// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

#nullable disable

using System;
using Microsoft.AspNetCore.Razor.Language.Syntax.InternalSyntax;

namespace Microsoft.AspNetCore.Razor.Language.Legacy;

internal class TokenizerView<TTokenizer> : IDisposable
    where TTokenizer : Tokenizer
{
    public TokenizerView(TTokenizer tokenizer)
    {
        Tokenizer = tokenizer;
    }

    public TTokenizer Tokenizer { get; private set; }
    public bool EndOfFile { get; private set; }
    public SyntaxToken Current { get; private set; }

    public SeekableTextReader Source
    {
        get { return Tokenizer.Source; }
    }

    public bool Next()
    {
        Current = Tokenizer.NextToken();
        EndOfFile = (Current == null);
        return !EndOfFile;
    }

    public void PutBack(SyntaxToken token)
    {
        Reset(Source.Position - token.Content.Length);
    }

    public void Reset(int position)
    {
        Source.Position = position;
        Current = null;
        EndOfFile = Source.Position >= Source.Length;
        Tokenizer.Reset(Source.Position);
    }

    public void Dispose()
    {
        Tokenizer.Dispose();
    }
}