using System;
using System.Collections;
using System.Text;

namespace OSC.NET
{
    /// <summary>
    /// OSCPacket
    /// </summary>
    abstract public class OSCPacket
    {
        protected string address;

        protected byte[] binaryData;

        protected ArrayList values;

        public string Address
        {
            get
            {
                return address;
            }
            set
            {
                // TODO: validate
                address = value;
            }
        }

        public byte[] BinaryData
        {
            get
            {
                pack();
                return binaryData;
            }
        }

        public ArrayList Values
        {
            get { return (ArrayList)values.Clone(); }
        }

        public OSCPacket()
        {
            this.values = new ArrayList();
        }

        public static OSCPacket Unpack(byte[] bytes)
        {
            int start = 0;
            return Unpack(bytes, ref start, bytes.Length);
        }

        public static OSCPacket Unpack(byte[] bytes, ref int start, int end)
        {
            if (bytes[start] == '#') return OSCBundle.Unpack(bytes, ref start, end);
            else return OSCMessage.Unpack(bytes, ref start);
        }

        abstract public void Append(object value);

        abstract public bool IsBundle();

        protected static void addBytes(ArrayList data, byte[] bytes)
        {
            foreach (byte b in bytes)
            {
                data.Add(b);
            }
        }

        protected static byte[] packDouble(double value)
        {
            byte[] data = BitConverter.GetBytes(value);
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return data;
        }

        protected static byte[] packFloat(float value)
        {
            byte[] data = BitConverter.GetBytes(value);
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return data;
        }

        protected static byte[] packInt(int value)
        {
            byte[] data = BitConverter.GetBytes(value);
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return data;
        }

        protected static byte[] packLong(long value)
        {
            byte[] data = BitConverter.GetBytes(value);
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return data;
        }

        protected static byte[] packString(string value)
        {
            return System.Text.Encoding.ASCII.GetBytes(value);
        }

        protected static void padNull(ArrayList data)
        {
            byte zero = 0;
            int pad = 4 - (data.Count % 4);
            for (int i = 0; i < pad; i++)
            {
                data.Add(zero);
            }
        }

        protected static byte[] swapEndian(byte[] data)
        {
            byte[] swapped = new byte[data.Length];
            for (int i = data.Length - 1, j = 0; i >= 0; i--, j++)
            {
                swapped[j] = data[i];
            }
            return swapped;
        }

        protected static double unpackDouble(byte[] bytes, ref int start)
        {
            byte[] data = new byte[8];
            for (int i = 0; i < 8; i++, start++) data[i] = bytes[start];
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return BitConverter.ToDouble(data, 0);
        }

        protected static float unpackFloat(byte[] bytes, ref int start)
        {
            byte[] data = new byte[4];
            for (int i = 0; i < 4; i++, start++) data[i] = bytes[start];
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return BitConverter.ToSingle(data, 0);
        }

        protected static int unpackInt(byte[] bytes, ref int start)
        {
            byte[] data = new byte[4];
            for (int i = 0; i < 4; i++, start++) data[i] = bytes[start];
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return BitConverter.ToInt32(data, 0);
        }

        protected static long unpackLong(byte[] bytes, ref int start)
        {
            byte[] data = new byte[8];
            for (int i = 0; i < 8; i++, start++) data[i] = bytes[start];
            if (BitConverter.IsLittleEndian) data = swapEndian(data);
            return BitConverter.ToInt64(data, 0);
        }

        protected static string unpackString(byte[] bytes, ref int start)
        {
            int count = 0;
            for (int index = start; bytes[index] != 0; index++, count++) ;
            string s = Encoding.ASCII.GetString(bytes, start, count);
            start += count + 1;
            start = (start + 3) / 4 * 4;
            return s;
        }

        abstract protected void pack();
    }
}