// @brief
// @file FormSerialTool.cs
// @date 2022-03-08
// Copyright (C) 2022 doublecat
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

using System;
using System.Diagnostics;
using System.IO;
using System.IO.Ports;
using System.Linq;
using System.Text;
using System.Threading;
using System.Windows.Forms;
using SerialTools.Properties;
using static System.Enum;

namespace SerialTools {
    public partial class FrmSerial : Form {
        private byte[] _buffer;

        private string       _logPath = string.Empty;
        private StreamWriter _logWriter;
        private int          _recvCount;
        private Thread       _recvThread;

        private bool _running;
        private int  _sendCount;

        public FrmSerial() {
            InitializeComponent();
        }

        private void frmSerial_Load(object sender, EventArgs e) {
            string[] vs = SerialPort.GetPortNames();
            cboPorts.Items.AddRange(vs);
            if (string.IsNullOrEmpty(Settings.Default.Port) || vs.All(p => p != Settings.Default.Port))
                cboPorts.SelectedIndex = 0;
            else
                cboPorts.SelectedItem = Settings.Default.Port;

            txtBaud.Text = Settings.Default.Baud.ToString();

            cboParity.Items.AddRange(GetNames(typeof(Parity)));
            cboParity.SelectedItem = Settings.Default.Parity.ToString();

            numDataBits.Value = Settings.Default.DataBits;

            cboStopBits.Items.AddRange(GetNames(typeof(StopBits)));
            cboStopBits.SelectedItem = Settings.Default.StopBits.ToString();

            _buffer = new byte[Settings.Default.RecvBufferSize];

            // 超时时间
            serialPort.WriteTimeout = serialPort.ReadTimeout = Settings.Default.Timeout;

            // Log文件名
            saveFileDialog.FileName = Settings.Default.LogFileName;
            lRecvFilePath.Text      = Settings.Default.LogFileName;
            if (!string.IsNullOrEmpty(Settings.Default.LogFileName)) {
                _logWriter = new StreamWriter(saveFileDialog.FileName);
            }
        }

        private void btnStart_Click(object sender, EventArgs e) {
            if (!serialPort.IsOpen) {
                serialPort.PortName = cboPorts.SelectedItem.ToString();
                serialPort.BaudRate = int.Parse(txtBaud.Text);
                serialPort.Parity   = (Parity) Parse(typeof(Parity), (string) cboParity.SelectedItem);
                serialPort.DataBits = (int) numDataBits.Value;
                serialPort.StopBits = (StopBits) Parse(typeof(StopBits), (string) cboStopBits.SelectedItem);

                serialPort.Open();
                lInfo.Text = $"打开端口{serialPort.PortName}";

                ParamtersSettingsEnable(false);

                // 开始运行
                _recvThread      = new Thread(RecvThreadStart);
                _recvThread.Name = "RecvThread";
                _recvThread.Start();
            } else {
                lInfo.Text = "端口已经打开！";
            }
        }

        private void RecvThreadStart() {
            int    rv = 0;
            string s;
            _running = true;
            while (_running) {
                // 检查接收缓冲区是否有数据
                if (serialPort.BytesToRead > 0) {
                    rv         =  serialPort.Read(_buffer, 0, _buffer.Length);
                    _recvCount += rv;
                    s          =  Encoding.ASCII.GetString(_buffer, 0, rv);

                    // 当清除接收信息后，可能会卡在此处；
                    // 需要将Invoke()改为BeginInvoke()
                    txtRecv.BeginInvoke((Action<string>) (rs => {
                        txtRecv.AppendText(rs);
                        lRecv.Text = $"接收：{_recvCount.ToString()}";
                    }), s);

                    // 保存数据到文件
                    if (_logWriter != null) {
                        _logWriter.Write(s);
                        _logWriter.Flush();
                    }
                }

                // 需要释放一下cpu,以便刷新UI，否则可能会造成UI无反应;使用Thread.Yeild()也会出现UI冻结的情况！！！
                Thread.Sleep(100);
            }
        }

        private void ParamtersSettingsEnable(bool v) {
            if (v) {
                btnStart.Enabled    = true;
                cboPorts.Enabled    = true;
                txtBaud.Enabled     = true;
                numDataBits.Enabled = true;
                cboStopBits.Enabled = true;
                cboParity.Enabled   = true;
            } else {
                btnStart.Enabled    = false;
                cboPorts.Enabled    = false;
                txtBaud.Enabled     = false;
                numDataBits.Enabled = false;
                cboStopBits.Enabled = false;
                cboParity.Enabled   = false;
            }
        }

        private void btnStop_Click(object sender, EventArgs e) {
            if (serialPort.IsOpen) {
                // 停止后台接收线程
                _running = false;

