using System.Text;

namespace Nbt;

public sealed class IndentedWriter(TextWriter baseWriter, string indent, bool leaveOpen = false) : TextWriter
{
    private readonly TextWriter baseWriter = baseWriter;
    private readonly string indent = indent;
    private readonly bool leaveOpen = leaveOpen;
    private uint depth = 0u;

    public IndentedWriter(StringBuilder sb, string indent) : this(new StringWriter(sb), indent) { }

    public override Encoding Encoding => baseWriter.Encoding;

    public IndentationLevel NewIndentationLevel() => new(this);

    public override void Write(char value) => baseWriter.Write(value);

    public override void WriteLine()
    {
        baseWriter.WriteLine();

        for (var i = 0u; i < depth; i++)
        {
            baseWriter.Write(indent);
        }
    }

    public override async Task WriteAsync(char value) => await baseWriter.WriteAsync(value);

    public override async Task WriteLineAsync()
    {
        await baseWriter.WriteLineAsync();

        for (var i = 0u; i < depth; i++)
        {
            await baseWriter.WriteAsync(indent);
        }
    }

    protected override void Dispose(bool disposing)
    {
        try
        {
            if (disposing)
            {
                if (!leaveOpen)
                {
                    baseWriter.Dispose();
                }
            }
        }
        finally
        {
            base.Dispose(disposing);
        }
    }

    public override async ValueTask DisposeAsync()
    {
        try
        {
            if (!leaveOpen)
            {
                await baseWriter.DisposeAsync();
            }
        }
        finally
        {
            await base.DisposeAsync();
        }
    }

    public readonly struct IndentationLevel : IDisposable
    {
        private readonly IndentedWriter writer;

        public IndentationLevel(IndentedWriter writer)
        {
            this.writer = writer;

            writer.depth++;
        }

        public void Dispose()
        {
            writer.depth--;
        }
    }
}