using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO.Ports;
using System.Text.RegularExpressions;
using System.Net.Sockets;
using System.IO;
using Newtonsoft.Json;
using System.Threading;


namespace Gidrolock_Modbus_Scanner
{
    public partial class App : Form
    {
        public static int[] BaudRate = new int[]
        {
            110, 300, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, 76800, 115200, 230300, 460800, 921600
        };
        public static int[] DataBits = new int[] { 7, 8 };
        Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp);

        byte[] message = new byte[255];
        public bool isAwaitingResponse = false;
        public short[] res = new short[12];
        SerialPort port = Modbus.port;
        public int expectedLength = 0;
        Datasheet datasheet;
        public SelectedPath selectedPath = SelectedPath.Folder;

        public static Device device; // Deserialized .json object
        string path = String.Empty; // Path to selected file/folder
        string defaultPath = Application.StartupPath + "\\Configs"; // Default folder path
        OpenFileDialog ofd = new OpenFileDialog();
        FolderBrowserDialog fbd = new FolderBrowserDialog();

        Dictionary<CheckEntry, List<Device>> juju = new Dictionary<CheckEntry, List<Device>>(); // dictionary for device identification
        string[] configs;

        public byte[] latestMessage;

        DateTime dateTime;
        #region Initialization
        public App()
        {
            InitializeComponent();
            Modbus.Init();
            Modbus.ResponseReceived += OnResponseReceived;
            ofd.InitialDirectory = Application.StartupPath;
            ofd.Filter = "JSON files (*.json)|*.json";
            ofd.FilterIndex = 2;
            ofd.RestoreDirectory = true;

            this.UpDown_ModbusID.Value = 30;
            TextBox_Log.Text = "Приложение готово к работе.";

            CBox_Function.Items.Add("01 Read Coil");
            CBox_Function.Items.Add("02 Read Discrete Input");
            CBox_Function.Items.Add("03 Read Holding Register");
            CBox_Function.Items.Add("04 Read Input Register");
            CBox_Function.Items.Add("05 Write Single Coil");
            CBox_Function.Items.Add("06 Write Single Register");
            CBox_Function.Items.Add("0F Write Multiple Coils");
            CBox_Function.Items.Add("10 Write Multiple Registers");
            CBox_Function.SelectedItem = CBox_Function.Items[0];

            CBox_BaudRate.Items.Add("110");
            CBox_BaudRate.Items.Add("300");
            CBox_BaudRate.Items.Add("1200");
            CBox_BaudRate.Items.Add("2400");
            CBox_BaudRate.Items.Add("4800");
            CBox_BaudRate.Items.Add("9600");
            CBox_BaudRate.Items.Add("14400");
            CBox_BaudRate.Items.Add("19200");
            CBox_BaudRate.Items.Add("28800");
            CBox_BaudRate.Items.Add("38400");
            CBox_BaudRate.Items.Add("57600");
            CBox_BaudRate.Items.Add("76800");
            CBox_BaudRate.Items.Add("115200");
            CBox_BaudRate.Items.Add("230300");
            CBox_BaudRate.Items.Add("460800");
            CBox_BaudRate.Items.Add("921600");
            CBox_BaudRate.SelectedIndex = 5;

            CBox_DataBits.Items.Add("7");
            CBox_DataBits.Items.Add("8");
            CBox_DataBits.SelectedIndex = 1;

            CBox_StopBits.Items.Add("Нет");
            CBox_StopBits.Items.Add("1");
            CBox_StopBits.Items.Add("1.5");
            CBox_StopBits.Items.Add("2");
            CBox_StopBits.SelectedIndex = 1;

            CBox_Parity.Items.Add("Нет");
            CBox_Parity.Items.Add("Четн.");
            CBox_Parity.Items.Add("Нечетн.");
            CBox_Parity.SelectedIndex = 0;


            UpDown_RegAddress.Minimum = 0;
            UpDown_RegAddress.Maximum = 65535;

            UpDown_Value.Minimum = 0;
            UpDown_Value.Maximum = 65535; // 2^16 

            Radio_SerialPort.Checked = true;
            GBox_Ethernet.Enabled = false;
            TBox_IP.Text = "192.168.3.7";
            TBox_Port.Text = "8887";
            TBox_Timeout.Text = "3";
            if (Directory.GetDirectories(Application.StartupPath).Contains(Application.StartupPath + "\\Configs") == false)
            {
                Task.Delay(1500).ContinueWith(t =>
                {
                    MessageBox.Show("Приложение не нашло стандартную папку для конфигураций. Была создана папка 'Configs' в папке с приложением.");
                    Directory.CreateDirectory(Application.StartupPath + "\\Configs");
                    Console.WriteLine("New initial directory for OpenFile: " + ofd.InitialDirectory);
                });
            }
            ofd.InitialDirectory = Application.StartupPath + "\\Configs";
            path = defaultPath;
            UpdatePathLabel();
        }
        void UpdatePathLabel()
        {
            Label_ConfPath.Text = path;
        }
        void App_FormClosed(object sender, FormClosedEventArgs e)
        {
            port.Close();
            if (!port.IsOpen)
                Application.Exit();
        }

