using Edge.Core.Processor;using Edge.Core.IndustryStandardInterface.Pump;
using Edge.Core.Parser.BinaryParser.Util;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Edge.Core.Processor.Communicator;

namespace HengShan_Pump_TQC_IFSF
{
    public class StateMachineMessageCutter : IMessageCutter<byte[]>
    {
        public byte[] Message { get; private set; }

        public event EventHandler OnMessageCut;
        public event EventHandler<MessageCutterInvalidMessageReadEventArg> OnInvalidMessageRead;
        //static ILog innerLogger = log4net.LogManager.GetLogger("StateMachineMessageCutter");
        static NLog.Logger innerLogger = NLog.LogManager.LoadConfiguration("nlog.config").GetLogger("StateMachineMessageCutter");

        private string loggerAppendix = "HengShan_Pump_TQC_IFSF msgCutter ";
        private readonly SizableWindow<byte> window;
        private State nextState = State.Uninitialized;

        /// <summary>
        /// 
        /// </summary>
        public StateMachineMessageCutter()
        {
            //this.initWindowSize = initWindowSize;
            this.window = new SizableWindow<byte>(2);
            this.window.OnWindowFull += (data) =>
            {
                switch (nextState)
                {
                    case State.Uninitialized:
                        // minimal msg is heartbeat msg, which is 4 bytes
                        var len = this.window.ToInt32();
                        if (len < 4)
                        {
                            innerLogger.Error(this.loggerAppendix + "Unexpected ifsf 2 len bytes read(value must >=4): " + data.Take(2).ToHexLogString());
                            this.window.Clear();
                            return;
                        }

                        if (innerLogger.IsDebugEnabled)
                            innerLogger.Debug(this.loggerAppendix + " Ifsf Msg len(2 bytes) read with: " + len);
                        this.window.NewSize = len + 2;
                        this.nextState = State.LengthReadWaitForBody;
                        break;
                    case State.LengthReadWaitForBody:
                        if (innerLogger.IsDebugEnabled)
                            innerLogger.Debug(this.loggerAppendix + " Ifsf Msg read with(2 bytes len at header): " + this.window.ToHexLogString());
                        this.Message = this.window.Skip(2).ToArray();
                        var safe = this.OnMessageCut;
                        safe?.Invoke(this, null);
                        this.nextState = State.Uninitialized;
                        this.window.Clear();
                        break;
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            };
        }

        private enum State
        {
            Uninitialized,
            LengthReadWaitForBody,
        }

        public void Feed(byte[] next)
        {
            //innerLogger.Debug(this.loggerAppendix + " " + next.ToHexLogString() + " is feed in Window in state: " + nextState);
            for (int i = 0; i < next.Length; i++)
                this.window.Add(next[i]);
        }
    }
}