using System;
using System.IO;

namespace VGMToolbox.format
{
    public class Mpeg1Stream : MpegStream
    {
        public const string DefaultAudioExtension = ".mp2";
        public const string DefaultVideoExtension = ".m1v";

        public Mpeg1Stream(string path)
            : base(path)
        {
            this.FileExtensionAudio = DefaultAudioExtension;
            this.FileExtensionVideo = DefaultVideoExtension;

            base.BlockIdDictionary[BitConverter.ToUInt32(MpegStream.PacketStartBytes, 0)] = new BlockSizeStruct(PacketSizeType.Static, 0xC); // Pack Header
        }

        protected override int GetAudioPacketHeaderSize(Stream readStream, long currentOffset)
        {
            int paddingByteCount = 0;
            readStream.Position = currentOffset + 6;

            // skip stuffing bytes
            while (readStream.ReadByte() == 0xFF)
            {
                paddingByteCount++;
            }

            return paddingByteCount + 7;
        }

        protected override int GetVideoPacketHeaderSize(Stream readStream, long currentOffset)
        {
            return 0xC;
        }
    }
}