        void Form1_Load(object sender, EventArgs e)
        {
            CBox_Ports.Items.AddRange(SerialPort.GetPortNames());
            if (CBox_Ports.Items.Count > 0)
                CBox_Ports.SelectedIndex = 0;
            Init();
        }

        void Init()
        {
            if (UpDown_ModbusID.Value == 0)
                Button_Connect.Text = "Найти адрес";
            else Button_Connect.Text = "Подключиться";
        }
        #endregion

        // Send a custom message
        async Task SendMessageAsync(FunctionCode functionCode, ushort address, ushort length)
        {
            if (CBox_Ports.Text == "")
                MessageBox.Show("Необходимо выбрать COM порт.", "Ошибка", MessageBoxButtons.OK);
            if (UpDown_ModbusID.Value == 0)
                MessageBox.Show("Глобальное вещание пока не поддерживается");

            /* - Port Setup - */
            if (port.IsOpen)
                port.Close();

            port.Handshake = Handshake.None;
            port.PortName = CBox_Ports.Text;
            port.BaudRate = BaudRate[CBox_BaudRate.SelectedIndex];
            port.Parity = Parity.None;
            port.DataBits = DataBits[CBox_DataBits.SelectedIndex];
            port.StopBits = (StopBits)CBox_StopBits.SelectedIndex;

            port.ReadTimeout = 3000;
            port.WriteTimeout = 3000;


            message = new byte[255];
            port.Open();


            /* - Reading from Registers - */
            if (CBox_Function.SelectedIndex < 4)
            {
                try
                {
                    var send = await Modbus.ReadRegAsync(port, (byte)UpDown_ModbusID.Value, functionCode, address, length);
                    isAwaitingResponse = true;
                    await Task.Delay(port.ReadTimeout).ContinueWith(_ =>
                    {
                        if (isAwaitingResponse)
                        {
                            MessageBox.Show("Истекло время ожидания ответа.", "Ошибка");
                            port.Close();
                        }
                    });
                }
                catch (Exception err)
                {
                    port.Close();
                    MessageBox.Show(err.Message, "Ошибка", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }

            /* - Writing to Registers - */
            else
            {
                try
                {
                    if (CBox_Function.SelectedIndex < 6) // Single Registers
                    {
                        byte[] request = new byte[8];
                        Modbus.BuildMessage((byte)UpDown_ModbusID.Value, (byte)(1 + functionCode), address, length, ref request);
                        string messageParsed = Modbus.ByteArrayToString(request);

                        var send = await Modbus.WriteSingle(port, functionCode, (byte)UpDown_ModbusID.Value, address, (ushort)UpDown_Value.Value);
                    }
                    else // Multiple Registers
                    {
                        byte[] request = new byte[(int)UpDown_RegLength.Value * 2 + 6];
                        // TODO
                    }
                }
                catch (Exception err)
                {
                    port.Close();
                    MessageBox.Show(err.Message, "Ошибка", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }

        }

        private async void ButtonConnect_Click(object sender, EventArgs e)
        {
            progressBar1.Value = 0;
            if (path == String.Empty)
            {
                MessageBox.Show("Выберите конфигурацию для подключения и опроса устройства.");
                return;
            }
            if (CBox_Ports.SelectedItem.ToString() == "COM1")
            {
                DialogResult res = MessageBox.Show("Выбран серийный порт COM1, который обычно является портом PS/2 или RS-232, не подключенным к Modbus устройству. Продолжить?", "Внимание", MessageBoxButtons.OKCancel);
                if (res == DialogResult.Cancel)
                    return;
            }

            /* - Port Setup - */
            if (port.IsOpen)
                port.Close();

            port.Handshake = Handshake.None;
            port.PortName = CBox_Ports.Text;
            port.BaudRate = BaudRate[CBox_BaudRate.SelectedIndex];
            port.Parity = Parity.None;
            port.DataBits = DataBits[CBox_DataBits.SelectedIndex];
            port.StopBits = (StopBits)CBox_StopBits.SelectedIndex;

            port.ReadTimeout = 3000;
            port.WriteTimeout = 3000;


            message = new byte[255];
            port.Open();

