/*

  This Source Code Form is subject to the terms of the Mozilla Public

  License, v. 2.0. If a copy of the MPL was not distributed with this

  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  Copyright (C) 2010 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System;

using System.Collections.Generic;

using System.Globalization;

using System.IO.Ports;

using System.Security;

using System.Text;

using System.Threading;

using Microsoft.Win32;

namespace OpenHardwareMonitor.Hardware.Heatmaster {

  internal class HeatmasterGroup : IGroup {

    private readonly List<Heatmaster> hardware = new List<Heatmaster>();

    private readonly StringBuilder report = new StringBuilder();

    private static string ReadLine(SerialPort port, int timeout) {

      int i = 0;

      StringBuilder builder = new StringBuilder();

      while (i < timeout) {

        while (port.BytesToRead > 0) {

          byte b = (byte)port.ReadByte();

          switch (b) {

            case 0xAA: return ((char)b).ToString();

            case 0x0D: return builder.ToString();

            default: builder.Append((char)b); break;

          }

        }

        i++;

        Thread.Sleep(1);

      }

      throw new TimeoutException();

    }

    private static string[] GetRegistryPortNames() {

      List<string> result = new List<string>();

      string[] paths = { "", "&MI_00" };

      try {

        foreach (string path in paths) {

          RegistryKey key = Registry.LocalMachine.OpenSubKey(

            @"SYSTEM\CurrentControlSet\Enum\USB\VID_10C4&PID_EA60" + path);

          if (key != null) {

            foreach (string subKeyName in key.GetSubKeyNames()) {

              RegistryKey subKey =

                key.OpenSubKey(subKeyName + "\\" + "Device Parameters");

              if (subKey != null) {

                string name = subKey.GetValue("PortName") as string;

                if (name != null && !result.Contains(name))

                  result.Add(name);

              }

            }

          }

        }

      } catch (SecurityException) { }

      return result.ToArray();

    }

    public HeatmasterGroup(ISettings settings) {

      // No implementation for Heatmaster on Unix systems

      int p = (int)Environment.OSVersion.Platform;

      if ((p == 4) || (p == 128))

        return;

      string[] portNames = GetRegistryPortNames();      

      for (int i = 0; i < portNames.Length; i++) {

        bool isValid = false;

        try {        

          using (SerialPort serialPort =

            new SerialPort(portNames[i], 38400, Parity.None, 8, StopBits.One)) {

            serialPort.NewLine = ((char)0x0D).ToString();            

            report.Append("Port Name: "); report.AppendLine(portNames[i]);

            try {

              serialPort.Open();

            } catch (UnauthorizedAccessException) {

              report.AppendLine("Exception: Access Denied");

            }

            if (serialPort.IsOpen) {

              serialPort.DiscardInBuffer();

              serialPort.DiscardOutBuffer();

              serialPort.Write(new byte[] { 0xAA }, 0, 1);

              int j = 0;

              while (serialPort.BytesToRead == 0 && j < 10) {

                Thread.Sleep(20);

                j++;

              }

              if (serialPort.BytesToRead > 0) {

                bool flag = false;

                while (serialPort.BytesToRead > 0 && !flag) {

                  flag |= (serialPort.ReadByte() == 0xAA);

                }

                if (flag) {

                  serialPort.WriteLine("[0:0]RH");

                  try {

                    int k = 0;

                    int revision = 0;

                    while (k < 5) {

                      string line = ReadLine(serialPort, 100);

                      if (line.StartsWith("-[0:0]RH:",

                        StringComparison.Ordinal)) {

                        revision = int.Parse(line.Substring(9), 

                          CultureInfo.InvariantCulture);

                        break;

                      }

                      k++;

                    }

                    isValid = (revision == 770);

                    if (!isValid) {

                      report.Append("Status: Wrong Hardware Revision " +

                        revision.ToString(CultureInfo.InvariantCulture));

                    }

                  } catch (TimeoutException) {

                    report.AppendLine("Status: Timeout Reading Revision");

                  }

                } else {

                  report.AppendLine("Status: Wrong Startflag");

                }

              } else {

                report.AppendLine("Status: No Response");

              }

              serialPort.DiscardInBuffer();

            } else {

              report.AppendLine("Status: Port not Open");

            }            

          }

        } catch (Exception e) {

          report.AppendLine(e.ToString());

        }

        if (isValid) {

          report.AppendLine("Status: OK");

          hardware.Add(new Heatmaster(portNames[i], settings));

        }

        report.AppendLine();

      }

    }

    public IHardware[] Hardware {

      get {

        return hardware.ToArray();

      }

    }

    public string GetReport() {

      if (report.Length > 0) {

        StringBuilder r = new StringBuilder();

        r.AppendLine("Serial Port Heatmaster");

        r.AppendLine();

        r.Append(report);

        r.AppendLine();

        return r.ToString();

      } else

        return null;

    }

    public void Close() {

      foreach (Heatmaster heatmaster in hardware)

        heatmaster.Close();

    }

  }

}