using System.Collections.Generic;
using System.IO;

namespace AspClassic.Scripting.Runtime;

public abstract class TokenizerService
{
	public abstract object CurrentState { get; }

	public abstract SourceLocation CurrentPosition { get; }

	public abstract bool IsRestartable { get; }

	public abstract ErrorSink ErrorSink { get; set; }

	public abstract void Initialize(object state, TextReader sourceReader, SourceUnit sourceUnit, SourceLocation initialLocation);

	public abstract TokenInfo ReadToken();

	public virtual bool SkipToken()
	{
		return ReadToken().Category != TokenCategory.EndOfStream;
	}

	public virtual IEnumerable<TokenInfo> ReadTokens(int countOfChars)
	{
		List<TokenInfo> list = new List<TokenInfo>();
		int index = CurrentPosition.Index;
		while (CurrentPosition.Index - index < countOfChars)
		{
			TokenInfo item = ReadToken();
			if (item.Category == TokenCategory.EndOfStream)
			{
				break;
			}
			list.Add(item);
		}
		return list;
	}

	public bool SkipTokens(int countOfChars)
	{
		bool result = false;
		int index = CurrentPosition.Index;
		while (CurrentPosition.Index - index < countOfChars && (result = SkipToken()))
		{
		}
		return result;
	}
}