            /* - Checking - */
            if (selectedPath == SelectedPath.File)
            {
                var fileContent = string.Empty;
                var filePath = string.Empty;
                //Read the contents of the file into a stream
                var fileStream = ofd.OpenFile();

                using (StreamReader reader = new StreamReader(fileStream))
                {
                    fileContent = reader.ReadToEnd();
                }
                progressBar1.Value = 100;

                try
                {
                    device = JsonConvert.DeserializeObject<Device>(fileContent);
                    Label_ConfigTip.Text = device.name;
                }
                catch (Exception err) { MessageBox.Show(err.Message); }

                try
                {
                    AddLog("Попытка подключиться к устройству " + device.name);
                    datasheet = new Datasheet((byte)UpDown_ModbusID.Value);
                    datasheet.Show();
                }
                catch (Exception err) { MessageBox.Show(err.Message); }
            }
            else
            {
                string[] _configs = Directory.GetFiles(path, "*.json");
                if (configs != _configs)
                {
                    // something changed in the config folder, or we haven't gone through configs, 
                    // remake the dictionary
                    configs = _configs;
                    juju = new Dictionary<CheckEntry, List<Device>>();

                    var fileContent = string.Empty;
                    FileStream fileStream;
                    Device _device;

                    foreach (string path in configs)
                    {
                        fileStream = File.OpenRead(path);
                        using (StreamReader reader = new StreamReader(fileStream))
                            fileContent = reader.ReadToEnd();
                        // get device object from .json
                        _device = JsonConvert.DeserializeObject<Device>(fileContent);

                        // compare device object to key of each dictionary;
                        // add to that dictionary if device's check entry registers match the key
                        bool matched = false;
                        foreach (CheckEntry ce in juju.Keys)
                        {
                            if (_device.checkEntry.address == ce.address && _device.checkEntry.length == ce.length && _device.checkEntry.dataType == ce.dataType)
                            {
                                juju[ce].Add(_device);
                                matched = true;
                                break;
                            }
                        }
                        if (!matched)
                        {
                            juju.Add(_device.checkEntry, new List<Device>());
                            juju[_device.checkEntry].Add(_device);
                        }
                    } // all configs are sorted out, we can poll for each checkEntry 
                }
                // setup event listener
                byte[] message = null;
                Modbus.ResponseReceived += (sndr, msg) =>
                {
                    message = msg.Message;
                };

                foreach (CheckEntry ce in juju.Keys)
                {
                    await SendMessageAsync((FunctionCode)ce.registerType, ce.address, ce.length);   // send read request to device,

                    while (message is null) // wait for response to arrive
                        Thread.Sleep(10);

                    if (message[1] > 0x10) // checking for exception code
                        continue;
                    else
                    {
                        // get pure data
                        byte[] data = new byte[message[2]];
                        for (int i = 0; i < data.Length; i++)
                            data[i] = message[i + 3];

                        if (ce.dataType == "string")
                        {
                           
                            List<byte> bytes = new List<byte>();
                            for (int i = 0; i < data.Length; i++)
                            {
                                if (data[i] != 0)       // clean empty bytes from 16-bit registers
                                    bytes.Add(data[i]); 
                            }
                            string value = Encoding.UTF8.GetString(bytes.ToArray());
                            foreach (Device dev in juju[ce])
                            { 
                                if (dev.checkEntry.expectedValue == value)
                                {
                                    Console.WriteLine("It's a match!");
                                    device = dev;
                                    break;
                                }
                            }
                        }
                        else if (ce.dataType == "bool") 
                        {
                            // why would you even do that lmao
                        }
                        else if (ce.dataType == "uint16" || ce.dataType == "uint32")
                        {
                            byte[] _data = data;
                            Array.Reverse(_data);
                            if (ce.dataType == "uint16")
                            {
                                ushort value = BitConverter.ToUInt16(_data, 0);
                                foreach (Device dev in juju[ce])
                                {
                                    short expValue;
                                    if (Int16.TryParse(dev.checkEntry.expectedValue, out expValue) && expValue == value)
                                    {
                                        device = dev;
                                        break;
                                    }
                                }
                            }
                            else
                            {
                                int value = BitConverter.ToInt32(_data, 0);
                                foreach (Device dev in juju[ce])
                                {
                                    int expValue;
                                    if (Int32.TryParse(dev.checkEntry.expectedValue, out expValue) && expValue == value)
                                    {
                                        device = dev;
                                        break;
                                    }
                                }
                            }
                        }
                    }

                    if (!(device is null)) // found the correct device, abort loop
                        break;
                    message = null; // clear the array for the next item in case we haven't found the correct value
                }
                if (device is /* still */ null)
                {
                    // none of the configs match the device responses
                    MessageBox.Show("Ни один из файлов конфигурации не подходит для устройства.");
                    return;
                }
                else
                {
                    try
                    {
                        AddLog("Попытка подключиться к устройству " + device.name);
                        datasheet = new Datasheet((byte)UpDown_ModbusID.Value);
                        datasheet.Show();
                    }
                    catch (Exception err) { MessageBox.Show(err.Message); }
                }
                progressBar1.Value = 100;
            }