                // 此处可能会和线程中的异常处理代码冲突；
                while (_recvThread.IsAlive) Thread.Yield();

                serialPort.Close();
                lInfo.Text = $"关闭端口{serialPort.PortName}";

                ParamtersSettingsEnable(true);
            }
        }

        private void txtSend_KeyDown(object sender, KeyEventArgs e) {
            if (e.Control) {
                e.SuppressKeyPress = true;
                if (e.KeyCode == Keys.Enter)
                    if (serialPort.IsOpen) {
                        var bytes = Encoding.Default.GetBytes(txtSend.Text.ToCharArray());
                        serialPort.Write(bytes, 0, bytes.Length);
                        _sendCount += bytes.Length;
                        lSend.Text =  $"发送：{_sendCount}";
                    } else {
                        lErr.Text = "端口未打开！";
                    }
            }
        }

        private void frmSerial_FormClosing(object sender, FormClosingEventArgs e) {
            if (serialPort.IsOpen) {
                _running = false;
                while (_recvThread.IsAlive) ;
                serialPort.Close();
            }
            // 关闭log
            _logWriter.Close();

            // 保存配置
            Settings.Default.Port        = serialPort.PortName;
            Settings.Default.Parity      = serialPort.Parity;
            Settings.Default.Baud        = serialPort.BaudRate;
            Settings.Default.DataBits    = serialPort.DataBits;
            Settings.Default.StopBits    = serialPort.StopBits;
            Settings.Default.LogFileName = saveFileDialog.FileName;
            Settings.Default.Save();
        }

        private void ClearToolStripMenuItem_Click(object sender, EventArgs e) {
            var txt = (TextBox) mnuMessage.Tag;
            txt.Clear();
            if (txt.Name == "txtRecv") {
                _recvCount = 0;
            } else if (txt.Name == "txtSend") {
                _sendCount = 0;
            }
        }

        private void txtRecv_MouseEnter(object sender, EventArgs e) {
            mnuMessage.Tag = txtRecv;
        }

        private void txtSend_MouseEnter(object sender, EventArgs e) {
            mnuMessage.Tag = txtSend;
        }

        private void btnRecvDataSave_Click(object sender, EventArgs e) {
            saveFileDialog.InitialDirectory = Application.StartupPath;
            if (saveFileDialog.ShowDialog() == DialogResult.OK) {
                _logPath           = saveFileDialog.FileName;
                lRecvFilePath.Text = $"接收数据保存在：{saveFileDialog.FileName}";

                // 打开log文件
                if (_logWriter == null) {
                    _logWriter = new StreamWriter(saveFileDialog.FileName, true);
                }
            }
        }

        private void lRecvFilePath_Click(object sender, EventArgs e) {
            // 如果保存的文件路径为空则退出
            if (string.IsNullOrEmpty(saveFileDialog.FileName))
                return;

            ProcessStartInfo psi = new ProcessStartInfo(Settings.Default.Editor);
            psi.Arguments   = saveFileDialog.FileName;
            psi.WindowStyle = ProcessWindowStyle.Hidden;
            Process.Start(psi);
        }

        private void btnClearLog_Click(object sender, EventArgs e) {
            bool running = false;
            // 关闭接收
            if ((_recvThread != null) && (_recvThread.IsAlive)) {
                running  = true;
                _running = false;

                while (_recvThread.IsAlive) {
                }
            }

            if (!string.IsNullOrEmpty(saveFileDialog.FileName)) {
                _logWriter.Close();
                FileStream fs = File.Create(saveFileDialog.FileName);
                fs.Close();
                _logWriter = new StreamWriter(saveFileDialog.FileName);
            }

            if (running) {
                _recvThread      = new Thread(RecvThreadStart);
                _recvThread.Name = "RecvThread";
                _recvThread.Start();
            }
        }
    }
}