using Edge.Core.Processor;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using PressureGage_3051.MessageEntity;
using PressureGage_3051.MessageEntity.Outgoing;
using PressureGage_3051.MessageEntity.Incoming;
using System.Text.Json;

namespace PressureGage_3051
{
    public class SensorHandler
    {
        public byte DeviceAddress { get; set; } // It is also DeviceId
        public EventHandler<string> OnJsonDataRecieved;

        private IContext<byte[], MessageBase> context;
        private readonly Queue<MessageBase> requestQueue = new Queue<MessageBase>();
        private ILogger logger = null;
        private DeviceState deviceState = DeviceState.Disconnected;

        public SensorHandler(byte deviceAddress, ILogger logger)
        {
            DeviceAddress = deviceAddress;
            this.logger = logger;

            logger.LogInformation($"Create sensor handler with deviceAddress: {deviceAddress}");
        }

        public void Init(IContext<byte[], MessageBase> context)
        {
            this.context = context;
            this.context.Incoming.OnLongTimeNoSeeMessage += (_, __) =>
              {
                  this.deviceState = DeviceState.Disconnected;
                  FireStateChange(this.deviceState);
              };
            this.context.Incoming.LongTimeNoSeeMessageTimeout = 90000;
        }

        public void ReadRegister(MessageBase request)
        {
            if (requestQueue.Count > 8)
            {
                requestQueue.Dequeue();
            }
            requestQueue.Enqueue(request);
        }

        public MessageBase GetRequestMessage()
        {
            switch (this.deviceState)
            {
                case DeviceState.Connected:
                    {
                        if (requestQueue.Count > 0)
                        {
                            return requestQueue.Dequeue();
                        }
                        else
                            return new ReadPressure_Request(this.DeviceAddress);
                    }
                case DeviceState.Disconnected:
                    {
                        return new ReadPressure_Request(this.DeviceAddress); // PresetSingleRegister_Request(this.DeviceAddress, 0, "Pa");
                    }
                default: { return null; }
            };
        }

        public Task Process(IContext<byte[], MessageBase> context)
        {
            if (this.deviceState != DeviceState.Connected)
            {
                this.deviceState = DeviceState.Connected;
                FireStateChange(this.deviceState);
            }

            FireDataRecieved(context.Incoming.Message);
            return Task.CompletedTask;
        }

        private void FireDataRecieved(MessageBase message)
        {
            dynamic response = null;
            switch (message.FunctionCode)
            {
                case FunctionCode.READ_HOLDING_REGISTERS:
                    if (message.RawDataField[0] == 0x0A)
                    {
                        response = message as ReadUnit_Response;
                        logger.LogDebug($"Pressure Gage with addr {this.DeviceAddress} read PressureUnit {response.PressureUnit}, StaticPressureUnit {response.StaticPressureUnit},\n" +
                            $" DeviceType {response.DeviceType}, SensorType {response.SensorType}, MeasuringRange {response.MeasuringRange}");
                    }
                    else if (message.RawDataField[0] == 0x12)
                    {
                        response = message as ReadView_Response;
                        logger.LogDebug($"Pressure Gage with addr {this.DeviceAddress} read ViewType {response.ViewType}, MinMeasuringRange {response.MinMeasuringRange},\n" +
                            $" MaxMeasuringRange {response.MaxMeasuringRange}, DampPeriod {response.DampPeriod}, SmallSignalExcision {response.SmallSignalExcision}");
                    }
                    break;
                case FunctionCode.READ_INPUT_REGISTERS:
                    if (message.RawDataField[0] == 0x10)
                    {
                        response = message as ReadPressure_Response;
                        logger.LogDebug($"Pressure Gage with addr {this.DeviceAddress} read Pressure {response.Pressure.ToString("F1")}, PressurePercentage {response.PressurePercentage.ToString("F1")}");
                        OnJsonDataRecieved?.Invoke(this, JsonSerializer.Serialize(new { DeviceAddress = this.DeviceAddress, Pressure = response.Pressure }));
                    }
                    else if (message.RawDataField[0] == 0x08)
                    {
                        response = message as ReadAlarm_Response;
                        logger.LogDebug($"Pressure Gage with addr {this.DeviceAddress} read LowerAlert {response.LowerAlert}, UpperAlert {response.UpperAlert}");
                    }
                    break;
                case FunctionCode.PRESET_SINGLE_REGISTER:
                    response = message as PresetRegisters_Response;
                    logger.LogDebug($"Pressure Gage with addr {this.DeviceAddress} read WriteValue {response.WriteValue}");
                    break;
                default:
                    break;
            };
        }

        private void FireStateChange(DeviceState deviceState)
        {
            logger.LogInformation($"Device: {this.DeviceAddress}, DeviceState is {deviceState}");
            OnJsonDataRecieved?.Invoke(this, JsonSerializer.Serialize(new { DeviceAddress = this.DeviceAddress, DeviceState = deviceState.ToString() }));
        }
    }
}