using System;
using System.Collections.Generic;
using System.IO.Ports;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Threading;

namespace ConstantCurrentControl
{
    public partial class Window1 : Window
    {
        private SerialPort _serialPort;
        private bool _isConnected = false;
        private DispatcherTimer _readTimer;
        private List<byte> _receiveBuffer = new List<byte>();   // 接收缓存

        public Window1()
        {
            InitializeComponent();
            Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            cmbPort.ItemsSource = SerialPort.GetPortNames();
            if (cmbPort.Items.Count > 0) cmbPort.SelectedIndex = 0;

            // 初始化定时器（50ms 间隔，UI 线程）
            _readTimer = new DispatcherTimer();
            _readTimer.Interval = TimeSpan.FromMilliseconds(50);
            _readTimer.Tick += ReadTimer_Tick;
            cmbPort.Text = "COM2";
        }

        #region 串口连接
        private async void BtnConnect_Click(object sender, RoutedEventArgs e)
        {
            if (cmbPort.SelectedItem == null)
            {
                MessageBox.Show("请选择串口号");
                return;
            }
            try
            {
                string port = cmbPort.SelectedItem.ToString();
                int baud = int.Parse((cmbBaudrate.SelectedItem as ComboBoxItem).Content.ToString());
                _serialPort = new SerialPort(port, baud, Parity.None, 8, StopBits.One);
                _serialPort.ReadTimeout = 100;
                _serialPort.WriteTimeout = 1000;
                _serialPort.Open();

                _isConnected = true;
                btnConnect.IsEnabled = false;
                btnDisconnect.IsEnabled = true;
                AddLog($"已连接 {port} @ {baud} bps");

                // 清空接收缓存和串口缓冲区
                _receiveBuffer.Clear();
                _serialPort.DiscardInBuffer();

                // 启动定时器读取
                _readTimer.Start();

                // 发送配置命令（不跟踪模式，byte8=0）
                await ConfigureOptimalMode();
            }
            catch (Exception ex)
            {
                MessageBox.Show($"连接失败: {ex.Message}");
                _isConnected = false;
            }
        }

        private void BtnDisconnect_Click(object sender, RoutedEventArgs e)
        {
            if (_readTimer != null) _readTimer.Stop();
            if (_serialPort != null && _serialPort.IsOpen)
            {
                _serialPort.Close();
                _serialPort.Dispose();
                _serialPort = null;
            }
            _isConnected = false;
            btnConnect.IsEnabled = true;
            btnDisconnect.IsEnabled = false;
            AddLog("已断开连接");
        }
        #endregion

        #region 定时器读取数据
        private void ReadTimer_Tick(object sender, EventArgs e)
        {
            if (!_isConnected || _serialPort == null || !_serialPort.IsOpen)
                return;

            try
            {
                int bytesToRead = _serialPort.BytesToRead;
                if (bytesToRead > 0)
                {
                    byte[] buffer = new byte[bytesToRead];
                    _serialPort.Read(buffer, 0, bytesToRead);
                    _receiveBuffer.AddRange(buffer);

                    // 解析完整帧（12字节，以 FE FE 开头，FF FF 结尾）
                    ParseCompleteFrames();
                }
            }
            catch (Exception ex)
            {
                AddLog($"读取错误: {ex.Message}");
            }
        }

        private void ParseCompleteFrames()
        {
            for (int i = 0; i <= _receiveBuffer.Count - 12; i++)
            {
                if (_receiveBuffer[i] == 0xFE && _receiveBuffer[i + 1] == 0xFE &&
                    _receiveBuffer[i + 10] == 0xFF && _receiveBuffer[i + 11] == 0xFF)
                {
                    byte[] frame = _receiveBuffer.Skip(i).Take(12).ToArray();
                    ProcessFrame(frame);
                    // 移除已处理的帧
                    _receiveBuffer.RemoveRange(0, i + 12);
                    i = -1; // 重新扫描
                }
            }
            // 防止缓存无限增长
            if (_receiveBuffer.Count > 200)
                _receiveBuffer.RemoveRange(0, _receiveBuffer.Count - 200);
        }

        private void ProcessFrame(byte[] frame)
        {
            // 解析电流（byte4, byte5）
            int rawCurrent = (frame[4] << 8) | frame[5];
            double current = rawCurrent / 1000.0;