            /*
            if (Radio_SerialPort.Checked)
                await SendMessageAsync(FunctionCode.InputRegister, 200, 6);
            //else EthernetParse();
            */
        }

        async void EthernetParse()
        {
            string ipText = TBox_IP.Text;
            string portText = TBox_Port.Text;

            Regex ip = new Regex(@"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b");
            Regex port = new Regex(@"\d");

            if (!ip.IsMatch(ipText))
                MessageBox.Show("Неправильный формат IP-адреса.");
            else if (!port.IsMatch(portText))
                MessageBox.Show("Неправильный формат TCP-порта.");
            else
            {
                int portParsed = Int32.Parse(portText);
                await socket.ConnectAsync(ipText, portParsed);
                byte[] data = new byte[8];
                Modbus.BuildMessage(0x1E, 0x03, 128, 1, ref data);
                AddLog("Sending to " + ipText + ":" + portText + ":" + Modbus.ByteArrayToString(data));

                // set up an event listener to receive the response
                await SocketDataTransfer(data);
            }

        }

        void CBox_Ports_Click(object sender, EventArgs e)
        {
            CBox_Ports.Items.Clear();
            CBox_Ports.Items.AddRange(SerialPort.GetPortNames());
        }

        void OnResponseReceived(object sender, ModbusResponseEventArgs e)
        {
            isAwaitingResponse = false;
            TextBox_Log.Invoke((MethodInvoker)delegate { AddLog("Получен ответ: " + Modbus.ByteArrayToString(e.Message)); });
            TextBox_Log.Invoke((MethodInvoker)delegate { AddLog("UTF-8: " + e.Text); });
        }

        void AddLog(string message)
        {
            dateTime = DateTime.Now;
            TextBox_Log.AppendText(Environment.NewLine + "[" + dateTime.Hour + ":" + dateTime.Minute + ":" + dateTime.Second + "] " + message);
        }

        private async void Button_SendCommand_Click(object sender, EventArgs e)
        {
            FunctionCode functionCode = (FunctionCode)CBox_Function.SelectedIndex + 1;
            ushort address = (ushort)UpDown_RegAddress.Value;
            ushort length = (ushort)UpDown_RegLength.Value;

            await SendMessageAsync(functionCode, address, length);
        }

        private void OnSelectedFunctionChanged(object sender, EventArgs e)
        {
            if (CBox_Function.SelectedIndex < 4)
                UpDown_Value.Enabled = false;
            else
            {
                if (CBox_Function.SelectedIndex == 4 || CBox_Function.SelectedIndex == 6)
                    UpDown_Value.Maximum = 1;
                else UpDown_Value.Maximum = 65535;

                UpDown_Value.Enabled = true;
            }
        }

        private void Radio_SerialPort_CheckedChanged(object sender, EventArgs e)
        {
            if (Radio_SerialPort.Checked)
                GBox_Serial.Enabled = true;
            else GBox_Serial.Enabled = false;
        }

        private void Radio_Ethernet_CheckedChanged(object sender, EventArgs e)
        {
            if (Radio_Ethernet.Checked)
                GBox_Ethernet.Enabled = true;
            else GBox_Ethernet.Enabled = false;
        }

        private async Task<bool> SocketDataTransfer(byte[] data)
        {
            await Task.Run(() => { socket.Send(data); });
            byte[] res = new byte[64];
            await Task.Run(() =>
            {
                while (true)
                {
                    int bytesReceived = socket.Receive(res);

                    if (bytesReceived == 0)
                        break;

                    string resParsed = "";
                    Modbus.ParseResponse(res, ref resParsed);

                    Console.Out.WriteLine("Received data on TCP socket: " + resParsed);
                    AddLog("Response from TCP Server: " + resParsed);
                }
            });
            return true;
        }

        private void LoadConfig(object sender, EventArgs e)
        {
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                //Get the path of specified file
                path = ofd.FileName;
                Label_ConfPath.Text = ofd.FileName;

                selectedPath = SelectedPath.File;
            }
            UpdatePathLabel();
        }

        private void LoadFolder(object sender, EventArgs e)
        {

            fbd.RootFolder = Environment.SpecialFolder.MyComputer;
            if (fbd.ShowDialog() == DialogResult.OK)
            {
                path = fbd.SelectedPath;
                Label_ConfPath.Text = fbd.SelectedPath;
                selectedPath = SelectedPath.Folder;
            }
            UpdatePathLabel();
        }

        private void CBox_Ports_Click(object sender, MouseEventArgs e)
        {

        }
    }
}

public enum FunctionCode { ReadCoil = 1, ReadDiscrete = 2, ReadHolding = 3, ReadInput = 4, WriteCoil = 5, WriteRegister = 6, WriteMultCoils = 15, WriteMultRegisters = 16 };
public enum SelectedPath { File, Folder };