using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using SuperSocket.ClientEngine;
using WebSocket4Net.Common;
using WebSocket4Net.Protocol;

namespace WebSocket4Net
{
    public class WebSocketCommandInfo : ICommandInfo
    {
        public WebSocketCommandInfo()
        {

        }

        public WebSocketCommandInfo(string key)
        {
            Key = key;
        }

        public WebSocketCommandInfo(string key, string text)
        {
            Key = key;
            Text = text;
        }

        public WebSocketCommandInfo(IList<WebSocketDataFrame> frames)
        {
            var opCode = frames[0].OpCode;
            Key = opCode.ToString();

            int offset, length;

            if (opCode == OpCode.Close)
            {
                var firstFrame = frames[0];

                length = (int)firstFrame.ActualPayloadLength;
                offset = firstFrame.InnerData.Count - length;

                var stringBuilder = new StringBuilder();

                if (length >= 2)
                {
                    offset = firstFrame.InnerData.Count - length;

                    var closeStatusCode = firstFrame.InnerData.ToArrayData(offset, 2);
                    CloseStatusCode = (short)(closeStatusCode[0] * 256 + closeStatusCode[1]);

                    if (length > 2)
                    {
                        stringBuilder.Append(firstFrame.InnerData.Decode(Encoding.UTF8, offset + 2, length - 2));
                    }
                }
                else if (length > 0)
                {
                    stringBuilder.Append(firstFrame.InnerData.Decode(Encoding.UTF8, offset, length));
                }

                if (frames.Count > 1)
                {
                    for (var i = 1; i < frames.Count; i++)
                    {
                        var frame = frames[i];

                        offset = frame.InnerData.Count - (int)frame.ActualPayloadLength;
                        length = (int)frame.ActualPayloadLength;

                        if (frame.HasMask)
                        {
                            frame.InnerData.DecodeMask(frame.MaskKey, offset, length);
                        }

                        stringBuilder.Append(frame.InnerData.Decode(Encoding.UTF8, offset, length));
                    }
                }

                Text = stringBuilder.ToString();
                return;
            }

            if (opCode != 2)
            {
                var stringBuilder = new StringBuilder();

                for (var i = 0; i < frames.Count; i++)
                {
                    var frame = frames[i];

                    offset = frame.InnerData.Count - (int)frame.ActualPayloadLength;
                    length = (int)frame.ActualPayloadLength;

                    if (frame.HasMask)
                    {
                        frame.InnerData.DecodeMask(frame.MaskKey, offset, length);
                    }

                    stringBuilder.Append(frame.InnerData.Decode(Encoding.UTF8, offset, length));
                }

                Text = stringBuilder.ToString();
            }
            else
            {
                var resultBuffer = new byte[frames.Sum(f => (int)f.ActualPayloadLength)];

                int copied = 0;

                for (var i = 0; i < frames.Count; i++)
                {
                    var frame = frames[i];

                    offset = frame.InnerData.Count - (int)frame.ActualPayloadLength;
                    length = (int)frame.ActualPayloadLength;

                    if (frame.HasMask)
                    {
                        frame.InnerData.DecodeMask(frame.MaskKey, offset, length);
                    }

                    frame.InnerData.CopyTo(resultBuffer, offset, copied, length);

                    copied += length;
                }

                Data = resultBuffer;
            }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="WebSocketCommandInfo"/> class.
        /// </summary>
        /// <param name="frame">The frame.</param>
        /// <param name="left">The left.</param>
        public WebSocketCommandInfo(WebSocketDataFrame frame)
        {
            Key = frame.OpCode.ToString();

            int length = (int)frame.ActualPayloadLength;
            int offset = frame.InnerData.Count - (int)frame.ActualPayloadLength;


            if (frame.HasMask && length > 0)
            {
                frame.InnerData.DecodeMask(frame.MaskKey, offset, length);
            }

            if (frame.OpCode == OpCode.Close)
            {
                if (length >= 2)
                {
                    var closeStatusCode = frame.InnerData.ToArrayData(offset, 2);
                    CloseStatusCode = (short)(closeStatusCode[0] * 256 + closeStatusCode[1]);

                    if (length > 2)
                    {
                        Text = frame.InnerData.Decode(Encoding.UTF8, offset + 2, length - 2);
                    }
                    else
                    {
                        Text = string.Empty;
                    }

                    return;
                }
            }

            if (frame.OpCode != 2)
            {
                if (length > 0)
                    Text = frame.InnerData.Decode(Encoding.UTF8, offset, length);
                else
                    Text = string.Empty;
            }
            else
            {
                if (length > 0)
                    Data = frame.InnerData.ToArrayData(offset, length);
                else
                    Data = new byte[0];
            }
        }

        public string Key { get; set; }

        public byte[] Data { get; set; }

        public string Text { get; set; }

        public short CloseStatusCode { get; private set; }
    }
}