            AddLog($"回采帧: {BitConverter.ToString(frame)} 电流={current:F3}A");
        }
        #endregion

        #region 发送命令（只写，不等待读）
        private async Task<bool> SendCommand(byte[] command)
        {
            if (!_isConnected || _serialPort == null || !_serialPort.IsOpen)
            {
                AddLog("串口未打开");
                return false;
            }

            try
            {
                await _serialPort.BaseStream.WriteAsync(command, 0, command.Length);
                AddLog($"发送: {BitConverter.ToString(command)}");
                return true;
            }
            catch (Exception ex)
            {
                AddLog($"发送失败: {ex.Message}");
                return false;
            }
        }

        private async Task ConfigureOptimalMode()
        {
            byte[] configCmd = new byte[12];
            configCmd[0] = 0xFE;
            configCmd[1] = 0xFE;
            configCmd[2] = 0x55;
            configCmd[3] = 0xAA;
            configCmd[4] = 0x00;
            configCmd[5] = 0x00;
            configCmd[6] = 0x01;   // PC调节
            configCmd[7] = rb50Hz.IsChecked == true ? (byte)1 : (byte)2;
            configCmd[8] = 0x00;   // 不跟踪（你实测稳定）
            configCmd[9] = 0x00;
            configCmd[10] = 0xFF;
            configCmd[11] = 0xFF;
            await SendCommand(configCmd);
        }
        #endregion

        #region UI操作
        private async void BtnSet_Click(object sender, RoutedEventArgs e)
        {
            if (!_isConnected)
            {
                MessageBox.Show("请先连接串口");
                return;
            }
            if (!double.TryParse(txtSetCurrent.Text, out double target) || target < 0 || target > 5)
            {
                MessageBox.Show("电流需为 0~5.000 A");
                return;
            }

            int raw = (int)(target * 1000);
            byte cmdH = (byte)((raw >> 8) & 0xFF);
            byte cmdL = (byte)(raw & 0xFF);

            byte[] currentCmd = new byte[12];
            currentCmd[0] = 0xFE;
            currentCmd[1] = 0xFE;
            currentCmd[2] = 0x55;
            currentCmd[3] = 0xAA;
            currentCmd[4] = cmdH;
            currentCmd[5] = cmdL;
            currentCmd[6] = 0x01;
            currentCmd[7] = rb50Hz.IsChecked == true ? (byte)1 : (byte)2;
            currentCmd[8] = 0x00;   // 不跟踪
            currentCmd[9] = 0x00;
            currentCmd[10] = 0xFF;
            currentCmd[11] = 0xFF;

            await SendCommand(currentCmd);
            AddLog($"设定电流 = {target:F3} A");
        }

        private async void BtnStop_Click(object sender, RoutedEventArgs e)
        {
            if (!_isConnected) return;
            byte[] stopCmd = new byte[12];
            stopCmd[0] = 0xFE;
            stopCmd[1] = 0xFE;
            stopCmd[2] = 0x55;
            stopCmd[3] = 0xAA;
            stopCmd[4] = 0x00;
            stopCmd[5] = 0x00;
            stopCmd[6] = 0x01;
            stopCmd[7] = rb50Hz.IsChecked == true ? (byte)1 : (byte)2;
            stopCmd[8] = 0x00;   // 不跟踪
            stopCmd[9] = 0x00;
            stopCmd[10] = 0xFF;
            stopCmd[11] = 0xFF;
            await SendCommand(stopCmd);
            AddLog("禁止输出 (0A)");
        }

        private void AddLog(string msg)
        {
            Dispatcher.Invoke(() =>
            {
                lstLog.Items.Insert(0, $"{DateTime.Now:HH:mm:ss} {msg}");
                if (lstLog.Items.Count > 50) lstLog.Items.RemoveAt(lstLog.Items.Count - 1);
            });
        }
        #endregion
    }
}