using System;
using System.IO;

namespace Org.BouncyCastle.Bcpg.Attr
{
	/// <remarks>Basic type for a image attribute packet.</remarks>
    public class ImageAttrib
		: UserAttributeSubpacket
    {
		public enum Format : byte
		{
			Jpeg = 1
		}

		private static readonly byte[] Zeroes = new byte[12];

		private int     hdrLength;
        private int     _version;
        private int     _encoding;
        private byte[]  imageData;

        public ImageAttrib(
            byte[] data)
            : base(UserAttributeSubpacketTag.ImageAttribute, data)
        {
            hdrLength = ((data[1] & 0xff) << 8) | (data[0] & 0xff);
            _version = data[2] & 0xff;
            _encoding = data[3] & 0xff;

            imageData = new byte[data.Length - hdrLength];
            Array.Copy(data, hdrLength, imageData, 0, imageData.Length);
        }

		public ImageAttrib(
			Format	imageType,
			byte[]	imageData)
			: this(ToByteArray(imageType, imageData))
		{
		}

		private static byte[] ToByteArray(
			Format	imageType,
			byte[]	imageData)
		{
			MemoryStream bOut = new MemoryStream();
			bOut.WriteByte(0x10); bOut.WriteByte(0x00); bOut.WriteByte(0x01);
			bOut.WriteByte((byte) imageType);
			bOut.Write(Zeroes, 0, Zeroes.Length);
			bOut.Write(imageData, 0, imageData.Length);
			return bOut.ToArray();
		}

		public int Version
        {
			get { return _version; }
        }

        public int Encoding
        {
			get { return _encoding; }
        }

		public byte[] GetImageData()
        {
            return imageData;
        }
    }
}
