtils.Matchers
{
	/// <summary>
	/// Matches events formatted as UE log channel output
	/// </summary>
	class LogChannelEventMatcher : ILogEventMatcher
	{
		static readonly Regex s_pattern = new Regex(
			@"^(\s*)" +
			@"(?:\[[\d\.\-: ]+\])*" +
			@"(?<channel>[a-zA-Z_][a-zA-Z0-9_]*):\s*" +
			@"(?<severity>Error|Warning|Display): "
		);

		/// <inheritdoc/>
		public LogEventMatch? Match(ILogCursor input)
		{
			if (input.TryMatch(s_pattern, out Match? match))
			{

				if (input.Contains("There is not enough space on the disk."))
				{
					return new LogEventBuilder(input).ToMatch(LogEventPriority.Low, LogLevel.Error, KnownLogEvents.Systemic_OutOfDiskSpace);
				}

				LogEventBuilder builder = new LogEventBuilder(input);
				builder.Annotate(match.Groups["channel"], LogEventMarkup.Channel);
				builder.Annotate(match.Groups["severity"], LogEventMarkup.Severity);
				
				while(builder.IsNextLineHanging())
				{
					builder.MoveNext();
				}

				LogLevel level = match.Groups["severity"].Value switch
				{
					"Error" => LogLevel.Error,
					"Warning" => LogLevel.Warning,
					_ => LogLevel.Information,
				};

				return builder.ToMatch(LogEventPriority.Low, level, KnownLogEvents.Engine_LogChannel);
				
			}
			return null;
		}
	}
}