/*

  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) 2011 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System;

using System.Collections.Generic;

using System.IO;

using System.IO.Compression;

using System.Runtime.InteropServices;

using System.Text;

namespace OpenHardwareMonitor.Hardware.Mainboard {

  internal class GigabyteTAMG {

    private byte[] table;

    private Sensor[] sensors;

    private struct Sensor {

      public string Name;

      public SensorType Type;

      public int Channel;

      public float Value;

    }

    private enum SensorType {

      Voltage = 1,

      Temperature = 2,      

      Fan = 4,

      Case = 8,

    }

    public GigabyteTAMG(byte[] table) {

      if (table == null)

        throw new ArgumentNullException("table");

      this.table = table;

      int index = IndexOf(table, Encoding.ASCII.GetBytes("$HEALTH$"), 0);

      if (index >= 0) {

        index += 8;

        using (MemoryStream m =

          new MemoryStream(table, index, table.Length - index))

        using (BinaryReader r = new BinaryReader(m)) {

          try {

            r.ReadInt64();

            int count = r.ReadInt32();

            r.ReadInt64();

            r.ReadInt32();

            sensors = new Sensor[count];

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

              sensors[i].Name = new string(r.ReadChars(32)).TrimEnd('\0');

              sensors[i].Type = (SensorType)r.ReadByte();

              sensors[i].Channel = r.ReadInt16();

              sensors[i].Channel |= r.ReadByte() << 24;

              r.ReadInt64();

              int value = r.ReadInt32();

              switch (sensors[i].Type) {

                case SensorType.Voltage:

                  sensors[i].Value = 1e-3f * value; break;

                default:

                  sensors[i].Value = value; break;

              }

              r.ReadInt64();

            }

          } catch (IOException) { sensors = new Sensor[0]; }

        }

      } else {

        sensors = new Sensor[0]; 

      }

    }

    public static int IndexOf(byte[] array, byte[] pattern, int startIndex) {

      if (array == null || pattern == null || pattern.Length > array.Length)

        return -1;

      for (int i = startIndex; i < array.Length - pattern.Length; i++) {

        bool found = true;

        for (int j = 0; j < pattern.Length; j++) {

          if (array[i + j] != pattern[j]) {

            found = false;

            break;

          }

        }

        if (found) 

          return i;

      }

      return -1;

    }

    private string GetCompressedAndEncodedTable() {

      string base64;

      using (MemoryStream m = new MemoryStream()) {

        using (GZipStream c = new GZipStream(m, CompressionMode.Compress)) {

          c.Write(table, 0, table.Length);          

        }

        base64 = Convert.ToBase64String(m.ToArray());

      }

      StringBuilder r = new StringBuilder();

      for (int i = 0; i < Math.Ceiling(base64.Length / 64.0); i++) {

        r.Append(" ");

        for (int j = 0; j < 0x40; j++) {

          int index = (i << 6) | j;

          if (index < base64.Length) {

            r.Append(base64[index]);

          }

        }

        r.AppendLine();

      }

      return r.ToString();

    }

    public string GetReport() {

      StringBuilder r = new StringBuilder();

      if (sensors.Length > 0) {

        r.AppendLine("Gigabyte TAMG Sensors");

        r.AppendLine();

        foreach (Sensor sensor in sensors) {

          r.AppendFormat(" {0,-10}: {1,8:G6} ({2})", sensor.Name, sensor.Value,

            sensor.Type);

          r.AppendLine();

        }

        r.AppendLine();

      }

      if (table.Length > 0) {

        r.AppendLine("Gigabyte TAMG Table");

        r.AppendLine();

        r.Append(GetCompressedAndEncodedTable());

        r.AppendLine();

      }

      return r.ToString();

    }

  }

}