using System;
using System.Xml;
using Aitex.Core.RT.Device;
using Aitex.Core.RT.Event;
using Aitex.Core.RT.IOCore;
using Aitex.Core.Util;

namespace Aitex.Core.RT.Device.Unit
{
    /// <summary>
    /// 心跳包机制
    ///
    /// 功能：
    /// 1.C#送出给PLC，如果PLC检测到C#心跳信号停止，则判定C#程序运行异常，从而触发安全逻辑动作。
    /// 2.C#检测PLC返回的心跳包信号，如果检测到PLC心跳信号停止，则判定PLC程序运行异常，从而进行报警处理。
    /// </summary>
    public class IoHeartbeat : BaseDevice, IDevice
    {
        private readonly int PLC_Heart_Beat_Timeout_ms = 1000 * 120;
        private readonly AIAccessor _ai;
        private readonly AOAccessor _ao;
        private readonly DeviceTimer _updateTimer = new DeviceTimer();  //更新 AO信号 给PLC
        private readonly int MAX = 0x7FFF;
        private float _prevAiValue;
        private readonly DeviceTimer _connectTimer = new DeviceTimer();
        private readonly R_TRIG _trigConnectionLost = new R_TRIG();

        // --------------------------Constructor-----------------------
        // 
        public IoHeartbeat(string module, XmlElement node, string ioModule = "")
        {
            base.Module = module;
            base.Name = node.GetAttribute("id");
            base.Display = node.GetAttribute("display");
            base.DeviceID = node.GetAttribute("schematicId");

            _ai = ParseAiNode("ai", node, ioModule);
            _ao = ParseAoNode("ao", node, ioModule);
        }

        public bool Initialize()
        {
            _updateTimer.Start(500);
            _connectTimer.Start(PLC_Heart_Beat_Timeout_ms);
            return true;
        }

        public void Monitor()
        {
            if (Math.Abs(_prevAiValue - _GetRealFloat(_ai)) > 0.01)
            {
                _connectTimer.Start(PLC_Heart_Beat_Timeout_ms);
            }

            _trigConnectionLost.CLK = _connectTimer.IsTimeout();
            if (_trigConnectionLost.Q)
            {
                EV.PostMessage(Module, EventEnum.PlcHeartBeatFail, Module, Display);
            }

            _prevAiValue = _GetRealFloat(_ai);

            //如果计时到达，则翻转心跳信号
            if (_updateTimer.IsTimeout())
            {
                float beat_val = _GetRealFloat(_ao);
                beat_val++;

                if (beat_val >= MAX)
                {
                    beat_val = 0;
                }
                _SetRealFloat(_ao, beat_val);

                _updateTimer.Start(2000);       //500 ms
            }
        }

        public void Terminate() {  }

        public void Reset()
        {
            _connectTimer.Start(PLC_Heart_Beat_Timeout_ms);
            _trigConnectionLost.RST = true;
        }
    }
}